WorldWideScience

Sample records for surface plasma resonance

  1. A 'rational' explanation of resonant surfaces in toroidal plasmas

    International Nuclear Information System (INIS)

    Cross, R.C.

    1983-05-01

    Resonant surfaces are of fundamental importance in toroidal plasmas, particularly in relation to stability theory. A simple explanation as to why these surfaces are 'resonant' is given in terms of the propagation of localized torsional Alfven and ion acoustic wave packets. These packets are guided along helical field lines in toroidal plasmas, leading to the formation of unstable standing waves on those field lines which close on themselves after one or more toroidal revolutions

  2. Surface Plasmon Resonances of an Axially Magnetized Plasma Column in the Presence of Collisional Loss

    Science.gov (United States)

    Es'kin, V. A.; Ivoninsky, A. V.; Kudrin, A. V.

    2018-02-01

    Surface plasmon resonances arising in the course of scattering of an H-polarized plane electromagnetic wave by an axially magnetized plasma column are analyzed. Main attention is paid to the behavior of these resonances in the presence of collisional loss in the magnetoplasma filling the scatterer. The frequencies, Q factors, and amplitude coefficients of the electromagnetic field of multipole surface plasmon resonances of different orders are found, and conditions under which the collisional loss in the plasma completely suppresses a given resonance are determined.

  3. Carboxyl-rich plasma polymer surfaces in surface plasmon resonance immunosensing

    Science.gov (United States)

    Makhneva, Ekaterina; Obrusník, Adam; Farka, Zdeněk; Skládal, Petr; Vandenbossche, Marianne; Hegemann, Dirk; Zajíčková, Lenka

    2018-01-01

    Stable carboxyl-rich plasma polymers (PPs) were deposited onto the gold surface of surface plasmon resonance (SPR) chips under conditions that were chosen based on lumped kinetic model results. Carboxyl-rich films are of high interest for bio-applications thanks to their high reactivity, allowing the formation of covalent linkages between biomolecules and a surface. Accordingly, the monoclonal antibody, specific to human serum albumin (HSA), was immobilized and the performance of SPR immunosensors was evaluated by the immunoassay flow test. The developed sensors performed high level of stability and provided selective and high response to the HSA antigen solutions. The achieved results confirmed that the presented methodologies for the grafting of biomolecules on the gold surfaces have great potential for biosensing applications.

  4. Diagnostics of microwave assisted electron cyclotron resonance plasma source for surface modification of nylon 6

    Science.gov (United States)

    More, Supriya E.; Das, Partha Sarathi; Bansode, Avinash; Dhamale, Gayatri; Ghorui, S.; Bhoraskar, S. V.; Sahasrabudhe, S. N.; Mathe, Vikas L.

    2018-01-01

    Looking at the increasing scope of plasma processing of materials surface, here we present the development and diagnostics of a microwave assisted Electron Cyclotron Resonance (ECR) plasma system suitable for surface modification of polymers. Prior to the surface-treatment, a detailed diagnostic mapping of the plasma parameters throughout the reactor chamber was carried out by using single and double Langmuir probe measurements in Ar plasma. Conventional analysis of I-V curves as well as the elucidation form of the Electron Energy Distribution Function (EEDF) has become the source of calibration of plasma parameters in the reaction chamber. The high energy tail in the EEDF of electron temperature is seen to extend beyond 60 eV, at much larger distances from the ECR zone. This proves the suitability of the rector for plasma processing, since the electron energy is much beyond the threshold energy of bond breaking in most of the polymers. Nylon 6 is used as a representative candidate for surface processing in the presence of Ar, H2 + N2, and O2 plasma, treated at different locations inside the plasma chamber. In a typical case, the work of adhesion is seen to almost get doubled when treated with oxygen plasma. Morphology of the plasma treated surface and its hydrophilicity are discussed in view of the variation in electron density and electron temperature at these locations. Nano-protrusions arising from plasma treatment are set to be responsible for the hydrophobicity. Chemical sputtering and physical sputtering are seen to influence the surface morphology on account of sufficient electron energies and increased plasma potential.

  5. Surface plasmon resonance investigation of optical detection in plasma-modified phospholipid layers

    Energy Technology Data Exchange (ETDEWEB)

    Park, Byoungchoo; Cho, Chanyoun; Choi, Kyoungho; Jeon, Honggoo [Kwangwoon University, Seoul (Korea, Republic of)

    2012-03-15

    We herein report on a study of surface plasmon resonance (SPR) in thin gold (Au) films coated with thin layers of phospholipid material, which had been exposed to an atmospheric pressure (AP) plasma containing both pure Ar and Ar mixed with O{sub 2} (Ar/O{sub 2}, 0.8%). The phospholipid material that we used for the SPR experiments was lecithin, and the AP plasma system was applied in air by means of a radio-frequency (RF) plasma generator. A thin (∼60 nm) film of Au and a thin (∼15 nm) layer of lecithin were deposited and attached to the face of a prism, and surface plasmon modes were excited along the interfaces of the prism-Au-lecithin-air system by means of prism coupling using a He-Ne Laser (632.8 nm). The experimental SPR reflectance curves of the Au-lecithin-air modes were found to be shifted towards those of the Au-air mode with increasing applications of AP RF plasma treatment. From the shifts in the SPR curves, we found that the estimated thickness of the lecithin layer treated with a pure Ar plasma showed a linear decrease with etching rate of about 3 nm per treatment while the thickness of the lecithin layer treated with a mixed Ar/O{sub 2} plasma showed a tendency to saturate following a large initial decrease (ca. 14 nm). All these results demonstrate that the use of SPR sensing could facilitate the detection of extremely small variations in plasma-treated films of biomaterials.

  6. Surface plasmon resonance biosensor for parallelized detection of protein biomarkers in diluted blood plasma

    Czech Academy of Sciences Publication Activity Database

    Piliarik, Marek; Bocková, Markéta; Homola, Jiří

    2010-01-01

    Roč. 26, č. 4 (2010), s. 1656-1661 ISSN 0956-5663 R&D Projects: GA AV ČR KAN200670701 Institutional research plan: CEZ:AV0Z20670512 Keywords : Surface plasmon resonance * Protein array * Cancer marker Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering Impact factor: 5.361, year: 2010

  7. Real/time monitoring of biomolecular interactions in blood plasma using a surface plasmon resonance biosensor

    Czech Academy of Sciences Publication Activity Database

    Špringer, Tomáš; Piliarik, Marek; Homola, Jiří

    2010-01-01

    Roč. 398, č. 5 (2010), s. 1955-1961 ISSN 1618-2642 R&D Projects: GA AV ČR KAN200670701; GA MŠk OC09058 Institutional research plan: CEZ:AV0Z20670512 Keywords : surface plasmon resonance * molecular interaction analysis * microfluidics * optical biosensor Subject RIV: BO - Biophysics Impact factor: 3.841, year: 2010

  8. Surface plasmon resonance biosensor for detection of pregnancy associated plasma protein A2 in clinical samples

    Czech Academy of Sciences Publication Activity Database

    Bocková, Markéta; Chadtová Song, Xue; Gedeonová, Erika; Levová, K.; Kalousová, M.; Zima, T.; Homola, Jiří

    2016-01-01

    Roč. 408, č. 26 (2016), s. 7265-7269 ISSN 1618-2642 R&D Projects: GA ČR(CZ) GBP205/12/G118 Grant - others:AV ČR(CZ) AP1101 Program:Akademická prémie - Praemium Academiae Institutional support: RVO:67985882 Keywords : Nanoparticles * Blood sample * Surface plasmon resonance Subject RIV: BO - Biophysics Impact factor: 3.431, year: 2016

  9. Model for resonant plasma probe.

    Energy Technology Data Exchange (ETDEWEB)

    Warne, Larry Kevin; Johnson, William Arthur; Hebner, Gregory Albert; Jorgenson, Roy E.; Coats, Rebecca Sue

    2007-04-01

    This report constructs simple circuit models for a hairpin shaped resonant plasma probe. Effects of the plasma sheath region surrounding the wires making up the probe are determined. Electromagnetic simulations of the probe are compared to the circuit model results. The perturbing effects of the disc cavity in which the probe operates are also found.

  10. Heparainization of gas plasma-modified polystyrene surfaces and the interactions of these surfaces with proteins studied with surface plasmon resonance

    NARCIS (Netherlands)

    van Delden, C.J.; van Delden, C.J.; Lens, J.P.; Lens, J.P.; Kooyman, R.P.H.; Engbers, G.H.M.; Feijen, Jan

    1997-01-01

    Polystyrene surfaces obtained by spin-coating a solution of polystyrene in toluene on a gold layer were functionalized with carboxylic acid groups by preadsorption of the sodium salt of undecylenic acid, followed by an argon plasma treatment. A conjugate of albumin and heparin (alb-hep) was

  11. Comparison of surface vacuum ultraviolet emissions with resonance level number densities. II. Rare-gas plasmas and Ar-molecular gas mixtures

    Energy Technology Data Exchange (ETDEWEB)

    Boffard, John B., E-mail: jboffard@wisc.edu; Lin, Chun C. [Department of Physics, University of Wisconsin, Madison, Wisconsin 53706 (United States); Wang, Shicong; Wendt, Amy E. [Department of Electrical and Computer Engineering, University of Wisconsin, Madison, Wisconsin 53706 (United States); Culver, Cody [Materials Science Program, University of Wisconsin, Madison, Wisconsin 53706 (United States); Radovanov, Svetlana; Persing, Harold [Applied Materials Inc., Gloucester, Massachusetts 01939 (United States)

    2015-03-15

    Vacuum ultraviolet (VUV) emissions from excited plasma species can play a variety of roles in processing plasmas, including damaging the surface properties of materials used in semiconductor processing. Depending on their wavelength, VUV photons can easily transmit thin upper dielectric layers and affect the electrical characteristics of the devices. Despite their importance, measuring VUV fluxes is complicated by the fact that few materials transmit at VUV wavelengths, and both detectors and windows are easily damaged by plasma exposure. The authors have previously reported on measuring VUV fluxes in pure argon plasmas by monitoring the concentrations of Ar(3p{sup 5}4s) resonance atoms that produce the VUV emissions using noninvasive optical emission spectroscopy in the visible/near-infrared wavelength range [Boffard et al., J. Vac. Sci. Technol., A 32, 021304 (2014)]. Here, the authors extend this technique to other rare-gases (Ne, Kr, and Xe) and argon-molecular gas plasmas (Ar/H{sub 2}, Ar/O{sub 2}, and Ar/N{sub 2}). Results of a model for VUV emissions that couples radiation trapping and the measured rare-gas resonance level densities are compared to measurements made with both a calibrated VUV photodiode and a sodium salicylate fluorescence detection scheme. In these more complicated gas mixtures, VUV emissions from a variety of sources beyond the principal resonance levels of the rare gases are found to contribute to the total VUV flux.

  12. Surface plasmon resonance biosensor based on engineered proteins for direct detection of interferon-gamma in diluted blood plasma

    Czech Academy of Sciences Publication Activity Database

    Šípová, Hana; Ševců, Veronika; Kuchař, Milan; Ahmad, Jawid Nazir; Mikulecký, Pavel; Osičková, Adriana; Malý, Petr; Homola, Jiří

    2012-01-01

    Roč. 174, č. 11 (2012), s. 306-311 ISSN 0925-4005 R&D Projects: GA AV ČR KAN200670701 Institutional support: RVO:67985882 ; RVO:61388971 ; RVO:86652036 Keywords : Interferon gamma * Surface plasmon resonance * Biosensor Subject RIV: JB - Sensors, Measurment, Regulation Impact factor: 3.535, year: 2012

  13. Electron waves and resonances in bounded plasmas

    CERN Document Server

    Vandenplas, Paul E

    1968-01-01

    General theoretical methods and experimental techniques ; the uniform plasma slab-condenser system ; the hollow cylindrical plasma ; scattering of a plane electromagnetic wave by a plasma column in steady magnetic fields (cold plasma approximation) ; hot non-uniform plasma column ; metallic and dielectric resonance probes, plasma-dielectric coated antenna, general considerations.

  14. Plasma-surface interactions

    International Nuclear Information System (INIS)

    Goeckner, M J; Nelson, C T; Sant, S P; Jindal, A K; Joseph, E A; Zhou, B S; Padron-Wells, G; Jarvis, B; Pierce, R; Overzet, L J

    2008-01-01

    Materials processing is at a crossroads. Currently a large fraction of industrially viable materials processing is via plasmas. Until recently it has been economical to just examine the influence the plasma properties on the desired surface processes and through this ultimately optimize manufacturing. For example, it is well known that the surface processes (etch or deposition), occur in the top few mono-layers of the surface. Thus, in film growth one requires that molecules from the gas-phase land and bond on the surface. However as processing has reached the nano-scale, development of viable processes has become more and more difficult. In part, this is because of all of the free parameters that exist in plasmas. To overcome this economic issue, tool vendors and semiconductor companies have turned to complex computational models of processing plasmas. For those models to work, one requires a through understanding of all of the gas-phase and surface-phase processes that are exhibited in plasmas. Unfortunately, these processes, particularly those at the surface, are not well understood. In this article we describe a viable model of the surface-phase based on cross sections for processes that occur. While originally developed of fluorocarbon systems, the model also appears to be applicable to hydrocarbon systems.

  15. Spectra of resonance surface photoionization

    Energy Technology Data Exchange (ETDEWEB)

    Antsiferov, V.V.; Smirnov, G.I.; Telegin, G.G. [Budker Nuclear Physics Institute, Novosibirsk (Russian Federation)

    1995-09-01

    The theory of nonactivated electron transfer between atoms interacting reasonantly with coherent radiation and a metal surface is developed. The spectral resonances in photoabsorption and surface photoionization are found to be related to nonlinear interference effects in the interaction between discrete atomic levels and the continuum formed by the quasi-continuous electron spectrum of a normal metal. The asymmetry in the resonance surface photoionization spectrum is shown to have a shape typical of the Fano autoionization resonances. 18 refs.

  16. Electron plasma waves and plasma resonances

    International Nuclear Information System (INIS)

    Franklin, R N; Braithwaite, N St J

    2009-01-01

    In 1929 Tonks and Langmuir predicted of the existence of electron plasma waves in an infinite, uniform plasma. The more realistic laboratory environment of non-uniform and bounded plasmas frustrated early experiments. Meanwhile Landau predicted that electron plasma waves in a uniform collisionless plasma would appear to be damped. Subsequent experimental work verified this and revealed the curious phenomenon of plasma wave echoes. Electron plasma wave theory, extended to finite plasmas, has been confirmed by various experiments. Nonlinear phenomena, such as particle trapping, emerge at large amplitude. The use of electron plasma waves to determine electron density and electron temperature has not proved as convenient as other methods.

  17. Effects of initial layers on surface roughness and crystallinity of microcrystalline silicon thin films formed by remote electron cyclotron resonance silane plasma

    CERN Document Server

    Murata, K; Hori, Masaki; Goto, T; Ito, M

    2002-01-01

    We have observed mu c-Si:H films grown in the glass substrate in electron cyclotron resonance plasma-enhanced chemical vapor deposition employing two-step growth (TSG) method, where the seed layer was formed without charged species firstly, and subsequently, the film with charged species. The mu c-Si:H films with smooth surface and high crystallinity were synthesized with a relatively high deposition rate at a low substrate temperature by TSG. By Fourier transform infrared attenuated-total reflection, it was found that the surface roughness and crystallinity of seed layer were related to the ratio of SiH bonds over SiH sub 2 ones in the film. Consequently, the control of chemical bonds at the initial layer is of importance and TSG method is effective for the formation of mu c-Si:H film with high quality.

  18. Josephson plasma resonance in superconducting multilayers

    DEFF Research Database (Denmark)

    Pedersen, Niels Falsig

    1999-01-01

    We derive an analytical solution for the josephson plasma resonance of superconducting multilayers. This analytical solution is derived mainly for low T-c systems with magnetic coupling between the superconducting layers, but many features of our results are more general, and thus an application...... to the recently derived plasma resonance phenomena for high T-c superconductors of the BSCCO type is discussed....

  19. Plasma surface cleaning in a microwave plasma source

    Energy Technology Data Exchange (ETDEWEB)

    Tsai, C.C.; Nelson, W.D.; Haselton, H.H.; Schechter, D.E. [Oak Ridge National Lab., TN (United States); Thompson, L.M.; Campbell, V.B.; Glover, A.L.; Googin, J.M. [Oak Ridge Y-12 Plant, TN (United States)

    1994-03-01

    A microwave electron cyclotron resonance (ECR) plasma source has been operated to produce reactive plasmas of oxygen and its mixture with argon. Aluminum samples (0.95 cm by 1.9 cm) were coated with thin films (<20 {mu}m in thickness) of Shell Vitrea oil and cleaned by using such reactive plasmas. The plasma cleaning was done in discharge conditions of microwave power up to 1300 W, radio frequency power up to 200 W, biased potential up to 400 V, gas pressures up to 5 mtorr, and operating time up to 35 min. The surface texture of the postcleaned samples has been examined visually. Mass loss of the samples after plasma cleaning was measured to estimate cleaning rates. Measured clean rates of low-pressure (0.5-mtorr) argon/oxygen plasmas were as high as 2.7 {mu}m/min. X-ray photoelectron spectroscopy (XPS) was used to determine cleanliness of the sample surfaces after plasma cleaning. The XPS study on polished samples confirmed the effectiveness of plasma cleaning in achieving atomic level of surface cleanliness. In this technical memorandum plasma properties, cleaning phenomena, and significant results are reported and discussed.

  20. Characterization of surface hardening in a nitrated chromium steel by microwave plasma type ECR (Electron Cyclotron Resonance)

    International Nuclear Information System (INIS)

    La O C, G. de.

    1995-01-01

    With this work it is demonstrated the possibility of performing the nitriding process by using a CVD-ECR source, based on the results obtained after treating several samples of AISI H-12 steel. Also, the main operating parameters (time of treatment, sample temperatures and gas mixture) are determined during nitriding of this steel with the mentioned source. Samples used before nitriding were quenched and tempered at 580 Centigrade degrees. Several experiments were done by using a pure nitrogen plasma with exposure times of the samples of 20 minutes at temperatures from 450 to 550 Centigrade degrees, and by using a N 2 - H 2 plasma with exposure times of the samples of 20, 30 and 40 minutes at temperatures from 350 to 550 Centigrade degrees. Metallography, microhardness, EDS and Auger analysis were done to observe changes suffered for the samples after treatment. (Author)

  1. Resonance cones in non-Maxwellian plasmas

    International Nuclear Information System (INIS)

    Oelerich-Hill, G.; Piel, A.

    1989-01-01

    Resonance cones are studied experimentally in hot drifting plasmas and in various beam--plasma situations. In a drifting plasma the upstream--downstream asymmetry of the main cone is suitable for diagnostics of plasma drifts. The evaluation of electron temperature from the interference pattern is discussed in terms of the low-temperature--low-drift approximation (LTLDA) and by comparing with numerical kinetic theory calculations. In this way the range of applicability of this method is extended above the LTLDA. In a beam--plasma situation, the downstream resonance cone exhibits a new interference pattern, which can be attributed to resonant particle effects. The upstream resonance cone is only slightly affected and is found still applicable for T/sub e/ and n/sub e/ diagnostics. As a result of comparison with numerical calculations, in which the actual distribution function is used, the downstream interference pattern is proposed to be useful as a diagnostic method for obtaining the mean beam energy. The waves generated by the beam--plasma interaction are analyzed by digital cross-correlation techniques, and found to propagate obliquely to the magnetic field direction at the resonance cone angle

  2. Resonance cones in non-Maxwellian plasmas

    International Nuclear Information System (INIS)

    Oelerich-Hill, G.; Piel, A.

    1988-05-01

    Resonance cones are studied experimentally in hot drifting plasmas and in various beam-plasma situations. In a drifting plasma the upstream-downstream asymmetry of the main cone is suitable for diagnostics of plasma drifts. The evaluation of electron temperature from the interference pattern is discussed in terms of the low-temperature-low-drift-approximation (LTLDA) and by comparing with numerical kinetic theory calculations. In this way the range of applicability of this method is extended above the LTLDA. In a beam-plasma situation, the downstream resonance cone exhibits a new interference pattern, which can be attributed to resonant particle effects. The upstream resonance cone is only slightly affected and is found still applicable for T e and n e diagnostics. As a result of the comparison with numerical calculations, in which the actual distribution function is used, the downstream interference pattern is proposed to be useful as a diagnostic method for obtaining the mean beam energy. The waves generated by the beam plasma interaction are analyzed by digital cross-correlation techniques. They are found to be Whistler waves propagating obliquely to the magnetic field direction at the resonance cone angle. (orig.)

  3. Plasma diagnostics by resonant interferometry and holography

    Energy Technology Data Exchange (ETDEWEB)

    Dreiden, G.V.; Zaidel, A.N.; Ostrovskaya, G.V.; Ostrovskii, Yu.I.; Pobedonostseva, N.A.; Tanin, L.V.; Filippov, V.N.; Shedova, E.N.

    1975-01-01

    The methods of resonant interferometry and holography are discussed, and their ranges of applicability are estimated. Resonant methods enjoy a high sensitivity and a high selectivity in comparison with ordinary interferometric and holographic methods. Their primary field of application is with dense plasmas, although in individual cases it is possible to determine atomic densities down to N/sub a/ = 10/sup 9/ cm/sup -3/ and below. For a plasma with N/sub a/ = 10/sup 18/-10/sup 19/ cm/sup -3/ the minimum detectable atomic density is about N/sub a/ = 10/sup 14/ cm/sup -3/. The specific requirements on light sources and methods for studying them are described. The capabilities of these methods are demonstrated for the cases of potassium, sodium, lithium, and hydrogen plasmas; the atomic and electron densities are determined, and the plasma dynamics is studied.

  4. Josephson plasma resonance in superconducting multilayers

    DEFF Research Database (Denmark)

    Pedersen, Niels Falsig; Sakai, S

    1998-01-01

    We derive an analytical solution for the Josephson plasma resonance of superconducting multilayers. This analytical solution is derived mainly for low-T-c systems with magnetic coupling between the superconducting layers. but many features of our results are more general, and thus an application...

  5. Josephson plasma resonance in superconducting multilayers

    DEFF Research Database (Denmark)

    Pedersen, Niels Falsig

    1999-01-01

    We derive an analytical solution for the josephson plasma resonance of superconducting multilayers. This analytical solution is derived mainly for low T-c systems with magnetic coupling between the superconducting layers, but many features of our results are more general, and thus an application...

  6. Resonant power absorption in helicon plasma sources

    International Nuclear Information System (INIS)

    Chen Guangye; Arefiev, Alexey V.; Bengtson, Roger D.; Breizman, Boris N.; Lee, Charles A.; Raja, Laxminarayan L.

    2006-01-01

    Helicon discharges produce plasmas with a density gradient across the confining magnetic field. Such plasmas can create a radial potential well for nonaxisymmetric whistlers, allowing radially localized helicon (RLH) waves. This work presents new evidence that RLH waves play a significant role in helicon plasma sources. An experimentally measured plasma density profile in an argon helicon discharge is used to calculate the rf field structure. The calculations are performed using a two-dimensional field solver under the assumption that the density profile is axisymmetric. It is found that RLH waves with an azimuthal wave number m=1 form a standing wave structure in the axial direction and that the frequency of the RLH eigenmode is close to the driving frequency of the rf antenna. The calculated resonant power absorption, associated with the RLH eigenmode, accounts for most of the rf power deposited into the plasma in the experiment

  7. Resonant and Ground Experimental Study on the Microwave Plasma Thruster

    Science.gov (United States)

    Yang, Juan; He, Hongqing; Mao, Genwang; Qu, Kun; Tang, Jinlan; Han, Xianwei

    2002-01-01

    chemistry. Therefore, the application of EP for the attitude control and station keeping of satellite, the propulsion of deep space exploration craft allows to reduce substantially the mass of on-board propellant and the launching cost. The EP research is now receiving high interest everywhere. microwave generating subsystem, the propellant supplying subsystem and the resonator (the thruster). Its principle is that the magnetron of the microwave generating subsystem transfers electric energy into microwave energy at given frequency which is introduced into a resonant cavity. Microwave will resonate within the cavity when it is adjusted. When the propellant gas (N2, Ar, He, NH3 or H2) is put into the cavity and coupled with microwave energy at the maximal electric intensity place, it will be broken down to form free-floating plasma, which flows from nozzle with high speed to produce thrust. Its characteristic is high efficiency, simple power supply and without electrode ablation, its specific impulse is greater than arcjet. 2450MHz, have been developed. The microwave generating subsystem and resonator of lower power MPT, 70-200W, are coaxial. The resonator with TEM resonating mode is section of coaxial wave-guide, of which one end is shorted, another is semi-opened. The maximal electric intensity field is in the lumped capacity formed between the end surface of inner conductor, retracting in the cavity, and the semi-opened surface of outer conductor. It provides favorable condition for gas breakdown. The microwave generating system and resonator of middle power MPT, 500-1,000W, are wave-guide cavity. The resonator with TM011 resonating mode is cylinder wave-guide cavity, of which two end surface are shorted. The distribution of electromagnetic field is axial symmetry, its maximal electric intensity field locates on the axis and closes to the exit of nozzle, where the propellant gas is breakdown to form free floating plasma. The plasma is free from the wall of

  8. Characterization of electron cyclotron resonance hydrogen plasmas

    International Nuclear Information System (INIS)

    Outten, C.A.

    1990-01-01

    Electron cyclotron resonance (ECR) plasmas yield low energy and high ion density plasmas. The characteristics downstream of an ECR hydrogen plasma were investigated as a function of microwave power and magnetic field. A fast-injection Langmuir probe and a carbon resistance probe were used to determine plasma potential (V p ), electron density (N e ), electron temperature (T e ), ion energy (T i ), and ion fluence. Langmuir probe results showed that at 17 cm downstream from the ECR chamber the plasma characteristics are approximately constant across the center 7 cm of the plasma for 50 Watts of absorbed power. These results gave V p = 30 ± 5 eV, N e = 1 x 10 8 cm -3 , and T e = 10--13 eV. In good agreement with the Langmuir probe results, carbon resistance probes have shown that T i ≤ 50 eV. Also, based on hydrogen chemical sputtering of carbon, the hydrogen (ion and energetic neutrals) fluence rate was determined to be 1 x 10 16 /cm 2 -sec. at a pressure of 1 x 10 -4 Torr and for 50 Watts of absorbed power. 19 refs

  9. Plasma production for electron acceleration by resonant plasma wave

    Energy Technology Data Exchange (ETDEWEB)

    Anania, M.P., E-mail: maria.pia.anania@lnf.infn.it [INFN - LNF, via Enrico Fermi, 40, 00044 Frascati (Italy); Biagioni, A.; Chiadroni, E. [INFN - LNF, via Enrico Fermi, 40, 00044 Frascati (Italy); Cianchi, A. [University of Rome Tor Vergata - INFN, via della Ricerca Scientifica, 1, 00133 Roma (Italy); INFN, Via della Ricerca Scientifica, 1, 00133 Roma (Italy); Croia, M.; Curcio, A. [INFN - LNF, via Enrico Fermi, 40, 00044 Frascati (Italy); University of Rome La Sapienza, Piazzale Aldo Moro, 2, 00185 Roma (Italy); Di Giovenale, D.; Di Pirro, G.P. [INFN - LNF, via Enrico Fermi, 40, 00044 Frascati (Italy); Filippi, F. [University of Rome La Sapienza, Piazzale Aldo Moro, 2, 00185 Roma (Italy); Ghigo, A.; Lollo, V.; Pella, S.; Pompili, R. [INFN - LNF, via Enrico Fermi, 40, 00044 Frascati (Italy); Romeo, S. [INFN - LNF, via Enrico Fermi, 40, 00044 Frascati (Italy); University of Rome La Sapienza, Piazzale Aldo Moro, 2, 00185 Roma (Italy); Ferrario, M. [INFN - LNF, via Enrico Fermi, 40, 00044 Frascati (Italy)

    2016-09-01

    Plasma wakefield acceleration is the most promising acceleration technique known nowadays, able to provide very high accelerating fields (10–100 GV/m), enabling acceleration of electrons to GeV energy in few centimeter. However, the quality of the electron bunches accelerated with this technique is still not comparable with that of conventional accelerators (large energy spread, low repetition rate, and large emittance); radiofrequency-based accelerators, in fact, are limited in accelerating field (10–100 MV/m) requiring therefore hundred of meters of distances to reach the GeV energies, but can provide very bright electron bunches. To combine high brightness electron bunches from conventional accelerators and high accelerating fields reachable with plasmas could be a good compromise allowing to further accelerate high brightness electron bunches coming from LINAC while preserving electron beam quality. Following the idea of plasma wave resonant excitation driven by a train of short bunches, we have started to study the requirements in terms of plasma for SPARC-LAB (Ferrario et al., 2013 [1]). In particular here we focus on hydrogen plasma discharge, and in particular on the theoretical and numerical estimates of the ionization process which are very useful to design the discharge circuit and to evaluate the current needed to be supplied to the gas in order to have full ionization. Eventually, the current supplied to the gas simulated will be compared to that measured experimentally.

  10. Modification of Plasma Solitons by Resonant Particles

    DEFF Research Database (Denmark)

    Karpman, Vladimir; Lynov, Jens-Peter; Michelsen, Poul

    1980-01-01

    A consistent theory of plasma soliton interaction with resonant particles is developed. A simple derivation of a perturbed Korteweg–de Vries equation with the interaction term is presented. It is shown how the known limit cases (such as Ott–Sudan’s, etc.) can be derived from the general equations...... and what their regions of applicability are. Some effects caused by the soliton‐particle interaction (amplitude change‐rate, tail formation, etc.) are analyzed by means of a recently developed perturbation method. The analytical results are compared with a direct numerical integration of the perturbed...... Korteweg–de Vries equation. Laboratory measurements carried out in a strongly magnetized, plasma‐filled waveguide and results from particle simulation are interpreted in terms of the analytical results....

  11. Fabrication and enhanced photocatalytic properties of Pt@SiO2@TiO2 composites by surface plasma resonance from Pt nanoparticles

    Science.gov (United States)

    Zhang, Fangfang; Liu, Wei; Liu, Yousong; Wang, Junyi; Ji, Guangbin

    2015-02-01

    Pt@SiO2@TiO2 composites with an average diameter of about 120 nm were synthesized by an aqueous method. Morphology, microstructure, and light absorption performance of as-prepared samples were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, and UV-Vis diffuse reflectance spectroscopy. The results indicate that 5-nm-thick SiO2 interlayer coated on the Pt nanoparticles were used to separate the Pt from the TiO2. The covering SiO2 layer between Pt nanoparticles and TiO2 layer present a wide spectral response. The enhanced photocatalytic efficiency under both the full spectrum and visible light can be attributed to the existence of Pt nanoparticles and interlayer SiO2. The coupling processes between TiO2 and plasmon were presented and the mechanism was discussed. The localized surface plasmon resonance effect of Pt nanoparticles is the main reason for the enhanced photocatalytic activity of the composite Pt@SiO2@TiO2.

  12. Spectrum of resonant plasma oscillations in long Josephson junctions

    International Nuclear Information System (INIS)

    Holst, T.

    1996-01-01

    An analysis is presented for the amplitude of the plasma oscillations in the zero-voltage state of a long and narrow Josephson tunnel junction. The calculation is valid for arbitrary normalized junction length and arbitrary bias current. The spectrum of the plasma resonance is found numerically as solutions to an analytical equation. The low-frequency part of the spectrum contains a single resonance, which is known to exist also in the limit of a short and narrow junction. Above a certain cutoff frequency, a series of high-frequency standing wave plasma resonances is excited, a special feature of long Josephson junctions. copyright 1996 The American Physical Society

  13. Standing surface waves in dusty microwave slot-excited plasma

    International Nuclear Information System (INIS)

    Ostrikov, K.N.; Yu, M.Y.; Sugai, H.

    2000-01-01

    Full text: The effect of charged dust particles on microwave slot-excited plasma has been studied. The dusts absorb significant proportion of the plasma electrons, which leads to a substantial modification of the electromagnetic field structure. The overall charge balance and the eigenfrequencies of the standing TM electromagnetic surface modes are modified by the presence of dust. It has been found that the originally excited surface waves can be shifted out of resonance. For certain proportions of dusts, mode conversion appears to be possible. Microwave gas discharges sustained by surface waves (SW) are promising for many industrial applications as sources of large-volume and large-area low-temperature plasmas. Here, we study the surface-wave sustained microwave plasma reactor contaminated by fine dust particles that usually appear as a substrate-etching product or as a result of polymerization in the gaseous phase. The structure that models the slot-excited planar plasma source is considered. A vertical circular cylinder is short-circuited at its top by a metal plate. A dielectric layer isolates the cylinder top from the plasma, and the chamber bottom is open. We have shown that uncontrolled release of the dusts in the discharge chamber can adversely affect the discharge performance and under certain conditions cause a discharge disruption. This can best be understood by noting that macroparticles absorb a significant proportion of plasma electrons and hence modify the ionization-recombination balance. Moreover, stable operation of the microwave surface-wave sustained discharge depends on the resonant conditions for the operating mode, and it is thus crucial to understand how dusts affect the eigenfrequencies of the SWs. We have demonstrated that introduction of additional amounts of contaminant results in a significant shift of the electron plasma density from its resonant value for the initially excited resonant mode. The system can thus be moved out of

  14. Electron cyclotron resonance breakdown studies in a linear plasma ...

    Indian Academy of Sciences (India)

    ECR surface (B = 875.0 G) resides at the geometrical centre of the plasma system. ECR breakdown parameters such as plasma delay time and plasma decay time from plasma density measurements are carried out at the centre using a Langmuir probe. The operating parameters such as working gas pressure (1 × 10−5–1 ...

  15. Electron cyclotron resonance heating in a short cylindrical plasma ...

    Indian Academy of Sciences (India)

    Abstract. Electron cyclotron resonance (ECR) plasma is produced and studied in a small cylindrical system. Microwave power is delivered by a CW magnetron at 2.45 GHz in TE10 mode and launched radially to have extraordinary (X) wave in plasma. The axial magnetic field required for ECR in the system is such that the ...

  16. Electron cyclotron resonance heating in a short cylindrical plasma ...

    Indian Academy of Sciences (India)

    Electron cyclotron resonance (ECR) plasma is produced and studied in a small cylindrical system. Microwave power is delivered by a CW magnetron at 2.45 GHz in TE10 mode and launched radially to have extraordinary (X) wave in plasma. The axial magnetic field required for ECR in the system is such that the first two ...

  17. The numerical simulation of plasma flow in cylindrical resonant cavity of microwave plasma thruster

    International Nuclear Information System (INIS)

    Tang, J.-L.; He, H.-Q; Mao, G.-W.

    2004-01-01

    Microwave Plasma Thruster (MPT) is an electro-thermal propulsive device. MPT consists of microwave generator, gas storing and supplying system, resonant cavity and accelerative nozzle. It generates free-floating plasma brought by the microwave discharge breakdown gas in the resonant cavity, and the plasma exhausted from nozzle produces thrust. MPT has prospective application in spacecraft because of its advantages of high thrust, moderate specific impulse and high efficiency. In this paper, the numerical simulation of the coupling flow field of microwave plasma in resonant cavity under different frequencies will be discussed. The results of numerical simulation are as follows: 1) When the resonant model TM 011 was used, the higher the microwave frequency was, the smaller the size of MPT. The distribution of the electromagnetic field in small cavity, however, remain unchanged. 2) When the resonant model was used, the distribution of the temperature, the pressure and the electronic density in the resonant cavity remained unchanged under different resonant frequencies. 3) When the resonant frequency was increased with a fixed pressure distribution in a small cavity, compare to the MPT with lower frequency, the gas flow rate, the microwave power and the nozzle throat diameter of MPT all decreased. 4) The electromagnetic field in the cylindrical resonant cavity for all MPT with different frequencies was disturbed by the plasma formation. The strong disturbance happened in the region close to the plasma. (author)

  18. Fano resonance Rabi splitting of surface plasmons.

    Science.gov (United States)

    Liu, Zhiguang; Li, Jiafang; Liu, Zhe; Li, Wuxia; Li, Junjie; Gu, Changzhi; Li, Zhi-Yuan

    2017-08-14

    Rabi splitting and Fano resonance are well-known physical phenomena in conventional quantum systems as atoms and quantum dots, arising from strong interaction between two quantum states. In recent years similar features have been observed in various nanophotonic and nanoplasmonic systems. Yet, realization of strong interaction between two or more Fano resonance states has not been accomplished either in quantum or in optical systems. Here we report the observation of Rabi splitting of two strongly coupled surface plasmon Fano resonance states in a three-dimensional plasmonic nanostructure consisting of vertical asymmetric split-ring resonators. The plasmonic system stably supports triple Fano resonance states and double Rabi splittings can occur between lower and upper pairs of the Fano resonance states. The experimental discovery agrees excellently with rigorous numerical simulations, and is well explained by an analytical three-oscillator model. The discovery of Fano resonance Rabi splitting could provide a stimulating insight to explore new fundamental physics in analogous atomic systems and could be used to significantly enhance light-matter interaction for optical sensing and detecting applications.

  19. Doubly localized surface plasmon resonance in bimodally distributed silver nanoparticles.

    Science.gov (United States)

    Ranjan, M

    2012-06-01

    Growth of bimodally distributed silver nanoparticles using sequential physical vapour deposition (PVD) is reported. Growth conditions of nanoparticles are defined in the following three steps: In the first step, nanoparticles are grown at a heated substrate and then exposed to atmosphere, in the second step, nanoparticles are vacuum annealed and finally re-deposition of silver is performed in the third step. This special way of deposition leads to the formation of bimodally distributed nanoparticles. It has been investigated that by changing the deposition time, different sets of bimodally distributed nanoparticles can be grown. Localized surface plasmon resonance (LSPR) of such bimodally distributed nanoparticles generates double plasmon resonance peaks with overlapped absorption spectra. Double plasmon resonance peaks provide a quick indication of the existence of two sets of nanoparticles. LSPR spectra of such bimodally distributed nanoparticles could be modeled with double Lorentz oscillator model. Inclusion of double Lorentz oscillator model indicates that there exist two sets of non-interacting nanoparticles resonating at different plasma frequencies. It is also reported that silver nanoparticles grown at a heated substrate, again attain the new shape while being exposed to atmosphere, followed by vacuum annealing at the same temperature. This is because of physisorption of oxygen at the silver surface and change in surface free energy. The re-shaping due to the adsorbed oxygen on the surface is responsible for bimodal size distribution of nanoparticles.

  20. Study of Planar Surface Wave Excited Plasma

    Science.gov (United States)

    Tian, Caizhong

    2008-10-01

    The need for plasma processing has increased as miniaturization in semiconductor manufacturing goes ahead. In these processes, a large-diameter plasma source is required with respect to 300mm wafer size. A Radial Line Slot Antenna (RLSA) driven surface-wave-sustained plasma is a potential best candidate to various applications with respect to damage free process. Many researches focus on the control of plasma density and electron temperature in RLSA technique. However, the plasma stability and uniformity control are less implemented in the practice. In recent years, we study sheath formation and plasma behavior at the interface, where the surface wave propagate, by using electromagnetic particle-in-cell simulation techniques. The simulations include the effects of ionization, and allow us to study the buildup of plasma density associated with ionization in the presence of the large fields of the RF-enhanced sheath. Our results show both the mechanism of plasma generation and heating at the plasma dielectric interface and the strong effect on geometric design of dielectric. Various scenarios are of interest, and help us to design an optimal RLSA driven plasma source, where the plasma stability and uniformity are firmly sustained under the various process conditions. Plasma diagnosis is carried out to reveal the more essential difference in plasma behavior between our RLSA and a custom inductively coupled plasma (ICP) source.

  1. Surface disorder production during plasma immersion implantation

    NARCIS (Netherlands)

    Lohner, T.; Khanh, N.Q.; Petrik, P.; Biro, L.P.; Fried, M.; Pinter, I.; Lehnert, W.; Frey, L.; Ryssel, H.; Wentink, D.J.; Gyulai, J.

    1998-01-01

    Comparative investigations were performed using high-depth-resolution Rutherford backscattering (RBS) combined with channeling, spectroellipsometry (SE) and atomic force microscopy (AFM) to analyze surface disorder and surface roughness formed during plasma immersion implantation of silicon (100)

  2. Surface studies of plasma processed Nb samples

    International Nuclear Information System (INIS)

    Tyagi, Puneet V.; Doleans, Marc; Hannah, Brian S.; Afanador, Ralph; Stewart, Stephen; Mammosser, John; Howell, Matthew P; Saunders, Jeffrey W; Degraff, Brian D; Kim, Sang-Ho

    2015-01-01

    Contaminants present at top surface of superconducting radio frequency (SRF) cavities can act as field emitters and restrict the cavity accelerating gradient. A room temperature in-situ plasma processing technology for SRF cavities aiming to clean hydrocarbons from inner surface of cavities has been recently developed at the Spallation Neutron Source (SNS). Surface studies of the plasma-processed Nb samples by Secondary ion mass spectrometry (SIMS) and Scanning Kelvin Probe (SKP) showed that the NeO 2 plasma processing is very effective to remove carbonaceous contaminants from top surface and improves the surface work function by 0.5 to 1.0 eV.

  3. Surface studies of plasma processed Nb samples

    Energy Technology Data Exchange (ETDEWEB)

    Tyagi, Puneet V. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Spallation Neutron Source (SNS); Doleans, Marc [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Spallation Neutron Source (SNS); Hannah, Brian S. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Spallation Neutron Source (SNS); Afanador, Ralph [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Spallation Neutron Source (SNS); Stewart, Stephen [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Spallation Neutron Source (SNS); Mammosser, John [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Spallation Neutron Source (SNS); Howell, Matthew P [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Spallation Neutron Source (SNS); Saunders, Jeffrey W [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Spallation Neutron Source (SNS); Degraff, Brian D [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Spallation Neutron Source (SNS); Kim, Sang-Ho [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Spallation Neutron Source (SNS)

    2015-01-01

    Contaminants present at top surface of superconducting radio frequency (SRF) cavities can act as field emitters and restrict the cavity accelerating gradient. A room temperature in-situ plasma processing technology for SRF cavities aiming to clean hydrocarbons from inner surface of cavities has been recently developed at the Spallation Neutron Source (SNS). Surface studies of the plasma-processed Nb samples by Secondary ion mass spectrometry (SIMS) and Scanning Kelvin Probe (SKP) showed that the NeO2 plasma processing is very effective to remove carbonaceous contaminants from top surface and improves the surface work function by 0.5 to 1.0 eV.

  4. Analysis of cell surface antigens by Surface Plasmon Resonance imaging

    NARCIS (Netherlands)

    Stojanovic, Ivan; Schasfoort, Richardus B.M.; Terstappen, Leonardus Wendelinus Mathias Marie

    2013-01-01

    Surface Plasmon Resonance (SPR) is most commonly used to measure bio-molecular interactions. SPR is used significantly less frequent for measuring whole cell interactions. Here we introduce a method to measure whole cells label free using the specific binding of cell surface antigens expressed on

  5. γ -Ray Generation from Plasma Wakefield Resonant Wiggler

    Science.gov (United States)

    Lei, Bifeng; Wang, Jingwei; Kharin, Vasily; Zepf, Matt; Rykovanov, Sergey

    2018-03-01

    A flexible gamma-ray radiation source based on the resonant laser-plasma wakefield wiggler is proposed. The wiggler is achieved by inducing centroid oscillations of a short laser pulse in a plasma channel. Electrons (self-)injected in such a wakefield experience both oscillations due to the transverse electric fields and energy gain due to the longitudinal electric field. The oscillations are significantly enhanced when the laser pulse centroid oscillations are in resonance with the electron betatron oscillations, extending the radiation spectrum to the gamma-ray range. The polarization of the radiation can be easily controlled by adjusting the injection of the laser pulse into the plasma channel.

  6. Magnetic Field Dependence and Q of the Josephson Plasma Resonance

    DEFF Research Database (Denmark)

    Pedersen, Niels Falsig; Finnegan, T. F.; Langenberg, D. N.

    1972-01-01

    The results of an experimental study of the magnetic field dependence of the Josephson-plasma-resonance frequency and linewidth in Pb-Pb oxide-Pb tunnel junctions are reported. In the presence of an external magnetic field, the plasma mode is found to be sensitive to an antisymmetric component...... of supercurrent density which is not observed in conventional measurements of the field-dependent critical current. The frequency and field dependence of the plasma-resonance linewidth are interpreted as evidence that the previously unobserved quasiparticle-pair-interference tunnel current predicted by Josephson...

  7. Resonant absorption of radar waves by a magnetized collisional plasma

    International Nuclear Information System (INIS)

    Sun Aiping; Tong Honghui; Shen Liru; Tang Deli; Qiu Xiaoming

    2001-01-01

    The propagation of radar waves in a magnetized collisional plasma slab is studied numerically. It is found for uniform plasma that: first, the wave attenuation and absorbed power show a peak value, i.e., resonant absorption when the collision frequency f en = 0.1, 0.5, 1 GHz and the wave frequency nears upper hybrid frequency. Secondly, the attenuation, absorbed, and transmitted power curves become flat at f en = 5, 10 Ghz. thirdly, the attenuation and absorbed power increase with plasma density, and the attenuation and the proportion of absorbed power can reach 100 dB and 80%, respectively, at the plasma density n = 10 11 cm -3 . For nonuniform plasma, the peak value of reflected power is larger than that in uniform plasma. So, uniform magnetized plasma is of more benefit to plasma cloaking

  8. Experimental validation of tunable features in laser-induced plasma resonators

    Science.gov (United States)

    Colón Quiñones, Roberto A.; Cappelli, Mark A.

    2017-08-01

    Measurements are presented which examine the use of gaseous plasma elements as highly-tunable resonators. The resonator considered here is a laser-induced plasma kernel generated by focusing the fundamental output from a Q-switched Nd:YAG laser through a lens and into a gas at constant pressure. The near-ellipsoidal plasma element interacts with incoming microwave radiation through excitation of low-order, electric-dipole resonances similar to those seen in metallic spheres. The tunability of these elements stems from the dispersive nature of plasmas arising from their variable electron density, electron momentum transfer collision frequency, and the concomitant e↵ect of these properties on the excited surface plasmon resonance. Experiments were carried out in the Ku band of the microwave spectrum to characterize the scattering properties of these resonators for di↵erent values of electron density. The experimental results are compared with results from theoretical approximations and finite element method electromagnetic simulations. The described tunable resonators have the potential to be used as the building blocks in a new class of all-plasma metamaterials with fully three-dimensional structural flexibility.

  9. Interaction of plasma vortices with resonant particles

    DEFF Research Database (Denmark)

    Jovanovic, D.; Pécseli, Hans; Juul Rasmussen, J.

    1990-01-01

    Kinetic effects associated with the electron motion along magnetic field lines in low‐beta plasmas are studied. Using the gyrokinetic description of electrons, a kinetic analog of the reduced magnetohydrodynamic equations is derived, and it is shown that in the strongly nonlinear regime they poss...... particles. The evolution equations indicate the possibility of excitation of plasma vortices by electron beams....

  10. Surface Acoustic Wave (SAW Resonators for Monitoring Conditioning Film Formation

    Directory of Open Access Journals (Sweden)

    Siegfried Hohmann

    2015-05-01

    Full Text Available We propose surface acoustic wave (SAW resonators as a complementary tool for conditioning film monitoring. Conditioning films are formed by adsorption of inorganic and organic substances on a substrate the moment this substrate comes into contact with a liquid phase. In the case of implant insertion, for instance, initial protein adsorption is required to start wound healing, but it will also trigger immune reactions leading to inflammatory responses. The control of the initial protein adsorption would allow to promote the healing process and to suppress adverse immune reactions. Methods to investigate these adsorption processes are available, but it remains difficult to translate measurement results into actual protein binding events. Biosensor transducers allow user-friendly investigation of protein adsorption on different surfaces. The combination of several transduction principles leads to complementary results, allowing a more comprehensive characterization of the adsorbing layer. We introduce SAW resonators as a novel complementary tool for time-resolved conditioning film monitoring. SAW resonators were coated with polymers. The adsorption of the plasma proteins human serum albumin (HSA and fibrinogen onto the polymer-coated surfaces were monitored. Frequency results were compared with quartz crystal microbalance (QCM sensor measurements, which confirmed the suitability of the SAW resonators for this application.

  11. Resonant and hollow beam generation of plasma channels

    International Nuclear Information System (INIS)

    Alexeev, I.; Kim, K.Y.; Fan, J.; Parra, E.; Milchberg, H.M.; Margolin, L.Ya.; Pyatnitskii, L.N.

    2001-01-01

    We report two variations on plasma channel generation using the propagation of intense Bessel beams. In the first experiment, the propagation of a high intensity Bessel beam in neutral gas is observed to give rise to resonantly enhanced plasma channel generation, resulting from resonant self-trapping of the beam and enhanced laser-plasma heating. In the second experiment, a high power, hollow Bessel beam (J 5 ) is produced and the optical breakdown of a gas target and the generation of a tubular plasma channel with such a beam is realized for the first time. Hydrodynamic simulations of the laser-plasma interaction of are in good agreement with the results of both experiments

  12. High intensity surface plasma waves, theory and PIC simulations

    Science.gov (United States)

    Raynaud, M.; Héron, A.; Adam, J.-C.

    2018-01-01

    With the development of intense (>1019 W cm‑2) short pulses (≤25 fs) laser with very high contrast, surface plasma wave (SPW) can be explored in the relativistic regime. As the SPW propagates with a phase velocity close to the speed of light it may results in a strong acceleration of electron bunches along the surface permitting them to reach relativistic energies. This may be important e.g. for applications in the field of plasma-based accelerators. We investigate in this work the excitation of SPWs on grating preformed over-dense plasmas for laser intensities ranging from 1019 up to 1021 W cm‑2. We discuss the nature of the interaction with respect to the solid case in which surface plasmon can be resonantly excited with weak laser intensity. In particular, we show the importance of the pulse duration and focalization of the laser beam on the amplitude of the SPW.

  13. Plasma diagnostics surface analysis and interactions

    CERN Document Server

    Auciello, Orlando

    2013-01-01

    Plasmas and their interaction with materials have become subjects of major interest because of their importance in modern forefront technologies such as microelectronics, fusion energy, and space. Plasmas are used in microelectronics to process semiconductors (etching of patterns for microcircuits, plasma-induced deposition of thin films, etc.); plasmas produce deleterious erosion effects on surfaces of materials used for fusion devices and spaceships exposed to the low earth environment.Diagnostics of plasmas and materials exposed to them are fundamental to the understanding of the physical a

  14. Modification of polycarbonate surface in oxidizing plasma

    Science.gov (United States)

    Ovtsyn, A. A.; Smirnov, S. A.; Shikova, T. G.; Kholodkov, I. V.

    2017-11-01

    The properties of the surface of the film polycarbonate Lexan 8010 were experimentally studied after treatment in a DC discharge plasma in oxygen and air at pressures of 50-300 Pa and a discharge current of 80 mA. The contact angles of wetting and surface energies are measured. The topography of the surface was investigated by atomic force microscopy. The chemical composition of the surface was determined from the FT-IR spectroscopy data in the variant of total internal reflection, as well as X-ray photoelectron spectroscopy. Treatment in the oxidizing plasma leads to a change in morphology (average roughness increases), an increase in the surface energy, and the concentration of oxygen-containing groups (hydroxyl groups, carbonyl groups in ketones or aldehydes and in oxyketones) on the surface of the polymer. Possible reasons for the difference in surface properties of polymer under the action of oxygen and air plasma on it are discussed.

  15. Stochastic resonance in a surface dipole

    Energy Technology Data Exchange (ETDEWEB)

    Heinsalu, E., E-mail: els@ifisc.uib-csic.es [IFISC, Instituto de Fisica Interdisciplinar y Sistemas Complejos (CSIC-UIB), E-07122 Palma de Mallorca (Spain); National Institute of Chemical Physics and Biophysics, Raevala 10, 15042 Tallinn (Estonia); Patriarca, M. [IFISC, Instituto de Fisica Interdisciplinar y Sistemas Complejos (CSIC-UIB), E-07122 Palma de Mallorca (Spain); National Institute of Chemical Physics and Biophysics, Raevala 10, 15042 Tallinn (Estonia); Marchesoni, F. [Dipartimento di Fisica, Universita di Camerino, I-62032 Camerino (Italy)

    2010-10-05

    The dynamics of a neutral dipole diffusing on a one-dimensional symmetric periodic substrate is numerically investigated in the presence of an ac electric field. It is observed that the amplitude of the forced oscillations of the dipole can be enhanced by tuning the noise strength, i.e., the substrate temperature. Such a manifestation of stochastic resonance turns out to be extremely sensitive to the mechanical properties of the dipole. This phenomenon has immediate applications in surface physics and nanodevice technology.

  16. Application of resonance interferometry and holography for plasma diagnostics

    International Nuclear Information System (INIS)

    Drejden, G.V.; Zajdel', A.N.; Ostrovksya, G.V.; Ostrovskij, Yu.I.; Pobedonostseva, N.A.; Tanin, L.V.; Filippov, V.N.; Shedova, E.N.

    1975-01-01

    Methods of resonance interferometry and holography are discussed, and limits of their applications are considered. Resonance methods are distinguished by high sensitivity and selectivity in the comparison with conventional interferometric and holographic methods. Methods discussed are mainly applied in a comparatively dense plasma, although in some cases it can determine atom densities up to Nsub(a) = 10 9 cm -3 and lower. In the case of the plasma with Nsub(e) = 10 18 -10 19 cm -3 a minimal atom density observable is near Nsub(a) = 10 14 cm -3 . Requirements light sources are specified, and investigation methods are described. For potassium, sodium, lithium, and hydrogen plasma as examples the applicability of these methods is illustrated: atom and electron density are determined, and the plasma dynamics is investigated

  17. Multiplexed infrared plasmonic surface lattice resonances

    Science.gov (United States)

    Gutha, Rithvik R.; Sadeghi, Seyed M.; Sharp, Christina; Wing, Waylin J.

    2018-01-01

    We demonstrate that arrays of flat gold nanodisks with rectangular lattices can support a tunable hybrid frequency gap formed by the surface lattice resonances in the substrate ((+1, 0)sub) and the superstrate ((-1, 0)sup). For a certain polarization, rotation of the arrays reduces this gap, forming a band crossing (degenerate state) wherein both surface lattice resonances happen around a single wavelength (˜1300 nm). This highlights a situation wherein hybridization of the Rayleigh anomaly with localized surface plasmon resonances with different multipolar natures happens around the same wavelength. We demonstrate that for a different polarization of the incident light the arrays support the formation of a photonic-plasmonic state at about 1650 nm. Our results show that as the projection of the wave vector of the incident light on the planes of the nanodisk arrays increases, within a given wavelength range, the (+1, 0) mode of this state becomes amplified. Under this condition, this mode can undergo a significant blue shift without broadening, while its amplitude increases.

  18. Breathing-mode resonance of a complex plasma disk

    International Nuclear Information System (INIS)

    Sheridan, T.E.; Buckey, C.R.; Cox, D.J.; Merrill, R.J.; Theisen, W.L.

    2004-01-01

    We have experimentally characterized the breathing mode oscillation of a strongly-coupled, dusty plasma disk. Steady-state oscillations are excited by sinusoidally modulating the plasma density, creating a single-frequency, in-plane driving force. Resonance curves agree well with damped harmonic oscillator theory. A response at the second harmonic is observed and found to increase with the square of the driving force, indicating a quadratic nonlinearity

  19. Electron Cyclotron Resonance Heating of a High-Density Plasma

    DEFF Research Database (Denmark)

    Hansen, F. Ramskov

    1986-01-01

    Various schemes for electron cyclotron resonance heating of tokamak plasmas with the ratio of electron plasma frequency to electron cyclotron frequency, "»pe/^ce* larger than 1 on axis, are investigated. In particular, a mode conversion scheme is investigated using ordinary waves at the fundamental......-relativistic plasma. Radial profiles for the power deposition and the non-inductive wave-driven current due to the Bernstein waves are calculated for realistic antenna radiation patterns with parameters corresponding to the Danish tokamak DANTE and to Princeton's PLT....

  20. Electron cyclotron resonance breakdown studies in a linear plasma ...

    Indian Academy of Sciences (India)

    Abstract. Electron cyclotron resonance (ECR) plasma breakdown is studied in a small linear cylindrical system with four different gases – hydrogen, helium, argon and nitrogen. Microwave power in the experimental system is delivered by a magnetron at 2.45 ± 0.02. GHz in TE10 mode and launched radially to have ...

  1. Impulse Plasma In Surface Engineering - a review

    Science.gov (United States)

    Zdunek, K.; Nowakowska-Langier, K.; Chodun, R.; Okrasa, S.; Rabinski, M.; Dora, J.; Domanowski, P.; Halarowicz, J.

    2014-11-01

    The article describes the view of the plasma surface engineering, assuming the role of non-thermal energy effects in the synthesis of materials and coatings deposition. In the following study it was underlined that the vapor excitation through the application of an electric field during coatings deposition gives new possibilities for coatings formation. As an example the IPD method was chosen. During the IPD (Impulse Plasma Deposition) the impulse plasma is generated in the coaxial accelerator by strong periodic electrical pulses. The impulse plasma is distributed in the form of energetic plasma pockets. Due to the almost completely ionization of gas, the nucleation of new phases takes place on ions directly in the plasma itself. As a result the coatings of metastable materials with nano-amorphous structure and excellent adhesion to the non-heated intentionally substrates could be deposited. Recently the novel way of impulse plasma generation during the coatings deposition was proposed and developed by our group. An efficient tool for plasma process control, the plasma forming gas injection to the interelectrode space was used. Periodic changing the gas pressure results in increasing both the degree of dispersion and the dynamics of the plasma pulses. The advantage of the new technique in deposition of coatings with exceptionally good properties has been demonstrated in the industrial scale not only in the case of the IPD method but also in the case of very well known magnetron sputtering method.

  2. Prediction and Migration of Surface-related Resonant Multiples

    KAUST Repository

    Guo, Bowen

    2015-08-19

    Surface-related resonant multiples can be migrated to achieve better resolution than migrating primary reflections. We now derive the formula for migrating surface-related resonant multiples, and show its super-resolution characteristics. Moreover, a method is proposed to predict surface-related resonant multiples with zero-offset primary reflections. The prediction can be used to indentify and extract the true resonant multiple from other events. Both synthetic and field data are used to validate this prediction.

  3. Parametric plasma surface instabilities with p-polarized radiation

    International Nuclear Information System (INIS)

    Rappaport, H.L.

    1994-01-01

    The authors argue that parametric plasma surface mode excitation is a viable broadband instability mechanism in the microwave regime since the wavelength of incident radiation can be large compared to plasma ion density gradient scale lengths. The authors restrict their attention to plasmas which are uniform in the planes perpendicular to the density gradients. The boundary region is characterized by three parameters: (1) the ion density gradient length; (2) the electron Debye length; and (3) the excursion of boundary electrons as they move in response to monochromatic p-polarized radiation. A thin vacuum plasma transition layer, in which the ion density gradient scale length is large compared with the Debye length and the electron excursion, is included in the analysis of plasma stability. The recently proposed Lagrangian Frame Two-Plasmon Decay mode (LFTPD) is investigated in the regime in which the instability is not resonantly coupled to surface waves propagating along the boundary region. In this case they have found both spatially dependent growth rate profiles and spatially dependent transit layer magnetic fields due to nonlinear surface currents. LFTPD growth rate profiles are displayed as a function of pump amplitude. The results of a time domain simulation of this mode is also shown

  4. Multi-analyte surface plasmon resonance biosensing

    Czech Academy of Sciences Publication Activity Database

    Homola, Jiří; Vaisocherová, Hana; Dostálek, Jakub; Piliarik, Marek

    2005-01-01

    Roč. 37, č. 1 (2005), s. 26-36 ISSN 1046-2023 R&D Projects: GA ČR(CZ) GA303/03/0249; GA ČR(CZ) GA203/02/1326; GA ČR(CZ) GA102/03/0633 Grant - others:European Commision(XE) QLK4-CT-2002-02323 Institutional research plan: CEZ:AV0Z20670512 Keywords : biosensors * surface plasmon resonance * optical sensors Subject RIV: FA - Cardiovascular Diseases incl. Cardiotharic Surgery Impact factor: 3.591, year: 2005

  5. Plasma-surface interactions under high heat and particle fluxes

    NARCIS (Netherlands)

    De Temmerman, G.; Bystrov, K.; Liu, F.; Liu, W.; Morgan, T.; Tanyeli, I.; van den Berg, M.; Xu, H.; Zielinski, J.

    2013-01-01

    The plasma-surface interactions expected in the divertor of a future fusion reactor are characterized by extreme heat and particle fluxes interacting with the plasma-facing surfaces. Powerful linear plasma generators are used to reproduce the expected plasma conditions and allow plasma-surface

  6. Plasma assisted surface treatments of biomaterials.

    Science.gov (United States)

    Minati, L; Migliaresi, C; Lunelli, L; Viero, G; Dalla Serra, M; Speranza, G

    2017-10-01

    The biocompatibility of an implant depends upon the material it is composed of, in addition to the prosthetic device's morphology, mechanical and surface properties. Properties as porosity and pore size should allow, when required, cells penetration and proliferation. Stiffness and strength, that depend on the bulk characteristics of the material, should match the mechanical requirements of the prosthetic applications. Surface properties should allow integration in the surrounding tissues by activating proper communication pathways with the surrounding cells. Bulk and surface properties are not interconnected, and for instance a bone prosthesis could possess the necessary stiffness and strength for the application omitting out prerequisite surface properties essential for the osteointegration. In this case, surface treatment is mandatory and can be accomplished using various techniques such as applying coatings to the prosthesis, ion beams, chemical grafting or modification, low temperature plasma, or a combination of the aforementioned. Low temperature plasma-based techniques have gained increasing consensus for the surface modification of biomaterials for being effective and competitive compared to other ways to introduce surface functionalities. In this paper we review plasma processing techniques and describe potentialities and applications of plasma to tailor the interface of biomaterials. Copyright © 2017 Elsevier B.V. All rights reserved.

  7. Surface wave propagation characteristics in atmospheric pressure plasma column

    International Nuclear Information System (INIS)

    Pencheva, M; Benova, E; Zhelyazkov, I

    2007-01-01

    In the typical experiments of surface wave sustained plasma columns at atmospheric pressure the ratio of collision to wave frequency (ν/ω) is much greater than unity. Therefore, one might expect that the usual analysis of the wave dispersion relation, performed under the assumption ν/ω = 0, cannot give adequate description of the wave propagation characteristics. In order to study these characteristics we have analyzed the wave dispersion relationship for arbitrary ν/ω. Our analysis includes phase and wave dispersion curves, attenuation coefficient, and wave phase and group velocities. The numerical results show that a turning back point appears in the phase diagram, after which a region of backward wave propagation exists. The experimentally observed plasma column is only in a region where wave propagation coefficient is higher than the attenuation coefficient. At the plasma column end the electron density is much higher than that corresponding to the turning back point and the resonance

  8. Resonant surface acoustic wave chemical detector

    Science.gov (United States)

    Brocato, Robert W.; Brocato, Terisse; Stotts, Larry G.

    2017-08-08

    Apparatus for chemical detection includes a pair of interdigitated transducers (IDTs) formed on a piezoelectric substrate. The apparatus includes a layer of adsorptive material deposited on a surface of the piezoelectric substrate between the IDTs, where each IDT is conformed, and is dimensioned in relation to an operating frequency and an acoustic velocity of the piezoelectric substrate, so as to function as a single-phase uni-directional transducer (SPUDT) at the operating frequency. Additionally, the apparatus includes the pair of IDTs is spaced apart along a propagation axis and mutually aligned relative to said propagation axis so as to define an acoustic cavity that is resonant to surface acoustic waves (SAWs) at the operating frequency, where a distance between each IDT of the pair of IDTs ranges from 100 wavelength of the operating frequency to 400 wavelength of the operating frequency.

  9. Three-dimensional modeling of plasma edge transport and divertor fluxes during application of resonant magnetic perturbations on ITER

    Czech Academy of Sciences Publication Activity Database

    Schmitz, O.; Becoulet, M.; Cahyna, Pavel; Evans, T.E.; Feng, Y.; Frerichs, H.; Loarte, A.; Pitts, R.A.; Reiser, D.; Fenstermacher, M.E.; Harting, D.; Kirschner, A.; Kukushkin, A.; Lunt, T.; Saibene, G.; Reiter, D.; Samm, U.; Wiesen, S.

    2016-01-01

    Roč. 56, č. 6 (2016), č. článku 066008. ISSN 0029-5515 Institutional support: RVO:61389021 Keywords : resonant magnetic perturbations * plasma edge physics * 3D modeling * neutral particle physics * ITER * divertor heat and particle loads * ELM control Subject RIV: BL - Plasma and Gas Discharge Physics OBOR OECD: Fluids and plasma physics (including surface physics) Impact factor: 3.307, year: 2016 http://iopscience.iop.org/article/10.1088/0029-5515/56/6/066008/meta

  10. Improved ion acceleration via laser surface plasma waves excitation

    Energy Technology Data Exchange (ETDEWEB)

    Bigongiari, A. [CEA/DSM/LSI, CNRS, Ecole Polytechnique, 91128 Palaiseau Cedex (France); TIPS/LULI, Université Paris 6, CNRS, CEA, Ecole Polytechnique, 3, rue Galilée, 94200 Ivry-sur-Seine (France); Raynaud, M. [CEA/DSM/LSI, CNRS, Ecole Polytechnique, 91128 Palaiseau Cedex (France); Riconda, C. [TIPS/LULI, Université Paris 6, CNRS, CEA, Ecole Polytechnique, 3, rue Galilée, 94200 Ivry-sur-Seine (France); Héron, A. [CPHT, CNRS, Ecole Polytechnique, 91128 Palaiseau Cedex (France)

    2013-05-15

    The possibility of enhancing the emission of the ions accelerated in the interaction of a high intensity ultra-short (<100 fs) laser pulse with a thin target (<10λ{sub 0}), via surface plasma wave excitation is investigated. Two-dimensional particle-in-cell simulations are performed for laser intensities ranging from 10{sup 19} to 10{sup 20} Wcm{sup −2}μm{sup 2}. The surface wave is resonantly excited by the laser via the coupling with a modulation at the target surface. In the cases where the surface wave is excited, we find an enhancement of the maximum ion energy of a factor ∼2 compared to the cases where the target surface is flat.

  11. Plasma technology of the surface polymer activation

    International Nuclear Information System (INIS)

    Dutra, Jorge C.N.; Mello, Sandra C.; Massi, Marcos; Otani, Choyu; Maciel, Homero S.; Bittencourt, Edison

    2005-01-01

    A number of polymers, especially rubbers, require surface treatment to achieve a satisfactory level of adhesion. The surface of EPDM rubber vulcanized is high hydrophobicity and is not suited for a number of potential applications, in particular, for adhering to the polyurethane liner of solid rocket propellants. In this case, plasma treatment can be a very attractive process because it can efficiently increase the surface energy attributed to surface oxidation with the introduction of polar groups 1, 2. In order to investigate the influence of the parameters on the modifications of the treated surface samples of EPDM rubber by plasma generated by gas oxygen and argon, the water and methylene iodide contact angles were measured at room temperature with an image analyzing using the sessile drop technique 3 - 6 . (author)

  12. Preparation of poly(2-chloroaniline) membrane and plasma surface modification

    International Nuclear Information System (INIS)

    Kir, E.; Oksuz, L.; Helhel, S.

    2006-01-01

    P2ClAn membranes were obtained from chemically synthesized poly(2-chloroaniline) (P2ClAn) by casting method. These membranes were cast from dimethyl formamide (DMF) and were in the undoped state. P2ClAn membranes were characterized by Fourier infrared spectroscopy and scanning electron microscopy. Measurements of water content capacity, membrane thickness and ion-exchange capacity of the cast membranes were carried out. P2ClAn membranes were treated by electron cylotron resonance (ECR) plasma for surface modification. Plasma treatment has been successfully utilized for improving the surface properties of P2ClAn membranes such as increasing pore diameters and number of pores for better anion or molecule transportation

  13. Studies of electron cyclotron resonance ion source plasma physics

    International Nuclear Information System (INIS)

    Tarvainen, O.

    2005-01-01

    This thesis consists of an introduction to the plasma physics of electron cyclotron resonance ion sources (ECRIS) and a review of the results obtained by the author and co-workers including discussion of related work by others. The thesis begins with a theoretical discussion dealing with plasma physics relevant for the production of highly charged ions in ECR ion source plasmas. This is followed by an overview of different techniques, such as gas mixing and double frequency heating, that can be used to improve the performance of this type of ion source. The experimental part of the work consists of studies related to ECRIS plasma physics. The effect of the gas mixing technique on the production efficiency of different ion beams was studied with both gaseous and solid materials. It was observed that gas mixing improves the confinement of the heavier element while the confinement of the lighter element is reduced. When the effect of gas mixing on MIVOC-plasmas was studied with several mixing gases it was observed that applying this technique can reduce the inevitable carbon contamination by a significant factor. In order to understand the different plasma processes taking place in ECRIS plasmas, a series of plasma potential and emittance measurements was carried out. An instrument, which can be used to measure the plasma potential in a single measurement without disturbing the plasma, was developed for this work. Studying the plasma potential of ECR ion sources is important not only because it helps to understand different plasma processes, but also because the information can be used as an input parameter for beam transport simulations and ion source extraction design. The experiments performed have revealed clear dependencies of the plasma potential on certain source parameters such as the amount of carbon contamination accumulated on the walls of the plasma chamber during a MIVOC-run. It was also observed that gas mixing affects not only the production efficiency

  14. Polymer surface modification by plasmas and photons

    Science.gov (United States)

    Chan, C.-M.; Ko, T.-M.; Hiraoka, H.

    1996-05-01

    Polymers have been applied successfully in fields such as adhesion, biomaterials, protective coatings, friction and wear, composites, microelectronic devices, and thin-film technology. In general, special surface properties with regard to chemical composition, hydrophilicity, roughness, crystallinity, conductivity, lubricity, and cross-linking density are required for the success of these applications. Polymers very often do not possess the surface properties needed for these applications. However, they have excellent bulk physical and chemical properties, are inexpensive, and are easy to process. For these reasons, surface modification techniques which can transform these inexpensive materials into highly valuable finished products have become an important part of the plastics and many other industries. In recent years, many advances have been made in developing surface treatments to alter the chemical and physical properties of polymer surfaces without affecting bulk properties. Common surface modification techniques include treatments by flame, corona, plasmas, photons, electron beams, ion beams, X-rays, and γ-rays. Plasma treatment is probably the most versatile surface treatment technique. Different types of gases such as argon, oxygen, nitrogen, fluorine, carbon dioxide, and water can produce the unique surface properties required by various applications. For example, oxygen-plasma treatment can increase the surface energy of polymers, whereas fluorine-plasma treatment can decrease the surface energy and improve the chemical inertness. Cross-linking at a polymer surface can be introduced by an inert-gas plasma. Modification by plasma treatment is usually confined to the top several hundred ångströms and does not affect the bulk properties. The main disadvantage of this technique is that it requires a vacuum system, which increases the cost of operation. Thin polymer films with unique chemical and physical properties are produced by plasma polymerization

  15. Axisymmetric Alfvén resonances in a multi-component plasma at finite ion gyrofrequency

    Directory of Open Access Journals (Sweden)

    D. Yu. Klimushkin

    2006-05-01

    Full Text Available This paper deals with the spatial structure of zero azimuthal wave number ULF oscillations in a 1-D inhomogeneous multi-component plasma when a finite ion gyrofrequency is taken into account. Such oscillations may occur in the terrestrial magnetosphere as Pc1-3 waves or in the magnetosphere of the planet Mercury. The wave field was found to have a sharp peak on some magnetic surfaces, an analogy of the Alfvén (field line resonance in one-fluid MHD theory. The resonance can only take place for waves with frequencies in the intervals ω<ωch or Ω0<ω< ωcp, where ωch and ωcp are heavy and light ions gyrofrequencies, and Ω0 is a kind of hybrid frequency. Contrary to ordinary Alfvén resonance, the wave resonance under consideration takes place even at the zero azimuthal wave number. The radial component of the wave electric field has a pole-type singularity, while the azimuthal component is finite but has a branching point singularity on the resonance surface. The later singularity can disappear at some frequencies. In the region adjacent to the resonant surface the mode is standing across the magnetic shells.

  16. Axisymmetric Alfvén resonances in a multi-component plasma at finite ion gyrofrequency

    Directory of Open Access Journals (Sweden)

    D. Yu. Klimushkin

    2006-05-01

    Full Text Available This paper deals with the spatial structure of zero azimuthal wave number ULF oscillations in a 1-D inhomogeneous multi-component plasma when a finite ion gyrofrequency is taken into account. Such oscillations may occur in the terrestrial magnetosphere as Pc1-3 waves or in the magnetosphere of the planet Mercury. The wave field was found to have a sharp peak on some magnetic surfaces, an analogy of the Alfvén (field line resonance in one-fluid MHD theory. The resonance can only take place for waves with frequencies in the intervals ω<ωch or Ω0<ω< ωcp, where ωch and ωcp are heavy and light ions gyrofrequencies, and Ω0 is a kind of hybrid frequency. Contrary to ordinary Alfvén resonance, the wave resonance under consideration takes place even at the zero azimuthal wave number. The radial component of the wave electric field has a pole-type singularity, while the azimuthal component is finite but has a branching point singularity on the resonance surface. The later singularity can disappear at some frequencies. In the region adjacent to the resonant surface the mode is standing across the magnetic shells.

  17. Plasma surface interactions in controlled fusion devices

    Energy Technology Data Exchange (ETDEWEB)

    Ghendrih, Ph.; Becoulet, M.; Costanzo, L. [and others

    2000-07-01

    This report brings together all the contributions of EURATOM/CEA association to the 14. international conference on plasma surface interactions in controlled fusion devices. 24 papers are presented and they deal mainly with the ergodic divertor and the first wall of Tore-supra tokamak.

  18. Plasma-Surface Interaction Activities in KSTAR

    NARCIS (Netherlands)

    Hong, S. H.; Yu, Y.; Kim, K. P.; Bak, J. G.; Park, H. J.; Oh, Y. S.; Chung, J.; Nam, Y. U.; Bang, E. N.; Kim, K. R.; Litnovsky, A.; Hellwig, M.; Matveev, D.; Komm, M.; van den Berg, M. A.; Kim, W. C.; Kim, H. K.; Rho, T. H.; Chu, Y.; Oh, Y. K.; Yang, H. L.; Park, K. R.; Chung, K. S.; Kstar Team,

    2013-01-01

    Selected topics of Plasma-Surface Interaction (PSI) activities in KSTAR are briefly introduced. SOL parameter measurements, particle balance and fuel retention, in-vessel dust research, and finally tungsten R & D are discussed. Some quantitative numbers from the initial phase of the operation

  19. The multipole resonance probe: A concept for simultaneous determination of plasma density, electron temperature, and collision rate in low-pressure plasmas

    International Nuclear Information System (INIS)

    Lapke, M.; Mussenbrock, T.; Brinkmann, R. P.

    2008-01-01

    A diagnostic concept is presented which enables the simultaneous determination of plasma density, electron temperature, and collision rate in low-pressure gas discharges. The proposed method utilizes a radio-frequency driven probe of particular spherical design which is immersed in the plasma to excite a family of spatially bounded surface resonances. An analysis of the measured absorption spectrum S(ω) of the probe provides information on the distribution of the plasma in its vicinity, from which the values of the plasma parameters can be inferred. In its simplest realization, the probe consists of two dielectrically shielded, conducting hemispheres, which are symmetrically driven by an radio-frequency source, and the excited resonances can be classified as multipole fields, which allows an analytical evaluation of the measured signal. The proposed method is robust, calibration free, economical, and can be used for ideal and reactive plasmas alike

  20. Metal surface nitriding by laser induced plasma

    Science.gov (United States)

    Thomann, A. L.; Boulmer-Leborgne, C.; Andreazza-Vignolle, C.; Andreazza, P.; Hermann, J.; Blondiaux, G.

    1996-10-01

    We study a nitriding technique of metals by means of laser induced plasma. The synthesized layers are composed of a nitrogen concentration gradient over several μm depth, and are expected to be useful for tribological applications with no adhesion problem. The nitriding method is tested on the synthesis of titanium nitride which is a well-known compound, obtained at present by many deposition and diffusion techniques. In the method of interest, a laser beam is focused on a titanium target in a nitrogen atmosphere, leading to the creation of a plasma over the metal surface. In order to understand the layer formation, it is necessary to characterize the plasma as well as the surface that it has been in contact with. Progressive nitrogen incorporation in the titanium lattice and TiN synthesis are studied by characterizing samples prepared with increasing laser shot number (100-4000). The role of the laser wavelength is also inspected by comparing layers obtained with two kinds of pulsed lasers: a transversal-excited-atmospheric-pressure-CO2 laser (λ=10.6 μm) and a XeCl excimer laser (λ=308 nm). Simulations of the target temperature rise under laser irradiation are performed, which evidence differences in the initial laser/material interaction (material heated thickness, heating time duration, etc.) depending on the laser features (wavelength and pulse time duration). Results from plasma characterization also point out that the plasma composition and propagation mode depend on the laser wavelength. Correlation of these results with those obtained from layer analyses shows at first the important role played by the plasma in the nitrogen incorporation. Its presence is necessary and allows N2 dissociation and a better energy coupling with the target. Second, it appears that the nitrogen diffusion governs the nitriding process. The study of the metal nitriding efficiency, depending on the laser used, allows us to explain the differences observed in the layer features

  1. Surface modification of polyethylene by plasma

    International Nuclear Information System (INIS)

    Colin O, E.

    2003-01-01

    The products made of polyethylene (PE) go from construction materials, electric insulating until packing material. The films for bags and pack occupy 83.6% of the distribution of the market of PE approximately. The enormous quantity of PE that is generated by its indiscriminate use brings as consequence a deterioration to the atmosphere, due to the long life that they present as waste. This work is a study on the modification of low density polyethylene films. In this type of thin materials, the changes in the surface meet with largely on the conformation of the rest of the material. To induce changes that modify the surface of PE, plasmas were used with reactive atmospheres of air, oxygen and nitrogen. The experimentation that was carries out went to introduce the PE to a cylindrical reactor where it was generated the plasma of air, oxygen and nitrogen to different times of exposure. After having carried out the exposure to the plasma, it was found that in the polyethylene it modifies their morphology, crystallinity, hydrophobicity, composition and electric conductivity. The analytical techniques that were used to characterize later to the polyethylene of being in contact with the plasma were: X-ray diffraction, Scanning Electron Microscopy, Infrared spectroscopy, Electric conductivity, Angle of contact and finally Thermal Gravimetric Analysis. The content of this work it is presented in five chapters: In the chapter 1 there are presented some general concepts of plasma and of the one polymer in study PE. In the chapter 2 it is made a general revision on modification of surfaces, as well as the properties that were modified in polymeric materials that were exposed to plasma in previous works. In the chapter 3 the experimental part and the conditions used are described in the modification of the PE. Also in this chapter a brief description it is made of the used characterization techniques. The results and discussion are presented in the chapter 4. These results

  2. XIX Conference on Plasma Surface Interactions

    International Nuclear Information System (INIS)

    Kurnaev, V A; Gasparyan, Yu M

    2016-01-01

    The 19 th Conference on Plasma Surface Interactions (PSI-2016) was held at National Research Nuclear University MEPhI (Moscow Engineering Physics Institute) on 28-29 January 2016. This is a traditional annual meeting organized by MEPhI for many years and devoted to the recent achievements of Russian scientists and foreign colleagues in experimental and computer simulations of plasma and its components' interactions with plasma faced materials (PFM) for fusion devices and plasma technologies. The conference agenda covered a broad list of topics including: • plasma induced erosion and modification of materials; • radiation damage in materials; • lithium and liquid metals as PFM; • modeling of plasma surface interaction and processes in SOL of tokamak plasma; • diagnostics of plasma-surface interaction. The aim of the conference was to present and discuss new results in PSI in a wide audience with different areas of expertise. The important feature of the conference is to give PhD and undergraduate students the opportunity for approbation of results of their scientific activity and improve their knowledge in the novel directions of R and D in the field of fusion and plasma technologies. In total, more than 80 experienced and young researchers participated in the conference. These Proceedings contain 21 papers selected for publication, which were reviewed by the invited international team of editors (T. Tanabe, S. Petrovich, Ch. Grisolia, Yu. Martynenko, S. Krasheninnikov, L. Begrambekov, A. Pisarev). The Conference as well as editing of this issue were supported by National Research Nuclear University MEPhI in the framework of the Russian Academic Excellence Project (contract No. 02.a03.21.0005, 27.08.2013). Finally, we would like to thank all of the speakers, participants and organizing committee members for their contribution to the conference. Acknowledgements The organizers of the conference would like to thank for the support from National Research

  3. Subwavelength topological structures resulting from surface two-plasmon resonance by femtosecond laser exposure solid surface.

    Science.gov (United States)

    Song, Hai-Ying; Liu, Shi-Bing; Liu, H Y; Wang, Yang; Chen, Tao; Dong, Xiang-Ming

    2016-05-30

    We present that surface two-plasmon resonance (STPR) in electron plasma sheet produced by a femtosecond laser irradiating a solid surface is the self-formation mechanism of periodic subwavelength ripple structures. Peaks of overdense electrons, formed by resonant two-plasmon wave mode, pull bound ions out of the metal surface. Thus, the wave pattern of STPR is "carved" on the surface by Coulomb ablation (removal) due to periodic distributed strong electrostatic field produced by charge separation. To confirm the STPR model, we have performed analogical carving experiments by two femtosecond laser beams with perpendicular polarizations and time delay. The results explicitly show that two wave patterns of STPR generated by each beam are independently created in the pulse exposure area of a target surface, which is like the traditional "layer-carving" technique by comparison with the structured topological features. The time-scale of ablation dynamics and the electron temperature in ultrafast interaction are also verified by a time-resolved spectroscopy experiment and numerical simulation, respectively. The present model can self-consistently explain the formation of subwavelength ripple structures even with spatial periods shorter than half of the laser wavelength, shedding light on the understanding of ultrafast laser-solid interaction.

  4. Half bridge resonant converter for ignition of thermal plasmas

    International Nuclear Information System (INIS)

    Pena E, L.

    1997-01-01

    In this work the background, design, implementation and performance of a half bridge resonant converter (HBRC) used as an electronic ignition system for arc plasma torch generation is presented. The significance of the design lies in its simplicity, versatility and low cost. The system operates like a high voltage supply attached to electrodes before gaseous breakdown and like open circuit when electric arc is established. Resonant converter is implemented with a high voltage and high speed power driver intended for control the power MOSFET transistors connected in half bridge topology with L C load. The HBRC operates besides interference into domestic electric supply line (120 V, 60 Hz) as well electric measurement devices. Advantages and limitations of the converter are reviewed. Experimental impedance variation in the medium as a function of frequency operation and some experiences in striking arcs are also presented. (Author)

  5. Self-consistent Langmuir waves in resonantly driven thermal plasmas

    International Nuclear Information System (INIS)

    Lindberg, R. R.; Charman, A. E.; Wurtele, J. S.

    2007-01-01

    The longitudinal dynamics of a resonantly driven Langmuir wave are analyzed in the limit that the growth of the electrostatic wave is slow compared to the bounce frequency. Using simple physical arguments, the nonlinear distribution function is shown to be nearly invariant in the canonical particle action, provided both a spatially uniform term and higher-order spatial harmonics are included along with the fundamental in the longitudinal electric field. Requirements of self-consistency with the electrostatic potential yield the basic properties of the nonlinear distribution function, including a frequency shift that agrees closely with driven, electrostatic particle simulations over a range of temperatures. This extends earlier work on nonlinear Langmuir waves by Morales and O'Neil [G. J. Morales and T. M. O'Neil, Phys. Rev. Lett. 28, 417 (1972)] and Dewar [R. L. Dewar, Phys. Plasmas 15, 712 (1972)], and could form the basis of a reduced kinetic treatment of plasma dynamics for accelerator applications or Raman backscatter

  6. Surface resistivity measurement of plasma treated polymers

    International Nuclear Information System (INIS)

    Simon, D.; Pigram, P.J.; Liesegang, J.

    2000-01-01

    Full text: Resistivity of insulators is an important property of materials used within the integrated circuit and packaging industries. The measurement of electrical resistivity of insulator materials in the surface region in this work is interpreted through observations of surface charge decay. A self-field driven and diffusion charge transport theory is used to model the process and resistivity values obtained computationally. Data for the charge decay of surface charged samples are collected by suspending them inside a coaxial cylinder connected to an electrometer. Samples used have been low density polyethylene LDPE sheet, both pristine and surface treated. Some samples have been treated by air plasma at low vacuum pressures for different periods of time; others have been washed in ethyl acetate and then plasma treated before the resistivity measurement. The sets of resistivity measurements form the various treatments are compared below. X-ray photoelectron spectroscopy (XPS) has also been used to investigate and account for the observed variations in surface resistivity

  7. Synergistic effects in plasma surface interactions

    International Nuclear Information System (INIS)

    Roberto, J.B.; Behrisch, R.

    1984-01-01

    The possible synergistic effects which can contribute to plasma surface interaction phenomena in fusion devices are reviewed. These effects include the influence of reactive ions, surface modification, temperature, radiation damage, and external forces and fields on erosion yields, hydrogen retention and release, and other surface processes. The important synergistic effects are described in terms of surface and edge conditions encountered in present fusion devices and expected in future reactors. Priority data needs include the chemical erosion of graphite at high particle fluxes, melt-layer stability under disruption-induced eddy current forces, the influence of bulk neutron damage on hydrogen retention, and an in-situ evaluation of synergistic effects in operating fusion devices

  8. Atmospheric pressure plasma and electron cyclotron resonance plasma and their applications

    Science.gov (United States)

    Koretzky, Edward Van

    1999-03-01

    Based on a capacitively coupled electrical discharge scheme, an array of plasma torches is generated to form a dense plasma layer in the open air. In order to use a single power source to supply several torches simultaneously, capacitors are used as ballasting impedances coupling all the torches together. Several diagnostics are performed on a single plasma torch to find its temperature, dimensions, and plasma density. To ease constructing an atmospheric pressure plasma source, a modular system is then presented. The design and construction of the plasma torch module is described. The electrical characteristics of the module is studied for the case of a single module and two capacitively coupled modules. For understanding the plasma torch, each is represented by a parallel RC circuit, in which both R and C are time dependent due to the plasma. The dynamics of the plasma is described by the rate equations for the various plasma species. Numerical simulations have been performed to determine the parameter space for efficient generation of the plasma. Scattering (and absorption) of electromagnetic waves by the plasma torches in a rectangular waveguide is studied experimentally and theoretically. By changing the number of torches appearing in the waveguide, the dependence of the microwave power loss on the plasma volume is determined. ECR plasma-assisted chemical vapor deposition (PACVD) is a technique currently receiving much interest because the ECR plasma system offers a more complex parameter space than the conventional PACVD process. Moreover, a unique feature of the ECR plasma is the production of an energetic electron tail, establishing a large sheath potential on the substrate surface for energizing the bombarding ions, which enhances the nucleation rate. An ECR system for PACVD of diamond film on silicon substrates is designed and built. After surface treatment by the ECR produced energetic ions, the low pressure ECR plasma operation is switched, in situ, to a

  9. Self-consistent modeling of plasma density control using self-excited electron resonance spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Brinkmann, R.P. [Siemens AG, Munich (Germany); Klick, M.; Rehak, W. [Adolf-Slaby Inst., Berlin (Germany)

    1998-12-31

    Plasma processing, such as the structuring of wafer surfaces or the deposition of thin films, plays a pivotal role in the manufacturing of VLSI microelectronics and other semiconductors. Increasing wafer diameters and decreasing device dimensions put an ever-growing demand on the stability of the process conditions. Closed loop feed-back control is thought to ensure this stability, even in the presence of run-to-run variations in the chamber state, or similar drifts in the external process parameters. Traditional plasma diagnostics either provides very indirect plasma information, or causes intolerable disturbances of the process itself. Recently, however, a novel method was proposed which allows to characterize an RF plasma in a strictly passive way. This method, termed Self-Excited Electron Resonance Spectroscopy or SEERS, is based on the excitation of global oscillations in the plasma body due to nonlinearities in the sheath. In this work, the authors study the behavior of an inductively coupled, high density plasma reactor (ICP/HDP) under the action of a SEERS-based closed loop control. The approach employs a period-averaged plasma simulator which allows to predict, for any input power P, the secular evolution of the charge distribution in the plasma bulk, and the spatially resolved capacitance of the boundary sheath. Note that the control scheme is realizable, in the sense that it makes use only of that plasma information which is physically available. The results show that already a simple--even only proportional--SEERS-based feedback control can considerably increase the long time stability of industrial plasma processes.

  10. Surface plasma wave assisted second harmonic generation of laser over a metal film

    International Nuclear Information System (INIS)

    Chauhan, Santosh; Parashar, J.

    2015-01-01

    Second harmonic generation of laser mode converted surface plasma wave (SPW) over a corrugated metal film is studied. The laser, impinged on the metal film, under attenuated total reflection configuration, excites SPW over the metal–vacuum interface. The excited SPW extends over a much wider surface area than the laser spot cross-section. It exerts a second harmonic ponderomotive force on metal electrons, imparting them velocity that beats with the surface ripple to produce a nonlinear current, driving resonant second harmonic surface plasma wave

  11. On the gyro resonance electron-whistler interaction in transition layers of near-earth plasma

    International Nuclear Information System (INIS)

    Erokhin, N.S.; Zol'nikova, N.N.; Mikhajlovskaya, L.A.

    1996-01-01

    Gyro resonance interaction of electrons with low amplitude triggered whistler in the transition layers of the ionospheric and magnetospheric plasma that correspond to the blurred jumps of the magnetic field and plasma concentration was studied

  12. On the plasma confinement by acoustic resonance. An innovation for electrodeless high-pressure discharge lamps

    Science.gov (United States)

    Courret, Gilles; Nikkola, Petri; Wasterlain, Sébastien; Gudozhnik, Olexandr; Girardin, Michel; Braun, Jonathan; Gavin, Serge; Croci, Mirko; Egolf, Peter W.

    2017-08-01

    In an applied research project on the development of a pulsed microwave sulfur lamp prototype of 1 kW, we have discovered an amazing phenomenon in which the plasma forms a ball staying at the center of the bulb despite gravity, thus protecting the glass from melting. In this paper, it is shown that this results from an acoustic resonance in a spherical mode. Measurements of the plasma response to short pulses are presented showing beats at the spherical resonance. It is demonstrated that the beats could result from the simultaneous excitation of two normal modes with a frequency difference of approximately 1%. One of the two frequencies matches precisely the microwave pulses repetition, a little below 30 kHz. Thus this one is due to a forced oscillation, whereas the other one is due to a free oscillation. The phase velocity of sound was calculated as a function of temperature in order to find the series of temperatures at which a resonance would occur if the bulb were an isothermal solid sphere. The mean temperature inside the actual bulb was determined from the only doublet of this series, that has characteristic frequencies close enough to cause the observed beats. In addition, one of these two modes has a spherical symmetry that can explain the plasma ball formation. The obtained mean temperature is consistent with the direct measurements on the bulb surface as well as with the temperature in the core of a similar plasma found in the literature. We have also proposed a model of the resonance onset based on the acoustic dispersion and the sound amplification due to electromagnetic coupling.

  13. Lage-area planar RF plasma productions by surface waves

    International Nuclear Information System (INIS)

    Nonaka, S.

    1994-01-01

    Large-area rf plasmas are confirmed to be produced by means of RF discharges inside a large-area dielectric tube. The plasma space is 73 cm x 176 cm and 2.5 cm. The plasma is thought to be produced by an odd plasma-surface wave (PSW ο ) in case of using large-area electrodes and by an even plasma-surface wave (PSW ο ) in case of without the electrodes. (author). 7 refs, 4 figs

  14. Electron transport in the plasma edge with rotating resonant magnetic perturbations at the TEXTOR tokamak

    Energy Technology Data Exchange (ETDEWEB)

    Stoschus, Henning

    2011-10-13

    Small three-dimensional (3D) magnetic perturbations can be used as a tool to control the edge plasma parameters in magnetically confined plasmas in high confinement mode (''H-mode'') to suppress edge instabilities inherent to this regime, the Edge Localized Modes (ELMs). In this work, the impact of rotating 3D resonant magnetic perturbation (RMP) fields on the edge plasma structure characterized by electron density and temperature fields is investigated. We study a low confinement (L-mode) edge plasma (r/a>0.9) with high resistivity (edge electron collisionality {nu}{sup *}{sub e}>4) at the TEXTOR tokamak. The plasma structure in the plasma edge is measured by a set of high resolution diagnostics: a fast CCD camera ({delta}t=20 {mu}s) is set up in order to visualize the plasma structure in terms of electron density variations. A supersonic helium beam diagnostic is established as standard diagnostic at TEXTOR to measure electron density n{sub e} and temperature T{sub e} with high spatial ({delta}r=2 mm) and temporal resolution ({delta}t=20 {mu}s). The measured plasma structure is compared to modeling results from the fluid plasma and kinetic neutral transport code EMC3-EIRENE. A sequence of five new observations is discussed: (1) Imaging of electron density variations in the plasma edge shows that a fast rotating RMP field imposes an edge plasma structure, which rotates with the external RMP rotation frequency of vertical stroke {nu}{sub RMP} vertical stroke =1 kHz. (2) Measurements of the electron density and temperature provide strong experimental evidence that in the far edge a rotating 3D scrape-off layer (SOL) exists with helical exhaust channels to the plasma wall components. (3) Radially inward, the plasma structure at the next rational flux surface is found to depend on the relative rotation between external RMP field and intrinsic plasma rotation. For low relative rotation the plasma structure is dominated by a particle and energy loss

  15. Magnetohydrodynamic simulation study of plasma jets and plasma-surface contact in coaxial plasma accelerators

    Science.gov (United States)

    Subramaniam, Vivek; Raja, Laxminarayan L.

    2017-06-01

    Recent experiments by Loebner et al. [IEEE Trans. Plasma Sci. 44, 1534 (2016)] studied the effect of a hypervelocity jet emanating from a coaxial plasma accelerator incident on target surfaces in an effort to mimic the transient loading created during edge localized mode disruption events in fusion plasmas. In this paper, we present a magnetohydrodynamic (MHD) numerical model to simulate plasma jet formation and plasma-surface contact in this coaxial plasma accelerator experiment. The MHD system of equations is spatially discretized using a cell-centered finite volume formulation. The temporal discretization is performed using a fully implicit backward Euler scheme and the resultant stiff system of nonlinear equations is solved using the Newton method. The numerical model is employed to obtain some key insights into the physical processes responsible for the generation of extreme stagnation conditions on the target surfaces. Simulations of the plume (without the target plate) are performed to isolate and study phenomena such as the magnetic pinch effect that is responsible for launching pressure pulses into the jet free stream. The simulations also yield insights into the incipient conditions responsible for producing the pinch, such as the formation of conductive channels. The jet-target impact studies indicate the existence of two distinct stages involved in the plasma-surface interaction. A fast transient stage characterized by a thin normal shock transitions into a pseudo-steady stage that exhibits an extended oblique shock structure. A quadratic scaling of the pinch and stagnation conditions with the total current discharged between the electrodes is in qualitative agreement with the results obtained in the experiments. This also illustrates the dominant contribution of the magnetic pressure term in determining the magnitude of the quantities of interest.

  16. Radial thermal diffusivity of toroidal plasma affected by resonant magnetic perturbations

    International Nuclear Information System (INIS)

    Kanno, Ryutaro; Nunami, Masanori; Satake, Shinsuke; Takamaru, Hisanori; Okamoto, Masao

    2012-04-01

    We investigate how the radial thermal diffusivity of an axisymmetric toroidal plasma is modified by effect of resonant magnetic perturbations (RMPs), using a drift kinetic simulation code for calculating the thermal diffusivity in the perturbed region. The perturbed region is assumed to be generated on and around the resonance surfaces, and is wedged in between the regular closed magnetic surfaces. It has been found that the radial thermal diffusivity χ r in the perturbed region is represented as χ r = χ r (0) {1 + c r parallel 2 >}. Here r parallel 2 > 1/2 is the strength of the RMPs in the radial directions, means the flux surface average defined by the unperturbed (i.e., original) magnetic field, χ r (0) is the neoclassical thermal diffusivity, and c is a positive coefficient. In this paper, dependence of the coefficient c on parameters of the toroidal plasma is studied in results given by the δ f simulation code solving the drift kinetic equation under an assumption of zero electric field. We find that the dependence of c is given as c ∝ ω b /ν eff m in the low collisionality regime ν eff b , where ν eff is the effective collision frequency, ω b is the bounce frequency and m is the particle mass. In case of ν eff > ω b , the thermal diffusivity χ r evaluated by the simulations becomes close to the neoclassical thermal diffusivity χ r (0) . (author)

  17. Culturing photosynthetic bacteria through surface plasmon resonance

    Energy Technology Data Exchange (ETDEWEB)

    Ooms, Matthew D.; Bajin, Lauren; Sinton, David [Department of Mechanical and Industrial Engineering and Centre for Sustainable Energy, University of Toronto, Toronto M5S 3G8 (Canada)

    2012-12-17

    In this work, cultivation of photosynthetic microbes in surface plasmon enhanced evanescent fields is demonstrated. Proliferation of Synechococcus elongatus was obtained on gold surfaces excited with surface plasmons. Excitation over three days resulted in 10 {mu}m thick biofilms with maximum cell volume density of 20% vol/vol (2% more total accumulation than control experiments with direct light). Collectively, these results indicate the ability to (1) excite surface-bound cells using plasmonic light fields, and (2) subsequently grow thick biofilms by coupling light from the surface. Plasmonic light delivery presents opportunities for high-density optofluidic photobioreactors for microalgal analysis and solar fuel production.

  18. Culturing photosynthetic bacteria through surface plasmon resonance

    Science.gov (United States)

    Ooms, Matthew D.; Bajin, Lauren; Sinton, David

    2012-12-01

    In this work, cultivation of photosynthetic microbes in surface plasmon enhanced evanescent fields is demonstrated. Proliferation of Synechococcus elongatus was obtained on gold surfaces excited with surface plasmons. Excitation over three days resulted in 10 μm thick biofilms with maximum cell volume density of 20% vol/vol (2% more total accumulation than control experiments with direct light). Collectively, these results indicate the ability to (1) excite surface-bound cells using plasmonic light fields, and (2) subsequently grow thick biofilms by coupling light from the surface. Plasmonic light delivery presents opportunities for high-density optofluidic photobioreactors for microalgal analysis and solar fuel production.

  19. Surface plasmon resonance fiber optic biosensor-based graphene and photonic crystal

    Science.gov (United States)

    Tong, Kai; Guo, Jia; Dang, Peng; Wang, Meiyu; Wang, Fucheng; Zhang, Yungang; Wang, Meiting

    2018-02-01

    A new sensor — transverse electric (TE) polarized excite surface plasmon resonance (SPR) fiber optic biosensor is proposed. The graphene is the plasma layer. The transfer matrix method and the finite difference time domain method are applied to conduct the numerical simulation of the four layers (fiber core/photonic crystals/graphene/sample) of fiber optic biosensor. The results show that the relationship between refractive index and resonant wavelength is linear and the sensitivity of the fiber optic biosensor reaches 1942 nm/RIU.

  20. Platelet rich plasma in ocular surface.

    Science.gov (United States)

    Riestra, A C; Alonso-Herreros, J M; Merayo-Lloves, J

    2016-10-01

    The use of platelet-rich preparations has experienced a significant increase in recent years due to its role in tissue-repair and regeneration. The aim of this study is to examine the available evidence regarding the application of plasma rich in growth factors, and its variations, on the ocular surface. A review is also presented on the effects of platelet-derived growth factors, the implications of the preparation methods, and the existing literature on the safety and efficacy of these therapies in ocular surface diseases. Despite the widespread use of platelet preparations there is no consensus on the most appropriate preparation method, and growth factors concentration vary with different systems. These preparations have been used in the treatment of ocular surface diseases, such as dry eye or persistent epithelial defects, among others, with good safety and efficacy profiles, but further studies are needed to compare to the currently available alternatives. Copyright © 2016 Sociedad Española de Oftalmología. Published by Elsevier España, S.L.U. All rights reserved.

  1. Edge localized mode control by resonant magnetic perturbations in tokamak plasmas

    International Nuclear Information System (INIS)

    Orain, Francois

    2014-01-01

    The growth of plasma instabilities called Edge Localized Modes (ELMs) in tokamaks results in the quasi-periodic relaxation of the edge pressure profile. These relaxations induce large heat fluxes which might be harmful for the divertor in ITER, thus ELM control is mandatory in ITER. One of the promising control methods planned in ITER is the application of external resonant magnetic perturbations (RMPs), already efficient for ELM mitigation/suppression in current tokamak experiments. However a better understanding of the interaction between ELMs, RMPs and plasma flows is needed to explain the experimental results and make reliable predictions for ITER. In this perspective, non-linear modeling of ELMs and RMPs is done with the reduced MHD code JOREK, in toroidal geometry including the X-point and the Scrape-Off Layer. The initial model has been further developed to describe self-consistent plasma flows - with the addition of the bi-fluid diamagnetic drifts, the neoclassical friction and a source of parallel rotation - and to simulate the RMP penetration consistently with the plasma response. As a first step, the plasma response to RMPs (without ELMs) is studied for JET, MAST and ITER realistic plasma parameters and geometry. The general behaviour of the plasma/RMP interaction is similar for the three studied cases: RMPs are generally screened by the formation of response currents, induced by the plasma rotation on the resonant surfaces. RMPs however penetrate at the very edge where an ergodic zone is formed. The amplification of the non-resonant spectrum of the magnetic perturbations is also observed in the core. The edge ergodization induces an enhanced transport at the edge, which slightly degrades the pedestal profiles. RMPs also generate the 3D-deformation of the plasma boundary with a maximum deformation near the X-point where lobe structures are formed. Then the full dynamics of a multi-ELM cycle (without RMPs) is modeled for the first time in realistic

  2. Nucleic acid detection with surface plasmon resonance using cationic latex

    NARCIS (Netherlands)

    de Vries, E.F.A.; Schasfoort, Richardus B.M.; van der Plas, J.; Greve, Jan

    1994-01-01

    An affinity sensor based on Surface Plasmon Resonance (SPR) was used to detect nucleic acids. SPR is an optical technique that is able to detect small changes in the refractive index of the immediate vicinity of a metal surface. After a specific amplification of DNA, achieved using the polymerase

  3. Plasma rotation effect on interaction of low frequency fields with plasmas at the rational surfaces in tokamaks

    International Nuclear Information System (INIS)

    Rondan, E.R.; Elfimov, A.G.; Galvao, R.M.O.; Pires, C.J.A.

    2006-01-01

    The effect of plasma rotation on low frequency (LF) field penetration, absorption and ponderomotive forces in TEXTOR and in Tokamak Chauffage Alfven Bresilien (TCABR) is investigated in the frequency band of 1-10 kHz. The LF fields are driven by the dynamic ergodic divertor in TEXTOR and the ergodic magnetic limiter in TCABR. Alfven wave mode conversion is responsible for the LF field absorption at the rational magnetic surface where q = -M/N is the integer. Analytical and numerical calculations show the maxima of the LF field absorption at the local Alfven wave resonance ω - k · U = k parallel c A , where ω and k are the frequency and the wave vector, respectively, and c A is the Alfven velocity at the rational magnetic surface q = 2, 3 in TEXTOR and TCABR. The rotation velocity U along the magnetic surfaces, taken into account in the dielectric tensor, can strongly modify the LF field and dissipated power profiles. The absorption in the local AW resonances begins to be non-symmetric in relation to the resonance surface. Calculations show that coil impedance has a maximum related to excitation of some stable (possibly Suydam) modes for waves travelling in the direction of plasma rotation

  4. Theory and Applications of Surface Plasmon Resonance, Resonant Mirror, Resonant Waveguide Grating, and Dual Polarization Interferometry Biosensors

    Directory of Open Access Journals (Sweden)

    Billy W. Day

    2010-11-01

    Full Text Available Biosensors have been used extensively in the scientific community for several purposes, most notably to determine association and dissociation kinetics, protein-ligand, protein-protein, or nucleic acid hybridization interactions. A number of different types of biosensors are available in the field, each with real or perceived benefits over the others. This review discusses the basic theory and operational arrangements of four commercially available types of optical biosensors: surface plasmon resonance, resonant mirror, resonance waveguide grating, and dual polarization interferometry. The different applications these techniques offer are discussed from experiments and results reported in recently published literature. Additionally, recent advancements or modifications to the current techniques are also discussed.

  5. Negative ion surface plasma source development for plasma trap injectors in Novosibirsk

    International Nuclear Information System (INIS)

    Bel'chenko, Yu.I.; Dimov, G.I.; Dudnikov, V.G.; Kupriyanov, A.S.

    1989-01-01

    Work on high-current ion sources carried out at the Novosibirsk Institute of Nuclear Physics (INP) is presented. The INP investigations on ''pure plasma'' planotron and ''pure surface'' secondary emission systems of H - generation, which preceded the surface-plasma concept developed in Novosibirsk, are described. The physical basis of the surface-plasma method of negative-ion production is considered. The versions and operating characteristics of different surface-plasma sources including the multi-ampere (approx-gt 10A) source are discussed. Research on efficient large-area (∼10 2 cm 2 ) negative ion surface-plasma emitters is described. The INP long-pulse multiaperture surface- plasma generators, with a current of about 1A, are described. 38 refs., 17 figs

  6. A Nanosecond Pulsed Plasma Brush for Surface Decontamination

    Science.gov (United States)

    Neuber, Johanna; Malik, Muhammad; Song, Shutong; Jiang, Chunqi

    2015-11-01

    This work optimizes a non-thermal, atmospheric pressure plasma brush for surface decontamination. The generated plasma plumes with a maximum length of 2 cm are arranged in a 5 cm long, brush-like array. The plasma was generated in ambient air with Acinetobacter baumannii. Laminate surfaces inoculated with over-night cultured bacteria were subject to the plasma treatment for varying water concentrations in He, flow rates and discharge voltages. It was found that increasing the water content of the feed gas greatly enhanced the bactericidal effect. Emission spectroscopy was performed to identify the reactive plasma species that contribute to this variation. Additional affiliation: Frank Reidy Research Center for Bioelectrics

  7. Towards higher stability of resonant absorption measurements in pulsed plasmas

    International Nuclear Information System (INIS)

    Britun, Nikolay; Michiels, Matthieu; Snyders, Rony

    2015-01-01

    Possible ways to increase the reliability of time-resolved particle density measurements in pulsed gaseous discharges using resonant absorption spectroscopy are proposed. A special synchronization, called “dynamic source triggering,” between a gated detector and two pulsed discharges, one representing the discharge of interest and another being used as a reference source, is developed. An internal digital delay generator in the intensified charge coupled device camera, used at the same time as a detector, is utilized for this purpose. According to the proposed scheme, the light pulses from the reference source follow the gates of detector, passing through the discharge of interest only when necessary. This allows for the utilization of short-pulse plasmas as reference sources, which is critical for time-resolved absorption analysis of strongly emitting pulsed discharges. In addition to dynamic source triggering, the reliability of absorption measurements can be further increased using simultaneous detection of spectra relevant for absorption method, which is also demonstrated in this work. The proposed methods are illustrated by the time-resolved measurements of the metal atom density in a high-power impulse magnetron sputtering (HiPIMS) discharge, using either a hollow cathode lamp or another HiPIMS discharge as a pulsed reference source

  8. 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.

  9. Energy Accommodation from Surface Catalyzed Reactions in Air Plasmas

    Data.gov (United States)

    National Aeronautics and Space Administration — Understanding energy transport at the gas-surface interface between catalytic/reacting surfaces exposed to highly dissociated plasmas remains a significant research...

  10. Ultrasound enhanced plasma surface modification at atmospheric pressure

    DEFF Research Database (Denmark)

    Kusano, Yukihiro; Singh, Shailendra Vikram; Norrman, Kion

    irradiation, the water contact angle dropped markedly, and tended to decrease furthermore at higher power. The ultrasonic irradiation during the plasma treatment consistently improved the wettability. Oxygen containing polar functional groups were introduced at the surface by the plasma treatment......Atmospheric pressure plasma treatment can be highly enhanced by simultaneous high-power ultrasonic irradiation onto the treating surface. It is because ultrasonic waves with a sound pressure level (SPL) above approximately 140 dB can reduce the thickness of a boundary gas layer between the plasma...... are separated using a polyethylene film. The gliding arc was extended by a high speed air flow into ambient air, directed the polyester surface at an angle of approximately 30o. The ultrasonic waves were introduced vertically to the surface. After the plasma treatment using each plasma source without ultrasonic...

  11. Plasma Processing with Fluorine Chemistry for Modification of Surfaces Wettability

    Directory of Open Access Journals (Sweden)

    Veronica Satulu

    2016-12-01

    Full Text Available Using plasma in conjunction with fluorinated compounds is widely encountered in material processing. We discuss several plasma techniques for surface fluorination: deposition of fluorocarbon thin films either by magnetron sputtering of polytetrafluoroethylene targets, or by plasma-assisted chemical vapor deposition using tetrafluoroethane as a precursor, and modification of carbon nanowalls by plasma treatment in a sulphur hexafluoride environment. We showed that conformal fluorinated thin films can be obtained and, according to the initial surface properties, superhydrophobic surfaces can be achieved.

  12. Stimulated resonant scattering at stressed fused silica surface

    International Nuclear Information System (INIS)

    Bouchut, Philippe; Reymermier, Maryse

    2015-01-01

    The radiative emission in CO 2 laser heated stressed fused silica is radically modified when gold microspheres are on the surface. At high heating rates, the emission dynamics changes from thermoluminescence to stimulated resonant scattering with an emission rate that is increased tenfold and the near infrared (NIR) spectrum is red-shifted. We show that the dynamic tensile stress that rises in heated silica is coupled with a fluctuating electromagnetic field that enables electromagnetic friction between moving OH emitters from silica bulk and NIR resonant scatterers at the silica surface. (paper)

  13. Surface resonance on the NiFe(001) alloy surface

    Czech Academy of Sciences Publication Activity Database

    Ondráček, Martin; Máca, František; Kudrnovský, Josef; Redinger, J.

    2006-01-01

    Roč. 56, č. 1 (2006), s. 69-74 ISSN 0011-4626. [Symposium on Surface Physics /10./. Praha, 11.07.2005-15.07.2005] R&D Projects: GA ČR(CZ) GA202/04/0583 Institutional research plan: CEZ:AV0Z10100520 Keywords : NiFe alloy * surface electronic structure * surface geometry * density functional calculation Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 0.568, year: 2006

  14. Propagation of quasi-static wave and resonance cone in magnetized plasma

    International Nuclear Information System (INIS)

    Serbeto, A.P.B.

    1980-08-01

    The potential created by an oscillating punctual source in a magnetized homogeneous cold plasma, using quasistatic approximation is studied. The resonance cone structure in this plasma is theoretically obtained and it is verified that the conic field structure remains finite for an inhomogeneous cold plasma. The temperature effect in the resonance cone structure in layers where w->Ω e ,w->w PC and w->w nh for magnetized homogeneous electron plasma is studied. An approximated expression for dispersion relations is obtained, so that an analytical solution for the potential in these layers can be calculated. The theorem of energy conservation for quasistatic waves is developed. (M.C.K.) [pt

  15. Surface Modification of Nonwoven fabrics by Atmospheric Brush Plasma

    Science.gov (United States)

    Oksuz, Lutfi; Uygun, Emre; Bozduman, Ferhat; Yurdabak Karaca, Gozde; Asan, Orkun Nuri; Uygun Oksuz, Aysegul

    2017-10-01

    Polypropylene nonwoven fabrics (PPNF) are used in disposable absorbent articles, such as diapers, feminine care products, wipes. PPNF need to be wettable by water or aqueous-based liquid. Plasma surface treatment/modification has turned out to be a well-accepted method since it offers superior surface property enhancement than other chemical methods. The cold plasma brush can most efficiently use the discharge power as well as the plasma gas for material and surface treatment. The very low power consumption of such an atmospheric argon plasma brush provides many unique advantages in practical application. The purpose of this study was to reveal the effectiveness of non-thermal atmospheric plasma brush in surface wettability and modification of two different nonwoven surfaces.

  16. Study of Pulsed vs. RF Plasma Properties for Surface Processing Applications

    Science.gov (United States)

    Tang, Ricky; Hopkins, Matthew; Barnat, Edward; Miller, Paul

    2015-09-01

    The ability to manipulate the plasma parameters (density, E/N) was previously demonstrated using a double-pulsed column discharge. Experiments extending this to large-surface plasmas of interest to the plasma processing community were conducted. Differences between an audio-frequency pulsed plasma and a radio-frequency (rf) discharge, both prevalent in plasma processing applications, were studied. Optical emission spectroscopy shows higher-intensity emission in the UV/visible range for the pulsed plasma comparing to the rf plasma at comparable powers. Data suggest that the electron energy is higher for the pulsed plasma leading to higher ionization, resulting in increased ion density and ion flux. Diode laser absorption measurements of the concentration of the 1S5 metastable and 1S4 resonance states of argon (correlated with the plasma E/N) provide comparisons between the excitation/ionization states of the two plasmas. Preliminary modeling efforts suggest that the low-frequency polarity switch causes a much more abrupt potential variation to support interesting transport phenomena, generating a ``wave'' of higher temperature electrons leading to more ionization, as well as ``sheath capture'' of a higher density bolus of ions that are then accelerated during polarity switch.

  17. Evaluation of surface fractal dimension of carbon for plasma-facing material damaged by hydrogen plasma

    International Nuclear Information System (INIS)

    Nishino, Nobuhiro

    1997-01-01

    The surface structure of the plasma facing materials (PFM) changes due to plasma-surface interaction in a nuclear fusion reactor. Usually B 4 C coated graphite block are used as PFM. In this report, the surface fractal was applied to study the surface structure of plasma-damaged PFM carbon. A convenient flow-type adsorption apparatus was developed to evaluate the surface fractal dimension of materials. Four branched alkanol molecules with different apparent areas were used as the probe adsorbates. The samples used here were B 4 C coated isotopic graphite which were subjected to hydrogen plasma for various periods of exposure. The monolayer capacities of these samples for alkanols were determined by applying BET theory. The surface fractal dimension was calculated using the monolayer capacities and molecular areas for probe molecules and was found to increase from 2 to 3 with the plasma exposure time. (author)

  18. Study of plasma-material surface interaction using Langmuir probe technique during plasma treatment

    International Nuclear Information System (INIS)

    Saloum, S.; Akel, M.

    2009-06-01

    In this study, we tried to understand the plasma-surface interactions by using Langmuir probes. Two different types of plasmas were studied, the first is the electropositive plasma in Argon and the second is the electronegative plasma in Sulfur Hexafluoride. In the first type, the effects of Argon gas pressure, the injection of Helium in the remote zone and the substrate bias on the measurements of the Electron Energy Probability Function (EEPF) and on the plasma parameters (electron density (n e ), effective electron temperature (T e ff), plasma potential (V p ) and floating potential (V f )) have been investigated. The obtained EEPFs and plasma parameters have been used to control two remote plasma processes. The first is the remote Plasma Enhanced Chemical Vapor Deposition (PE-CVD) of thin films, on silicon wafers, from Hexamethyldisoloxane (HMDSO) precursor diluted in the remote Ar-He plasma. The second is the pure Argon remote plasma treatment of polymethylmethacrylate (PMMA) polymer surface. In the second type, the plasma diagnostics were performed in the remote zone as a function of SF 6 flow rate, where relative concentrations of fluorine atoms were measured using actinometry optical emission spectroscopy; electron density, electron temperature and plasma potential were determined using single cylindrical Langmuir probe, positive ion flux and negative ion fraction were determined using an planar probe. The silicon etching process in SF 6 plasma was studied. (author)

  19. Resonant Excitation of Terahertz Surface Plasmons in Subwavelength Metal Holes

    Directory of Open Access Journals (Sweden)

    Weili Zhang

    2007-01-01

    Full Text Available We present a review of experimental studies of resonant excitation of terahertz surface plasmons in two-dimensional arrays of subwavelength metal holes. Resonant transmission efficiency higher than unity was recently achieved when normalized to the area occupied by the holes. The effects of hole shape, hole dimensions, dielectric function of metals, polarization dependence, and array film thickness on resonant terahertz transmission in metal arrays were investigated by the state-of-the-art terahertz time-domain spectroscopy. In particular, extraordinary terahertz transmission was demonstrated in arrays of subwavelength holes made even from Pb, a generally poor metal, and having thickness of only one-third of skin depth. Terahertz surface plasmons have potential applications in terahertz imaging, biosensing, interconnects, and development of integrated plasmonic components for terahertz generation and detection.

  20. Surface cleaning of metal wire by atmospheric pressure plasma

    International Nuclear Information System (INIS)

    Nakamura, T.; Buttapeng, C.; Furuya, S.; Harada, N.

    2009-01-01

    In this study, the possible application of atmospheric pressure dielectric barrier discharge plasma for the annealing of metallic wire is examined and presented. The main purpose of the current study is to examine the surface cleaning effect for a cylindrical object by atmospheric pressure plasma. The experimental setup consists of a gas tank, plasma reactor, and power supply with control panel. The gas assists in the generation of plasma. Copper wire was used as an experimental cylindrical object. This copper wire was irradiated with the plasma, and the cleaning effect was confirmed. The result showed that it is possible to remove the tarnish which exists on the copper wire surface. The experiment reveals that atmospheric pressure plasma is usable for the surface cleaning of metal wire. However, it is necessary to examine the method for preventing oxidization of the copper wire.

  1. Two-resonance probe for measuring electron density in low-pressure plasmas

    Science.gov (United States)

    Kim, D. W.; You, S. J.; Kim, S. J.; Kim, J. H.; Oh, W. Y.

    2017-04-01

    A technique for measuring double-checked electron density using two types of microwave resonance is presented. Simultaneous measurement of the resonances (plasma and quarter-wavelength resonator resonances), which were used for the cutoff probe (CP) and hairpin probe (HP), was achieved by the proposed microwave resonance probe. The developed two-resonance probe (TRP) consists of parallel separated coaxial cables exposing the radiation and detection tips. The structure resembles that of the CP, except the gapped coaxial cables operate not only as a microwave feeder for the CP but also as a U- shaped quarter-wavelength resonator for the HP. By virtue of this structure, the microwave resonances that have typically been used for measuring the electron density for the CP and HP were clearly identified on the microwave transmission spectrum of the TRP. The two types of resonances were measured experimentally under various power and pressure conditions for the plasma. A three-dimensional full-wave simulation model for the TRP is also presented and used to investigate and reproduce the resonances. The electron densities inferred from the resonances were compared and showed good agreement. Quantitative differences between the densities were attributed to the effects of the sheath width and spatial density gradient on the resonances. This accessible technique of using the TRP to obtain double-checked electron densities may be useful for comparative study and provides complementary uses for the CP and HP.

  2. Fundamental ion cyclotron resonance heating of JET deuterium plasmas

    International Nuclear Information System (INIS)

    Krasilnikov, A V; Amosov, V N; Kaschuck, Yu A; Van Eester, D; Lerche, E; Ongena, J; Bonheure, G; Biewer, T; Crombe, K; Ericsson, G; Giacomelli, L; Hellesen, C; Hjalmarsson, A; Esposito, B; Marocco, D; Jachmich, S; Kiptily, V; Leggate, H; Mailloux, J; Kallne, J

    2009-01-01

    Radio frequency heating of majority ions is of prime importance for understanding the basic role of auxiliary heating in the activated D-T phase of ITER. Majority deuterium ion cyclotron resonance heating (ICRH) experiments at the fundamental cyclotron frequency were performed in JET. In spite of the poor antenna coupling at 25 MHz, this heating scheme proved promising when adopted in combination with D neutral beam injection (NBI). The effect of fundamental ICRH of a D population was clearly demonstrated in these experiments: by adding ∼25% of heating power the fusion power was increased up to 30-50%, depending on the type of NBI adopted. At this power level, the ion and electron temperatures increased from T i ∼ 4.0 keV and T e ∼ 4.5 keV (NBI-only phase) to T i ∼ 5.5 keV and T e ∼ 5.2 keV (ICRH + NBI phase), respectively. The increase in the neutron yield was stronger when 80 keV rather than 130 keV deuterons were injected in the plasma. It is shown that the neutron rate, the diamagnetic energy and the electron as well as the ion temperature scale roughly linearly with the applied RF power. A synergistic effect of the combined use of ICRF and NBI heating was observed: (i) the number of neutron counts measured by the neutron camera during the combined ICRF + NBI phases of the discharges exceeded the sum of the individual counts of the NBI-only and ICRF-only phases; (ii) a substantial increase in the number of slowing-down beam ions was detected by the time of flight neutron spectrometer when ICRF power was switched on; (iii) a small D subpopulation with energies slightly above the NBI launch energy was detected by the neutral particle analyzer and γ-ray spectroscopy.

  3. Sub-micron surface plasmon resonance sensor systems

    Science.gov (United States)

    Glazier, James A. (Inventor); Amarie, Dragos (Inventor)

    2013-01-01

    Wearable or implantable devices combining microfluidic control of sample and reagent flow and micro-cavity surface plasmon resonance sensors functionalized with surface treatments or coatings capable of specifically binding to target analytes, ligands, or molecules in a bodily fluid are provided. The devices can be used to determine the presence and concentration of target analytes in the bodily fluids and thereby help diagnose, monitor or detect changes in disease conditions.

  4. Surface and temperature effects in isovector giant resonances

    International Nuclear Information System (INIS)

    Lipparini, E.; Stringari, S.

    1988-01-01

    Using the liquid droplet model (LDM) we investigate three different sum rules for the isovector dipole and monopole excitations. Analytical formulae are derived for the excitation energies of these resonances and the predictions are compared with experiments. The role of the surface and the effects of temperature are explicitly discussed. (orig.)

  5. Surface plasmon resonance optical cavity enhanced refractive index sensing

    Czech Academy of Sciences Publication Activity Database

    Giorgini, A.; Avino, S.; Malara, P.; Gagliardi, G.; Casalino, M.; Coppola, G.; Iodice, M.; Adam, Pavel; Chadt, Karel; Homola, Jiří; De Natale, P.

    2013-01-01

    Roč. 38, č. 11 (2013), s. 1951-1953 ISSN 0146-9592 R&D Projects: GA ČR GBP205/12/G118 Institutional support: RVO:67985882 Keywords : Resonators * Surface plasmons * Optical sensing and sensors Subject RIV: BH - Optics, Masers, Lasers Impact factor: 3.179, year: 2013

  6. Surface plasmon resonance sensing of nucleic acids: A review

    Czech Academy of Sciences Publication Activity Database

    Šípová, Hana; Homola, Jiří

    -, č. 773 (2013), s. 9-23 ISSN 0003-2670 R&D Projects: GA MŠk(CZ) LH11102 Institutional support: RVO:67985882 Keywords : Surface plasmon resonance * Nucleic acid * Biosensor Subject RIV: JB - Sensors, Measurment, Regulation Impact factor: 4.517, year: 2013

  7. A Surface Plasmon Resonance Immunobiosensor for Detection of Phytophthora infestans

    DEFF Research Database (Denmark)

    Skottrup, Peter; Frøkiær, Hanne; Hejgaard, Jørn

    2006-01-01

    In this study we focused on the development of a Surface Plasmon Resonance (SPR) immunosensor for Phytophthora infestans detection. The fungus-like organism is the cause of potato late blight and is a major problem in potato growing regions of the world. Efficient control is dependent on early...

  8. Resonant photopumping of a neon lasant plasma by a sodium pump plasma

    International Nuclear Information System (INIS)

    Young, F.C.; Apruzese, J.P.; Burkhalter, P.G.; Cooperstein, G.; Davis, J.; Mosher, D.; Ottinger, P.F.; Scherrer, V.E.; Stephanakis, S.J.; Mehlman, C.; Welch, B.L.

    1988-01-01

    Resonant photopumping of heliumlike neon by helium like sodium is being investigated to extend this pumping technique to the soft x-ray region. In the Na-pump/Ne-lasant system, the 1s 2 -1s2p 1 P 1 line of Na X at 11.0027 A differs by 2 parts in 10 4 from the 1s 2 -1s 4 p 1 P 1 line of Ne 1X at 11.0003 A. This wavelength difference corresponds to about one Doppler width at the sodium plasma temperatures (200-500 eV) required for strong Na X pump radiation. Sodium line radiation of sufficient power irradiating a properly prepared neon plasma will cause overpopulation of the Ne 1X n = 4 singlet level leading to lasing in the 4-3, 4-2, and possibly 3-2 singlet transitions. Experimentally, the current pulse from the NRL Gamble-II generator is used to produce side-by-side z-pinch plasmas of sodium fluoride (NaF) and neon. The discharges are viewed radially with x-ray diagnostics including time-integrated pinhole cameras, time-resolved x-ray diodes, and a time-integrated curved-crystal spectrograph. Measurements of the neon plasma indicate that a discharge current of about 200 kA is required to produce a neon lasant with a dominant heliumlike ground-state population. For fluorescence experiments, appropriate neon lasant conditions (density of about 10 18 cm -3 and temperature of 50-100 eV) must be produced at the time of the intense sodium pump-line radiation. Fluorescence is demonstrated by observing enhancement of the 4-1 line (He-γ) from the neon plasma relative to the 3-1 line (He-γ) when the neon is pumped by sodium. An increase in this γ-to-β ratio of 25% has been observed when the sodium pump radiation is present. The results of recent experiments are reported, and their implications for future experiments are discussed

  9. Protective coatings of metal surfaces by cold plasma treatment

    Science.gov (United States)

    Manory, R.; Grill, A.

    1985-01-01

    The cold plasma techniques for deposition of various types of protective coatings are reviewed. The main advantage of these techniques for deposition of ceramic films is the lower process temperature, which enables heat treating of the metal prior to deposition. In the field of surface hardening of steel, significant reduction of treatment time and energy consumption were obtained. A simple model for the plasma - surface reactions in a cold plasma system is presented, and the plasma deposition techniques are discussed in view of this model.

  10. Production of hydrogen and deuterium negative ions in an electron cyclotron resonance driven plasma

    Energy Technology Data Exchange (ETDEWEB)

    Dougar-Jabon, V.D. [Industrial Univ. of Santander, Bucaramanga (Colombia)

    2001-04-01

    An electron cyclotron resonance source with driven plasma rings for hydrogen isotope ion production is studied. Extracted currents of positive and negative ions depending on gas pressure, microwave power value and extraction voltage are obtained. The study shows that the negative ion yield is an order of magnitude higher than the yield of positive particles when a driven ring is in contact with the surface of the plasma electrode. The production of negative ions of deuterium, D{sup -}, is close to the production of negative ions of light hydrogen isotope, H{sup -}. The comparison of the experimental data with the calculated ones shows that the most probable process of the H{sup -} and D{sup -} ion formation in the electron cyclotron driven plasma is dissociative attachment of electrons to molecules in high Rydberg states. For hydrogen ions and ions of deuterium, the negative current at a microwave power of 200 W through a 3-mm aperture and 8 kV extraction voltage are 4.7 mA and 3.1 mA respectively. (orig.)

  11. Characteristics of electron cyclotron resonance plasma formed by ...

    Indian Academy of Sciences (India)

    The plasma produced by the above mechanism is further used to characterize the ECR-assisted low voltage Ohmic start-up discharges. During this part of the experiments, Ohmic plasma is formed using capacitor banks. The plasma loop voltage is gradually decreased, till the discharge ceases to form. The same is repeated ...

  12. Surface plasmon resonance sensors based on uniform-waist tapered fibers in a reflective configuration

    Science.gov (United States)

    Esteban, Óscar; Díaz-Herrera, Natalia; Navarrete, María-Cruz; González-Cano, Agustín

    2006-10-01

    We present a configuration for surface plasmon resonance sensors based on uniform-waist tapered optical fibers and reflective elements. Once the fiber is tapered fulfilling the adiabatic criterion, a multilayer including a metallic medium is asymmetrically deposited on the uniform waist of the fiber. This feature provides the resonant excitation of multiple surface plasma waves. In addition, a mirror is produced at the fiber tip by a chemical Tollens reaction. In this way, the sensor operates in a reflective mode, more convenient for dip probes. When these sensors are spectrally interrogated, a high sensitivity of 10-4 refractive index units per nanometer is attained. These devices can be advantageously used for any kind of chemical sensing and biosensing.

  13. Influence of ECR-RF plasma modification on surface and thermal properties of polyester copolymer

    Directory of Open Access Journals (Sweden)

    Fray Miroslawa El

    2015-12-01

    Full Text Available In this paper we report a study on influence of radio-frequency (RF plasma induced with electron cyclotron resonance (ECR on multiblock copolymer containing butylene terephthalate hard segments (PBT and butylene dilinoleate (BDLA soft segments. The changes in thermal properties were studied by DSC. The changes in wettability of PBT-BDLA surfaces were studied by water contact angle (WCA. We found that ECR-RF plasma surface treatment for 60 s led to decrease of WCA, while prolonged exposure of plasma led to increase of WCA after N2 and N2O2 treatment up to 70°–80°. The O2 reduced the WCA to 50°–56°. IR measurements confirmed that the N2O2 plasma led to formation of polar groups. SEM investigations showed that plasma treatment led to minor surfaces changes. Collectively, plasma treatment, especially O2, induced surface hydrophilicity what could be beneficial for increased cell adhesion in future biomedical applications of these materials.

  14. Resonant Absorption of Surface Sausage and Surface Kink Modes under Photospheric Conditions

    Science.gov (United States)

    Yu, Dae Jung; Van Doorsselaere, Tom; Goossens, Marcel

    2017-11-01

    We study the effect of resonant absorption of surface sausage and surface kink modes under photospheric conditions where the slow surface sausage modes undergo resonant damping in the slow continuum and the surface kink modes in the slow and Alfvén continua at the transitional layers. We use recently derived analytical formulas to obtain the damping rate (time). By considering linear density and linear pressure profiles for the transitional layers, we show that resonant absorption in the slow continuum could be an efficient mechanism for the wave damping of the slow surface sausage and slow surface kink modes while the damping rate of the slow surface kink mode in the Alfvén continuum is weak. It is also found that the resonant damping of the fast surface kink mode is much stronger than that of the slow surface kink mode, showing a similar efficiency as under coronal conditions. It is worth noting that the slow body sausage and kink modes can also resonantly damp in the slow continuum for those linear profiles.

  15. Wake-Field Wave Resonant Excitation in Magnetized Plasmas by Electromagnetic Pulse

    International Nuclear Information System (INIS)

    Milant'ev, V.P.; Turikov, V.A.

    2006-01-01

    In this paper the space charge wave excitation process at electromagnetic pulse propagation along external magnetic field in vicinity of electron cyclotron resonance. In hydrodynamic approach it is obtained an equation for plasma density under ponderomotive force action. With help of this equation we investigated a wake-field wave amplitude dependence from resonance detuning. The numerical simulation using a PIC method electromagnetic pulse propagation process in the resonant conditions was done

  16. Resonant emission of electromagnetic waves by plasma solitons

    International Nuclear Information System (INIS)

    Mironov, V.A.; Sergeev, A.M.; Khimich, A.V.

    1988-01-01

    The ability of plasma-wave solitons to radiate electromagnetic waves at the frequency of the natural oscillations of the field is considered. It is shown that this radiation is the main energy dissipation channel for strong plasma turbulence in a magnetoactive plasma. An interpretation is proposed for the artificial radio emission produced when the ionosphere is acted upon by beams of strong electromagnetic waves. The use of this phenomenon for plasma turbulence, particularly in the outer-space plasma near the earth, is discussed

  17. Computational study of plasma-assisted photoacoustic response from gold nanoparticles irradiated by off-resonance ultrafast laser

    Energy Technology Data Exchange (ETDEWEB)

    Hatef, Ali, E-mail: alih@nipissingu.ca; Darvish, Behafarid [Nipissing University, Nipissing Computational Physics Laboratory (NCPL), Department of Computer Science and Mathematics (Canada); Sajjadi, Amir Yousef [Massachusetts General Hospital, Cutaneous Biology Research Center (United States)

    2017-02-15

    The gold nanoparticles (AuNPs) are capable of enhancing the incident laser field in the form of scattered near field for even an off-resonance irradiation where the incident laser wavelength is far away from the localized surface plasmon resonance (LSPR). If the intensity of the pulse laser is large enough, this capability can be employed to generate a highly localized free electron (plasma) in the vicinity of the particles. The generated plasma can absorb more energy during the pulse, and this energy deposition can be considered as an energy source for structural mechanics calculations in the surrounding media to generate a photoacoustic (PA) signal. To show this, in this paper, we model plasma-mediated PA pressure wave propagation from a 100-nm AuNPs and the surrounding media irradiated by an ultrashort pulse laser. In this model, the AuNP is immersed in water and the laser pulse width is ranging from 70 fs to 2 ps at the wavelength of 800 nm (off-resonance). Our results qualitatively show the substantial impact of the energy deposition in plasma on the PA signal through boosting the pressure amplitudes up to ∼1000 times compared to the conventional approach.

  18. Magneto-acoustic resonance in a non-uniform current carrying plasma column

    OpenAIRE

    Vaclavik, J.

    2017-01-01

    The forced radial magneto-acoustic oscillations in a plasma column with nonuniform mass density and temperature are investigated. It turns out that the oscillations have a resonant character similar to that of the magneto-acoustic oscillations in a uniform plasma column. The properties of the axial and azimuthal components of the oscillating magnetic field are discussed in detail

  19. Plasma equilibrium profiles with applied resonant fields on TBR-1 tokamak

    International Nuclear Information System (INIS)

    Castro, R.M. de; Heller, M.V.A.P.; Caldas, I.L.; Silva, R.P. da; Brasilio, Z.A.; Oda, G.A.

    1995-01-01

    In this work we present the measurements of the plasma potential, in the edge and in the scrape-off layer regions of plasma, with and without the presence of the magnetic field perturbations produced by resonant helical windings. (author). 6 refs., 6 figs

  20. Theory of inelastic effects in resonant atom-surface scattering

    International Nuclear Information System (INIS)

    Evans, D.K.

    1983-01-01

    The progress of theoretical and experimental developments in atom-surface scattering is briefly reviewed. The formal theory of atom-surface resonant scattering is reviewed and expanded, with both S and T matrix approaches being explained. The two-potential formalism is shown to be useful for dealing with the problem in question. A detailed theory based on the S-matrix and the two-potential formalism is presented. This theory takes account of interactions between the incident atoms and the surface phonons, with resonant effects being displayed explicitly. The Debye-Waller attenuation is also studied. The case in which the atom-surface potential is divided into an attractive part V/sub a/ and a repulsive part V/sub r/ is considered at length. Several techniques are presented for handling the scattering due to V/sub r/, for the case in which V/sub r/ is taken to be the hard corrugated surface potential. The theory is used to calculate the scattered intensities for the system 4 He/LiF(001). A detailed comparison with experiment is made, with polar scans, azimuthal scans, and time-of-flight measurements being considered. The theory is seen to explain the location and signature of resonant features, and to provide reasonable overall agreement with the experimental results

  1. Propagation of high frequency electrostatic surface waves along the planar interface between plasma and dusty plasma

    Science.gov (United States)

    Mishra, Rinku; Dey, M.

    2018-04-01

    An analytical model is developed that explains the propagation of a high frequency electrostatic surface wave along the interface of a plasma system where semi-infinite electron-ion plasma is interfaced with semi-infinite dusty plasma. The model emphasizes that the source of such high frequency waves is inherent in the presence of ion acoustic and dust ion acoustic/dust acoustic volume waves in electron-ion plasma and dusty plasma region. Wave dispersion relation is obtained for two distinct cases and the role of plasma parameters on wave dispersion is analyzed in short and long wavelength limits. The normalized surface wave frequency is seen to grow linearly for lower wave number but becomes constant for higher wave numbers in both the cases. It is observed that the normalized frequency depends on ion plasma frequencies when dust oscillation frequency is neglected.

  2. Dependence of radial thermal diffusivity on parameters of toroidal plasma affected by resonant magnetic perturbations

    International Nuclear Information System (INIS)

    Kanno, Ryutaro; Nunami, Masanori; Satake, Shinsuke; Takamaru, Hisanori; Okamoto, Masao

    2013-01-01

    We investigate how the neoclassical thermal diffusivity of an axisymmetric toroidal plasma is modified by the effect of resonant magnetic perturbations (RMPs), using a drift-kinetic simulation code for calculating the radial thermal diffusivity of ion in the perturbed region under an assumption of zero electric field. Here, the perturbed region is assumed to be generated on and near the resonance surfaces, and is wedged in between the regular closed magnetic surfaces. We find that the dependence of the radial thermal diffusivity on parameters of the toroidal plasma is represented as χ r =χ r (0) {1+ c 0 (ω b /ν eff Δ b 2 ) r || 2 >/|B t0 | 2 }, where χ (0) r is the neoclassical thermal diffusivity and c 0 is a positive coefficient. Here, ω b is the bounce frequency, ν eff is the effective collision frequency, Δ b is the banana width, 〈‖δB r ‖ 2 〉 1/2 is the strength of the RMPs in the radial directions, and |B t0 | is the strength of the magnetic field on the magnetic axis. The value of c-tilde 0 :=c 0 /(qR ax /√(ε t )) 2 is significantly reduced to c-tilde 0 ∼10 -4 in the simulations because of the drift motion affected by the Coulomb collision, as contrasted with c-tilde 0 =π predicted by the so-called field-line diffusion theory, where q is the safety factor, R ax is the major radius of the magnetic axis, and ϵ t is the inverse aspect ratio. (paper)

  3. Surface Modification of Polymeric Materials by Plasma Treatment

    Directory of Open Access Journals (Sweden)

    E.F. Castro Vidaurre

    2002-03-01

    Full Text Available Low-temperature plasma treatment has been used in the last years as a useful tool to modify the surface properties of different materials, in special of polymers. In the present work low temperature plasma was used to treat the surface of asymmetric porous substrates of polysulfone (PSf membranes. The main purpose of this work was to study the influence of the exposure time and the power supplied to argon plasma on the permeability properties of the membranes. Three rf power levels, respectively 5, 10 and 15 W were used. Treatment time ranged from 1 to 50 min. Reduction of single gas permeability was observed with Ar plasma treatments at low energy bombardment (5 W and short exposure time (20 min. Higher power and/or higher plasma exposition time causes a degradation process begins. The chemical and structural characterization of the membranes before and after the surface modification was done by AFM, SEM and XPS.

  4. Effect of Energetic Plasma Flux on Flowing Liquid Lithium Surfaces

    Science.gov (United States)

    Kalathiparambil, Kishor; Jung, Soonwook; Christenson, Michael; Fiflis, Peter; Xu, Wenyu; Szott, Mathew; Ruzic, David

    2014-10-01

    An operational liquid lithium system with steady state flow driven by thermo-electric magneto-hydrodynamic force and capable of constantly refreshing the plasma exposed surface have been demonstrated at U of I. To evaluate the system performance in reactor relevant conditions, specifically to understand the effect of disruptive plasma events on the performance of the liquid metal PFCs, the setup was integrated to a pulsed plasma generator. A coaxial plasma generator drives the plasma towards a theta pinch which preferentially heats the ions, simulating ELM like flux, and the plasma is further guided towards the target chamber which houses the flowing lithium system. The effect of the incident flux is examined using diagnostic tools including triple Langmuir probe, calorimeter, rogowski coils, Ion energy analyzers, and fast frame spectral image acquisition with specific optical filters. The plasma have been well characterized and a density of ~1021 m-3, with electron temperature ~10 - 20 eV is measured, and final plasma velocities of 34 - 74 kms-1 have been observed. Calorimetric measurements using planar molybdenum targets indicate a maximum plasma energy (with 6 kV plasma gun and 20 kV theta pinch) of 0.08 MJm-2 with plasma divergence effects resulting in marginal reduction of 40 +/- 23 J in plasma energy. Further results from the other diagnostic tools, using the flowing lithium targets and the planar targets coated with lithium will be presented. DOE DE-SC0008587.

  5. Resonant characteristics and sensitivity dependency on the contact surface in QCM-micropillar-based system of coupled resonator sensors

    International Nuclear Information System (INIS)

    Kashan, M A M; Kalavally, V; Ramakrishnan, N; Lee, H W

    2016-01-01

    We report the characteristics and sensitivity dependence over the contact surface in coupled resonating sensors (CRSs) made of high aspect ratio resonant micropillars attached to a quartz crystal microbalance (QCM). Through experiments and simulation, we observed that when the pillars of resonant heights were placed in maximum displacement regions the resonance frequency of the QCM increased following the coupled resonance characteristics, as the pillar offered elastic loading to the QCM surface. However, the same pillars when placed in relatively lower displacement regions, in spite of their resonant dimension, offered inertial loading and resulted in a decrease in QCM resonance frequency, as the displacement amplitude was insufficient to couple the vibrations from the QCM to the pillars. Accordingly, we discovered that the coupled resonance characteristics not only depend on the resonant structure dimensions but also on the contact regions in the acoustic device. Further analysis revealed that acoustic pressure at the contact surface also influences the resonance frequency characteristics and sensitivity of the CRS. To demonstrate the significance of the present finding for sensing applications, humidity sensing is considered as the example measurand. When a sensing medium made of resonant SU-8 pillars was placed in a maximum displacement region on a QCM surface, the sensitivity increased by 14 times in comparison to a resonant sensing medium placed in a lower displacement region of a QCM surface. (paper)

  6. Resonant characteristics and sensitivity dependency on the contact surface in QCM-micropillar-based system of coupled resonator sensors

    Science.gov (United States)

    Kashan, M. A. M.; Kalavally, V.; Lee, H. W.; Ramakrishnan, N.

    2016-05-01

    We report the characteristics and sensitivity dependence over the contact surface in coupled resonating sensors (CRSs) made of high aspect ratio resonant micropillars attached to a quartz crystal microbalance (QCM). Through experiments and simulation, we observed that when the pillars of resonant heights were placed in maximum displacement regions the resonance frequency of the QCM increased following the coupled resonance characteristics, as the pillar offered elastic loading to the QCM surface. However, the same pillars when placed in relatively lower displacement regions, in spite of their resonant dimension, offered inertial loading and resulted in a decrease in QCM resonance frequency, as the displacement amplitude was insufficient to couple the vibrations from the QCM to the pillars. Accordingly, we discovered that the coupled resonance characteristics not only depend on the resonant structure dimensions but also on the contact regions in the acoustic device. Further analysis revealed that acoustic pressure at the contact surface also influences the resonance frequency characteristics and sensitivity of the CRS. To demonstrate the significance of the present finding for sensing applications, humidity sensing is considered as the example measurand. When a sensing medium made of resonant SU-8 pillars was placed in a maximum displacement region on a QCM surface, the sensitivity increased by 14 times in comparison to a resonant sensing medium placed in a lower displacement region of a QCM surface.

  7. Oxygen Plasma Treatment of Rubber Surface by the Atmospheric Pressure Cold Plasma Torch

    DEFF Research Database (Denmark)

    Lee, Bong-ju; Kusano, Yukihiro; Kato, Nobuko

    1997-01-01

    adhesive. The adhesion property was improved by treatment of the rubber compound with plasma containing oxygen radicals. Physical and chemical changes of the rubber surface as a result of the plasma treatment were analyzed by field emission scanning electron microscopy (FE-SEM) and fourier transform......A new application of the atmospheric cold plasma torch has been investigated. Namely, the surface treatment of an air-exposed vulcanized rubber compound. The effect of plasma treatment was evaluated by the bondability of the treated rubber compound with another rubber compound using a polyurethane...

  8. Plasma Creatinine, Age and Body Surface Area in Nigerian Children ...

    African Journals Online (AJOL)

    In a bid to establish reference values for plasma creatinine in children and adolescents using age, and body surface area (BSA), 462 apparently healthy Nigerian children/adolescents aged one day to 15 years were studied. They were recruited from well baby clinics, as well as primary and secondary schools. Plasma ...

  9. Excitation of surface plasma waves over corrugated slow-wave ...

    Indian Academy of Sciences (India)

    Abstract. A microwave propagating along vacuum–dielectric–plasma interface excites surface plasma wave (SPW). A periodic slow-wave structure placed over dielectric slows down the SPW. The phase velocity of slow SPW is sensitive to height, periodicity, number of periods, thickness and the separation between ...

  10. Nonlinear interaction of the surface waves at a plasma boundary

    International Nuclear Information System (INIS)

    Dolgopolov, V.V.; El-Naggar, I.A.; Hussein, A.M.; Khalil, Sh.M.

    1976-01-01

    Amplitudes of electromagnetic waves with combination frequencies, radiating from the plasma boundary due to nonlinear interaction of the surface waves, have been found. Previous papers on this subject did not take into account that the tangential components of the electric field of waves with combination frequencies were discontinuous at the plasma boundary. (Auth.)

  11. Modification of surface properties of LLDPE by water plasma discharge

    International Nuclear Information System (INIS)

    Chantara Thevy Ratnam; Hill, D.J.T.; Firas Rasoul; Whittaker, A.K.; Imelda Keen

    2007-01-01

    Linear low density polyethylene (LLDPE) surface was modified by water plasma treatment. The LLDPE surface was treated at 10 and 20 W discharge power at various exposure times. A laboratory scale Megatherm radio frequency (RF) plasma apparatus that operates at 27 MHz was used to generate the water plasmas. The changes in chemical structure of the LLDPE polymeric chain upon plasma treatment were characterized by FTIR and XPS techniques. The selectivity of trifluoroacetic anhydride (TFAA) toward hydroxyl groups is used to quantify the hydroxyl groups formed on the polymer surface upon plasma treatment. After exposition to the plasma discharge a decline in water contact angle were observed. FTIR and XPS measurements indicate an oxidation of degraded polymeric chains and creation of hydroxyl, carbonyl, ether, ester and carboxyl groups. Chemical derivatization with TFAA of water plasma treated polymer surfaces has shown that under the conditions employed, a very small (less than 5%) of the oxygen introduced by the water plasma treatment was present as hydroxyl group. (Author)

  12. An Investigation on the He−(1s2s2 2S Resonance in Debye Plasmas

    Directory of Open Access Journals (Sweden)

    Arijit Ghoshal

    2017-01-01

    Full Text Available The effect of Debye plasma on the 1 s 2 s 2 2 S resonance states in the scattering of electron from helium atom has been investigated within the framework of the stabilization method. The interactions among the charged particles in Debye plasma have been modelled by Debye–Huckel potential. The 1 s 2 s excited state of the helium atom has been treated as consisting of a H e + ionic core plus an electron moving around. The interaction between the core and the electron has then been modelled by a model potential. It has been found that the background plasma environment significantly affects the resonance states. To the best of our knowledge, such an investigation of 1 s 2 s 2 2 S resonance states of the electron–helium system embedded in Debye plasma environment is the first reported in the literature.

  13. A microwave resonator for limiting depth sensitivity for electron paramagnetic resonance spectroscopy of surfaces.

    Science.gov (United States)

    Sidabras, Jason W; Varanasi, Shiv K; Mett, Richard R; Swarts, Steven G; Swartz, Harold M; Hyde, James S

    2014-10-01

    A microwave Surface Resonator Array (SRA) structure is described for use in Electron Paramagnetic Resonance (EPR) spectroscopy. The SRA has a series of anti-parallel transmission line modes that provides a region of sensitivity equal to the cross-sectional area times its depth sensitivity, which is approximately half the distance between the transmission line centers. It is shown that the quarter-wave twin-lead transmission line can be a useful element for design of microwave resonators at frequencies as high as 10 GHz. The SRA geometry is presented as a novel resonator for use in surface spectroscopy where the region of interest is either surrounded by lossy material, or the spectroscopist wishes to minimize signal from surrounding materials. One such application is in vivo spectroscopy of human finger-nails at X-band (9.5 GHz) to measure ionizing radiation dosages. In order to reduce losses associated with tissues beneath the nail that yield no EPR signal, the SRA structure is designed to limit depth sensitivity to the thickness of the fingernail. Another application, due to the resonator geometry and limited depth penetration, is surface spectroscopy in coating or material science. To test this application, a spectrum of 1.44 μM of Mg(2+) doped polystyrene 1.1 mm thick on an aluminum surface is obtained. Modeling, design, and simulations were performed using Wolfram Mathematica (Champaign, IL; v. 9.0) and Ansys High Frequency Structure Simulator (HFSS; Canonsburg, PA; v. 15.0). A micro-strip coupling circuit is designed to suppress unwanted modes and provide a balanced impedance transformation to a 50 Ω coaxial input. Agreement between simulated and experimental results is shown.

  14. Ion-driven instabilities of surface dust ion-acoustic waves in bounded plasma devices

    Science.gov (United States)

    Lee, Myoung-Jae; Jung, Young-Dae

    2018-02-01

    The growth rates of the dust ion-acoustic surface wave in the plasma slab device containing ion streaming passing through the stationary electrons and dusty grains at the speed of wave phase velocity are derived and numerically analyzed. We have found that the growth rates for the resonant symmetric and antisymmetric waves are similar to the case of semi-bounded plasma when we have a thick slab. However, in the case of the symmetric wave, the growth rate moves towards the bulk wave as the slab thickness reduces. In the case of the antisymmetric wave, the growth rate increases fast as the slab thickness decreases. The growth rates of surface waves in a plasma slab are compared with those of semi-bounded and bulk waves.

  15. Surface plasmon oscillations in a semi-bounded semiconductor plasma

    Science.gov (United States)

    M, SHAHMANSOURI; A, P. MISRA

    2018-02-01

    We study the dispersion properties of surface plasmon (SP) oscillations in a semi-bounded semiconductor plasma with the effects of the Coulomb exchange (CE) force associated with the spin polarization of electrons and holes as well as the effects of the Fermi degenerate pressure and the quantum Bohm potential. Starting from a quantum hydrodynamic model coupled to the Poisson equation, we derive the general dispersion relation for surface plasma waves. Previous results in this context are recovered. The dispersion properties of the surface waves are analyzed in some particular cases of interest and the relative influence of the quantum forces on these waves are also studied for a nano-sized GaAs semiconductor plasma. It is found that the CE effects significantly modify the behaviors of the SP waves. The present results are applicable to understand the propagation characteristics of surface waves in solid density plasmas.

  16. Dielectric barrier discharge plasma treatment of cellulose nanofibre surfaces

    DEFF Research Database (Denmark)

    Kusano, Yukihiro; Madsen, Bo; Berglund, Linn

    2017-01-01

    Dielectric barrier discharge plasma treatment was applied to modify cellulose nanofibre (CNF) surfaces with and without ultrasonic irradiation. The plasma treatment improved the wetting by deionised water and glycerol, and increased the contents of oxygen, carbonyl group, and carboxyl group...... and amorphous phases. Ultrasonic irradiation also improved the uniformity of the treatment. Altogether, it is demonstrated that atmospheric pressure plasma treatment is a promising technique to modify the CNF surface before composite processing....... on the nanofibre surface. Ultrasonic irradiation further enhanced the wetting and oxidation of the nanofibre coating. Scanning electron microscopic observations showed skeleton-like features on the plasma-treated surface, indicating preferential etching of weaker domains, such as low-molecular weight domains...

  17. Enhanced surface functionality via plasma modification and plasma deposition techniques to create more biologically relevant materials

    Science.gov (United States)

    Shearer, Jeffrey C.

    Functionalizing nanoparticles and other unusually shaped substrates to create more biologically relevant materials has become central to a wide range of research programs. One of the primary challenges in this field is creating highly functionalized surfaces without modifying the underlying bulk material. Traditional wet chemistry techniques utilize thin film depositions to functionalize nanomaterials with oxygen and nitrogen containing functional groups, such as --OH and --NHx. These functional groups can serve to create surfaces that are amenable to cell adhesion or can act as reactive groups for further attachment of larger structures, such as macromolecules or antiviral agents. Additional layers, such as SiO2, are often added between the nanomaterial and the functionalized coating to act as a barrier films, adhesion layers, and to increase overall hydrophilicity. However, some wet chemistry techniques can damage the bulk material during processing. This dissertation examines the use of plasma processing as an alternative method for producing these highly functionalized surfaces on nanoparticles and polymeric scaffolds through the use of plasma modification and plasma enhanced chemical vapor deposition techniques. Specifically, this dissertation will focus on (1) plasma deposition of SiO2 barrier films on nanoparticle substrates; (2) surface functionalization of amine and alcohol groups through (a) plasma co-polymerization and (b) plasma modification; and (3) the design and construction of plasma hardware to facilitate plasma processing of nanoparticles and polymeric scaffolds. The body of work presented herein first examines the fabrication of composite nanoparticles by plasma processing. SiOxC y and hexylamine films were coated onto TiO2 nanoparticles to demonstrate enhanced water dispersion properties. Continuous wave and pulsed allyl alcohol plasmas were used to produce highly functionalized Fe2 O3 supported nanoparticles. Specifically, film composition was

  18. Surface plasmon resonance sensing of nucleic acids: A review

    Energy Technology Data Exchange (ETDEWEB)

    Šípová, Hana [Institute of Photonics and Electronics, Academy of Sciences of the Czech Republic, Chaberská 57, Prague (Czech Republic); Homola, Jiří, E-mail: homola@ufe.cz [Institute of Photonics and Electronics, Academy of Sciences of the Czech Republic, Chaberská 57, Prague (Czech Republic)

    2013-04-22

    Highlights: ► Advances of nucleic acid (NA) surface plasmon resonance (SPR) sensors are presented. ► Bioanalytical applications of NA SPR biosensors are reviewed. ► Applications for study of molecular interactions involving NAs are also discussed. -- Abstract: Biosensors based on surface plasmon resonance (SPR) have become a central tool for the investigation and quantification of biomolecules and their interactions. Nucleic acids (NAs) play a vital role in numerous biological processes and therefore have been one of the major groups of biomolecules targeted by the SPR biosensors. This paper discusses the advances of NA SPR biosensor technology and reviews its applications both in the research of molecular interactions involving NAs (NA–NA, NA–protein, NA–small molecule), as well as for the field of bioanalytics in the areas of food safety, medical diagnosis and environmental monitoring.

  19. Plasma based Ar+ beam assisted poly(dimethylsiloxane) surface modification

    International Nuclear Information System (INIS)

    Vladkova, T.G.; Keranov, I.L.; Dineff, P.D.; Youroukov, S.Y.; Avramova, I.A.; Krasteva, N.; Altankov, G.P.

    2005-01-01

    Plasma based Ar + beam performed in RF (13.56 MHz) low-pressure (200 mTorr) glow discharge (at 100 W, 1200 W and 2500 W) with a serial capacitance was employed for surface modification of poly(dimethylsiloxane) (PDMS) aimed at improvement of its interactions with living cells. The presence of a serial capacitance ensures arise of an ion-flow inside the plasma volume directed toward the treated sample and the vary of the discharge power ensures varied density of the ion-flow. XPS analysis was performed to study the changes in the surface chemical composition of the modified samples and the corresponding changes in the surface energy were monitored by contact angle measurements. We found that plasma based Ar + beam transforms the initially hydrophobic PDMS surface into a hydrophilic one mainly due to a raising of the polar component of the surface tension, this effect being most probably due to an enrichment of the modified surface layer with permanent dipoles of a [SiO x ]-based network and elimination of the original methyl groups. The initial adhesion of human fibroblast cells was studied on the described above plasma based Ar + beam modified and acrylic acid (AA) grafted or not fibronectin (FN) pre-coated or bare surfaces. The cell response seems to be related with the peculiar structure and wettability of the modified PDMS surface layer after plasma based Ar + beam treatment followed or not by AA grafting

  20. Optical properties study of silicone polymer PDMS substrate surfaces modified by plasma treatment

    Science.gov (United States)

    Zahid, A.; Dai, B.; Hong, R.; Zhang, D.

    2017-10-01

    In this study, PDMS (polydimethylsiloxane) substrates with a half-plain, half-rough surface were prepared on a plain and rough fused silica glass substrate using a molding technique. The molded PDMS surface morphology was changed into a half-smooth and half-rough surface after peeling. The modified PDMS surfaces’ optical properties were inspected with and without treatment. The treatment is exposed by oxygen plasma (15 W) for 3 min in a vacuum, down to a pressure of six torr, using a vacuum pump. An atomic force microscope (AMF) and interferometer (white light) indicated that the plasma O2 treatment increased the formation of the plain surface and decreased the formation of the rough surface. The optical properties via a spectrophotometer (lambda) show the resonance from 300 nm to 1200 nm on the rough surface, which is considered to be a faithful reproduction for transmittance and reflectance. The Raman spectra and FDTD simulation results are in excellent agreement; not to be confused with metal local surface plasmon resonances (LSPRs). The Raman spectra peaks and hotspot are the results of the PDMS Si-O backbone. The PDMS substrate presented the diversity of the optical properties, which makes the substrate complementary to various optical applications.

  1. Nuclear Fusion Research Understanding Plasma-Surface Interactions

    CERN Document Server

    Clark, Robert E.H

    2005-01-01

    It became clear in the early days of fusion research that the effects of the containment vessel (erosion of "impurities") degrade the overall fusion plasma performance. Progress in controlled nuclear fusion research over the last decade has led to magnetically confined plasmas that, in turn, are sufficiently powerful to damage the vessel structures over its lifetime. This book reviews current understanding and concepts to deal with this remaining critical design issue for fusion reactors. It reviews both progress and open questions, largely in terms of available and sought-after plasma-surface interaction data and atomic/molecular data related to these "plasma edge" issues.

  2. Interaction of blood plasma with antifouling surfaces

    Czech Academy of Sciences Publication Activity Database

    Rodriguez-Emmenegger, Cesar; Brynda, Eduard; Riedel, Tomáš; Sedláková, Zdeňka; Houska, Milan; Bologna Alles, A.

    2009-01-01

    Roč. 25, č. 11 (2009), s. 6328-6333 ISSN 0743-7463 R&D Projects: GA AV ČR KAN200670701 Institutional research plan: CEZ:AV0Z40500505 Keywords : blood plasma fouling * antigouling coatings * SPR biosensors Subject RIV: CE - Biochemistry Impact factor: 3.898, year: 2009

  3. Monitoring RAYT activity by surface plasmon resonance biosensor

    Czech Academy of Sciences Publication Activity Database

    Bocková, Markéta; Špringer, Tomáš; Nečasová, Iva; Nunvář, Jaroslav; Schneider, Bohdan; Homola, Jiří

    2015-01-01

    Roč. 407, č. 14 (2015), s. 3985-3993 ISSN 1618-2642 R&D Projects: GA ČR GAP305/12/1801 Grant - others:GA MŠk(CZ) CZ.1.05/1.1.00/02.0109 Institutional support: RVO:67985882 ; RVO:86652036 Keywords : Surface plasmon resonance * Biosensor * REP-associated tyrosine transposase Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering; EB - Genetics ; Molecular Biology (BTO-N) Impact factor: 3.125, year: 2015

  4. Detection of foodborne pathogens using surface plasmon resonance biosensors

    Czech Academy of Sciences Publication Activity Database

    Koubová, Vendula; Brynda, Eduard; Karasová, L.; Škvor, J.; Homola, Jiří; Dostálek, Jakub; Tobiška, Petr; Rošický, Jiří

    2001-01-01

    Roč. 74, 1/3 (2001), s. 100-105 ISSN 0925-4005 R&D Projects: GA ČR GA102/99/0549; GA AV ČR KSK2055603 Institutional research plan: CEZ:AV0Z4050913 Keywords : optical sensors * surface plasmon resonance * immunosensors Subject RIV: JB - Sensors, Measurment, Regulation Impact factor: 1.440, year: 2001

  5. Detection of foodborne pathogens using surface plasmon resonance biosensors

    Czech Academy of Sciences Publication Activity Database

    Koubová, Vendula; Brynda, Eduard; Krasová, B.; Škvor, J.; Homola, Jiří; Dostálek, Jakub; Tobiška, Petr; Rošický, Jiří

    B74, 1/3 (2001), s. 100-105 ISSN 0925-4005. [European Conference on Optical Chemical Sensors and Biosensors EUROPT(R)ODE /5./. Lyon-Villeurbanne, 16.04.2000-19.04.2000] R&D Projects: GA ČR GA102/99/0549 Institutional research plan: CEZ:AV0Z2067918 Keywords : optical sensors * surface plasmon resonance * biosensors Subject RIV: JB - Sensors, Measurment, Regulation Impact factor: 1.440, year: 2001

  6. Helium segregation on surfaces of plasma-exposed tungsten

    Science.gov (United States)

    Maroudas, Dimitrios; Blondel, Sophie; Hu, Lin; Hammond, Karl D.; Wirth, Brian D.

    2016-02-01

    We report a hierarchical multi-scale modeling study of implanted helium segregation on surfaces of tungsten, considered as a plasma facing component in nuclear fusion reactors. We employ a hierarchy of atomic-scale simulations based on a reliable interatomic interaction potential, including molecular-statics simulations to understand the origin of helium surface segregation, targeted molecular-dynamics (MD) simulations of near-surface cluster reactions, and large-scale MD simulations of implanted helium evolution in plasma-exposed tungsten. We find that small, mobile He n (1  ⩽  n  ⩽  7) clusters in the near-surface region are attracted to the surface due to an elastic interaction force that provides the thermodynamic driving force for surface segregation. This elastic interaction force induces drift fluxes of these mobile He n clusters, which increase substantially as the migrating clusters approach the surface, facilitating helium segregation on the surface. Moreover, the clusters’ drift toward the surface enables cluster reactions, most importantly trap mutation, in the near-surface region at rates much higher than in the bulk material. These near-surface cluster dynamics have significant effects on the surface morphology, near-surface defect structures, and the amount of helium retained in the material upon plasma exposure. We integrate the findings of such atomic-scale simulations into a properly parameterized and validated spatially dependent, continuum-scale reaction-diffusion cluster dynamics model, capable of predicting implanted helium evolution, surface segregation, and its near-surface effects in tungsten. This cluster-dynamics model sets the stage for development of fully atomistically informed coarse-grained models for computationally efficient simulation predictions of helium surface segregation, as well as helium retention and surface morphological evolution, toward optimal design of plasma facing components.

  7. Removal of Microbial Contamination from Surface by Plasma

    Science.gov (United States)

    Feng, Xinxin; Liu, Hongxia; Shen, Zhenxing; Wang, Taobo

    2018-01-01

    Microbial contamination is closely associated with human and environmental health, they can be tested on food surfaces, medical devices, packing material and so on. In this paper the removal of the microbial contamination from surface using plasma treatment is investigated. The Escherichia coli (E. coli) has been chosen as a bio-indicator enabling to evaluate the effect of plasma assisted microbial inactivation. Oxygen gas was as the working gas. The plasma RF power, plasma exposition time, gas flow and the concentration of organic pollutant were varied in order to see the effect of the plasma treatment on the Gram-negative germ removal. After the treatment, the microbial abatement was evaluated by the standard plate count method. This proved a positive effect of the plasma treatment on Gram-negative germ removal. The kinetics and mathematical model of removal were studied after plasma treatment, and then the removing course of E. coli was analyzed. This work is meaningful for deepening our understanding of the fundamental scientific principles regarding microbial contamination from surface by plasma.

  8. Atmospheric pressure plasma surface modification of carbon fibres

    DEFF Research Database (Denmark)

    Kusano, Yukihiro; Løgstrup Andersen, Tom; Michelsen, Poul

    2008-01-01

    Carbon fibres are continuously treated with dielectric barrier discharge plasma at atmospheric pressure in various gas conditions for adhesion improvement in mind. An x-ray photoelectron spectroscopic analysis indicated that oxygen is effectively introduced onto the carbon fibre surfaces by He, He....../O2 and Ar plasma treatments, mainly attributed to an increase in the density of the C-O single bond at the carbon fibre surfaces. The O/C ratio increased to 0.182 after 1-s He plasma treatment, and remained approximately constant after longer treatment. After exposure in an ambient air at room...

  9. Improvement of crystalline silicon surface passivation by hydrogen plasma treatment

    International Nuclear Information System (INIS)

    Martin, I.; Vetter, M.; Orpella, A.; Voz, C.; Puigdollers, J.; Alcubilla, R.; Kharchenko, A.V.; Roca i Cabarrocas, P.

    2004-01-01

    A completely dry low-temperature process has been developed to passivate 3.3 Ω cm p-type crystalline silicon surface with excellent results. Particularly, we have investigated the use of a hydrogen plasma treatment, just before hydrogenated amorphous silicon carbide (a-SiC x :H) deposition, without breaking the vacuum. We measured effective lifetime, τ eff , through a quasi-steady-state photoconductance technique. Experimental results show that hydrogen plasma treatment improves surface passivation compared to classical HF dip. S eff values lower than 19 cm s -1 were achieved using a hydrogen plasma treatment and an a-SiC x :H film deposited at 300 deg. C

  10. Osteoblast response to oxygen functionalised plasma polymer surfaces

    CERN Document Server

    Kelly, J M

    2001-01-01

    Thin organic films with oxygen-carbon functionalities were deposited from plasmas containing vapour of the small organic compounds: allyI alcohol, methyl vinyl ketone and acrylic acid with octadiene. Characterisation of the deposits was carried out using X-ray photoelectron spectroscopy, in conjunction with chemical derivatisation, and this showed that plasma polymers retained high levels of original monomer functionality when the plasmas were sustained at low power for a given monomer vapour flow rate. High levels of attachment of rat osteosarcoma (ROS 17/2.8) cells were observed on surfaces that had high concentrations of hydroxyl and carbonyl functionalities and intermediate concentrations of carboxyl functionality. Cells did not attach to the octadiene plasma polymer. Cell attachment to carboxyl and methyl functionalised self-assembled monolayers increased with increasing concentration of surface carboxyl groups. Adsorption of the extracellular matrix protein fibronectin to acrylic acid/octadiene plasma c...

  11. Ultrasound enhanced plasma surface modification at atmospheric pressure

    DEFF Research Database (Denmark)

    Kusano, Yukihiro; Singh, Shailendra Vikram; Norrman, Kion

    2012-01-01

    Efficiency of atmospheric pressure plasma treatment can be highly enhanced by simultaneous high power ultrasonic irradiation onto the treating surface. It is because ultrasonic waves with a sound pressure level (SPL) above ∼140 dB can reduce the thickness of a boundary gas layer between the plasma...... arc at atmospheric pressure to study adhesion improvement. The effect of ultrasonic irradiation with the frequency diapason between 20 and 40 kHz at the SPL of ∼150 dB was investigated. After the plasma treatment without ultrasonic irradiation, the wettability was significantly improved....... The ultrasonic irradiation during the plasma treatment consistently enhanced the treatment efficiency. The principal effect of ultrasonic irradiation can be attributed to enhancing surface oxidation during plasma treatment. In addition, ultrasonic irradiation can suppress arcing, and the uniformity...

  12. Cleaning of magnetic nanoparticle surfaces via cold plasmas treatments

    Directory of Open Access Journals (Sweden)

    Narayan Poudyal

    2017-05-01

    Full Text Available We report surface cleaning of magnetic nanoparticles (SmCo5 nanochips and CoFe2O4 nanoparticles by using cold plasma. SmCo5 nanochips and CoFe2O4 nanoparticles, coated with surfactants (oleic acid and oleylamine, respectively on their surfaces, were treated in cold plasmas generated in argon, hydrogen or oxygen atmospheres. The plasmas were generated using a capacitively coupled pulsed radio frequency discharge. Surface cleaning of nanoparticles was monitored by measurement of the reduction of surface carbon content as functions of plasma processing parameters and treatment times. EDX and XPS analyses of the nanoparticles, obtained after the plasma treatment, revealed significant reduction of carbon content was achieved via plasma treatment. The SmCo5 nanochips and CoFe2O4 nanoparticles treated in an argon plasma revealed reduction of atomic carbon content by more than 54 and 40 in atomic percentage, compared with the untreated nanoparticles while the morphology, crystal structures and magnetic properties are retained upon the treatments.

  13. The dispersion and matching characteristics of the helical resonator plasma source

    Energy Technology Data Exchange (ETDEWEB)

    Niazi, K.; Lichtenberg, A.J.; Lieberman, M.A. [Univ. of California, Berkeley, CA (United States)

    1995-10-01

    The dispersion characteristics and the fields of a helical resonator are obtained. The coil is approximated by a helical current layer with infinite conductivity along the current direction (a ``sheath helix``). The plasma column is modeled as a cylindrical dielectric in which the dielectric losses can be neglected in determining the propagation properties of the resonator. Assuming the plasma losses are known, the model can be used to study the matching of the helical resonator to an external power source which is connected to the helix by a tap. The resonator is modeled as a parallel connection of two transmission line segments on each side of the tap position. The authors determine the efficiency of power transfer to the resonator as a function of the tap position driving frequency, and plasma loading. They find that whereas for a small plasma loading it is possible to achieve perfect matching, there exists a critical value of plasma loading beyond which a perfect match is no longer possible.

  14. Scattering-Type Surface-Plasmon-Resonance Biosensors

    Science.gov (United States)

    Wang, Yu; Pain, Bedabrata; Cunningham, Thomas; Seshadri, Suresh

    2005-01-01

    Biosensors of a proposed type would exploit scattering of light by surface plasmon resonance (SPR). Related prior biosensors exploit absorption of light by SPR. Relative to the prior SPR biosensors, the proposed SPR biosensors would offer greater sensitivity in some cases, enough sensitivity to detect bioparticles having dimensions as small as nanometers. A surface plasmon wave can be described as a light-induced collective oscillation in electron density at the interface between a metal and a dielectric. At SPR, most incident photons are either absorbed or scattered at the metal/dielectric interface and, consequently, reflected light is greatly attenuated. The resonance wavelength and angle of incidence depend upon the permittivities of the metal and dielectric. An SPR sensor of the type most widely used heretofore includes a gold film coated with a ligand a substance that binds analyte molecules. The gold film is thin enough to support evanescent-wave coupling through its thickness. The change in the effective index of refraction at the surface, and thus the change in the SPR response, increases with the number of bound analyte molecules. The device is illuminated at a fixed wavelength, and the intensity of light reflected from the gold surface opposite the ligand-coated surface is measured as a function of the angle of incidence. From these measurements, the angle of minimum reflection intensity is determined

  15. Materials surface damage and modification under high power plasma exposures

    Science.gov (United States)

    Garkusha, I.; Makhlaj, V.; Byrka, O.; Taran, V.; Voitsenya, V.; Malykhin, S.; Herashchenko, S.; Surovitskiy, S.; Nowakowska-Langier, K.; Sadowski, M. J.; Skladnik-Sadowska, E.; Terentyev, D.

    2018-01-01

    Influence of powerful plasma impacts on several materials used for the construction of energy systems, i.e. different grades of steels as well as tungsten coatings, has been discussed. Irradiations of these materials with hydrogen and helium plasma streams have been performed in several high-current-pulse and quasi-stationary plasma accelerators which provided the variation of a power load upon the exposed surface as well as changes of the particle flux in wide ranges: the energy flux density in the range of 1-25 MJ/m2, particle flux - up to 1026-1029 ion/m2s, the plasma stream velocity - up to about 500 km/s, and the pulse duration in the range of 1-250 μs. A response of the investigated materials to extreme plasma loads, which are relevant to transient events in fusion reactors, is briefly discussed. It is demonstrated that a broad combination of mechanisms of powerful plasma interactions with various materials includes not only a surface damage caused by different erosion mechanisms, but under certain conditions it may also result in a significant improvement of material properties in the near-surface surface layer of several tens-μm in thickness. Some improvement of the structure and substructure of such a layer may be caused by the high-speed quenching, the shock wave formation and material alloying with plasma- and coating-species. The creation of unique surface structures and a considerable improvement of physical and mechanical properties of different materials can be achieved by the pulsed plasma alloying, i.e. pre-deposited coating modifications and mixing caused by the impacting plasma streams.

  16. Oxygen Plasma Treatment of Rubber Surface by the Atmospheric Pressure Cold Plasma Torch

    DEFF Research Database (Denmark)

    Lee, Bong-ju; Kusano, Yukihiro; Kato, Nobuko

    1997-01-01

    A new application of the atmospheric cold plasma torch has been investigated. Namely, the surface treatment of an air-exposed vulcanized rubber compound. The effect of plasma treatment was evaluated by the bondability of the treated rubber compound with another rubber compound using a polyurethane...

  17. Surface plasma functionalization influences macrophage behavior on carbon nanowalls

    Energy Technology Data Exchange (ETDEWEB)

    Ion, Raluca [University of Bucharest, Department of Biochemistry and Molecular Biology, 91-95 Spl. Independentei, 050095 Bucharest (Romania); Vizireanu, Sorin [National Institute for Laser, Plasma and Radiation Physics, 409 Atomistilor, PO Box MG-36, 077125, Magurele, Bucharest (Romania); Stancu, Claudia Elena [National Institute for Laser, Plasma and Radiation Physics, 409 Atomistilor, PO Box MG-36, 077125, Magurele, Bucharest (Romania); Leibniz Institute for Plasma Science and Technology (INP Greifswald), Felix-Hausdorff-Str. 2, 17489 Greifswald (Germany); Luculescu, Catalin [National Institute for Laser, Plasma and Radiation Physics, 409 Atomistilor, PO Box MG-36, 077125, Magurele, Bucharest (Romania); Cimpean, Anisoara, E-mail: anisoara.cimpean@bio.unibuc.ro [University of Bucharest, Department of Biochemistry and Molecular Biology, 91-95 Spl. Independentei, 050095 Bucharest (Romania); Dinescu, Gheorghe [National Institute for Laser, Plasma and Radiation Physics, 409 Atomistilor, PO Box MG-36, 077125, Magurele, Bucharest (Romania)

    2015-03-01

    The surfaces of carbon nanowall samples as scaffolds for tissue engineering applications were treated with oxygen or nitrogen plasma to improve their wettability and to functionalize their surfaces with different functional groups. X-ray photoelectron spectroscopy and water contact angle results illustrated the effective conversion of the carbon nanowall surfaces from hydrophobic to hydrophilic and the incorporation of various amounts of carbon, oxygen and nitrogen functional groups during the treatments. The early inflammatory responses elicited by un-treated and modified carbon nanowall surfaces were investigated by quantifying tumor necrosis factor-alpha and macrophage inflammatory protein-1 alpha released by attached RAW 264.7 macrophage cells. Scanning electron microscopy and fluorescence studies were employed to investigate the changes in macrophage morphology and adhesive properties, while MTT assay was used to quantify cell proliferation. All samples sustained macrophage adhesion and growth. In addition, nitrogen plasma treatment was more beneficial for cell adhesion in comparison with un-modified carbon nanowall surfaces. Instead, oxygen plasma functionalization led to increased macrophage adhesion and spreading suggesting a more activated phenotype, confirmed by elevated cytokine release. Thus, our findings showed that the chemical surface alterations which occur as a result of plasma treatment, independent of surface wettability, affect macrophage response in vitro. - Highlights: • N{sub 2} and O{sub 2} plasma treatments alter the CNW surface chemistry and wettability. • Cells seeded on CNW scaffolds are viable and metabolically active. • Surface functional groups, independent of surface wettability, affect cell response. • O{sub 2} plasma treatment of CNW leads to a more activated macrophage phenotype.

  18. Plasma surface modification of hydrogel films

    Czech Academy of Sciences Publication Activity Database

    Suchaneck, G.; Guenther, M.; Sorber, J.; Gerlach, G.; Arndt, K.F.; Deineka, Alexander; Jastrabík, Lubomír

    174-175, - (2003), s. 816-820 ISSN 0257-8972 R&D Projects: GA MŠk LN00A015; GA MŠk ME 441 Grant - others:GFMER(DE) CZE00/002 Institutional research plan: CEZ:AV0Z1010914 Keywords : polymers * radio-frequency plasma * photoelectron spectroscopy Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.410, year: 2003

  19. Contamination by sputtering in mirror field electron cyclotron resonance microwave ion plasma

    International Nuclear Information System (INIS)

    Gorbatikin, S.M.; Berry, L.A.

    1992-01-01

    Langmuir probe measurements, visual observation, and Rutherford backscattering spectrometry (RBS) have been used to investigate source chamber sputtering for electron cyclotron resonance (ECR) plasma systems operated with Ar, N 2 , and Cl 2 . Potentials in the source > 20eV combined with high plasma densities (>10 12 cm -3 ) led to source chamber sputtering and coating of the microwave entrance window. During Ar operation, the microwave entrance window coating caused significant absorption of incident microwave power and decreased source efficiency by as much as 40% in 11 cm 2 sec -1 . Cl 2 , operation did not result in microwave entrance window coating, however surface contamination from sputtering was detected. Operation of the source with an anodized aluminum liner was effective in reducing microwave entrance window coating but resulted in some heavy metal contamination due to sputtering of impurities in the liner itself. Also, checks with secondary ion mass spectrometry (SIMS) indicated some Al contamination from sputtering of the anodized aluminum liner material. Finally, a technique for in situ cleaning of the microwave entrance window was developed and expedited source contamination studies

  20. Modeling Field Line Resonances in the Inner Plasmasphere with the Field Line Interhemispheric Plasma Model

    Science.gov (United States)

    McCarthy, N. M.; Jorgensen, A. M.; Stone, W. D.; Zesta, E.

    2010-12-01

    Equatorial plasma mass density in the Inner Magnetosphere of the Earth has been traditionally derived from measurements of Field Line Resonances from pairs of ground magnetometers closely spaced in latitude. The full plasma mass density along the flux tube can be determined using such measurements in an inversion of the Field Line Resonance Equation. Cummings et al [1969] developed the Field Line Resonance equation and numerically solved for the Field Line Resonances by assuming a power law distribution that varied with the geocentric distance from the equatorial crossing point of the field lines and a dipole model for the Earth's magnetic field. So far all numerical solutions of the Field Line Resonance Equation use some form of a power law distribution of the mass density along the field line, that depends on the magnetic field model, typically assumed to be a dipole, with only one recent work exploring deviations from a dipole magnetic field. Another fundamental assumption in the solution of the Field Line Resonance Equation is that of perfectly conducting, flat ionospheres as the two boundaries of the field line. While this assumption is considered valid for L values greater than 2, recent works have found it to be invalid for L values of 3 or less. In the present paper we solve the Field Line Resonance Equation for L values less than 3.5 using a three dimensional ionosphere, and without assuming a power law for the mass density distribution along the field line. Instead we use plasma mass density data from the Field Line Interhemispheric Plasma (FLIP) model to numerically solve the Field Line Resonance Equation for the eigenfrequencies. We also examine how the resonance frequencies vary as a function of the driving parameters. Finally we examine two events in which we compare the derived frequencies with measurements from the SAMBA magnetometer array.

  1. Electron cyclotron resonance heating in a short cylindrical plasma ...

    Indian Academy of Sciences (India)

    For τp = 2.5 µs and nn = 3.3 × 1019 m−3 for an operating pressure of 1 × 10−3 mbar, plasma temperature in the system can be estimated from figure 2 as. Te ≈ 10 eV. (34). The experimentally observed plasma temperature Te is between 9 and 15 eV which is in good agreement with the theoretical estimation. 3.

  2. Surface transport in plasma-balls

    Energy Technology Data Exchange (ETDEWEB)

    Armas, Jay [Physique Théorique et Mathématique, Université Libre de Bruxelles andInternational Solvay Institutes,ULB-Campus Plaine CP231, B-1050 Brussels (Belgium); Bhattacharya, Jyotirmoy [Centre for Particle Theory & Department of Mathematical Sciences, Durham University,South Road, Durham DH1 3LE (United Kingdom); Kundu, Nilay [Harish-Chandra Research Institute,Chhatnag Road, Jhunsi, Allahabad 211019 (India)

    2016-06-06

    We study the surface transport properties of stationary localized configurations of relativistic fluids to the first two non-trivial orders in a derivative expansion. By demanding that these finite lumps of relativistic fluid are described by a thermal partition function with arbitrary stationary background metric and gauge fields, we are able to find several constraints among surface transport coefficients. At leading order, besides recovering the surface thermodynamics, we obtain a generalization of the Young-Laplace equation for relativistic fluid surfaces, by considering a temperature dependence in the surface tension, which is further generalized in the context of superfluids. At the next order, for uncharged fluids in 3+1 dimensions, we show that besides the 3 independent bulk transport coefficients previously known, a generic localized configuration is characterized by 3 additional surface transport coefficients, one of which may be identified with the surface modulus of rigidity. Finally, as an application, we study the effect of temperature dependence of surface tension on some explicit examples of localized fluid configurations, which are dual to certain non-trivial black hole solutions via the AdS/CFT correspondence.

  3. Characterization and conditioning of SSPX plasma facing surfaces

    International Nuclear Information System (INIS)

    Buchenauer, D.A.; Mills, B.E.; Wood, R.; Woodruff, S.; Hill, D.N.; Hooper, E.B.; Cowgill, D.F.; Clift, M.W.; Yang, N.Y.

    2001-01-01

    The Sustained Spheromak Physics Experiment (SSPX) will examine the confinement properties of spheromak plasmas sustained by DC helicity injection. Understanding the plasma-surface interactions is an important component of the experimental program since the spheromak plasma is in close contact with a stabilizing wall (flux conserver) and is maintained by a high current discharge in the coaxial injector region. Peak electron temperatures in the range of 400 eV are expected, so the copper plasma facing surfaces in SSPX have been coated with tungsten to minimize sputtering and plasma contamination. Here, we report on the characterization and conditioning of these surfaces used for the initial studies of spheromak formation in SSPX. The high pressure plasma-sprayed tungsten facing the SSPX plasma was characterized in situ using β-backscattering and ex situ using laboratory measurements on similarly prepared samples. Measurements showed that water can be desorbed effectively through baking while the removal rates of volatile impurity gases during glow discharge and shot conditioning indicated a large source of carbon and oxygen in the porous coating

  4. The surface modification of clay particles by RF plasma technique

    Science.gov (United States)

    Lee, Sang-Keol

    In this study, the surface coatings of ball clay, organoclay and exfoliated clay prepared by sol-gel process were done by RF plasma polymerization to improve the surface activity of the clay filler. Characterization of the above plasma-treated clays has been carried out by various techniques. The effects of plasma-treated clays as substitute of carbon black in styrene-butadiene rubber (SBR) and ethylene-propylene-diene monomer (EPDM) on the curing and mechanical properties were investigated. After plasma treatment, the tensile properties of organo and exfoliated clay were not unsatisfactory to that of carbon black filler system. Moreover, only 10 phr filler loading of plasma-treated organoclay in EPDM vulcanizates showed better results than 40 phr filler loading of carbon black in EPDM vulcanizates. The main objective of this study was to verify the applicability of the plasma technique for modifying clay surfaces for their use in the tire manufacturing industry. Another purpose was to reveal the advantage of the plasma technique used to obtain modified-clay and improved properties that those materials can display.

  5. Dust generation at interaction of plasma jet with surfaces

    Science.gov (United States)

    Ticos, Catalin; Toader, Dorina; Banu, Nicoleta; Scurtu, Adrian; Oane, Mihai

    2013-10-01

    Coatings of W and C with widths of a few microns will be exposed to plasma jet for studying the erosion of the surface and detachment of micron size dust particles. A coaxial plasma gun has been built inside a vacuum chamber for producing supersonic plasma jets. Its design is based on a 50 kJ coaxial plasma gun which has been successfully used for accelerating hypervelocity dust. Initial shots were carried out for a capacitor bank with C = 12 μF and charged up to 2 kV. Currents of tens of amps were measured with a Rogowsky coil and plasma flow speeds of 4 km/s were inferred from high-speed images of jet propagation. An upgrade consisting in adding capacitors in parallel will be performed in order to increase the energy up to 2 kJ. A coil will be installed at the gun muzzle to compress the plasma flow and increase the energy density of the jet on the sample surface. A CCD camera with a maximum recording speed of 100 k fps and a maximum resolution of 1024 × 1024 pixels was set for image acquisition of the plasma and dust. A laser system used to illuminate the ejected dust from the surface includes a laser diode emitting at 650 nm with a beam power of 25 mW. The authors acknowledge support from EURATOM WP13-IPH-A03-P2-02-BS22.

  6. Resonance surface enhanced Raman optical activity of myoglobin as a result of optimized resonance surface enhanced Raman scattering conditions

    DEFF Research Database (Denmark)

    Abdali, Salim; Johannessen, Christian; Nygaard, Jesper

    2007-01-01

    Using Surface enhanced ROA (SEROA), novel results are achieved by combining Raman Optical Activity (ROA) and resonance Surface Enhanced Raman Scattering (SERRS), applied on myoglobin. The novelty of this work is ascribed the first time reporting on chiral results of a study performed on a protein...... has shown that the SERS effect behaves consequently, depending on the concentration ratio of each component, i.e., myoglobin, Ag colloids and NaCl. Accordingly, it is shown here that SERS intensity has its maximum at certain concentration of these components, whereas below or above this value...

  7. Surface improvement of EPDM rubber by plasma treatment

    International Nuclear Information System (INIS)

    Moraes, J H; Silva Sobrinho, A S da; Maciel, H S; Dutra, J C N; Massi, M; Mello, S A C; Schreiner, W H

    2007-01-01

    The surface of ethylene-propylene-diene monomer (EPDM) rubber was treated in N 2 /Ar and N 2 /H 2 /Ar RF plasmas in order to achieve similar or better adhesion properties than NBR (acrylonitrile-butadiene) rubber, nowadays used as thermal protection of rocket chambers. The surface properties were studied by contact angle measurements and by x-ray photoelectron spectroscopy (XPS). The treated surfaces of the EPDM samples show a significant reduction in the contact angle measurement, indicating an increase in the surface energy. XPS analyses show the incorporation of polar nitrogen- and oxygen-containing groups on the rubber surface. After plasma treatment the presence of oxygen is observed due to surface oxidation which occurs when the samples are exposed to the air. Atomic force microscopy and scanning electron microscopy analyses indicate a decrease in the EPDM rubber surface roughness, promoted by surface etching during the plasma treatment. Strength tests indicate improvement of about 30% and 110% in the adhesion strength for the plasma treated EPDM/polyurethane liner interface and for the EPDM/epoxy adhesive interface, respectively. The adhesion strength of the EPDM/liner is similar to that obtained for the NBR/liner, which indicates that EPDM rubber can safely be used as thermal protection of the solid propellant rocket chamber

  8. High speed cine film studies of plasma behaviour and plasma surface interactions in tokamaks

    International Nuclear Information System (INIS)

    Goodall, D.H.J.

    1982-01-01

    High speed cine photography is a useful diagnostic aid for studying plasma behaviour and plasma surface interactions. Several workers have filmed discharges in tokamaks including ASDEX, DITE, DIVA, ISX, JFT2, TFR and PLT. These films are discussed and examples given of the observed phenomena which include plasma limiter interactions, diverted discharges, disruptions, magnetic islands and moving glowing objects often known as 'UFOs'. Examples of plasma structures in ASDEX and DITE not previously published are also given. The paper also reports experiments in DITE to determine the origin of UFOs. (orig.)

  9. High speed cine film studies of plasma behaviour and plasma surface interactions in tokamaks

    Energy Technology Data Exchange (ETDEWEB)

    Goodall, D.H.J. (Euratom/UKAEA Fusion Association, Abingdon (UK). Culham Lab.)

    High speed cine photography is a useful diagnostic aid for studying plasma behaviour and plasma surface interactions. Several workers have filmed discharges in tokamaks including ASDEX, DITE, DIVA, ISX, JFT2, TFR and PLT. These films are discussed and examples given of the observed phenomena which include plasma limiter interactions, diverted discharges, disruptions, magnetic islands and moving glowing objects often known as 'UFOs'. Examples of plasma structures in ASDEX and DITE not previously published are also given. The paper also reports experiments in DITE to determine the origin of UFOs.

  10. THz detectors using surface Josephson plasma waves in layered superconductors

    International Nuclear Information System (INIS)

    Savel'ev, Sergey; Yampol'skii, Valery; Nori, Franco

    2006-01-01

    We describe a proposal for THz detectors based on the excitation of surface waves, in layered superconductors, at frequencies lower than the Josephson plasma frequency ω J . These waves propagate along the vacuum-superconductor interface and are attenuated in both transverse directions out of the surface (i.e., towards the superconductor and towards the vacuum). The surface Josephson plasma waves are also important for the complete suppression of the specular reflection from a sample (Wood's anomalies, used for gratings) and produce a huge enhancement of the wave absorption, which can be used for the detection of THz waves

  11. Solar energy converter using surface plasma waves

    Science.gov (United States)

    Anderson, L. M. (Inventor)

    1984-01-01

    Sunlight is dispersed over a diffraction grating formed on the surface of a conducting film on a substrate. The angular dispersion controls the effective grating period so that a matching spectrum of surface plasmons is excited for parallel processing on the conducting film. The resulting surface plasmons carry energy to an array of inelastic tunnel diodes. This solar energy converter does not require different materials for each frequency band, and sunlight is directly converted to electricity in an efficient manner by extracting more energy from the more energetic photons.

  12. Surface plasmon enhanced interfacial electron transfer and resonance Raman, surface-enhanced resonance Raman studies of cytochrome C mutants

    Energy Technology Data Exchange (ETDEWEB)

    Zheng, Junwei [Iowa State Univ., Ames, IA (United States)

    1999-11-08

    Surface plasmon resonance was utilized to enhance the electron transfer at silver/solution interfaces. Photoelectrochemical reductions of nitrite, nitrate, and CO2 were studied on electrochemically roughened silver electrode surfaces. The dependence of the photocurrent on photon energy, applied potential and concentration of nitrite demonstrates that the photoelectrochemical reduction proceeds via photoemission process followed by the capture of hydrated electrons. The excitation of plasmon resonances in nanosized metal structures resulted in the enhancement of the photoemission process. In the case of photoelectrocatalytic reduction of CO2, large photoelectrocatalytic effect for the reduction of CO2 was observed in the presence of surface adsorbed methylviologen, which functions as a mediator for the photoexcited electron transfer from silver metal to CO2 in solution. Photoinduced reduction of microperoxidase-11 adsorbed on roughened silver electrode was also observed and attributed to the direct photoejection of free electrons of silver metal. Surface plasmon assisted electron transfer at nanostructured silver particle surfaces was further determined by EPR method.

  13. Laboratory measurements of dusty surface charging in plasma.

    Science.gov (United States)

    Chou, Kevin; Wang, Joseph

    2017-09-01

    A novel method is developed to study the charging of a conducting surface covered by a thin dust layer in plasma. The potential profile in the dust layer and the floating potential of the surface underneath are measured directly by embedding conducting wires in the dust and connecting the wires to a measurement plate outside the vacuum chamber, where a Trek non-contacting electrostatic voltmeter measures the floating potential of the measurement plate. Laboratory experiments are carried out to study plasma charging of a conducting plate covered by lunar dust simulant, JSC-1A. The results show that the plate potential is dependent on both the ambient plasma condition and the dust layer thickness. The current balance condition controls the floating potential of the dust surface while the dust layer acts as a capacitor and controls the potential of the plate with respect to the dust surface. Hence, a dust covered conducting plate will be charged more negatively than a clean plate.

  14. Relativistic Electron Acceleration by Surface Plasma Waves in the High Intensity Regime

    Science.gov (United States)

    Zhu, Xiaoming; Cerchez, Mirela; Swantusch, Marco; Aurand, Bastian; Prasad, Rajendra; Andreev, Alexander; Willi, Oswald

    2017-10-01

    High field plasmonics is one of the new research fields which has synergetically benefited from the advances in laser technology. The availability of radiation fields of intensities exceeding 1018 W/cm2 brought plasmonics into a new regime where relativistic and nonlinear effects start to dominate the dynamics of the surface plasma waves (SPWs). Moreover, surface plasma waves are a very efficient route to transfer the laser energy to the secondary sources including laser driven particle and radiation beams and to control and optimize the physical properties of these sources. We present here experimental evidence of a novel regime of the SPWs excitation by ultra-high intensity laser field (I>1020 W/cm2) on grating targets and its effect on high energy surface electron acceleration. The peak of the electron emission was detected at a laser incidence angle of 45°. The results indicate new conditions for resonant excitation of SPWs since in the limit of the linear regime (moderate intensities of 1019 W/cm2 and step preplasma profile), the resonance angle is predicted at 30°. 2D PIC simulations and a novel analytical model confirm the experimental data and reveal that, at laser intensities above 1020W/cm2, nonlinearities induced by the preplasma condition and relativistic effects change the SPWs resonance.

  15. The effect of surface modification by nitrogen plasma on photocatalytic degradation of polyvinyl chloride films

    Science.gov (United States)

    Xiao-jing, L.; Guan-jun, Q.; Jie-rong, C.

    2008-08-01

    The solid-phase photocatalytic degradation of poly(vinyl chloride) (PVC) films was investigated under the ambient air in order to assess the feasibility of developing photodegradable polymers. Nitrogen plasma was used to modify PVC films to enhance the photocatalytic degradation of PVC with nano-sized anatase TiO 2. The plasma parameter varied in this study is discharge power from 30 to 120 W for a constant treatment time of 60 s and a constant gas pressure of 10 Pa. The photodegradation of the plasma-treated PVC-TiO 2 films was compared with that of pure PVC films and PVC-TiO 2 films performing weight loss monitoring, scanning electron microscopy (SEM) analysis, contact angle measurements, electron spin resonance (ESR), Fourier transform infrared spectroscopy (FT-IR), and X-ray photoelectron spectroscopy (XPS). The wettability of the plasma-treated PVC is improved significantly. ESR revealed that the signal of radicals on the surface of the plasma-treated PVC film was enhanced after the treatment. Furthermore, the weight loss indicated that TiO 2 speeds up the photocatalytic degradation of PVC chains. The SEM image of the plasma-treated PVC-TiO 2 film showed a lot of crack on the film surface after irradiation. XPS indicated that the C and Cl atomic concentration reached minimum values on the surface of plasma-treated PVC-TiO 2 under identical photocatalytic condition. The experimental results reveal that plasma treatment can obviously enhance the photocatalytic degradation of PVC.

  16. Trends in interfacial design for surface plasmon resonance based immunoassays

    Energy Technology Data Exchange (ETDEWEB)

    Shankaran, Dhesingh Ravi [Art, Science and Technology Center for Cooperative Research, Kyushu University, Kasuga-shi, Fukuoka, 816-8580 (Japan); Miura, Norio [Art, Science and Technology Center for Cooperative Research, Kyushu University, Kasuga-shi, Fukuoka, 816-8580 (Japan)

    2007-12-07

    Immunosensors based on surface plasmon resonance (SPR) have become a promising tool in sensor technology for biomedical, food, environmental, industrial and homeland security applications. SPR is a surface sensitive optical technique, suitable for real-time and label-free analysis of biorecognition events at functional transducer surfaces. Fabrication of highly active and robust sensing surfaces is an important part in immunoassays because the quality, quantity, chemistry and topography of the interfacial biomembranes play a major role in immunosensor performance. Eventually, a variety of immobilization methods such as physical adsorption, covalent coupling, Langmuir-Blodgett film, polymer thin film, self-assembly, sol-gel, etc, have been introduced over the years for the immobilization of biomolecules (antibody or antigen) on the transducer surfaces. The selection of an immobilization method for an immunoassay is governed by several factors such as nature and stability of the biomolecules, target analyte, application, detection principle, mode of signal transduction, matrix complexity, etc. This paper provides an overview of the various surface modification methods for SPR based immunosensor fabrication. The preparation, structure and application of different functional interfacial surfaces have been discussed along with a brief introduction to the SPR technology, biomolecules and detection principles. (review article)

  17. Trends in interfacial design for surface plasmon resonance based immunoassays

    International Nuclear Information System (INIS)

    Shankaran, Dhesingh Ravi; Miura, Norio

    2007-01-01

    Immunosensors based on surface plasmon resonance (SPR) have become a promising tool in sensor technology for biomedical, food, environmental, industrial and homeland security applications. SPR is a surface sensitive optical technique, suitable for real-time and label-free analysis of biorecognition events at functional transducer surfaces. Fabrication of highly active and robust sensing surfaces is an important part in immunoassays because the quality, quantity, chemistry and topography of the interfacial biomembranes play a major role in immunosensor performance. Eventually, a variety of immobilization methods such as physical adsorption, covalent coupling, Langmuir-Blodgett film, polymer thin film, self-assembly, sol-gel, etc, have been introduced over the years for the immobilization of biomolecules (antibody or antigen) on the transducer surfaces. The selection of an immobilization method for an immunoassay is governed by several factors such as nature and stability of the biomolecules, target analyte, application, detection principle, mode of signal transduction, matrix complexity, etc. This paper provides an overview of the various surface modification methods for SPR based immunosensor fabrication. The preparation, structure and application of different functional interfacial surfaces have been discussed along with a brief introduction to the SPR technology, biomolecules and detection principles. (review article)

  18. Study on hydrophilicity of polymer surfaces improved by plasma treatment

    International Nuclear Information System (INIS)

    Lai Jiangnan; Sunderland, Bob; Xue Jianming; Yan, Sha; Zhao Weijiang; Folkard, Melvyn; Michael, Barry D.; Wang Yugang

    2006-01-01

    Surface properties of polycarbonate (PC), polypropylene (PP), polyethylene terephthalate (PET) samples treated by microwave-induced argon plasma have been studied with contact angle measurement, X-ray photoelectron spectroscopy (XPS) and scanned electron microscopy (SEM). It is found that plasma treatment modified the surfaces both in composition and roughness. Modification of composition makes polymer surfaces tend to be highly hydrophilic, which mainly depended on the increase of ratio of oxygen-containing group as same as other papers reported. And this experiment further revealed that C=O bond is Key factor to the improvement of the hydrophilicity of polymer surfaces. Our SEM observation on PET shown that the roughness of the surface has also been improved in micron scale and it has influence on the surface hydrophilicity

  19. Time-resolved resonance fluorescence spectroscopy for study of chemical reactions in laser-induced plasmas.

    Science.gov (United States)

    Liu, Lei; Deng, Leimin; Fan, Lisha; Huang, Xi; Lu, Yao; Shen, Xiaokang; Jiang, Lan; Silvain, Jean-François; Lu, Yongfeng

    2017-10-30

    Identification of chemical intermediates and study of chemical reaction pathways and mechanisms in laser-induced plasmas are important for laser-ablated applications. Laser-induced breakdown spectroscopy (LIBS), as a promising spectroscopic technique, is efficient for elemental analyses but can only provide limited information about chemical products in laser-induced plasmas. In this work, time-resolved resonance fluorescence spectroscopy was studied as a promising tool for the study of chemical reactions in laser-induced plasmas. Resonance fluorescence excitation of diatomic aluminum monoxide (AlO) and triatomic dialuminum monoxide (Al 2 O) was used to identify these chemical intermediates. Time-resolved fluorescence spectra of AlO and Al 2 O were used to observe the temporal evolution in laser-induced Al plasmas and to study their formation in the Al-O 2 chemistry in air.

  20. Helium atmospheric pressure plasma jets touching dielectric and metal surfaces

    Science.gov (United States)

    Norberg, Seth A.; Johnsen, Eric; Kushner, Mark J.

    2015-07-01

    Atmospheric pressure plasma jets (APPJs) are being investigated in the context plasma medicine and biotechnology applications, and surface functionalization. The composition of the surface being treated ranges from plastics, liquids, and biological tissue, to metals. The dielectric constant of these materials ranges from as low as 1.5 for plastics to near 80 for liquids, and essentially infinite for metals. The electrical properties of the surface are not independent variables as the permittivity of the material being treated has an effect on the dynamics of the incident APPJ. In this paper, results are discussed from a computational investigation of the interaction of an APPJ incident onto materials of varying permittivity, and their impact on the discharge dynamics of the plasma jet. The computer model used in this investigation solves Poisson's equation, transport equations for charged and neutral species, the electron energy equation, and the Navier-Stokes equations for the neutral gas flow. The APPJ is sustained in He/O2 = 99.8/0.2 flowing into humid air, and is directed onto dielectric surfaces in contact with ground with dielectric constants ranging from 2 to 80, and a grounded metal surface. Low values of relative permittivity encourage propagation of the electric field into the treated material and formation and propagation of a surface ionization wave. High values of relative permittivity promote the restrike of the ionization wave and the formation of a conduction channel between the plasma discharge and the treated surface. The distribution of space charge surrounding the APPJ is discussed.

  1. Quantification of air plasma chemistry for surface disinfection

    Science.gov (United States)

    Pavlovich, Matthew J.; Clark, Douglas S.; Graves, David B.

    2014-12-01

    Atmospheric-pressure air plasmas, created by a variety of discharges, are promising sources of reactive species for the emerging field of plasma biotechnology because of their convenience and ability to operate at ambient conditions. One biological application of ambient-air plasma is microbial disinfection, and the ability of air plasmas to decontaminate both solid surfaces and liquid volumes has been thoroughly established in the literature. However, the mechanism of disinfection and which reactive species most strongly correlate with antimicrobial effects are still not well understood. We describe quantitative gas-phase measurements of plasma chemistry via infrared spectroscopy in confined volumes, focusing on air plasma generated via surface micro-discharge (SMD). Previously, it has been shown that gaseous chemistry is highly sensitive to operating conditions, and the measurements we describe here extend those findings. We quantify the gaseous concentrations of ozone (O3) and nitrogen oxides (NO and NO2, or NOx) throughout the established ‘regimes’ for SMD air plasma chemistry: the low-power, ozone-dominated mode; the high-power, nitrogen oxides-dominated mode; and the intermediate, unstable transition region. The results presented here are in good agreement with previously published experimental studies of aqueous chemistry and parameterized models of gaseous chemistry. The principal finding of the present study is the correlation of bacterial inactivation on dry surfaces with gaseous chemistry across these time and power regimes. Bacterial decontamination is most effective in ‘NOx mode’ and less effective in ‘ozone mode’, with the weakest antibacterial effects in the transition region. Our results underscore the dynamic nature of air plasma chemistry and the importance of careful chemical characterization of plasma devices intended for biological applications.

  2. Shape of the Hα emission line in non resonant charge exchange in hydrogen plasmas

    International Nuclear Information System (INIS)

    Susino Bueno, A.; Zurro Hernandez, B.

    1977-01-01

    The Hα line shape emitted from a maxwellian hydrogen plasma and produced by non resonant change exchange has been calculated. Its explicit shape depends on the ion temperature, on background neutral energy and on the relative shape of the collision cross section. A comparison between theoretical and experimental shapes of the Hα line is carried out to check the model and to deduce the ion plasma temperature. (author) [es

  3. Detection of Carcinoembryonic Antigens Using a Surface Plasmon Resonance Biosensor

    Science.gov (United States)

    Su, Fengyu; Xu, Chunye; Taya, Minoru; Murayama, Kimie; Shinohara, Yasuro; Nishimura, Shin-Ichiro

    2008-01-01

    Carcinoembryonic antigen (CEA) is an oncofoetal cell-surface glycoprotein that serves as an important tumor marker for colorectal and some other carcinomas. In this work, a CEA immunoassay using a surface plasmon resonance (SPR) biosensor has been developed. SPR could provide label-free, real-time detection with high sensitivity, though its ability to detect CEA in human serum was highly dependent on the analytical conditions employed. We investigated the influences of various analytical conditions including immobilization methods for anti-CEA antibody and composition of sensor surface on the selective and sensitive detection of CEA. The results show that anti-CEA antibody immobilized via Protein A or Protein G caused a large increase in the resonance signal upon injection of human serum due to the interactions with IgGs in serum, while direct covalent immobilization of anti-CEA antibody could substantially reduce it. An optimized protocol based on further kinetic analysis and the use of 2nd and 3rd antibodies for the sandwich assay allowed detecting spiked CEA in human serum as low as 25 ng/mL. Furthermore, a self-assembled monolayer of mixed ethylene-glycol terminated alkanethiols on gold was found to have a comparable ability in detecting CEA as CM5 with thick dextran matrix and C1 with short flat layer on gold. PMID:27879935

  4. Nanostructure-enhanced surface plasmon resonance imaging (Conference Presentation)

    Science.gov (United States)

    Špašková, Barbora; Lynn, Nicholas S.; Slabý, Jiří Bocková, Markéta; Homola, Jiří

    2017-06-01

    There remains a need for the multiplexed detection of biomolecules at extremely low concentrations in fields of medical diagnostics, food safety, and security. Surface plasmon resonance imaging is an established biosensing approach in which the measurement of the intensity of light across a sensor chip is correlated with the amount of target biomolecules captured by the respective areas on the chip. In this work, we present a new approach for this method allowing for enhanced bioanalytical performance via the introduction of nanostructured sensing chip and polarization contrast measurement, which enable the exploitation of both amplitude and phase properties of plasmonic resonances on the nanostructures. Here we will discuss a complex theoretical analysis of the sensor performance, whereby we investigate aspects related to both the optical performance as well as the transport of the analyte molecules to the functionalized surfaces. This analysis accounts for the geometrical parameters of the nanostructured sensing surface, the properties of functional coatings, and parameters related to the detection assay. Based on the results of the theoretical analysis, we fabricated sensing chips comprised of arrays of gold nanoparticles (by electron-beam lithography), which were modified by a biofunctional coating to allow for the selective capturing of the target biomolecules in the regions with high sensitivity. In addition, we developed a compact optical reader with an integrated microfluidic cell, allowing for the measurement from 50 independent sensing channels. The performance of this biosensor is demonstrated through the sensitive detection of short oligonucleotides down to the low picomolar level.

  5. Characteristics of electron cyclotron resonance plasma formed by ...

    Indian Academy of Sciences (India)

    channel ADITYA LHCD system at reduced toroidal magnetic field, enabling the use of LHCD system as ECR wave ... the ECR experiments on this machine, the 3.7 GHz, 8-channel, LHCD system [24] is used at a toroidal magnetic ..... Experiments would be tried out with improved feedback controls to elongate the plasma ...

  6. Characteristics of electron cyclotron resonance plasma formed by ...

    Indian Academy of Sciences (India)

    single waveguide launching system, used in earlier tokamaks. Thus in this paper, we have characterized the ECR-formed plasma using ADITYA LHCD system at a reduced toroidal magnetic field. Hydrogen .... electronic charge, ρe is the electron Larmour radius and vth is the electron thermal velocity. For our experimental ...

  7. Phase mixing and surface wave decay in an inhomogeneous plasma

    International Nuclear Information System (INIS)

    Cally, P.S.; Sedlacek, Z.

    1992-02-01

    The decay rate is calculated of an Alfven or plasma surface wave propagating along an inhomogeneous layer of plasma. The inhomogeneous profile is thin and odd, but otherwise arbitrary. The wave's decay rate is determined using two fundamentally different methods, the integral-differential equation approach of Sedlacek and the Fourier expansion technique of Cally, and found by both to depend only on the slope of the Alfven or plasma frequency profile at the r esonant point , and not on other details of its shape. The result is verified numerically. This problem represents a good example with which to compare and contrast the two methods. (author) 3 figs., 7 refs

  8. Surface plasmon resonance for detecting clenbuterol: Influence of monolayer structure

    Science.gov (United States)

    Suherman; Morita, Kinichi; Kawaguchi, Toshikazu

    2015-03-01

    Surface plasmon resonance sensor equipped with a fabricated immunosensor chip is used for detecting clenbuterol in this study. Since clenbuterol is a small analyte, indirect competitive inhibition immunoassay is employed. For fabricating the immunosurface, the Au-chip was functionalized by succinimidyl-terminated alkanethiol, and the terminal N-hydroxysuccinimide group of the self-assembled monolayer was either replaced with clenbuterol or blocked with ethanolamine. Scanning tunneling microscope experiments and electrochemical measurements depicted the domain structures of the succinimide group of succinimidyl-terminated propanethiol monolayer. The surface concentration and the orientation of succinimide group was significantly dependent on the concentration of dithiobis(succinimidyl) propionate (DSP) used in fabricating the monolayer. Furthermore, the structure of monolayer significantly influenced both the surface concentration and the orientation of clenbuterol on the sensor surface. Consequently, high coverage and standing-up configuration of clenbuterol showed high affinity for clenbuterol antibody. However, high affinity constant exhibited by the sensor surface was coupled with a low sensitivity. By contrast, lowest concentration of DSP solution (0.1 mM) used in fabricating the immunosurface showed a detection sensitivity of 3 ppt - the highest reported sensitivity for clenbuterol. For regeneration the immunosurface, 0.1 M NaOH was used and the same sensor surface could be reused for performing >100 rapid immunoreaction.

  9. Gold split-ring resonators (SRRs) as substrates for surface-enhanced raman scattering

    KAUST Repository

    Yue, Weisheng

    2013-10-24

    We used gold split ring resonators (SRRs) as substrates for surface-enhanced Raman scattering (SERS). The arrays of SRRs were fabricated by electron-beam lithography in combination with plasma etching. In the detection of rhodamine 6G (R6G) molecules, SERS enhancement factors of the order of 105 was achieved. This SERS enhancement increased as the size of the split gap decrease as a consequence of the matching between the resonance wavelength of the SRRs and the excitation wavelength of SERS. As the size of the split gap decreased, the localized surface plasmon resonance shifted to near the excitation wavelength and, thus, resulted in the increase in the electric field on the nanostructures. We used finite integration method (FIT) to simulate numerically the electromagnetic properties of the SRRs. The results of the simulation agreed well with our experimental observations. We anticipate this work will provide an approach to manipulate the SERS enhancement by modulating the size of split gap with SRRs without affecting the area and structural arrangement. © 2013 American Chemical Society.

  10. Surface plasmon resonance biosensor based on integrated optical waveguide

    Czech Academy of Sciences Publication Activity Database

    Dostálek, Jakub; Čtyroký, Jiří; Homola, Jiří; Brynda, Eduard; Skalský, Miroslav; Nekvindová, P.; Špirková, J.; Škvor, J.; Schröfel, J.

    2001-01-01

    Roč. 76, 1/3 (2001), s. 8-12 ISSN 0925-4005. [International Meeting on Chemical Sensors IMCS /8./. Basel, 02.07.2000-05.07.2000] R&D Projects: GA ČR GA102/99/M057; GA ČR GA102/99/0549; GA ČR GA102/00/1536 Institutional research plan: CEZ:AV0Z2067918 Keywords : surface plasmon resonance * optical sensors * integrated optics * biosensors * optical waveguides Subject RIV: JB - Sensors, Measurment, Regulation Impact factor: 1.440, year: 2001

  11. Focusing of Intense Laser via Parabolic Plasma Concave Surface

    Science.gov (United States)

    Zhou, Weimin; Gu, Yuqiu; Wu, Fengjuan; Zhang, Zhimeng; Shan, Lianqiang; Cao, Leifeng; Zhang, Baohan

    2015-12-01

    Since laser intensity plays an important role in laser plasma interactions, a method of increasing laser intensity - focusing of an intense laser via a parabolic plasma concave surface - is proposed and investigated by three-dimensional particle-in-cell simulations. The geometric focusing via a parabolic concave surface and the temporal compression of high harmonics increased the peak intensity of the laser pulse by about two orders of magnitude. Compared with the improvement via laser optics approaches, this scheme is much more economic and appropriate for most femtosecond laser facilities. supported by National Natural Science Foundation of China (Nos. 11174259, 11175165), and the Dual Hundred Foundation of China Academy of Engineering Physics

  12. Surface tension in plasmas related to double layer formation

    Energy Technology Data Exchange (ETDEWEB)

    Popescu, Sebastian; Lozneanu, Erzilia [Al. I. Cuza University, Dept. of Plasma Physics, Iasi (Romania)

    2001-07-01

    Self-organized space charge configurations bordered by electric double layers appear in plasma as the result of the transition into a state characterized by local minimum of the free energy. Considering the self-assemblage process of such a complex well-confined space-charge configuration in plasma, known by the name of ball of fire, as a nucleation process, it becomes possible to define an equivalent surface tension for the double layer that covers the core of the ball of fire and to make some predictions for its surface tension coefficient and capacitance. (author)

  13. Fullerene-rare gas mixed plasmas in an electron cyclotron resonance ion source.

    Science.gov (United States)

    Asaji, T; Ohba, T; Uchida, T; Minezaki, H; Ishihara, S; Racz, R; Muramatsu, M; Biri, S; Kitagawa, A; Kato, Y; Yoshida, Y

    2014-02-01

    A synthesis technology of endohedral fullerenes such as Fe@C60 has developed with an electron cyclotron resonance (ECR) ion source. The production of N@C60 was reported. However, the yield was quite low, since most fullerene molecules were broken in the ECR plasma. We have adopted gas-mixing techniques in order to cool the plasma and then reduce fullerene dissociation. Mass spectra of ion beams extracted from fullerene-He, Ar or Xe mixed plasmas were observed with a Faraday cup. From the results, the He gas mixing technique is effective against fullerene destruction.

  14. Dry cleaning of fluorocarbon residues by low-power electron cyclotron resonance hydrogen plasma

    CERN Document Server

    Lim, S H; Yuh, H K; Yoon Eui Joon; Lee, S I

    1988-01-01

    A low-power ( 50 W) electron cyclotron resonance hydrogen plasma cleaning process was demonstrated for the removal of fluorocarbon residue layers formed by reactive ion etching of silicon dioxide. The absence of residue layers was confirmed by in-situ reflection high energy electron diffraction and cross-sectional high resolution transmission electron microscopy. The ECR hydrogen plasma cleaning was applied to contact cleaning of a contact string structure, resulting in comparable contact resistance arising during by a conventional contact cleaning procedure. Ion-assisted chemical reaction involving reactive atomic hydrogen species generated in the plasma is attributed for the removal of fluorocarbon residue layers.

  15. PISCES program plasma-surface interactions research

    International Nuclear Information System (INIS)

    1989-05-01

    This paper discusses the following about the Pisces program: Major objectives of the program; Staff in the PISCES program at UCLA; Highlights in the program; Collaborations with other institutions; PISCES-A facility; PISCES-B facility; Fast scanning Langmuir probe; Omegatron mass spectrometer; Spectroscopic diagnostics; Data acquisition system; Redeposition effect on carbon chemical erosion; Erosion of carbon tokamakium from TFTR; Effect of boron-doping on carbon chemical erosion; Radiation enhanced sublimation of carbon; Surface analysis of TEXTOR titles; Spectroscopic analysis of carbon impurities; Biased limiter and divertor; Biased divertor channel; Gaseous divertor experiments; Presheath profile measurements; Particle transport in CCT tokamak; and Biased divertor experiments in CCT

  16. Effect of anisotropic thermal transport on the resistive plasma response to resonant magnetic perturbation field

    Science.gov (United States)

    Bai, Xue; Liu, Yueqiang; Gao, Zhe

    2017-10-01

    Plasma response to the resonant magnetic perturbation (RMP) field is numerically investigated by an extended toroidal fluid model, which includes anisotropic thermal transport physics parallel and perpendicular to the total magnetic field. The thermal transport is found to be effective in eliminating the toroidal average curvature induced plasma screening (the so called Glasser-Green-Johnson, GGJ screening) in a slow toroidal flow regime, whilst having minor effect on modifying the conventional plasma screening regimes at faster flow. This physics effect of interaction between thermal transport and GGJ screening is attributed to the modification of the radial structure of the shielding current, which resulted from the plasma response to the applied field. The modification of the plasma response (shielding current, response field, plasma displacement, and the perturbed velocity) also has direct consequence on the toroidal torques produced by RMP. Modelling results show that thermal transport reduces the resonant electromagnetic torque as well as the torque associated with the Reynolds stress, but enhances the neoclassical toroidal viscous torque at slow plasma flow.

  17. Production and testing of an s-band resonator with a Nb3Sn surface

    International Nuclear Information System (INIS)

    Peiniger, M.

    1983-01-01

    This report describes the preparation of a niobium s-band resonator with Nb3Sn surface using a special vapor phase deposition method. High-frequency superconductivity tests were performed on this resonator. Measurements of transition temperature, penetration depth, energy gap, and temperature dependence of surface conductivity of Nb3Sn, and resonator behaviour at high electrical field strengths are reported. (GSCH)

  18. Resonant soft x-ray scattering from stepped surfaces of SrTiO3

    NARCIS (Netherlands)

    Schlappa, J.; Chang, C.F.; Hu, Z.; Schierle, E.; Ott, H.; Weschke, E.; Kaindl, G.; Huijben, Mark; Rijnders, Augustinus J.H.M.; Blank, David H.A.; Tjeng, L.H.; Schüssler-Langeheine, C.

    2012-01-01

    We studied the resonant diffraction signal from stepped surfaces of SrTiO3 at the Ti 2p ¿ 3d (L2,3) resonance in comparison with x-ray absorption (XAS) and specular reflectivity data. The steps on the surface form an artificial superstructure suitable as a model system for resonant soft x-ray

  19. Novel Chiroptical Analysis of Hemoglobin by Surface Enhanced Resonance Raman Optical Activity Spectroscopy

    DEFF Research Database (Denmark)

    Brazhe, Nadezda; Brazhe, Alexey; Sosnovtseva, Olga

    2010-01-01

    The metalloprotein hemoglobin (Hb) was studied using surface enhanced resonance Raman spectroscopy (SERRS) and surface enhanced resonance Raman optical activity (SERROA). The SERROA results are analyzed and compared with the SERRS, and the later to the resonance Raman (RRS) performed on Hb...

  20. Compact Surface Plasmon Resonance Biosensor for Fieldwork Environmental Detection

    Science.gov (United States)

    Boyd, Margrethe; Drake, Madison; Stipe, Kristian; Serban, Monica; Turner, Ivana; Thomas, Aaron; Macaluso, David

    2017-04-01

    The ability to accurately and reliably detect biomolecular targets is important in innumerable applications, including the identification of food-borne parasites, viral pathogens in human tissue, and environmental pollutants. While detection methods do exist, they are typically slow, expensive, and restricted to laboratory use. The method of surface plasmon resonance based biosensing offers a unique opportunity to characterize molecular targets while avoiding these constraints. By incorporating a plasmon-supporting gold film within a prism/laser optical system, it is possible to reliably detect and quantify the presence of specific biomolecules of interest in real time. This detection is accomplished by observing shifts in plasmon formation energies corresponding to optical absorption due to changes in index of refraction near the gold-prism interface caused by the binding of target molecules. A compact, inexpensive, battery-powered surface plasmon resonance biosensor based on this method is being developed at the University of Montana to detect waterborne pollutants in field-based environmental research.

  1. Systematic screening of viral entry inhibitors using surface plasmon resonance.

    Science.gov (United States)

    Kumar, Penmetcha K R

    2017-11-01

    Viral binding and entry into host cells for various viruses have been studied extensively, yielding a detailed understanding of the overall viral entry process. As cell entry is an essential and requisite process by which a virus initiates infection, it is an attractive target for therapeutic intervention. The advantages of targeting viral entry are an extracellular target site, relatively easy access for biological interventions, and lower toxicity. Several cell-based strategies and biophysical techniques have been used to screen compounds that block viral entry. These studies led to the discovery of inhibitors against HIV, HCV, influenza, Ebola, and RSV. In recent years, several compounds screened by fragment-based drug discovery have been approved as drugs or are in the final stages of clinical trials. Among fragment screening technologies, surface plasmon resonance has been widely used because it provides accurate information on binding kinetics, allows real-time monitoring of ligand-drug interactions, requires very small sample amounts to perform analyses, and requires no modifications to or labeling of ligands. This review focuses on surface plasmon resonance-based schemes for screening viral entry inhibitors. Copyright © 2017 John Wiley & Sons, Ltd.

  2. Nano Sensing and Energy Conversion Using Surface Plasmon Resonance (SPR

    Directory of Open Access Journals (Sweden)

    Iltai (Isaac Kim

    2015-07-01

    Full Text Available Nanophotonic technique has been attracting much attention in applications of nano-bio-chemical sensing and energy conversion of solar energy harvesting and enhanced energy transfer. One approach for nano-bio-chemical sensing is surface plasmon resonance (SPR imaging, which can detect the material properties, such as density, ion concentration, temperature, and effective refractive index in high sensitivity, label-free, and real-time under ambient conditions. Recent study shows that SPR can successfully detect the concentration variation of nanofluids during evaporation-induced self-assembly process. Spoof surface plasmon resonance based on multilayer metallo-dielectric hyperbolic metamaterials demonstrate SPR dispersion control, which can be combined with SPR imaging, to characterize high refractive index materials because of its exotic optical properties. Furthermore, nano-biophotonics could enable innovative energy conversion such as the increase of absorption and emission efficiency and the perfect absorption. Localized SPR using metal nanoparticles show highly enhanced absorption in solar energy harvesting. Three-dimensional hyperbolic metamaterial cavity nanostructure shows enhanced spontaneous emission. Recently ultrathin film perfect absorber is demonstrated with the film thickness is as low as ~1/50th of the operating wavelength using epsilon-near-zero (ENZ phenomena at the wavelength close to SPR. It is expected to provide a breakthrough in sensing and energy conversion applications using the exotic optical properties based on the nanophotonic technique.

  3. Electron paramagnetic resonance spectra of lithium-6 deuteride exposed to ultraviolet radiation and gas discharge plasma

    International Nuclear Information System (INIS)

    Bunyatova, E.I.; Bubnov, N.N.; Solodovnikov, S.P.

    1992-01-01

    Electron paramagnetic resonance spectra of Li 6 D exposed to ultraviolet (UV) radiation and gas discharge plasma are investigated. A possibility of F center formation in 6 LiD crystals exposed to UV irradiation and gas discharged is shown. 8 refs.; 2 figs

  4. Resonant RF network antennas for large-area and large-volume inductively coupled plasma sources

    International Nuclear Information System (INIS)

    Hollenstein, Ch; Howling, A A; Guittienne, Ph

    2013-01-01

    Large-area and large-volume radio frequency (RF) plasmas are produced by different arrangements of an elementary electrical mesh consisting of two conductors interconnected by a capacitor at each end. The obtained cylindrical and planar RF networks are resonant and generate very high RF currents. The input impedance of such RF networks shows the behaviour of an RLC parallel resonance equivalent circuit. The real impedance at the resonance frequency is of great advantage for power matching compared with conventional inductive devices. Changes in the RLC equivalent circuit during the observed E–H transition will allow future interpretation of the plasma–antenna coupling. Furthermore, high power transfer efficiencies are found during inductively coupled plasma (ICP) operation. For the planar RF antenna network it is shown that the E–H transition occurs simultaneously over the entire antenna. The underlying physics of these discharges induced by the resonant RF network antenna is found to be identical to that of the conventional ICP devices described in the literature. The resonant RF network antenna is a new versatile plasma source, which can be adapted to applications in industry and research. (paper)

  5. Plasma functionalized surface of commodity polymers for dopamine detection

    Energy Technology Data Exchange (ETDEWEB)

    Fabregat, Georgina [Departament d’Enginyeria Química, E.T.S. d’Enginyeria Industrial de Barcelona, Universitat Politècnica de Catalunya, Diagonal 647, 08028, Barcelona (Spain); Center for Research in Nano-Engineering, Universitat Politècnica de Catalunya, Campus Sud, Edifici C’, C/Pasqual i Vila s/n, Barcelona, E-08028 (Spain); Osorio, Joaquin [Departament d’Enginyeria Química, E.T.S. d’Enginyeria Industrial de Barcelona, Universitat Politècnica de Catalunya, Diagonal 647, 08028, Barcelona (Spain); Castedo, Alejandra [Center for Research in Nano-Engineering, Universitat Politècnica de Catalunya, Campus Sud, Edifici C’, C/Pasqual i Vila s/n, Barcelona, E-08028 (Spain); Institut de Tècniques Energètiques, E.T.S. d’Enginyeria Industrial de Barcelona, Universitat Politècnica de Catalunya, Diagonal 647, 08028, Barcelona (Spain); Armelin, Elaine [Departament d’Enginyeria Química, E.T.S. d’Enginyeria Industrial de Barcelona, Universitat Politècnica de Catalunya, Diagonal 647, 08028, Barcelona (Spain); Center for Research in Nano-Engineering, Universitat Politècnica de Catalunya, Campus Sud, Edifici C’, C/Pasqual i Vila s/n, Barcelona, E-08028 (Spain); and others

    2017-03-31

    Highlights: • Electrochemically inert polymers become electroactive after plasma functionalization. • Selective dopamine detection has been achieved functionalizing polymers with plasma. • Plasma-functionalized polymers are sensitive dopamine detectors. • XPS analyses reflect the transformation of inert polymers into electrosensors. - Abstract: We have fabricated potentially generalizable sensors based on polymeric-modified electrodes for the electrochemical detection of dopamine. Sensitive and selective sensors have been successfully obtained by applying a cold-plasma treatment during 1–2 min not only to conducting polymers but also to electrochemically inert polymers, such as polyethylene, polypropylene, polyvinylpyrrolidone, polycaprolactone and polystyrene. The effects of the plasma in the electrode surface activation, which is an essential requirement for the dopamine detection when inert polymers are used, have been investigated using X-ray photoelectron spectroscopy. Results indicate that exposure of polymer-modified electrodes to cold-plasma produces the formation of a large variety of reactive species adsorbed on the electrode surface, which catalyse the dopamine oxidation. With this technology, which is based on the application of a very simple physical functionalization, we have defined a paradox-based paradigm for the fabrication of electrochemical sensors by using inert and cheap plastics.

  6. Plasma surface interactions in Q-enhanced mirror systems

    International Nuclear Information System (INIS)

    Post, R.F.

    1978-01-01

    Two approaches to enhancement of the Q (energy gain) factor of mirror systems are under study at Livermore. These include the Tandem Mirror and the Field Reversed Mirror. Both of these new ideas preserve features of conventional mirror systems as far as plasma-wall interactions are concerned. Specifically in both approaches field lines exit from the ends of the system and impinge on walls located at a distance from the confinement chamber. It is possible to predict some aspects of the plasma/surface interactions of TM and FRM systems from experience obtained in the Livermore 2XIIB experiment. In particular, as observed in 2XIIB, effective isolation of the plasma from thermal contact with the ends owing to the development of sheath-like regions is to be expected. Studies presently underway directed toward still further enhancing the decoupling of the plasma from the effects of plasma surface interactions at the walls will be discussed, with particular reference to the problem of minimizing the effects of refluxing secondary electrons produced by plasma impact on the end walls

  7. Hydrophilic Surface Modification of PDMS Using Atmospheric RF Plasma

    International Nuclear Information System (INIS)

    Hong, Sung M; Kim, Seong H; Kim, Jeong H; Hwang, Hak I

    2006-01-01

    Control of surface properties in microfluidics systems is an indispensable prerequisite for the success of bioanalytical applications. Poly(dimethylsiloxane) (PDMS) microfluidic devices are hampered from unwanted adsorption of biomolecules and the lack of methods to control electroosmotic flow(EOF). Among the various methods of hydrophilic treatment, a new cleaner technology was chosen to treat PDMS. By using atmospheric RF plasma, hydrophilic surfaces can be created. Thus, analysis was conducted with AFM, XPS, and contact angle before and after plasma treatment. Constructing hydrophilic surfaces without changing the true character of that surface has previously been costly and time consuming. But by using atmospheric plasma cost and time are both greatly reduced. There are many other benefits of hydrophilic surface treatment, including the capability to increase adhesion and capillary effects, etc. Also, with hydrophilic treatment of the micro channels on the PDMS surface, surface tension is reduced thus allowing fluids to move easily along those channels. However, the most important aim is to increase the capillary effects without any deposition or chemical treatment

  8. Control of surface composition and hydrogen recycling by plasma conditioning

    International Nuclear Information System (INIS)

    Clausing, R.E.; Heatherly, L.

    1984-01-01

    Data from a laboratory simulator, TEXTOR, JET, and other tokamaks are used to show that oxygen and carbon surface impurities on the walls of plasma chambers are interrelated and can be manipulated by controlling the composition of the gas used for plasma surface conditioning. Not only can oxygen be reduced to low levels, but carbon (and other elements) can be either removed or deposited and reacted with the substrate. In the case of carbon deposits, a thin metal-carbide layer can be formed or thicker deposits of elemental carbon can be made. Surface compositions can be reproduced easily and reversibly in a controlled way. Furthermore, these composition changes can alter the hydrogen recycling speed and plasma impurity levels by an order of magnitude or more. In the simulator we have related gas composition to surface composition changes and resulting recycling behavior. Surface oxygen levels can be reduced from 30 to less than 3 at.% in less than 45 min of discharge cleaning. Carbon and oxygen levels as well as those of other surface active impurities are interrelated. Examples are shown and discussed. Comparisons are made to show the changes in the hydrogen recycling behavior caused by various surface preparations (compositions). (orig.)

  9. Lunar electric fields, surface potential and associated plasma sheaths

    Science.gov (United States)

    Freeman, J. W.; Ibrahim, M.

    1975-01-01

    A review is given of studies of the electric-field environment of the moon. Surface electric potentials are reported for the dayside and terminator regions, electron and ion densities in the plasma sheath adjacent to each surface-potential regime are evaluated, and the corresponding Debye lengths are estimated. The electric fields, which are approximated by the surface potential over the Debye length, are shown to be at least three orders of magnitude higher than the pervasive solar-wind electric field and to be confined to within a few tens of meters of the lunar surface.

  10. Electron cyclotron resonance plasma reactor for production of carbon stripper foil

    Science.gov (United States)

    Faith Romero, Camille; Kanamori, Keita; Kinsho, Michikazu; Yoshimoto, Masahiro; Wada, Motoi

    2018-01-01

    A graphite antenna for the production of carbon-containing hydrogen plasmas is being developed to prepare impurity-free charge exchange foils for high-energy synchrotrons. Microwave power at 2.45 GHz frequency drives a coaxial structure antenna with a 12-mm-diameter central graphite cylinder and a tapered surrounding cylinder serving as the ground electrode. The antenna was placed in a linear magnetic field to investigate how it performs under an electron cyclotron resonance (ECR) condition. A clear resonance phenomenon was observed in plasma luminosity, microwave power absorption, and microwave power reflection when the induction current used to produce a linear magnetic field was changed. The antenna realized the best microwave coupling to the plasma with the ECR zone formed 5 mm from the end of the center electrode. The antenna realized stable operation for more than 5 h with 100 W input microwave power and with operating hydrogen pressure from 0.5 to 50 Pa.

  11. Self-resonant wakefield excitation by intense laser pulse in plasmas

    International Nuclear Information System (INIS)

    Andreev, N.E.; Pogosova, A.A.; Gorbunov, L.M.; Ramazashvili, R.R.; Kirsanov, V.I.

    1993-01-01

    It is demonstrated by theoretical analysis and numerical calculations that in an underdense plasma the process of three-dimensional evolution of the short and strong laser pulse (with duration equal to several plasma periods) leads to compression and self-modulation of the pulse, so that during a fairly long period of time beats of pulse amplitude generates resonantly a strong and stable plasma wakefield. The intensity of the wake-field is so high that it can provide a new promising outlook for the plasma based accelerator concept. Linear analysis of dispersion relation predicts that taking into account transverse component of wavenumber considerably increases the growth rate of resonance instability of the pulse. The numerical simulations demonstrate that considered self-focusing and resonant-modulation instability are essentially three dimensional processes. Laser field evolution in each transverse cross section of the pulse is synchronized by the regular structure of plasma wave that is excited by the pulse. The considered effect of resonant modulation has a threshold. For the pulses with the intensity below the threshold the refraction dominates and no modulation appears. The studied phenomenon can be referred to as the Self-Resonant Wakefield (SRWF) excitation that is driven by self-focusing and self-modulation of laser pulse with quite a moderate initial duration. In fact, this method of excitation differs from both suggested in Ref.1 (PBWA) and in Refs.2,3 (LWFA), being even more than the combination of these concepts. Unlike the first scheme it does not require initially the two-frequency laser pulse, since the modulation here appears in the most natural way due to evolution of the pulse. In contrast with the LWFA, the considered SRWF generation scheme gives the possibility to raise the intensity of wake-excitation due to pulse self-focusing ( initial stage) and self modulation (second stage)

  12. Response of plasma rotation to resonant magnetic perturbations in J-TEXT tokamak

    Science.gov (United States)

    Yan, W.; Chen, Z. Y.; Huang, D. W.; Hu, Q. M.; Shi, Y. J.; Ding, Y. H.; Cheng, Z. F.; Yang, Z. J.; Pan, X. M.; Lee, S. G.; Tong, R. H.; Wei, Y. N.; Dong, Y. B.; J-TEXT Team

    2018-03-01

    The response of plasma toroidal rotation to the external resonant magnetic perturbations (RMP) has been investigated in Joint Texas Experimental Tokamak (J-TEXT) ohmic heating plasmas. For the J-TEXT’s plasmas without the application of RMP, the core toroidal rotation is in the counter-current direction while the edge rotation is near zero or slightly in the co-current direction. Both static RMP experiments and rotating RMP experiments have been applied to investigate the plasma toroidal rotation. The core toroidal rotation decreases to lower level with static RMP. At the same time, the edge rotation can spin to more than 20 km s‑1 in co-current direction. On the other hand, the core plasma rotation can be slowed down or be accelerated with the rotating RMP. When the rotating RMP frequency is higher than mode frequency, the plasma rotation can be accelerated to the rotating RMP frequency. The plasma confinement is improved with high frequency rotating RMP. The plasma rotation is decelerated to the rotating RMP frequency when the rotating RMP frequency is lower than the mode frequency. The plasma confinement also degrades with low frequency rotating RMP.

  13. Surface impedance of travelling--Wave antenna in magnetized plasma

    International Nuclear Information System (INIS)

    Denisenko, I.B.; Ostrikov, K.N.

    1993-01-01

    Wave properties of metal antennas immersed in a magnetoactive plasma are intensively studied nowadays with the objects of radio communications in ionosphere, plasma heating, gas discharge technique. Many papers are devoted to studies of sheath waves (SW) in magnetoplasma, which are surface by nature and propagate along the metal-low-density sheath-plasma waveguide structure. The results of these papers suggest that the existence of these waves makes significant contribution in antenna impedance. Note that the impedance measurement is one of possible ways of experimental surface waves characterization. In the present report the surface impedance of travelling SW antenna immersed in magnetoactive plasma is calculated and its dependence on the waveguide structure parameters such as plasma density, external magnetic field H 0 and electrons collisional frequency values, sheath region width, conductivity of metal surface is studied. The calculations have been carried out in a quasiplane approximation, when antenna radius greatly exceeds the SW skin depth. Note that the finite conductivity of metal is necessary to be taken into account to provide a finite surface impedance value. The surface impedance is calculated in two cases, namely when SW propagate along (Ζ parallel ) and across (Ζ perpendicular ) the external magnetic field. The relation between the values Ζ parallel and Ζ perpendicular is obtained. This relation shows that the values Ζ parallel and Ζ parallel may satisfy both inequalities Ζ parallel much-gt Ζ perpendicular and Ζ perpendicular approx-gt Ζ perpendicular dependent on the parameters of the structure. The comparison of dispersion properties of the SW propagating along Η 0 with the experimental results is carried out. The results are shown to satisfactorily correspond to the experimental results

  14. Surface plasmon oscillations on a quantum plasma half-space

    Energy Technology Data Exchange (ETDEWEB)

    Moradi, Afshin, E-mail: a.moradi@kut.ac.ir [Department of Engineering Physics, Kermanshah University of Technology, Kermanshah (Iran, Islamic Republic of); Department of Nano Sciences, Institute for Studies in Theoretical Physics and Mathematics (IPM), Tehran (Iran, Islamic Republic of)

    2015-01-15

    We investigate the propagation of surface electrostatic oscillations on a quantum plasma half-space, taking into account the quantum effects. We derive the quantum surface wave frequencies of the system, by means the quantum hydrodynamic theory in conjunction with the Poisson equation and applying the appropriate additional quantum boundary conditions. Numerical results show in the presence of the slow nonlocal variations, plasmon wave energies of the system are significantly modified and plasmonic oscillations with blue-shifted frequencies emerge.

  15. Parameters of radiation processes in the microwave resonant plasma

    Science.gov (United States)

    Andreev, V. V.; Voldiner, I. A.; Korneeva, M. A.

    2017-11-01

    This work presents results of experimental studies of the spectral and photometric characteristics of optical radiation generated by a pulse-periodic microwave discharge close to ECR (2.45 GHz, average power of up to 200 W, argon pressure of 10-4-10-1 Torr). Under these conditions, dense ( n e = 1010-4 × 1011 cm-3) low-temperature ( T e = 3-5 eV) plasma is produced in the working volume at an ionization rate of 10-3-5 × 10-5. It is shown that the increase in the electron density near the upper boundary of the pressure range at a constant level of the input power leads to a drastic change in the type and spectral composition of plasma radiation and a jumplike increase in the light flux. The results of probe and optical measurements made it possible to determine the range of the operating parameters defining the character and parameters of the radiation processes under study.

  16. Microcontact imprinted surface plasmon resonance sensor for myoglobin detection

    Energy Technology Data Exchange (ETDEWEB)

    Osman, Bilgen [Uludag University, Department of Chemistry, Bursa (Turkey); Uzun, Lokman [Hacettepe University, Department of Chemistry, Ankara (Turkey); Beşirli, Necati [Uludag University, Department of Chemistry, Bursa (Turkey); Denizli, Adil, E-mail: denizli@hacettepe.edu.tr [Hacettepe University, Department of Chemistry, Ankara (Turkey)

    2013-10-15

    In this study, we prepared surface plasmon resonance (SPR) sensor using the molecular imprinting technique for myoglobin detection in human serum. For this purpose, we synthesized myoglobin imprinted poly(hydroxyethyl methacrylate-N-methacryloyl-L-tryptophan methyl ester) [poly(HEMA-MATrp)] nanofilm on the surface of SPR sensor. We also synthesized non-imprinted poly(HEMA-MATrp) nanofilm without myoglobin for the control experiments. The SPR sensor was characterized with contact angle measurements, atomic force microscopy, X-ray photoelectron spectroscopy, and ellipsometry. We investigated the effectiveness of the sensor using the SPR system. We evaluated the ability of SPR sensor to sense myoglobin with myoglobin solutions (pH 7.4, phosphate buffer) in different concentration range and in the serum taken from a patient with acute myocardial infarction. We found that the Langmuir adsorption model was the most suitable for the sensor system. The detection limit was 87.6 ng/mL. In order to show the selectivity of the SPR sensor, we investigated the competitive detection of myoglobin, lysozyme, cytochrome c and bovine serum albumin. The results showed that the SPR sensor has high selectivity and sensitivity for myoglobin. - Highlights: • Micro-contact imprinted surface plasmon resonance sensor. • Real-time myoglobin detection in the serum taken from a patient with acute myocardial infarction • Reproducible results for consecutive myoglobin solution supplement • LOD and LOQ values of the SPR sensor were determined to be 26.3 and 87.6 ng/mL. • The SPR sensor has potential for myoglobin sensing during acute MI cases.

  17. Surface plasma waves over bismuth–vacuum interface

    Indian Academy of Sciences (India)

    Home; Journals; Pramana – Journal of Physics; Volume 61; Issue 3. Surface plasma waves over bismuth–vacuum interface. Ashim P Jain J Parashar. Brief Report Volume 61 Issue ... Author Affiliations. Ashim P Jain1 J Parashar1. Department of Applied Physics, Samrat Ashok Technological Institute, Vidisha 464 001, India ...

  18. Excitation of surface plasma waves over corrugated slow-wave ...

    Indian Academy of Sciences (India)

    elements in metal waveguides increase the number of their natural modes and give rise to new effects accompanying wave propagation, e.g. excitation of SPW in these waveguides. Such large area surface wave plasma sources have been reported using a microwave launcher of large aperture formed on a waveguide, ...

  19. Surface waves in the partially ionized solar plasma slab

    Science.gov (United States)

    Pandey, B. P.

    2013-12-01

    The properties of surface waves in the partially ionized, incompressible magnetized plasma slab are investigated in the present work. The waves are affected by the non-ideal magnetohydrodynamic (MHD) effects which cause the finite drift of the magnetic field in the medium. When the finite drift of the magnetic field is ignored, the characteristics of the wave propagation in the partially ionized plasma fluid are similar to the ideal MHD, except now the propagation properties depend on the fractional ionization of the medium. In the presence of the Hall diffusion, the propagation of the sausage and kink surface waves depends on the level of fractional ionization of the medium. For example, short wavelength surface modes cannot propagate in the medium if the scale over which Hall operates is comparable to the size of the plasma slab. With the increasing ionization, the surface modes of shorter wavelength are permitted in the system. When both the Hall and Pedersen diffusion are present in the medium, the waves undergo damping. In the case of Pedersen dominating Hall, the damping of the long wavelength fluctuations is dependent on the ratio of the plasma densities inside and outside the slab and on the square of the Pedersen diffusivity. For typical solar parameters, waves may damp over few minutes.

  20. Surface plasma waves over bismuth–vacuum interface

    Indian Academy of Sciences (India)

    electron laser, a fast emerging device of high power coherent radiation. In §2 we derive the dispersion relation for surface plasma waves using a fluid theory. In §3 we study the SPW excitation by an electron beam. A discussion of results is given in §4. 2. SPW propagation. Consider a bismuth (Bi)–free space interface (x = 0) ...

  1. Surface modification of polyethylene by diffuse barrier discharge plasma

    Czech Academy of Sciences Publication Activity Database

    Novák, I.; Števiar, M.; Popelka, A.; Chodák, I.; Mosnáček, J.; Špírková, Milena; Janigová, I.; Kleinová, A.; Sedliačik, J.; Šlouf, Miroslav

    2013-01-01

    Roč. 53, č. 3 (2013), s. 516-523 ISSN 0032-3888 R&D Projects: GA AV ČR(CZ) IAAX08240901 Institutional research plan: CEZ:AV0Z40500505 Keywords : low-density polyethylene * plasma discharge * surface modification Subject RIV: JI - Composite Materials Impact factor: 1.441, year: 2013

  2. Surface plasma waves over bismuth–vacuum interface

    Indian Academy of Sciences (India)

    A surface plasma wave (SPW) over bismuth–vacuum interface has a signature of mass anisotropy of free electrons. For SPW propagation along the trigonal axis there is no birefringence. The frequency cutoff of SPW cutoff= p / 2 ( L + ) lies in the far infrared region and can be accessed using free electron laser.

  3. Surface plasma waves over bismuth–vacuum interface

    Indian Academy of Sciences (India)

    A surface plasma wave (SPW) over bismuth–vacuum interface has a signature of mass anisotropy of free electrons. For SPW propagation along the trigonal axis there is no birefringence. The frequency cutoff of SPW ωcutoff = ωp/. Ô. 2(εL +ε) lies in the far infrared region and can be accessed using free electron laser.

  4. Modulating Protein Adsorption on Oxygen Plasma Modified Polysiloxane Surfaces

    International Nuclear Information System (INIS)

    Marletta, G.

    2006-01-01

    In the present paper we report the study on the adsorption behaviour of three model globular proteins, Human Serum Albumin, Lactoferrin and Egg Chicken Lysozyme onto both unmodified surfaces of a silicon-based polymer and the corresponding plasma treated surfaces. In particular, thin films of hydrophobic polysiloxane (about 90 degree of static water contact angle, WCA) were converted by oxygen plasma treatment at reduced pressure into very hydrophilic phases of SiOx (WCA less than 5 degree). The kinetics of protein adsorption processes were investigated by QCM-D technique, while the chemical structure and topography of the protein adlayer have been studied by Angular resolved-XPS and AFM respectively. It turned out that Albumin and Lysozyme exhibited the opposite preferential adsorption respectively onto the hydrophobic and hydrophilic surfaces, while Lactoferrin did not exhibit significant differences. The observed protein behaviour are discussed both in terms of surface-dependent parameters, including surface free energy and chemical structure, and in terms of protein-dependent parameters, including charge as well as the average molecular orientation in the adlayers. Finally, some examples of differential adsorption behaviour of the investigated proteins are reported onto nanopatterned polysiloxane surfaces consisting of hydrophobic nanopores surrounded by hydrophilic (plasma-treated) matrix and the reverse

  5. Semi-analytical model of laser resonance absorption in plasmas with a parabolic density profile

    International Nuclear Information System (INIS)

    Pestehe, S J; Mohammadnejad, M

    2010-01-01

    Analytical expressions for mode conversion and resonance absorption of electromagnetic waves in inhomogeneous, unmagnetized plasmas are required for laboratory and simulation studies. Although most of the analyses of this problem have concentrated on the linear plasma density profile, there are a few research works that deal with different plasma density profiles including the parabolic profile. Almost none of them could give clear analytical formulae for the electric and magnetic components of the electromagnetic field propagating through inhomogeneous plasmas. In this paper, we have considered the resonant absorption of laser light near the critical density of plasmas with parabolic electron density profiles followed by a uniform over-dense region and have obtained expressions for the electric and magnetic vectors of laser light propagating through the plasma. An estimation of the fractional absorption of laser energy has also been carried out. It has been shown that, in contrast to the linear density profile, the energy absorption depends explicitly on the value of collision frequency as well as on a new parameter, N, called the over-dense density order.

  6. Combined surface acoustic wave and surface plasmon resonance measurement of collagen and fibrinogen layer physical properties

    Directory of Open Access Journals (Sweden)

    J.-M. Friedt

    2016-12-01

    Full Text Available We use an instrument combining optical (surface plasmon resonance and acoustic (Love mode surface acoustic wave device real-time measurements on a same surface for the identification of water content in collagen and fibrinogen protein layers. After calibration of the surface acoustic wave device sensitivity by copper electrodeposition and surfactant adsorption, the bound mass and its physical properties – density and optical index – are extracted from the complementary measurement techniques and lead to thickness and water ratio values compatible with the observed signal shifts. Such results are especially usefully for protein layers with a high water content as shown here for collagen on an hydrophobic surface. We obtain the following results: collagen layers include 70±20% water and are 16±3 to 19±3 nm thick for bulk concentrations ranging from 30 to 300 μg/ml. Fibrinogen layers include 50±10% water for layer thicknesses in the 6±1.5 to 13±2 nm range when the bulk concentration is in the 46 to 460 μg/ml range. Keywords: surface acoustic wave, surface plasmon resonance, collagen, fibrinogen, density, thickness

  7. Surface martensitization of Carbon steel using Arc Plasma Sintering

    Science.gov (United States)

    Wahyudi, Haris; Dimyati, Arbi; Sebayang, Darwin

    2018-03-01

    In this paper new technology of surface structure modification of steel by short plasma exposure in Arc Plasma Sintering (APS) device is presented. APS is an apparatus working based on plasma generated by DC pulsed current originally used for synthesizing materials via sintering and melting. Plasma exposure in APS was applied into the specimens for 1 and 3 seconds which generate temperature approximately about 1300-1500°C. The SUP9, pearlitic carbon steel samples were used. The hardness, hardening depth and microstructure of the specimens have been investigated by Vickers micro hardness test and Scanning Electron Microscopy (SEM) supported by Energy Dispersive X-Ray Spectroscopy (EDX). The results have showed that the mechanical property was significantly improved due to the formation of single martensitic structures as identified by SEM. The hardness of treated surface evaluated by Vickers hardness test showed significant improvement nearly three time from 190 VHN before to 524 VHN after treatment. Furthermore, EDX confirmed that the formation of martensite layer occurred without altering its composition. The APS also produced uniform hardened layer up to 250 μm. The experiment has demonstrated that arc plasma process was successfully improved the mechanical properties of steel in relatively very short time.

  8. Surface plasmon resonance of Ag organosols: Experimental and theoretical investigations

    Directory of Open Access Journals (Sweden)

    Vodnik Vesna

    2012-01-01

    Full Text Available The aim of this paper is to investigate and compare the changes in surface plasmon resonance (SPR of silver (Ag hydrosol and organosols obtained by experimental and theoretical approaches. Silver nanoparticles (Ag NPs of 5 ± 1.5 nm in diameter were prepared in water by reduction of silver nitrate with sodium borohydride. Nanoparticles were subsequently transferred into different organic solvents (chloroform, hexane, toluene, 1,2-dichlorobenzene using oleylamine as a transfer agent. These solvents were chosen because of the differences in their refractive indices. Using UV-Vis absorption spectrophotometry and transmission electron microscopy (TEM, we confirmed that there were no shape and size changes of the nanoparticles upon the transfer to the organic phase. The absorption spectra of the obtained Ag organosols showed only changes in the position of SPR band depending on dielectric property of the used solvent. To analyze these changes, absorption spectra were modelled using Mie theory for small spherical particles. The experimental and theoretical resonance values were compared with those predicted by Drude model and its limitations in the analysis of absorption behavior of Ag NPs in organic solvents were briefly discussed.

  9. Synthetic Strategies for Semiconductor Nanocrystals Expressing Localized Surface Plasmon Resonance.

    Science.gov (United States)

    Niezgoda, J Scott; Rosenthal, Sandra J

    2016-03-03

    The field of semiconductor plasmonics has grown rapidly since its outset, only roughly six years ago, and now includes many crystalline substances ranging from GeTe to wide-bandgap transition-metal oxides. One byproduct of this proliferation is the sea of differing synthetic methods to realize localized surface plasmon resonances (LSPRs) based on the studied material. Strategies vary widely from material to material, but all have the common goal of introducing extremely high carrier densities to the semiconductor system. This doping results in tunable, size-quantized, and on/off-switchable LSPR modes, which are a complete departure from traditional metal-nanoparticle-based plasmon resonances. This Minireview will provide an overview of the current state of nanocrystal and quantum-dot plasmonics and the physical basis thereof, however its main purpose is to summarize the methods for realizing LSPRs in the various syntheses and systems that have been reported to date. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Contributions of gas-phase plasma chemistry to surface modifications and gas-surface interactions: investigations of fluorocarbon rf plasmas

    Science.gov (United States)

    Cuddy, Michael F., II

    The fundamental aspects of inductively coupled fluorocarbon (FC) plasma chemistry were examined, with special emphasis on the contributions of gas-phase species to surface modifications. Characterization of the gas-phase constituents of single-source CF4-, C2F6-, C3F 8-, and C3F6-based plasmas was performed using spectroscopic and mass spectrometric techniques. The effects of varying plasma parameters, including applied rf power (P) and system pressure (p) were examined. Optical emission spectroscopy (OES) and laser-induced fluorescence (LIF) spectroscopy were employed to monitor the behavior of excited and ground CFx (x = 1,2) radicals, respectively. Mass spectrometric techniques, including ion energy analyses, elucidated behaviors of nascent ions in the FC plasmas. These gas-phase data were correlated with the net effect of substrate processing for Si and ZrO2 surfaces. Surface-specific analyses were performed for post-processed substrates via x-ray photoelectron spectroscopy (XPS) and contact angle goniometry. Generally, precursors with lower F/C ratios tended to deposit robust FC films of high surface energy. Precursors of higher F/C ratio, such as CF4, were associated with etching or removal of material from surfaces. Nonetheless, a net balance between deposition of FC moieties and etching of material exists for each plasma system. The imaging of radicals interacting with surfaces (IRIS) technique provided insight into the phenomena occurring at the interface of the plasma gas-phase and substrate of interest. IRIS results demonstrate that CFx radicals scatter copiously, with surface scatter coefficients, S, generally greater than unity under most experimental conditions. Such considerable S values imply surface-mediated production of the CFx radicals at FC-passivated sites. It is inferred that the primary route to surface production of CFx arises from energetic ion bombardment and ablation of surface FC films. Other factors which may influence the observed CFx

  11. Electrochemical surface plasmon resonance: basic formalism and experimental validation.

    Science.gov (United States)

    Wang, Shaopeng; Huang, Xinping; Shan, Xiaonan; Foley, Kyle J; Tao, Nongjian

    2010-02-01

    A quantitative formalism of electrochemical surface plasmon resonance (EC-SPR) was developed for studying electrochemical reactions. The EC-SPR signal from the reactions was found to be a convolution function of electrochemical current, and therefore, EC-SPR is a powerful tool that can provide information similar to the conventional current-based electrochemical techniques. As an example, potential-sweep EC-SPR was analyzed in details and was found to provide a new way to measure convolution voltammetry without the need of numerical integration. In addition to the benefits provided by the conventional convolution voltammetry, the EC-SPR has several unique advantages, including (1) spatial resolution that is particularly attractive for studying heterogeneous reactions, (2) optical properties of the reactions species that may assist identification of reaction mechanisms, and (3) high surface sensitivity for studying surface binding of the reaction species. Experiments and numerical simulations were carried out for a model system, hexaammineruthenium(III) chloride. The simultaneously measured electrochemical current and SPR response confirmed the relationship between the two quantities, and the numerical simulations were in excellent agreement with the measurements.

  12. Shape effects on localized surface plasmon resonances in metallic nanoparticles

    International Nuclear Information System (INIS)

    Sandu, Titus

    2012-01-01

    The effect of smooth shape changes of metallic nanoparticles on localized surface plasmon resonances is assessed with a boundary integral equation method. The boundary integral equation method allows compact expressions of nanoparticle polarizability which is expressed as an eigenmode sum of terms that depends on the eigenvalues and eigenfunctions of the integral operator associated to the boundary integral equation method. Shape variations change not only the eigenvalues but also their coupling weights to the electromagnetic field. Thus, rather small changes in the shape may induce large variations of the coupling weights. It has been found that shape changes that bring volume variations >12 % induce structural changes in the extinction spectrum of metallic nanoparticles. Also, the largest variations in eigenvalues and their coupling weights are encountered by shape changes along the smallest cross-sections of nanoparticles. These results are useful as guiding rules in the process of designing plasmonic nanostrucrures.

  13. Ultra high phase sensitive surface plasmon resonance biosensor

    Science.gov (United States)

    Li, Ying-Chang; Chou, Chien

    2009-02-01

    This study demonstrates a novel phase-sensitive surface plasman resonance biosensor (PS-SPRB) which is able to convert the phase modulation into amplitude modulation analytically via a differential amplifier. PS-SPRB is able to measure biomolecule interactions at ultra-low concentration relying on the properties of phase sensitive detection at shot-noise detection in a real-time. The common-phase noise-rejection mode is provided in PS-SPRB to be able to immune the background phase noise efficiently. The experimental results confirm the detection sensitivity of 0.00001 wt % concentration of sucrose solution and 10 fg/ml mouse IgG interaction with anti IgG in real time.

  14. Calibration of Surface Plasmon Resonance Imager for Biochemical Detection

    Directory of Open Access Journals (Sweden)

    T. Ktari

    2012-01-01

    Full Text Available We present a new Surface Plasmon Resonance imager (SPRi based on immobilized T4-phage for bacteria detection. First, we present the sensitivity of the SPR imager towards refractive index variation for biosensor application. The SPR imager can be calibrated versus different percentage of triethylene glycol mixture in ultrapure water. The system can be used as a refractometer with sensitivity below 5×10−5 in the range of 1.33300–1.34360. Second, bacteriophage (T4-phage can be physisorbed on gold microarray spots for bacteria detection. The kinetic physisorption of different concentrations of T4-phages can be observed in real time. Finally, two types of bacteria such as E. coli (gram negative and Lactobacillus (gram positive were used for positive and negative tests. The results show a selectivity of T4-phage toward E. coli with a detection limit below 104 CFU/mL and with good reproducibility.

  15. Design and evaluation of a 1.1-GHz surface coil resonator for electron paramagnetic resonance-based tooth dosimetry.

    Science.gov (United States)

    Sugawara, Hirotaka; Hirata, Hiroshi; Petryakov, Sergey; Lesniewski, Piotr; Williams, Benjamin B; Flood, Ann Barry; Swartz, Harold M

    2014-06-01

    This paper describes an optimized design of a surface coil resonator for in vivo electron paramagnetic resonance (EPR)-based tooth dosimetry. Using the optimized resonator, dose estimates with the standard error of the mean of approximately 0.5 Gy were achieved with irradiated human teeth. The product of the quality factor and the filling factor of the resonator was computed as an index of relative signal intensity in EPR tooth dosimetry by the use of 3-D electromagnetic wave simulator and radio frequency circuit design environment (ANSYS HFSS and Designer). To verify the simulated results of the signal intensity in our numerical model of the resonator and a tooth sample, we experimentally measured the radiation-induced signals from an irradiated tooth with an optimally designed resonator. In addition to the optimization of the resonator design, we demonstrated the improvement of the stability of EPR spectra by decontamination of the surface coil resonator using an HCl solution, confirming that contamination of small magnetic particles on the silver wire of the surface coil had degraded the stability of the EPR spectral baseline.

  16. Interaction of dense nitrogen plasma with SS304 surface using APF plasma focus device

    Science.gov (United States)

    Afrashteh, M.; Habibi, M.; Heydari, E.

    2012-04-01

    The nitridation of SS304 surfaces is obtained by irradiating nitrogen ions from Amirkabir plasma focus device, which use multiple focus deposition shots at optimum distance 10 cm from the anode. The Vickers Micro-Hardness values are improved more than twice for the nitrided samples comparing to the nonnitrided ones. The X-ray diffraction (XRD) analysis is carried out in order to explore the phase changes in the near surface structure of the metals. The results of Scanning Electron Microscopy (SEM) indicate changes in surface morphology which are the emergence of smooth and uniform film on the surface of the nitrided metals.

  17. Combined influence of azimuthal and axial magnetic fields on resonant electron acceleration in plasma

    Science.gov (United States)

    Singh, Arvinder; Rajput, Jyoti; Kant, Niti

    2017-11-01

    Resonant enhancement in electron acceleration due to a circularly polarized laser pulse in plasma, under the combined influence of external azimuthal and axial magnetic fields, is studied. We have investigated direct electron acceleration in plasma by employing a relativistic single particle simulation. The plasma is magnetized with an azimuthal magnetic field applied in the perpendicular plane and an axial magnetic field applied along the direction of laser beam propagation. Resonance takes place between electron and electric field of the laser pulse for the optimum value of the combined magnetic field, which supports electron acceleration to higher energies, up to the betatron resonance point. The optimum value of these magnetic fields is highly sensitive to laser initial intensity and laser initial spot size. The effects of laser intensity, initial spot size, and laser pulse duration are taken into consideration in optimizing the magnetic field for efficient electron acceleration. Higher electron energy gain, of the order of GeV, is observed by employing terawatt circularly polarized laser pulses in plasma under the influence of combined magnetic field of about 10 MG.

  18. Resonant Kα spectroscopy of solid-density aluminum plasmas

    Czech Academy of Sciences Publication Activity Database

    Cho, B.I.; Engelhorn, K.; Vinko, S.M.; Chung, H.-K.; Ciricosta, O.; Rackstraw, D.S.; Falcone, R.W.; Brown, C.R.D.; Burian, Tomáš; Chalupský, Jaromír; Graves, C.; Hájková, Věra; Higginbotham, A.; Juha, Libor; Krzywinski, J.; Lee, H.J.; Messersmidt, M.; Murphy, C.; Ping, Y.; Rohringer, N.; Scherz, A.; Schlotter, W.; Toleikis, S.; Turner, J.J.; Vyšín, Luděk; Wang, T.; Wu, B.; Zastrau, U.; Zhu, D.; Lee, R. W.; Nagler, B.; Wark, J. S.; Heimann, P.A.

    2012-01-01

    Roč. 109, č. 24 (2012), "245003-1"-"245003-6" ISSN 0031-9007 R&D Projects: GA MŠk ED1.1.00/02.0061; GA ČR(CZ) GAP108/11/1312; GA ČR GAP205/11/0571; GA ČR GAP208/10/2302; GA MŠk LA08024; GA MŠk(CZ) ME10046; GA MŠk EE.2.3.20.0087; GA MŠk EE2.3.30.0057 Grant - others:ELI Beamlines(XE) CZ.1.05/1.1.00/02.0061; OP VK 2 LaserGen(XE) CZ.1.07/2.3.00/20.0087; OP VK 4 POSTDOK(XE) CZ.1.07/2.3.00/30.0057; AVČR(CZ) M100101221 Institutional research plan: CEZ:AV0Z10100523 Keywords : Kα spectroscopy * free-electron lasers * solid-density aluminum plasmas Subject RIV: BH - Optics, Masers, Lasers Impact factor: 7.943, year: 2012

  19. Application of laser resonance scattering to the study of high-temperature plasma-wall interaction

    International Nuclear Information System (INIS)

    Maeda, Mitsuo; Muraoka, Katsunori; Hamamoto, Makoto; Akazaki, Masanori; Miyazoe, Yasushi

    1981-01-01

    Studies on laser resonance scattering and its application to the study of high-temperature plasma-wall interaction are reviewed. The application of dye laser beam to resonant scattering method has been developed. This method is able to detect low density atoms. The fluorescent photon counts can be estimated for a two-level system and a three-level system. The S/N ratio, Which is in close connection with the detection limit, has been estimated. The doppler effect due to the thermal motion of atoms is taken into consideration. The calibration of the absolute number of atoms is necessary. Tunable coherent light is used as the light source for resonance scattering method. This is able to excite atoms strongly and to increase the detection efficiency. As dye lasers, a N 2 laser, a YAG laser, and a KrF excimer laser have been studied. In VUV region, rare gas or rare gas halide lasers can be used. The strong output power can be expected when the resonance lines of atoms meet the synchronizing region of the excimer laser. The resonance scattering method is applied to the detection of impurity metal atoms in plasma. The studies of laser systems for the detection of hydrogen atoms are also in progress. (Kato, T.)

  20. Non thermal plasma surface cleaner and method of use

    KAUST Repository

    Neophytou, Marios

    2017-09-14

    Described herein are plasma generation devices and methods of use of the devices. The devices can be used for the cleaning of various surfaces and/or for inhibiting or preventing the accumulation of particulates, such as dust, or moisture on various surfaces. The devices can be used to remove dust and other particulate contaminants from solar panels and windows, or to avoid or minimize condensation on various surfaces. In an embodiment a plasma generation device is provided. The plasma generation device can comprise: a pair of electrodes (1,2) positioned in association with a surface of a dielectric substrate (3). The pair of electrodes (1,2) can comprise a first electrode (1) and a second electrode (2). The first electrode and second electrode can be of different sizes, one of the electrodes being smaller than the other of the electrodes. The first electrode and second electrode can be separated by a distance and electrically connected to a voltage source (4,5).

  1. High energy radiation precursors to the collapse of black holes binaries based on resonating plasma modes

    Science.gov (United States)

    Coppi, B.

    2018-05-01

    The presence of well organized plasma structures around binary systems of collapsed objects [1,2] (black holes and neutron stars) is proposed in which processes can develop [3] leading to high energy electromagnetic radiation emission immediately before the binary collapse. The formulated theoretical model supporting this argument shows that resonating plasma collective modes can be excited in the relevant magnetized plasma structure. Accordingly, the collapse of the binary approaches, with the loss of angular momentum by emission of gravitational waves [2], the resonance conditions with vertically standing plasma density and magnetic field oscillations are met. Then, secondary plasma modes propagating along the magnetic field are envisioned to be sustained with mode-particle interactions producing the particle populations responsible for the observable electromagnetic radiation emission. Weak evidence for a precursor to the binary collapse reported in Ref. [2], has been offered by the Agile X-γ-ray observatory [4] while the August 17 (2017) event, identified first by the LIGO-Virgo detection of gravitational waves and featuring the inferred collapse of a neutron star binary, improves the evidence of such a precursor. A new set of experimental observations is needed to reassess the presented theory.

  2. 4d--4f emission resonances in laser-produced plasmas

    International Nuclear Information System (INIS)

    O'Sullivan, G.; Carroll, P.K.

    1981-01-01

    Using targets containing compounds of the elements cesium through lutetium, we studied the spectra of laser-produced plasmas in the grazing-incidence region from 40 to 200 A. The spectra are characterized by strong regions of resonancelike emission extending typically over 9--18 eV. With increasing Z, the spectra show certain systematic variations in character and move monotonically toward shorter wavelengths. From a collisional-radiative plasma model, the ion stages responsible for the emision are identified as VIII through XVI. The resonances are attributed to 4-4f transitions that, because Dn = 0, tend to overlap for different ion stages of the same element

  3. Nonlinear dispersion of resonance extraordinary wave in a plasma with strong magnetic field

    International Nuclear Information System (INIS)

    Krasovitskiy, V. B.; Turikov, V. A.; Sotnikov, V. I.

    2007-01-01

    In this paper, the efficiency of electron acceleration by a short, powerful laser pulse propagating across an external magnetic field is investigated. Conditions for the decay of a laser pulse with frequency close to the upper hybrid resonance frequency are analyzed. It is also shown that a laser pulse propagating as an extraordinary wave in cold, magnetized, low-density plasma takes the form of a nonlinear wave with the modulated amplitude (envelope soliton). Finally, simulation results on the interaction of an electromagnetic pulse with a semi-infinite plasma, obtained with the help of an electromagnetic relativistic PIC code, are discussed and a comparison with the obtained theoretical results is presented

  4. Interaction of deuterium plasma with pre-nitrided tungsten surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Gao, Liang

    2016-06-15

    DE027289820Nitrogen (N{sub 2}) has been established as an optimal choice as seeding species to control the divertor heat load in ASDEX Upgrade. Based on a series of dedicated laboratory experiments, the present work is devoted to unravel the underlying physics of the interaction of W surfaces with N{sub 2}-seeded plasmas with respect to D retention in W, i.e., to answer ''how should the presence of N in W surfaces affect the hydrogen isotope retention in W after plasma loadings?''. Treated in a well-defined ECR plasma source (PlaQ) in Max-Planck-Institut fuer Plasmaphysik (IPP, Garching), the experiments in this thesis were performed under the following strategy. Namely, the interaction processes between W surfaces with mixed plasma was split into two major steps. Step one is the development and characterization of an appropriate model system for N-containing W layers and step two is the interaction of D plasmas with these model systems. As a first step, a model system for W:N layers formed at W surfaces during or after N{sub 2} seeding in fusion devices is established. By either N implantation into pure W surfaces or sputter-deposition of WN{sub x} films, two different W:N layers were produced. Different characterization techniques, such as XPS, RBS, NRA and TPD, were employed to characterize of these two different W:N layers, i.e., the implantation range of N into W surfaces, the diffusion of N in W, the determination of the N amount and the decomposition temperature of W:N layers. All the results from different techniques were cross-checked with each other, which allowed a reliable N content determination and its evolution during the consecutive D implantations. Based on these characterizations, sputter-deposited WN{sub x} films and N-implanted W surfaces under certain production conditions were selected for further investigation in the following D implantations. The second and main part of the experiments covers the exposure of

  5. Reference compensation for localized surface-plasmon resonance sensors

    Science.gov (United States)

    Nehru, Neha

    Noble metal nanoparticles supporting localized surface plasmon resonances (LSPR) have been extensively investigated for label free detection of various biological and chemical interactions. When compared to other optical sensing techniques, LSPR sensors offer label-free detection of biomolecular interactions in localized sensing volume solutions. However, these sensors also suffer from a major disadvantage---LSPR sensors remain highly susceptible to interference because they respond to both solution refractive index change and non-specific binding as well as specific binding of the target analyte. These interactions can severely compromise the measurement of the target analyte in a complex unknown media and hence limit the applicability and impact of the sensor. In spite of the extensive amount of work done in this field, there has been a clear absence of efforts to make LSPR sensors immune to interfering effects. The work presented in this document investigates, both experimentally and numerically, dual- and tri-mode LSPR sensors that utilize the multiple surface plasmon modes of gold nanostructures to distinguish target analyte from interfering bulk and non-specific binding effects. Finally, a series of biosensing experiments are performed to examine various regeneration assays for LSPR sensors built on indium tin oxide coated glass substrate.

  6. Response of fuzzy tungsten surfaces to pulsed plasma bombardment

    International Nuclear Information System (INIS)

    Nishijima, D.; Doerner, R.P.; Iwamoto, D.; Kikuchi, Y.; Miyamoto, M.; Nagata, M.; Sakuma, I.; Shoda, K.; Ueda, Y.

    2013-01-01

    Damage of fuzzy tungsten surfaces due to a transient plasma load is characterized in terms of mass loss, surface morphology, and optical properties. A single D pulsed (∼0.1–0.2 ms) plasma shot with surface absorbed energy density of ∼1.1 MJ m −2 leads to a mass loss of ∼80 μg, which cannot be explained by physical sputtering. Thus, macroscopic erosion processes such as droplets and dust release as well as arcing are thought to be responsible for the mass loss. In fact, scanning electron microscopy observations reveal the melting of the tips of fuzz and arc tracks. The optical reflectivity of the damaged (melted) surface is measured to be higher than that of an undamaged fuzzy surface (below ∼0.01%). Spectroscopic ellipsometry shows that the refractive index, n, and extinction coefficient, k, increase from n ≈ 1 and k ≈ 0 for an undamaged fuzzy surface with an increase in the degree of damage of fuzz

  7. Resonance localization and poloidal electric field due to cyclo- tron wave heating in tokamak plasmas

    International Nuclear Information System (INIS)

    Hsu, J.Y.; Chan, V.S.; Harvey, R.W.; Prater, R.; Wong, S.K.

    1984-01-01

    The perpendicular heating in cyclotron waves tends to pile up the resonant particles toward the low magnetic field side with their banana tips localized to the resonant surface. A poloidal electric field with an E x B drift comparable to the ion vertical drift in a toroidal magnetic field may result. With the assumption of anomalous electron and neoclassical ion transport, density variations due to wave heating are discussed

  8. Resonance parallel viscosity in the banana regime in poloidally rotating tokamak plasmas

    International Nuclear Information System (INIS)

    Shaing, K.C.; Hsu, C.T.; Dominguez, N.

    1994-01-01

    Parallel viscosity in the banana regime in a poloidally (ExB) rotating tokamak plasma is calculated to include the effects of orbit squeezing and to allow the poloidal ExB Mach number M p to have a value of order unity. Here, E is the electric field and B is the magnetic field. The effects of orbit squeezing not only modify the size of the particle orbit, but also change the fraction of poloidally trapped particles. Resonance between the particle parallel (to B) speed u and the poloidal component of the ExB velocity can only occur for those particles with energy (v/v t ) 2 >M 2 p (with v the particle speed and v t the thermal speed). Thus, the resonance parallel plasma viscosity in the banana regime decreases exponentially with M 2 p when M 2 p ≥1, and has a local maximum of M 2 p ∼1

  9. Model of charge-state distributions for electron cyclotron resonance ion source plasmas

    Directory of Open Access Journals (Sweden)

    D. H. Edgell

    1999-12-01

    Full Text Available A computer model for the ion charge-state distribution (CSD in an electron cyclotron resonance ion source (ECRIS plasma is presented that incorporates non-Maxwellian distribution functions, multiple atomic species, and ion confinement due to the ambipolar potential well that arises from confinement of the electron cyclotron resonance (ECR heated electrons. Atomic processes incorporated into the model include multiple ionization and multiple charge exchange with rate coefficients calculated for non-Maxwellian electron distributions. The electron distribution function is calculated using a Fokker-Planck code with an ECR heating term. This eliminates the electron temperature as an arbitrary user input. The model produces results that are a good match to CSD data from the ANL-ECRII ECRIS. Extending the model to 1D axial will also allow the model to determine the plasma and electrostatic potential profiles, further eliminating arbitrary user input to the model.

  10. Plasma surface interactions at the JET X-point tiles

    International Nuclear Information System (INIS)

    Martinelli, A.P.; Behrisch, R.; Coad, J.P.; Kock, L. de

    1989-01-01

    Operation with a magnetic divertor, which leads to a zero poloidal field inside the volume of the discharge vessel (the X-point) has led to substantial improvements in confinement time in JET. In this mode the diverted plasma is conducted to a large number of graphite tiles (X-point tiles) near the top of the vessel. The power handling capability of these tiles limits the maximum additional heating power to the discharge. The study of the surface modifications of the X-point tiles of JET is therefore of interest both to correlate the magnetic configuration and plasma particle and energy fluxes with the surface modifications, and also to get information about the erosion and deposition at these wall areas. (author) 5 refs., 4 figs

  11. INSTRUMENTS AND METHODS OF INVESTIGATION: Plasma isotope separation based on ion cyclotron resonance

    Science.gov (United States)

    Dolgolenko, Dmitrii A.; Muromkin, Yurii A.

    2009-04-01

    Experiments that have been conducted in the USA, France, and Russia to investigate isotopically selective ion cyclotron resonance (ICR) as a tool for plasma isotope separation are analyzed. Because this method runs into difficulties at low values of the relative isotope mass difference ΔM/M, for some elements (for gadolinium, as an example) isotope separation still remains a problem. There are ways to solve it, however, as experimental results and theoretical calculations suggest.

  12. Efficient laser-overdense plasma coupling via surface plasma waves and steady magnetic field generation

    Energy Technology Data Exchange (ETDEWEB)

    Bigongiari, A. [CEA/DSM/LSI, CNRS, Ecole Polytechnique, 91128 Palaiseau Cedex (France); TIPS/LULI, Universite Paris 6, CNRS, CEA, Ecole Polytechnique, 3, rue Galilee 94200, Ivry-sur-Seine (France); Raynaud, M. [CEA/DSM/LSI, CNRS, Ecole Polytechnique, 91128 Palaiseau Cedex (France); Riconda, C. [TIPS/LULI, Universite Paris 6, CNRS, CEA, Ecole Polytechnique, 3, rue Galilee 94200, Ivry-sur-Seine (France); Heron, A. [CPHT, CNRS, Ecole Polytechnique, 91128 Palaiseau Cedex (France); Macchi, A. [Consiglio Nazionale delle Ricerche, Istituto Nazionale di Ottica (CNR/INO), Dipartimento di Fisica ' ' E. Fermi' ' , Largo B. Pontecorvo 3, 56127 Pisa (Italy)

    2011-10-15

    The efficiency of laser overdense plasma coupling via surface plasma wave excitation is investigated. Two-dimensional particle-in-cell simulations are performed over a wide range of laser pulse intensity from 10{sup 15} to 10{sup 20} W cm{sup -2}{mu}m{sup 2} with electron density ranging from 25 to 100n{sub c} to describe the laser interaction with a grating target where a surface plasma wave excitation condition is fulfilled. The numerical studies confirm an efficient coupling with an enhancement of the laser absorption up to 75%. The simulations also show the presence of a localized, quasi-static magnetic field at the plasma surface. Two interaction regimes are identified for low (I{lambda}{sup 2} < 10{sup 17} W cm{sup -2}{mu}m{sup 2}) and high (I{lambda}{sup 2} > 10{sup 17} W cm{sup -2}{mu}m{sup 2}) laser pulse intensities. At ''relativistic'' laser intensity, steady magnetic fields as high as {approx}580 MG {mu}m/{lambda}{sub 0} at 7 x 10{sup 19} W cm{sup -2}{mu}m{sup 2} are obtained in the simulations.

  13. Surface modification of polyethylene by plasma; Modificacion superficial de polietileno por plasma

    Energy Technology Data Exchange (ETDEWEB)

    Colin O, E

    2003-07-01

    The products made of polyethylene (PE) go from construction materials, electric insulating until packing material. The films for bags and pack occupy 83.6% of the distribution of the market of PE approximately. The enormous quantity of PE that is generated by its indiscriminate use brings as consequence a deterioration to the atmosphere, due to the long life that they present as waste. This work is a study on the modification of low density polyethylene films. In this type of thin materials, the changes in the surface meet with largely on the conformation of the rest of the material. To induce changes that modify the surface of PE, plasmas were used with reactive atmospheres of air, oxygen and nitrogen. The experimentation that was carries out went to introduce the PE to a cylindrical reactor where it was generated the plasma of air, oxygen and nitrogen to different times of exposure. After having carried out the exposure to the plasma, it was found that in the polyethylene it modifies their morphology, crystallinity, hydrophobicity, composition and electric conductivity. The analytical techniques that were used to characterize later to the polyethylene of being in contact with the plasma were: X-ray diffraction, Scanning Electron Microscopy, Infrared spectroscopy, Electric conductivity, Angle of contact and finally Thermal Gravimetric Analysis. The content of this work it is presented in five chapters: In the chapter 1 there are presented some general concepts of plasma and of the one polymer in study PE. In the chapter 2 it is made a general revision on modification of surfaces, as well as the properties that were modified in polymeric materials that were exposed to plasma in previous works. In the chapter 3 the experimental part and the conditions used are described in the modification of the PE. Also in this chapter a brief description it is made of the used characterization techniques. The results and discussion are presented in the chapter 4. These results

  14. Proceedings of the joint meeting on Plasma Surface Interaction (PSI) and Plasma Facing Components (PFC)

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-03-01

    The joint meeting on Plasma Surface Interaction (PSI) and Plasma Facing Components (PFC) was held in Naka Fusion Establishment on December 1, 2000. This meeting has been held to enhance information exchange between PSI and PFC researchers. In the present meeting, there were 11 presentations which covered current status of PSI and PFC studies for large fusion devices such as ITER, JT-60 and LHD, and basic studies on Hydrogen isotope behavior in the fusion material. This report includes abstracts and view graphs of these presentations. (author)

  15. Comparative study of NO removal in surface-plasma and volume-plasma reactors based on pulsed corona discharges.

    Science.gov (United States)

    Malik, Muhammad Arif; Kolb, Juergen F; Sun, Yaohong; Schoenbach, Karl H

    2011-12-15

    Nitric oxide (NO) conversion has been studied for two different types of atmospheric-pressure pulsed-corona discharges, one generates a surface-plasma and the other provides a volume-plasma. For both types of discharges the energy cost for NO removal increases with decreasing oxygen concentration and initial concentration of NO. However, the energy cost for volume plasmas for 50% NO removal, EC(50), from air was found to be 120 eV/molecule, whereas for the surface plasma, it was only 70 eV/molecule. A smaller difference in energy cost, but a higher efficiency for removal of NO was obtained in a pure nitrogen atmosphere, where NO formation is restricted due to the lack of oxygen. For the volume plasma, EC(50) in this case was measured at 50 eV/molecule, and for the surface plasma it was 40 eV/molecule. Besides the higher NO removal efficiency of surface plasmas compared to volume plasmas, the energy efficiency of surface-plasmas was found to be almost independent of the amount of electrical energy deposited in the discharge, whereas the efficiency for volume plasmas decreases considerably with increasing energy. This indicates the possibility of operating surface plasma discharges at high energy densities and in more compact reactors than conventional volume discharges. Published by Elsevier B.V.

  16. Suppression of large edge localized modes with edge resonant magnetic fields in high confinement DIII-D plasmas

    International Nuclear Information System (INIS)

    Thomas, P.R.; Becoulet, M.; Evans, T.E.; Osborne, T.H.; Groebner, R.J.; Jackson, G.L.; Haye, R.J. La; Schaffer, M.J.; West, W.P.; Moyer, R.A.; Rhodes, T.L.; Rudakov, D.L.; Watkins, J.G.; Boedo, J.A.; Doyle, E.J.; Wang, G.; Zeng, L.; Fenstermacher, M.E.; Groth, M.; Lasnier, C.J.; Finken, K.H.; Harris, J.H.; Pretty, D.G.; Masuzaki, S.; Ohyabu, N.; Reimerdes, H.; Wade, M.R.

    2005-01-01

    Large divertor heat pulses due to Type-I edge localized modes (ELMs) have been eliminated reproducibly in DIII-D with small dc currents driven in a simple magnetic perturbation coil. The current required to eliminate all but a few isolated Type-I ELMs, during a coil pulse, is less than 0.4% of plasma current. Modelling shows that the perturbation fields resonate with plasma flux surfaces across most of the pedestal region (0.9 ≤ N ≤ 1.0), when q95 = 3.7±0.2 creating small remnant magnetic islands surrounded by weakly stochastic field lines. The stored energy, N , H-mode quality factor and global energy confinement time are unaltered by the magnetic perturbation. At high collisionality (ν* ∼0.5-1), there is no obvious effect of the perturbation on the edge profiles and yet ELMs are suppressed, nearly completely, for up to 9τ E . At low collisionality (ν* <0.1), there is a density pump-out and complete ELM suppression, reminiscent of the DIIID QH- mode. Other differences, specifically in the resonance condition and the magnetic fluctuations, suggest that different mechanisms are at play in the different collisionality regimes. In addition to a description and interpretation of the DIIID data, the application of this method to ELM control on other machines, such as JET and ITER will be discussed. (author)

  17. Gas detection by means of surface plasmon resonance enhanced ellipsometry

    Energy Technology Data Exchange (ETDEWEB)

    Nooke, Alida

    2012-11-01

    This thesis investigated gas sensing by means of surface plasmon resonance enhanced ellipsometry. Surface plasmons were excited in a 40 - 50 nm gold layer by a He-Ne-laser using the Kretschmann configuration, which was arranged on a self-made copper measuring cell. A fixed angle of incidence and the ellipsometric parameter {Delta} as the measured value were used to monitor changes in the gas phase. Different types of gases were investigated: flammable (hydrocarbons and hydrogen), oxidising (oxygen and ozone), toxic (carbon monoxide) and inert (helium and nitrogen). The gas types can be distinguished by their refractive indices, whereas the sensor responds instantly relative to the reference gas with an increase or a decrease in {Delta}. Diluting the analyte gas with a reference gas (nitrogen or air) allowed the detection limits to be determined, these lay in the low % range. The sensor stability was also enhanced as well as the sensitivity by modifying the gold layers with a 3-10 nm additional layer. These additional layers consisted of the inorganic materials TiO{sub 2}, ZrO{sub 2}, MgF{sub 2} and Fe: SnO{sub 2} which were deposited by different coating processes. Surface investigations were made of every utilised layer: scanning electron microscope and atomic force microscope measurements for surface topology and spectroscopic ellipsometry mapping to determine the optical constants and the layer thicknesses. All applied materials protected the gold layer from contaminations and thus prolonged the life span of the sensor. Furthermore, the detection limits were reduced significantly, to the low ppm range. The material Fe: SnO{sub 2} demonstrates a special behaviour in reaction with the toxic gas carbon monoxide: Due to the iron doping, the response to carbon monoxide is extraordinary and concentrations below 1 ppm were detected. In order to approach a future application in industry, the sensor system was adapted to a stainless steel tube. With this measuring

  18. Work function modifications of graphite surface via oxygen plasma treatment

    Science.gov (United States)

    Duch, J.; Kubisiak, P.; Adolfsson, K. H.; Hakkarainen, M.; Golda-Cepa, M.; Kotarba, A.

    2017-10-01

    The surface modification of graphite by oxygen plasma was investigated experimentally (X-ray diffraction, nanoparticle tracking analysis, laser desorption ionization mass spectrometry, thermogravimetry, water contact angle) and by molecular modelling (Density Functional Theory). Generation of surface functional groups (mainly sbnd OHsurf) leads to substantial changes in electrodonor properties and wettability gauged by work function and water contact angle, respectively. The invoked modifications were analyzed in terms of Helmholtz model taking into account the theoretically determined surface dipole moment of graphite-OHsurf system (μ = 2.71 D) and experimentally measured work function increase (from 0.75 to 1.02 eV) to determine the sbnd OH surface coverage (from 0.70 to 1.03 × 1014 groups cm-2). Since the plasma treatment was confined to the surface, the high thermal stability of the graphite material was preserved as revealed by the thermogravimetric analysis. The obtained results provide a suitable quantitative background for tuning the key operating parameters of carbon electrodes: electronic properties, interaction with water and thermal stability.

  19. Bactericidal performance of nanostructured surfaces by fluorocarbon plasma.

    Science.gov (United States)

    Vassallo, E; Pedroni, M; Silvetti, T; Morandi, S; Toffolatti, S; Angella, G; Brasca, M

    2017-11-01

    This study presents the characterization and antibacterial activity of nanostructured Si by plasma treatment method using a tetrafluoromethane (CF 4 ) and hydrogen (H 2 ) mixture. Nanostructured-Si is a synthetic nanomaterial that contains high aspect ratio nanoprotrusions on its surface, produced through a reactive-ion etching process. We have shown that the nanoprotrusions on the surfaces produce a mechanical bactericidal effect. Nanostructured-Si exhibited notable activity against three different microorganisms: Gram-negative (Escherichia coli), Gram-positive (Staphylococcus aureus) and spore-forming bacteria (Bacillus cereus) producing a > 5 log 10 reduction after 24h of incubation. Scanning electron microscopy was used to analysis the structure and morphology character of different surfaces evidencing the physical bactericidal activity of the Nanostructured-Si. These results provide excellent prospects for the development of a new generation of antibacterial surfaces. Copyright © 2017 Elsevier B.V. All rights reserved.

  20. Model for screening of resonant magnetic perturbations by plasma in a realistic tokamak geometry and its impact on divertor strike points

    Czech Academy of Sciences Publication Activity Database

    Cahyna, Pavel; Nardon, E.

    2011-01-01

    Roč. 415, č. 1 (2011), S927-S931 ISSN 0022-3115. [International Conference on Plasma-Surface Interactions in Controlled Fusion Device/19th./. San Diego, 24.05.2010-28.05.2010] R&D Projects: GA MŠk 7G09042; GA MŠk LA08048 Institutional research plan: CEZ:AV0Z20430508 Keywords : tokamaks * ELM control * resonant magnetic perturbations * divertor Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 2.052, year: 2011 http://dx.doi.org/10.1016/j.jnucmat.2011.01.117

  1. Production of electron cyclotron resonance plasma by using multifrequencies microwaves and active beam profile control on a large bore electron cyclotron resonance ion source with permanent magnets.

    Science.gov (United States)

    Kato, Yushi; Watanabe, Takeyoshi; Matsui, Yuuki; Hirai, Yoshiaki; Kutsumi, Osamu; Sakamoto, Naoki; Sato, Fuminobu; Iida, Toshiyuki

    2010-02-01

    A new concept on magnetic field with all magnets on plasma production and confinement has been proposed to enhance efficiency of an electron cyclotron resonance (ECR) plasma for broad and dense ion beam source under the low pressure. The magnetic field configuration is constructed by a pair of magnets assembly, i.e., comb-shaped magnet which cylindrically surrounds the plasma chamber. The resonance zones corresponding to the fundamental ECR for 2.45 GHz and 11-13 GHz frequencies are constructed at different positions. The profiles of the plasma parameters in the ECR ion source are different from each frequency of microwave. Large bore extractor is set at the opposite side against the microwave feeds. It is found that differences of their profiles also appear at those of ion beam profiles. We conducted to launch simultaneously multiplex frequencies microwaves controlled individually, and tried to control the profiles of the plasma parameters and then those of extracted ion beam.

  2. Surface-wave-sustained plasma torch for water treatment

    Science.gov (United States)

    Marinova, P.; Benova, E.; Todorova, Y.; Topalova, Y.; Yotinov, I.; Atanasova, M.; Krcma, F.

    2018-02-01

    In this study the effects of water treatment by surface-wave-sustained plasma torch at 2.45 GHz are studied. Changes in two directions are obtained: (i) changes of the plasma characteristics during the interaction with the water; (ii) water physical and chemical characteristics modification as a result of the plasma treatment. In addition, deactivation of Gram positive and Gram negative bacteria in suspension are registered. A number of charged and excited particles from the plasma interact with the water. As a result the water chemical and physical characteristics such as the water conductivity, pH, H2O2 concentration are modified. It is observed that the effect depends on the treatment time, wave power, and volume of the treated liquid. At specific discharge conditions determined by the wave power, gas flow, discharge tube radius, thickness and permittivity, the surface-wave-sustained discharge (SWD) operating at atmospheric pressure in argon is strongly non-equilibrium with electron temperature T e much higher than the temperature of the heavy particles (gas temperature T g). It has been observed that SWD argon plasma with T g close to the room temperature is able to produce H2O2 in the water with high efficiency at short exposure times (less than 60 sec). The H2O2 decomposition is strongly dependant on the temperature thus the low operating gas temperature is crucial for the H2O2 production efficiency. After scaling up the device, the observed effects can be applied for the waste water treatment in different facilities. The innovation will be useful especially for the treatment of waters and materials for medical application.

  3. Sterilization of Surfaces with a Handheld Atmospheric Pressure Plasma

    Science.gov (United States)

    Hicks, Robert; Habib, Sara; Chan, Wai; Gonzalez, Eleazar; Tijerina, A.; Sloan, Mark

    2009-10-01

    Low temperature, atmospheric pressure plasmas have shown great promise for decontaminating the surfaces of materials and equipment. In this study, an atmospheric pressure, oxygen and argon plasma was investigated for the destruction of viruses, bacteria, and spores. The plasma was operated at an argon flow rate of 30 L/min, an oxygen flow rate of 20 mL/min, a power density of 101.0 W/cm^3 (beam area = 5.1 cm^2), and at a distance from the surface of 7.1 mm. An average 6log10 reduction of viable spores was obtained after only 45 seconds of exposure to the reactive gas. By contrast, it takes more than 35 minutes at 121^oC to sterilize anthrax in an autoclave. The plasma properties were investigated by numerical modeling and chemical titration with nitric oxide. The numerical model included a detailed reaction mechanism for the discharge as well as for the afterglow. It was predicted that at a delivered power density of 29.3 W/cm^3, 30 L/min argon, and 0.01 volume% O2, the plasma generated 1.9 x 10^14 cm-3 O atoms, 1.6 x 10^12 cm-3 ozone, 9.3 x 10^13 cm-3 O2(^1δg), and 2.9 x 10^12 cm-3 O2(^1σ^+g) at 1 cm downstream of the source. The O atom density measured by chemical titration with NO was 6.0 x 10^14 cm-3 at the same conditions. It is believe that the oxygen atoms and the O2(^1δg) metastables were responsible for killing the anthrax and other microorganisms.

  4. Electron cyclotron resonance plasma heating in a flaring magnetic field zone

    International Nuclear Information System (INIS)

    Meis, C.; Compant la Fontaine, A.; Louvet, P.

    1991-01-01

    Electron Cyclotron Resonance plasma heating as well as Ion Cyclotron Resonance are successfully applied on the ERIC stable isotope separation device, in operation at CEN-Saclay. In this experiment, the plasma is created in the flaring magnetic field zone of a superconducting coil by ionizing the vapour issued from a sputtering plate (or a Joule oven), by electron cyclotron heating using 10, 18 or 29 GHz, 1.5 kW klystrons. A three-fluid model has been developed in order to describe the plasma source. In a first step, the values of the absorbed HF power, appearing in the equation of electrons energy conservation have to be determined. For this purpose, a ray tracing model is used. The preliminary results of the calculation are presented in this paper. The electron distribution function is assumed to be Maxwellian. The temperature effects are taken into account in the dielectric tensor. The polarization is also determined at any point of the wave propagation in the plasma

  5. ELECTROLYTIC-PLASMA TREATMENT OF INNER SURFACE OF TUBULAR PRODUCTS

    Directory of Open Access Journals (Sweden)

    Yu. G. Alekseev

    2016-01-01

    Full Text Available While manufacturing a number of important tubular products stringent requirements have been imposed on quality of their inner surfaces. The well-known methods for inner surface treatment of pipes include sandblasting, chemical cleaning with acid reagents (oxalic, formic, sulfamic, orthophosphoric acids and electrochemical polishing. Disadvantages of the chemical method are cleaning-up irregularities, high metal removal, limited number of reagent application, complicated selection of reagent chemical composition and concentration, complicated and environmentally harmful recycling of waste chemicals, high cost of reagents. Low productivity at a high cost, as well as hazardous impact on personnel due to high dispersion of abrasive dust are considered as disadvantages of sandblasting. Electrochemical polishing is characterized by the following disadvantages: low processing productivity because supply of high currents is rather difficult due to electrolyte scattering capacity away from the main electrode action zone, limited length of the cavity to be treated due to heating of flexible current leads at operating current densities, application of expensive aggressive electrolytes and high costs of their recycling. A new method for polishing and cleaning of inner surfaces of tubular products based on electrolyte-plasma treatment has been developed. In comparison with the existing methods the proposed methods ensures quality processing with high intensity while applying non-toxic, environmentally friendly and cheap electrolytes. The paper presents results of investigations on technological specific features of electrolyte-plasma treatment for inner surfaces of tubular products: influence of slotted nozzle width, electrolyte flow and rate on stability of gas-vapor blanket, current density and productivity. Results of the research have made it possible to determine modes that provide stability and high productivity in the process of electrolyte-plasma

  6. Resonance Raman Optical Activity and Surface Enhanced Resonance Raman Optical Activity analysis of Cytochrome C

    DEFF Research Database (Denmark)

    Johannessen, Christian; Abdali, Salim; White, Peter C.

    2007-01-01

    High quality Resonance Raman (RR) and resonance Raman Optical Activity (ROA) spectra of cytochrome c were obtained in order to perform full assignment of spectral features of the resonance ROA spectrum. The resonance ROA spectrum of cytochrome c revealed a distinct spectral signature pattern due...... Enhanced Raman Spectroscopy (ChERS) spectra of the protein were successfully obtained at very low concentration (as low as 1 µM). The assignment of spectral features was based on the information obtained from the RR and resonance ROA spectra. Excellent agreement between RR and SERRS spectra is reported...

  7. Plasma dike potential sustained by local electron cyclotron resonance along converging magnetic-field lines

    International Nuclear Information System (INIS)

    Kaneko, Toshiro; Miyahara, Yutaka; Hatakeyama, Rikizo; Sato, Noriyoshi

    2000-01-01

    Plasma potential formation with electron cyclotron heating is investigated in a fully-ionized collisionless plasma flow along converging magnetic-field lines (monotonously increasing magnetic field) in the presence of a single electron cyclotron resonance (ECR) point. When the ECR point is located in a region of good curvature of the magnetic line, a potential hump (plug potential) with a potential dip (thermal barrier) is generated around the ECR point. This potential structure persists in the steady state, working as a plasma-flow dike potential. In case that the ECR point is located in a region of bad curvature, on the other hand, the dike potential is only transiently formed, and collapses gradually as low frequency curvature-driven instabilities grow. (author)

  8. Field-aligned plasma-potential structure formed by local electron cyclotron resonance

    International Nuclear Information System (INIS)

    Hatakeyama, Rikizo; Kaneko, Toshiro; Sato, Noriyoshi

    2001-01-01

    The significance of basic experiments on field-aligned plasma-potential structure formed by local electron cyclotron resonance (ECR) is claimed based on the historical development of the investigation on electric double layer and electrostatic potential confinement of open-ended fusion-oriented plasmas. In the presence of a single ECR point in simple mirror-type configurations of magnetic field, a potential dip (thermal barrier) appears around this point, being followed by a subsequent potential hump (plug potential) along a collisionless plasma flow. The observed phenomenon gives a clear-cut physics to the formation of field-aligned plug potential with thermal barrier, which is closely related to the double layer formation triggered by a negative dip. (author)

  9. Plasma Treatment Maintains Surface Energy of the Implant Surface and Enhances Osseointegration

    Directory of Open Access Journals (Sweden)

    Fernando P. S. Guastaldi

    2013-01-01

    Full Text Available The surface energy of the implant surface has an impact on osseointegration. In this study, 2 surfaces: nonwashed resorbable blasting media (NWRBM; control and Ar-based nonthermal plasma 30 days (Plasma 30 days; experimental, were investigated with a focus on the surface energy. The surface energy was characterized by the Owens-Wendt-Rabel-Kaelble method and the chemistry by X-ray photoelectron spectroscopy (XPS. Five adult beagle dogs received 8 implants (n=2 per surface, per tibia. After 2 weeks, the animals were euthanized, and half of the implants (n=20 were removal torqued and the other half were histologically processed (n=20. The bone-to-implant contact (BIC and bone area fraction occupancy (BAFO were evaluated on the histologic sections. The XPS analysis showed peaks of C, Ca, O, and P for the control and experimental surfaces. While no significant difference was observed for BIC parameter (P>0.75, a higher level for torque (P<0.02 and BAFO parameter (P<0.01 was observed for the experimental group. The surface elemental chemistry was modified by the plasma and lasted for 30 days after treatment resulting in improved biomechanical fixation and bone formation at 2 weeks compared to the control group.

  10. Experimental Investigation of Surface Wave Plasma Excited by a Cylindrical Dielectric Rod

    International Nuclear Information System (INIS)

    Wu Zhonghang; Li Zebin; He Kongduo; Yang Xilu; Chen Zhenliu; Ou Qiongrong; Liang Rongqing; Ju Jiaqi; Yan Hang

    2014-01-01

    An improved surface wave plasma source equipped with a cylindrical quartz rod has been developed, which has great potential in processing inner wall of cylindrical workpieces. A cylindrical quartz rod not only excites the plasma around the rod, but also guides surface wave plasma along the rod. The distributions of plasma density and plasma temperature under different incident microwave powers and pressures are diagnosed by a Langmuir probe. The electron density near the rod is around the order of 10 11 cm −3 . When the incident power is 450 W, the length of surface wave plasma column can reach up to 420 mm at 20 Pa. (low temperature plasma)

  11. Surface Plasmon Resonance Biosensor Based on Smart Phone Platforms.

    Science.gov (United States)

    Liu, Yun; Liu, Qiang; Chen, Shimeng; Cheng, Fang; Wang, Hanqi; Peng, Wei

    2015-08-10

    We demonstrate a fiber optic surface plasmon resonance (SPR) biosensor based on smart phone platforms. The light-weight optical components and sensing element are connected by optical fibers on a phone case. This SPR adaptor can be conveniently installed or removed from smart phones. The measurement, control and reference channels are illuminated by the light entering the lead-in fibers from the phone's LED flash, while the light from the end faces of the lead-out fibers is detected by the phone's camera. The SPR-sensing element is fabricated by a light-guiding silica capillary that is stripped off its cladding and coated with 50-nm gold film. Utilizing a smart application to extract the light intensity information from the camera images, the light intensities of each channel are recorded every 0.5 s with refractive index (RI) changes. The performance of the smart phone-based SPR platform for accurate and repeatable measurements was evaluated by detecting different concentrations of antibody binding to a functionalized sensing element, and the experiment results were validated through contrast experiments with a commercial SPR instrument. This cost-effective and portable SPR biosensor based on smart phones has many applications, such as medicine, health and environmental monitoring.

  12. Size-dependent surface plasmon resonance in silver silica nanocomposites

    International Nuclear Information System (INIS)

    Thomas, Senoy; Nair, Saritha K; Jamal, E Muhammad Abdul; Anantharaman, M R; Al-Harthi, S H; Varma, Manoj Raama

    2008-01-01

    Silver silica nanocomposites were obtained by the sol-gel technique using tetraethyl orthosilicate (TEOS) and silver nitrate (AgNO 3 ) as precursors. The silver nitrate concentration was varied for obtaining composites with different nanoparticle sizes. The structural and microstructural properties were determined by x-ray diffractometry (XRD), Fourier transform infrared spectroscopy (FTIR) and transmission electron microscopy (TEM). X-ray photoelectron spectroscopic (XPS) studies were done for determining the chemical states of silver in the silica matrix. For the lowest AgNO 3 concentration, monodispersed and spherical Ag crystallites, with an average diameter of 5 nm, were obtained. Grain growth and an increase in size distribution was observed for higher concentrations. The occurrence of surface plasmon resonance (SPR) bands and their evolution in the size range 5-10 nm is studied. For decreasing nanoparticle size, a redshift and broadening of the plasmon-related absorption peak was observed. The observed redshift and broadening of the SPR band was explained using modified Mie scattering theory

  13. Compact Surface Plasmon Resonance Sensor for Underwater Chemical Sensing Robot

    Directory of Open Access Journals (Sweden)

    Yuichi Minagawa

    2017-01-01

    Full Text Available This paper reports on the development of compact surface plasmon resonance (SPR sensors for mobile robot olfaction. Underwater robots benefit from olfactory sensing capabilities in various tasks including the search for unexploded ordnance and undersea wreckage. Although the SPR-based chemical sensor is a promising sensing platform, the cumbersome optical setup has been limiting its use on mobile robots. The proposed sensor employs a periodic metal structure formed on a self-assembled layer of polystyrene particles of 200 nm in diameter. With the grating of this size, SPR can be excited even with a simple LED light source. The change in the absorbance is simply measured using a photodiode. Demonstration of the proposed SPR sensor is provided by mounting the sensors on an underwater crayfish robot that autonomously searches for a chemical source. The fabricated sensor shows linear response to ascorbic acid for a concentration range from 20 to 80 mM. Responses of the bare and thiol-coated gold nanostructure to different chemical substances are presented to show the change in the selectivity of the sensor by the coating. Discussions are made on the importance of sample collection for the sensor to attain sensitive chemical detection on a mobile robot.

  14. Clenbuterol Assay by Spectral Imaging Surface Plasmon Resonance Biosensor System.

    Science.gov (United States)

    Wu, Yichuan; Yao, Manwen; Fang, Xiangyi; Yang, Yucong; Cheng, Xiaoli

    2015-11-01

    To prevent illegal use of clenbuterol and for quality control in the food industry, more efficient and reliable methods for clenbuterol detection are needed. In this study, clenbuterol was detected using a spectral imaging surface plasmon resonance sensor system via two inhibition methods: (1) the target site compensation method, in which anti-clenbuterol antibody was immobilized on the sensor chip as a bioprobe and (2) the solution competition method in which a clenbuterol-BSA conjugate was immobilized on the sensor chip as the bioprobe. The detectable clenbuterol concentration ranged between 6.25 and 100 μg/mL for both methods. The clenbuterol limit of detection for the target site compensation method and solution competition method are estimated to be 6.7 and 4.5 μg/mL, respectively. The proposed methods were successfully applied to the detection of clenbuterol molecules and were found to have high specificity and high-throughput and were label free and operationally convenient.

  15. Influence of the shear flow on electron cyclotron resonance plasma confinement in an axisymmetric magnetic mirror trap of the electron cyclotron resonance ion source

    International Nuclear Information System (INIS)

    Izotov, I. V.; Razin, S. V.; Sidorov, A. V.; Skalyga, V. A.; Zorin, V. G.; Bagryansky, P. A.; Beklemishev, A. D.; Prikhodko, V. V.

    2012-01-01

    Influence of shear flows of the dense plasma created under conditions of the electron cyclotron resonance (ECR) gas breakdown on the plasma confinement in the axisymmetric mirror trap (''vortex'' confinement) was studied experimentally and theoretically. A limiter with bias potential was set inside the mirror trap for plasma rotation. The limiter construction and the optimal value of the potential were chosen according to the results of the preliminary theoretical analysis. This method of ''vortex'' confinement realization in an axisymmetric mirror trap for non-equilibrium heavy-ion plasmas seems to be promising for creation of ECR multicharged ion sources with high magnetic fields, more than 1 T.

  16. RF atmospheric plasma jet surface treatment of paper

    Science.gov (United States)

    Pawlat, Joanna; Terebun, Piotr; Kwiatkowski, Michał; Diatczyk, Jaroslaw

    2016-09-01

    A radio frequency RF atmospheric pressure plasma jet was used to enhance the wettability of cellulose-based paper of 90 g m-2 and 160 g m-2 grammage as a perspective platform for antibiotic sensitivity tests. Helium and argon were the carrier gases for oxygen and nitrogen; pure water and rapeseed oil were used for goniometric tests. The influence of the flow rate and gas type, the power of the discharge, and distance from the nozzle was examined. The surface structure was observed using an optical microscope. Attenuated total reflection Fourier transform infrared (ATR-FTIR) spectra were investigated in order to determine whether cellulose degradation processes occurred. The RF plasma jet allowed us to decrease the surface contact angle without drastic changes in other features of the tested material. Experiments confirmed the significant influence of the distance between the treated sample and reactor nozzle, especially for treatment times longer than 15 s due to the greater concentration of reactive species at the surface of the sample, which decreases with distance—and their accumulation effect with time. The increase of discharge power plays an important role in decreasing the surface contact angle for times longer than 10 s. Higher power had a positive effect on the amount of generated active particles and facilitated the ignition of discharge. However, a too high value can cause a rise in temperature of the material and heat-caused damage.

  17. Multielement surface plasmon resonance immunosensor for monitoring of blood circulation system

    Science.gov (United States)

    Kostyukevych, Sergey A.; Kostyukevych, Kateryna V.; Khristosenko, Roman V.; Lysiuk, Viktor O.; Koptyukh, Anastasiya A.; Moscalenko, Nadiya L.

    2017-12-01

    The problems related to the development of a multielement immunosensor device with the prism type of excitation of a surface plasmon resonance in the Kretschmann configuration and with the scanning of the incidence angle of monochromatic light aimed at the reliable determination of the levels of three molecular markers of the system of hemostasis (fibrinogen, soluble fibrin, and D-dimer) are considered. We have analyzed the influence of a technology for the production of a gold coating, modification of its surface, and noise effects on the enhancement of sensitivity and stability of the operation of devices. A means of oriented immobilization of monoclonal antibodies on the surface of gold using a multilayer film of copper aminopentacyanoferrate is developed. For the model proteins of studied markers, the calibrating curves (maximum sensitivity of 0.5 μg/ml) are obtained, and the level of fibrinogen in blood plasma of donors is determined. A four-channel modification of the device with an application of a reference channel for comparing the elimination of the noise of temperature fluctuations has been constructed. This device allows one to execute the express-diagnostics of prethrombotic states and the monitoring of the therapy of diseases of the blood circulation system.

  18. Kinetic computer modeling of microwave surface-wave plasma production

    International Nuclear Information System (INIS)

    Ganachev, Ivan P.

    2004-01-01

    Kinetic computer plasma modeling occupies an intermediate position between the time consuming rigorous particle dynamic simulation and the fast but rather rough cold- or warm-plasma fluid models. The present paper reviews the kinetic modeling of microwave surface-wave discharges with accent on recent kinetic self-consistent models, where the external input parameters are reduced to the necessary minimum (frequency and intensity of the applied microwave field and pressure and geometry of the discharge vessel). The presentation is limited to low pressures, so that Boltzmann equation is solved in non-local approximation and collisional electron heating is neglected. The numerical results reproduce correctly the bi-Maxwellian electron energy distribution functions observed experimentally. (author)

  19. Improvement of silicon direct bonding using surfaces activated by hydrogen plasma treatment

    CERN Document Server

    Choi, W B; Lee Jae Sik; Sung, M Y

    2000-01-01

    The plasma surface treatment, using hydrogen gas, of silicon wafers was studied as a pretreatment for silicon direct bonding. Chemical reactions of the hydrogen plasma with the surfaces were used for both surface activation and removal of surface contaminants. Exposure of the silicon wafers to the plasma formed an active oxide layer on the surface. This layer was hydrophilic. The surface roughness and morphology were examined as functions of the plasma exposure time and power. The surface became smoother with shorter plasma exposure time and lower power. In addition, the plasma surface treatment was very efficient in removing the carbon contaminants on the silicon surface. The value of the initial surface energy, as estimated by using the crack propagation method, was 506 mJ/M sup 2 , which was up to about three times higher than the value for the conventional direct bonding method using wet chemical treatments.

  20. Grafting hyaluronic acid onto gold surface to achieve low protein fouling in surface plasmon resonance biosensors.

    Science.gov (United States)

    Liu, Xia; Huang, Renliang; Su, Rongxin; Qi, Wei; Wang, Libing; He, Zhimin

    2014-08-13

    Antifouling surfaces capable of reducing nonspecific protein adsorption from natural complex media are highly desirable in surface plasmon resonance (SPR) biosensors. A new protein-resistant surface made through the chemical grafting of easily available hyaluronic acid (HA) onto gold (Au) substrate demonstrates excellent antifouling performance against protein adsorption. AFM images showed the uniform HA layer with a thickness of ∼10.5 nm on the Au surface. The water contact angles of Au surfaces decreased from 103° to 12° with the covalent attachment of a carboxylated HA matrix, indicating its high hydrophilicity mainly resulted from carboxyl and amide groups in the HA chains. Using SPR spectroscopy to investigate nonspecific adsorption from single protein solutions (bovine serum albumin (BSA), lysozyme) and complex media (soybean milk, cow milk, orange juice) to an HA matrix, it was found that ultralow or low protein adsorptions of 0.6-16.1 ng/cm(2) (e.g., soybean milk: 0.6 ng/cm(2)) were achieved on HA-Au surfaces. Moreover, anti-BSA was chosen as a model recognition molecule to characterize the immobilization capacity and the antifouling performance of anti-BSA/HA surfaces. The results showed that anti-BSA/HA sensor surfaces have a high anti-BSA loading of 780 ng/cm(2), together with achieving the ultralow (<3 ng/cm(2) for lysozyme and soybean milk) or low (<17 ng/cm(2) for cow milk and 10% blood serum) protein adsorptions. Additionally, the sensor chips also exhibited a high sensitivity to BSA over a wide range of concentrations from 15 to 700 nM. Our results demonstrate a promising antifouling surface using extremely hydrophilic HA as matrix to resist nonspecific adsorption from complex media in SPR biosensors.

  1. Hybrid Surface Plasmon Polariton Modes of Subwavelength Nanowire Resonators

    DEFF Research Database (Denmark)

    Filonenko, Konstantin; Duggen, Lars; Willatzen, Morten

    2015-01-01

    -localized gap plasmon mode are studied depending on the vacuum wavelength. In order to directly compare resonators, where metal and semiconductor nanowires are employed, we consider the two resonators, both including silver slab and magnesium fluoride gap region, as is shown in figure. The two compared......We perform Comsol simulations of two types of hybrid plasmonic resonator configurations, similar to those proposed for nanowire plasmonic laser in [1] and [2]. In both references the nanowire - based plasmonic resonators are studied, which overall sizes are larger than the wavelength in vacuum....... However, it is advantageous for the nanolaser to have subwavelength sizes at least in two dimensions. Therefore, we study the two configurations and the hybrid mode behavior in the case, where resonator sizes are smaller than the half of the wavelength in vacuum. First, we assume finite dimensions...

  2. Metal-in-metal localized surface plasmon resonance

    International Nuclear Information System (INIS)

    Smith, G B; Earp, A A

    2010-01-01

    Anomalous strong resonances in silver and gold nanoporous thin films which conduct are found to arise from isolated metal nano-islands separated from the surrounding percolating metal network by a thin loop of insulator. This observed resonant optical response is modelled. The observed peak position is in agreement with the observed average dimensions of the silver core and insulator shell. As the insulating ring thickness shrinks, the resonance moves to longer wavelengths and strengthens. This structure is the Babinet's principle counterpart of dielectric core-metal shell nanoparticles embedded in dielectric. Like for the latter, tuning of resonant absorption is possible, but here the matrix reflects rather than transmits, and tuning to longer wavelengths is more practical. A new class of metal mirror occurring as a single thin layer is identified using the same resonances in dense metal mirrors. Narrow band deep localized dips in reflectance result.

  3. Silver nanoparticles plasmon resonance-based method for the determination of uric acid in human plasma and urine samples

    International Nuclear Information System (INIS)

    Amjadi, M.; Rahimpour, E.

    2012-01-01

    We have developed a simple and sensitive colorimetric procedure for the quantification of trace amounts of uric acid. It is based on the finding that uric acid in a medium containing ammonia and sodium hydroxide at 65 0 C can reduce silver ions to form yellow silver nanoparticles (Ag NPs). These are stabilized in solution by using poly(vinyl alcohol) as a capping agent. The yellow color of the solution that results from the localized surface plasmon resonance of Ag NPs can be observed by the bare eye. The absorbance at 415 nm is proportional to the concentration of uric acid which therefore can be determined quantitatively. The calibration curve is linear in the concentration range from 10 to 200 nM, with a limit of detection of 3.3 nM. The method was successfully applied to the determination of uric acid in human plasma and urine samples. (author)

  4. Plasma studies of the permanent magnet electron cyclotron resonance ion source at Peking University

    Energy Technology Data Exchange (ETDEWEB)

    Ren, H. T.; Peng, S. X., E-mail: sxpeng@pku.edu.cn; Xu, Y.; Zhao, J.; Lu, P. N.; Chen, J.; Zhang, A. L.; Zhang, T.; Guo, Z. Y.; Chen, J. E. [State Key Laboratory of Nuclear Physics and Technology, Institute of Heavy Ion Physics, Peking University, Beijing 100871 (China)

    2014-02-15

    At Peking University (PKU) we have developed several 2.45 GHz Permanent Magnet Electron Cyclotron Resonance ion sources for PKUNIFTY, SFRFQ, Coupled RFQ and SFRFQ, and Dielectric-Wall Accelerator (DWA) projects (respectively, 50 mA of D{sup +}, 10 mA of O{sup +}, 10 mA of He{sup +}, and 50 mA of H{sup +}). In order to improve performance of these ion sources, it is necessary to better understand the principal factors that influence the plasma density and the atomic ion fraction. Theoretical analysis about microwave transmission and cut-off inside the discharge chamber were carried out to study the influence of the discharge chamber diameters. As a consequence, experimental studies on plasma density and ion fraction with different discharge chamber sizes have been carried out. Due to the difficulties in measuring plasma density inside the discharge chamber, the output beam current was measured to reflect the plasma density. Experimental results show that the plasma density increases to the maximum and then decreases significantly as the diameter changed from 64 mm to 30 mm, and the atomic ion fraction has the same tendency. The maximum beam intensity was obtained with the diameter of 35 mm, but the maximum atomic ion fraction with a diameter of 40 mm. The experimental results are basically accordant with the theoretical calculation. Details are presented in this paper.

  5. Nanostructure formation on refractory metal surfaces irradiated by helium plasmas

    International Nuclear Information System (INIS)

    Takamura, Shuichi; Kajita, Shin; Ohno, Noriyasu

    2013-01-01

    Helium defects on plasma-facing refractory metals like tungsten have been studied in fusion sciences from the view point of the effects on metal surface properties, concentrating on the bubble formation. However, the surface morphology over the lower surface temperature range was found recently to be changed drastically, something like cotton down or arborescence, sometimes called as “fuzz”. The formation process, although still open problem, would be discussed in terms of viscoelastic model with the effect of surface tension, taking account of its thermal properties and nano-bubbles inside the thin fibers. Some physical surface characteristics like electron emission, radiation emissivity and sputtering are quite influenced by its forest-like structure. Unipolar arcing has been newly studied by using such a surface structure which makes its initiation controllable. In the present report, other examples of nanostructure formation in a variety of particle incident conditions have been introduced as well as the possibility of its industrial applications to enhance interdisciplinary interests. (author)

  6. Active screen plasma nitriding enhances cell attachment to polymer surfaces

    International Nuclear Information System (INIS)

    Kaklamani, Georgia; Bowen, James; Mehrban, Nazia; Dong, Hanshan; Grover, Liam M.; Stamboulis, Artemis

    2013-01-01

    Active screen plasma nitriding (ASPN) is a well-established technique used for the surface modification of materials, the result of which is often a product with enhanced functional performance. Here we report the modification of the chemical and mechanical properties of ultra-high molecular weight poly(ethylene) (UHMWPE) using 80:20 (v/v) N 2 /H 2 ASPN, followed by growth of 3T3 fibroblasts on the treated and untreated polymer surfaces. ASPN-treated UHMWPE showed extensive fibroblast attachment within 3 h of seeding, whereas fibroblasts did not successfully attach to untreated UHMWPE. Fibroblast-coated surfaces were maintained for up to 28 days, monitoring their metabolic activity and morphology throughout. The chemical properties of the ASPN-treated UHMWPE surface were studied using X-ray photoelectron spectroscopy, revealing the presence of C-N, C=N, and C≡N chemical bonds. The elastic modulus, surface topography, and adhesion properties of the ASPN-treated UHMWPE surface were studied over 28 days during sample storage under ambient conditions and during immersion in two commonly used cell culture media.

  7. Physical plasma in biological solids: a possible mechanism for resonant interactions between low intensity microwaves and biological systems.

    Science.gov (United States)

    Zon, J R

    1979-01-01

    Observed semiconductor properties of biological material in vitro indicate possible involvement of semiconduction in biological processes. Since in inorganic semiconductors solid-state plasma occurs, it is hypothesized that in organic semiconductors solid-state plasma similarly occurs. Some results of experimental investigation of resonant effects of microwaves in biological systems are considered in the light of that hypothesis. The conditions necessary for the existence of physical plasma in biological solid structures are discussed, and certain parameters of physical plasma in these structures are evaluated. Its is proposed that microwave radiation may support or damp plasma oscillations, thereby stimulating or suppressing biological functions.

  8. Laser-induced plasma spectrometry: truly a surface analytical tool

    International Nuclear Information System (INIS)

    Vadillo, Jose M.; Laserna, J.

    2004-01-01

    For a long period, analytical applications of laser induced plasma spectrometry (LIPS) have been mainly restricted to overall and quantitative determination of elemental composition in bulk, solid samples. However, introduction of new compact and reliable solid state lasers and technological development in multidimensional intensified detectors have made possible the seeking of new analytical niches for LIPS where its analytical advantages (direct sampling from any material irrespective of its conductive status without sample preparation and with sensitivity adequate for many elements in different matrices) could be fully exploited. In this sense, the field of surface analysis could take advantage from the cited advantages taking into account in addition, the capability of LIPS for spot analysis, line scan, depth-profiling, area analysis and compositional mapping with a single instrument in air at atmospheric pressure. This review paper outlines the fundamental principles of laser-induced plasma emission relevant to sample surface studies, discusses the experimental parameters governing the spatial (lateral and in-depth) resolution in LIPS analysis and presents the applications concerning surface examination

  9. V.U.V. plasma spectroscopy diagnostic of electron cyclotron resonance multicharged ion sources

    International Nuclear Information System (INIS)

    Berreby, R.

    1997-12-01

    To characterize the multicharged ions within the plasma of an E.C.R. ion source, the V.U.V. spectroscopy is used as a non invasive diagnostic of excited matter. In E.C.R.I. S. (electron cyclotron resonance ion source) electrons are heated and magnetically confined within the mirror machine to overcome the successive ionization potentials of the desired elements. As the electrons bounce inside the magnetic configuration in their gyration movement, they interact with the microwaves injected into the source at the resonance frequency. To enhance the performances in high charge states and extracted currents delivered by E.C.R.I.S., the fundamental parameters of the plasma created in these machines must be known. The goal of spectroscopic diagnostics in the V.U.V. range installed on the sources is to determine electron density and temperature on one hand, and the ionic densities and confinement time on the other hand. We used microchannel plates as detector on a 3 meter grazing incidence spectrometer equipped with a 600 lines/mm holographic grating. The calibration of the whole grating with detector was performed by two different methods. These are the branching ratio and charge exchange methods. Identification of lines emitted by a plasma, which gather the whole charge states of ions is necessary to make an exhaustive study of the plasma state. And finally, the determination of plasma parameters like electron density and temperature and ion densities and confinement times that uses theoretical models were the aim of this work. (author)

  10. Surface Plasmon Resonance Immunosensor for the Detection of Campylobacter jejuni

    Directory of Open Access Journals (Sweden)

    Noor Azlina Masdor

    2017-05-01

    Full Text Available Campylobacteriosis is an internationally important foodborne disease caused by Campylobacter jejuni. The bacterium is prevalent in chicken meat and it is estimated that as much as 90% of chicken meat on the market may be contaminated with the bacterium. The current gold standard for the detection of C. jejuni is the culturing method, which takes at least 48 h to confirm the presence of the bacterium. Hence, the aim of this work was to investigate the development of a Surface Plasmon Resonance (SPR sensor platform for C. jejuni detection. Bacterial strains were cultivated in-house and used in the development of the sensor. SPR sensor chips were first functionalized with polyclonal antibodies raised against C. jejuni using covalent attachment. The gold chips were then applied for the direct detection of C. jejuni. The assay conditions were then optimized and the sensor used for C. jejuni detection, achieving a detection limit of 8 × 106 CFU·mL−1. The sensitivity of the assay was further enhanced to 4 × 104 CFU·mL−1 through the deployment of a sandwich assay format using the same polyclonal antibody. The LOD obtained in the sandwich assay was higher than that achieved using commercial enzyme-linked immunosorbent assay (ELISA (106–107 CFU·mL−1. This indicate that the SPR-based sandwich sensor method has an excellent potential to replace ELISA tests for C. jejuni detection. Specificity studies performed with Gram-positive and Gram-negative bacteria, demonstrated the high specific of the sensor for C. jejuni.

  11. Direct observation of a surface resonance state and surface band inversion control in black phosphorus

    Science.gov (United States)

    Ehlen, N.; Sanna, A.; Senkovskiy, B. V.; Petaccia, L.; Fedorov, A. V.; Profeta, G.; Grüneis, A.

    2018-01-01

    We report a Cs-doping-induced band inversion and the direct observation of a surface resonance state with an elliptical Fermi surface in black phosphorus (BP) using angle-resolved photoemission spectroscopy. By selectively inducing a higher electron concentration (1.7 ×1014cm-2 ) in the topmost layer, the changes in the Coulomb potential are sufficiently large to cause surface band inversion between the parabolic valence band of BP and a parabolic surface state around the Γ point of the BP Brillouin zone. Tight-binding calculations reveal that band gap openings at the crossing points in the two high-symmetry directions of the Brillouin zone require out-of-plane hopping and breaking of the glide mirror symmetry. Ab initio calculations are in very good agreement with the experiment if a stacking fault on the BP surface is taken into account. The demonstrated level of control over the band structure suggests the potential application of few-layer phosphorene in topological field-effect transistors.

  12. Development and studies on a compact electron cyclotron resonance plasma source

    Science.gov (United States)

    Ganguli, A.; Tarey, R. D.; Arora, N.; Narayanan, R.

    2016-04-01

    It is well known that electron cyclotron resonance (ECR) produced plasmas are efficient, high-density plasma sources and have many industrial applications. The concept of a portable compact ECR plasma source (CEPS) would thus become important from an application point of view. This paper gives details of such a CEPS that is both portable and easily mountable on a chamber of any size. It uses a fully integrated microwave line operating at 2.45 GHz, up to 800 W, cw. The required magnetic field is produced by a set of suitably designed NdFeB ring magnets; the device has an overall length of  ≈60 cm and weighs  ≈14 kg including the permanent magnets. The CEPS was attached to a small experimental chamber to judge its efficacy for plasma production. In the pressure range of 0.5-10 mTorr and microwave power of  ≈400-500 W the experiments indicate that the CEPS is capable of producing high-density plasma (≈9  ×  1011-1012 cm-3) with bulk electron temperature in the range  ≈2-3 eV. In addition, a warm electron population with density and temperature in the range ≈7  ×  108-109 cm-3 and  ≈45-80 eV, respectively has been detected. This warm population plays an important role at high pressures in maintaining the high-density plasma, when plasma flow from the CEPS into the test chamber is strongly affected.

  13. Comparison Between the Trajectories of Electric Field Resonances and those of Rational Surfaces in TJ-II

    International Nuclear Information System (INIS)

    Guasp, J.; Liniers, M.

    2000-01-01

    Both the radial electric field resonance case and the corresponding to rational magnetic surfaces, show a number of similar behaviours: a) Strong sensitivity of the passing particle loss fraction, and mainly of their los times, to lower order rational values of the ratio between the poloidal and toroidal rotation angular velocities. b) In both cases there exist similar simple analytical models that allow qualitative predictions for the phase space regions where resonant effects can be expected. c) Strong similitude of trajectories, as well in the Poincare diagrams as in the angular maps. Near the resonant regions a extreme minimization of the radial excursion appears, and both diagrams present a minimum filling. At both sides of these regions there are wide excursions, directed alternatively towards the inner and the outer parts of the plasma. Far from these resonant zones the diagrams filling comes back to be continuous. d) All these behaviours are more marked, and the topology change more sudden, the lower is the periodicity order of the resonance, and are extremely clear for the 1/3 and 1/2 cases. This wealth of similar behaviour suggests a single origin for all these phenomena, linked with the trajectory topology, that will be the subject of a specific study. (Author) 13 refs

  14. Infrared Surface-Plasmon-Resonance -- a novel biophysical tool for studying living cell

    OpenAIRE

    Golosovsky, M.; Lirtsman, V.; Yashunsky, V.; Davidov, D.; Aroeti, B.

    2009-01-01

    We discuss the Surface-Plasmon-Resonance (SPR) technique based on Fourier -Transform - InfraRed (FTIR) spectrometry. We explore the potential of the infrared surface plasmon resonance technique for biological studies in aqueous solutions and compare it to the conventional surface plasmon technique operating in the visible range. We demonstrate that the sensitivity of the SPR technique in the infrared range is not lower and in fact is even higher. We show several examples of applying FTIR-SPR ...

  15. Use of Atmospheric-Pressure Plasma Jet for Polymer Surface Modification: An Overview

    Energy Technology Data Exchange (ETDEWEB)

    Kuettner, Lindsey A. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-03-16

    Atmospheric-pressure plasma jets (APPJs) are playing an increasingly important role in materials processing procedures. Plasma treatment is a useful tool to modify surface properties of materials, especially polymers. Plasma reacts with polymer surfaces in numerous ways thus the type of process gas and plasma conditions must be explored for chosen substrates and materials to maximize desired properties. This report discusses plasma treatments and looks further into atmospheric-pressure plasma jets and the effects of gases and plasma conditions. Following the short literature review, a general overview of the future work and research at Los Alamos National Laboratory (LANL) is discussed.

  16. [Elimination of haloperidol from erythrocytes surfaces supernatant and blood plasma].

    Science.gov (United States)

    Shanidze, L A

    2005-01-01

    The aim of the study was to investigate the adsorption rate of haloperidol on erythrocytes surfaces. The pharmacokinetic and pharmacodynamic parameters of haloperidol were monitored in the experiment. The neuroleptic was administered to 12 adult dogs and the blood samples were collected for further analysis following 20, 30, 60, 180, 240, 360, 420 and 480 minutes after the injection. The groups of samples (blood plasma and supernatant) were monitored during this period. The differences between haloperidol concentration in the supernatant and blood plasma were compared. Our data have shown that dynamics of the elimination of intact and acidified forms of haloperidol from the supernatant and the blood serum are not the same. Intact and acidified forms are differently regulated by plasma. albumines and globulines. The process of redistribution of haloperidol between the both substrates takes place, while the supernatant has a donor function for the free form of haloperidol and represents the acceptor of the haloperidol's metabolites. This provides the possibility to develop multidiscipline approach to the optimization to the prescription of haloperidol.

  17. Investigation of plasma–surface interaction at plasma beam facilities

    Energy Technology Data Exchange (ETDEWEB)

    Kurnaev, V., E-mail: kurnaev@plasma.mephi.ru [National Research Nuclear University MEPhI (Moscow Engineering Physics Institute), Kashirskoe sh. 31, 115409 Moscow (Russian Federation); Vizgalov, I.; Gutorov, K. [National Research Nuclear University MEPhI (Moscow Engineering Physics Institute), Kashirskoe sh. 31, 115409 Moscow (Russian Federation); Tulenbergenov, T.; Sokolov, I.; Kolodeshnikov, A.; Ignashev, V.; Zuev, V.; Bogomolova, I. [Institute of Atomic Energy, National Nuclear Center the Republic of Kazakhstan, Street Krasnoarmejsky, 10, 071100 Kurchatov (Kazakhstan); Klimov, N. [SRC RF TRINITI, ul. Pushkovykh, vladenie 12, Troitsk, 142190 Moscow (Russian Federation)

    2015-08-15

    The new Plasma Beam Facility (PBF) has been put into operation for assistance in testing of plasma faced components at Material Science Kazakhstan Tokamak (KTM). PBF includes a powerful electron gun (up to 30 kV, 1 A) and a high vacuum chamber with longitudinal magnetic field coils (up to 0.2 T). The regime of high vacuum electron beam transportation is used for thermal tests with power density at the target surface up to 10 GW/m{sup 2}. The beam plasma discharge (BPD) regime with a gas-puff is used for generation of intensive ion fluxes up to 3 ⋅ 10{sup 22} m{sup −2} s{sup −1}. Initial tests of the KTM PBF’s capabilities were carried out: various discharge regimes, carbon deposits cleaning, simultaneous thermal and ion impacts on radiation cooled refractory targets. With a water-cooled target the KTM PBF could be used for high heat flux tests of materials (validated by the experiment with W mock-up at the PR-2 PBF)

  18. Enhanced biocompatibility of TiO2 surfaces by highly reactive plasma

    International Nuclear Information System (INIS)

    Junkar, Ita; Recek, Nina; Kovač, Janez; Mozetič, Miran; Kulkarni, Mukta; Iglič, Aleš; Drašler, Barbara; Rugelj, Neža; Drobne, Damjana; Humpolicek, Petr

    2016-01-01

    In the present study the biological response to various nanotopographic features after gaseous plasma treatment were studied. The usefulness of nanostructured surfaces for implantable materials has already been acknowledged, while less is known on the combined effect of nanostructured plasma modified surfaces. In the present work the influence of oxygen plasma treatment on nanostructured titanium oxide (TiO 2 ) surfaces was studied. Characterization of the TiO 2 surface chemical composition and morphological features was analyzed after plasma modification by x-ray photoelectron spectroscopy and by scanning electron microscopy while surface wettability was studied with measuring the water contact angle. Cell adhesion and morphology was assessed from images taken with scanning electron microscopy, whereas cell viability was measured with a calorimetric assay. The obtained results showed that oxygen plasma treatment of TiO 2 nanotube surfaces significantly influences the adhesion and morphology of osteoblast-like cells in comparison to untreated nanostructured surfaces. Marked changes in surface composition of plasma treated surfaces were observed, as plasma treatment removed hydrocarbon contamination and removed fluorine impurities, which were present due to the electrochemical anodization process. However no differences in wettability of untreated and plasma treated surfaces were noticed. Treatment with oxygen plasma stimulated osteoblast-like cell adhesion and spreading on the nanostructured surface, suggesting the possible use of oxygen plasma surface treatment to enhance osteoblast-like cell response. (paper)

  19. Surface temperature measurement of plasma facing components in tokamaks

    International Nuclear Information System (INIS)

    Amiel, Stephane

    2014-01-01

    During this PhD, the challenges on the non-intrusive surface temperature measurements of metallic plasma facing components in tokamaks are reported. Indeed, a precise material emissivity value is needed for classical infrared methods and the environment contribution has to be known particularly for low emissivities materials. Although methods have been developed to overcome these issues, they have been implemented solely for dedicated experiments. In any case, none of these methods are suitable for surface temperature measurement in tokamaks.The active pyrometry introduced in this study allows surface temperature measurements independently of reflected flux and emissivities using pulsed and modulated photothermal effect. This method has been validated in laboratory on metallic materials with reflected fluxes for pulsed and modulated modes. This experimental validation is coupled with a surface temperature variation induced by photothermal effect and temporal signal evolvement modelling in order to optimize both the heating source characteristics and the data acquisition and treatment. The experimental results have been used to determine the application range in temperature and detection wavelengths. In this context, the design of an active pyrometry system on tokamak has been completed, based on a bicolor camera for a thermography application in metallic (or low emissivity) environment.The active pyrometry method introduced in this study is a complementary technique of classical infrared methods used for thermography in tokamak environment which allows performing local and 2D surface temperature measurements independently of reflected fluxes and emissivities. (author) [fr

  20. Resonance-enhanced laser-induced plasma spectroscopy: ambient gas effects

    International Nuclear Information System (INIS)

    Lui, S.L.; Cheung, N.H.

    2003-01-01

    When performing laser-induced plasma spectroscopy for elemental analysis, the sensitivity could be significantly enhanced if the plume was resonantly rekindled by a dye laser pulse. The extent of the enhancement was found to depend on the ambient gas. Air, nitrogen, helium, argon and xenon at pressures ranging from vacuum to 1 bar were investigated. In vacuum, the analyte signal was boosted because of reduced cooling, but it soon decayed as the plume freely expanded. By choosing the right ambient gas at the right pressure, the expanding plume could be confined as well as thermally insulated to maximize the analyte signal. For instance, an ambient of 13 mbar xenon yielded a signal-to-noise ratio of 110. That ratio was 53 when the pellet was ablated in air, and decreased further to 5 if the dye laser was tuned off resonance

  1. Properties of the ion-ion hybrid resonator in fusion plasmas

    International Nuclear Information System (INIS)

    Morales, George J.

    2015-01-01

    The project developed theoretical and numerical descriptions of the properties of ion-ion hybrid Alfvn resonators that are expected to arise in the operation of a fusion reactor. The methodology and theoretical concepts were successfully compared to observations made in basic experiments in the LAPD device at UCLA. An assessment was made of the excitation of resonator modes by energetic alpha particles for burning plasma conditions expected in the ITER device. The broader impacts included the generation of basic insight useful to magnetic fusion and space science researchers, defining new avenues for exploration in basic laboratory experiments, establishing broader contacts between experimentalists and theoreticians, completion of a Ph.D. dissertation, and promotion of interest in science through community outreach events and classroom instruction.

  2. Surface Treatment of PET Nonwovens with Atmospheric Plasma

    International Nuclear Information System (INIS)

    Li Shufang

    2013-01-01

    In this study, polyethylene-terephthalate (PET) nonwovens are treated using an atmospheric plasma and the effects of the treatment time, treatment power and discharge distance on the ability of water-penetration into the nonwovens are investigated. The result indicates that the method can improve the wettability of PET nonwovens remarkably, but the aging decay of the sample's wettability is found to be notable as a function of the storage time after treatment due to the internal rotation of the single bond of surface macromolecules. As shown by SEM and XPS analysis, the etching and surface reaction are significant, and water-penetration weight is found to increase remarkably with the increasing power. This variation can be attributed to momentum transfer and enhanced higher-energy particle excitation.

  3. The parametric resonance features for theory of energy transfer in dusty plasma

    Science.gov (United States)

    Semyonov, V. P.; Timofeev, A. V.

    2015-11-01

    One of the mechanisms of energy transfer between degrees of freedom of dusty plasma system can be described by equations similar to Mathieu equation with account of stochastic forces. Such equation is studied by analytical approach. The solutions for higher order of accuracy are obtained. The method for numerical solution and resonance zone detection is proposed. The solution for the extended Mathieu equation is obtained for wide range of parameter values. The results of numerical solution are compared with analytical solutions of different order and known analytical results for Mathieu equation.

  4. Fractional Boltzmann equation for multiple scattering of resonance radiation in low-temperature plasma

    Energy Technology Data Exchange (ETDEWEB)

    Uchaikin, V V; Sibatov, R T, E-mail: vuchaikin@gmail.com, E-mail: ren_sib@bk.ru [Ulyanovsk State University, 432000, 42 Leo Tolstoy str., Ulyanovsk (Russian Federation)

    2011-04-08

    The fractional Boltzmann equation for resonance radiation transport in plasma is proposed. We start with the standard Boltzmann equation; averaging over photon frequencies leads to the appearance of a fractional derivative. This fact is in accordance with the conception of latent variables leading to hereditary and non-local dynamics (in particular, fractional dynamics). The presence of a fractional material derivative in the equation is concordant with heavy tailed distribution of photon path lengths and with spatiotemporal coupling peculiar to the process. We discuss some methods of solving the obtained equation and demonstrate numerical results in some simple cases.

  5. Fractional Boltzmann equation for multiple scattering of resonance radiation in low-temperature plasma

    International Nuclear Information System (INIS)

    Uchaikin, V V; Sibatov, R T

    2011-01-01

    The fractional Boltzmann equation for resonance radiation transport in plasma is proposed. We start with the standard Boltzmann equation; averaging over photon frequencies leads to the appearance of a fractional derivative. This fact is in accordance with the conception of latent variables leading to hereditary and non-local dynamics (in particular, fractional dynamics). The presence of a fractional material derivative in the equation is concordant with heavy tailed distribution of photon path lengths and with spatiotemporal coupling peculiar to the process. We discuss some methods of solving the obtained equation and demonstrate numerical results in some simple cases.

  6. Production of Polarized Ions with Nearly Resonant Charge-Exchange Collisions in Plasma

    Science.gov (United States)

    Belov, A. S.

    2008-02-01

    Review of results of development of polarized ion sources with nearly resonant charge-exchange plasma ionizer is presented. Pulsed beams of polarized protons with peak intensity up to 11 mA and polarization of 80% and polarized negative hydrogen ions with peak current of 4 mA and polarization of 91% have been obtained. Polarized deuterons, negative deuterium ions and 3He++ ions can be produced by this method as well. A study of a pulsed polarized atomic hydrogen beam has been performed. It was found that intensity of the pulsed atomic hydrogen beam is limited by a beam-skimmer interference and by noncomplete cooling of hydrogen atoms.

  7. Production of Polarized Ions with Nearly Resonant Charge-Exchange Collisions in Plasma

    International Nuclear Information System (INIS)

    Belov, A. S.

    2008-01-01

    Review of results of development of polarized ion sources with nearly resonant charge-exchange plasma ionizer is presented. Pulsed beams of polarized protons with peak intensity up to 11 mA and polarization of 80% and polarized negative hydrogen ions with peak current of 4 mA and polarization of 91% have been obtained. Polarized deuterons, negative deuterium ions and 3 He ++ ions can be produced by this method as well. A study of a pulsed polarized atomic hydrogen beam has been performed. It was found that intensity of the pulsed atomic hydrogen beam is limited by a beam-skimmer interference and by noncomplete cooling of hydrogen atoms

  8. Nonlocal weakly relativistic permittivity tensor of magnetized plasma near electron cyclotron resonances

    Science.gov (United States)

    Sakharov, A. S.

    2017-11-01

    Compact expressions are derived for the nonlocal permittivity tensor of weakly relativistic plasma in a 2D nonuniform magnetic field near the resonances at the second harmonic of the electron cyclotron frequency for an extraordinary wave and at the first harmonic for an ordinary wave. It is shown that the wave equation with allowance for the obtained thermal correction to the permittivity tensor in the form of a differential operator in transverse (with respect to the external magnetic field) coordinates possesses an integral in the form of the energy conservation law.

  9. Surface conductivity dependent dynamic behaviour of an ultrafine atmospheric pressure plasma jet for microscale surface processing

    Energy Technology Data Exchange (ETDEWEB)

    Abuzairi, Tomy [Graduate School of Science and Technology, Shizuoka University, Hamamatsu 432-8561 (Japan); Department of Electrical Engineering, Faculty of Engineering, Universitas Indonesia, Depok 16424 (Indonesia); Okada, Mitsuru [Department of Engineering, Shizuoka University, Hamamatsu 432-8561 (Japan); Bhattacharjee, Sudeep [Department of Physics, Indian Institute of Technology, Kanpur 208016 (India); Nagatsu, Masaaki, E-mail: nagatsu.masaaki@shizuoka.ac.jp [Graduate School of Science and Technology, Shizuoka University, Hamamatsu 432-8561 (Japan); Department of Engineering, Shizuoka University, Hamamatsu 432-8561 (Japan); Research Institute of Electronics, Shizuoka University, Hamamatsu 432-8561 (Japan)

    2016-12-30

    Highlights: • Spatio-temporal behaviors of capillary APPJs are studied for various substrates. • Plasma irradiation area depended on the substrate conductivity and permittivity. • Surface irradiation area was significantly broadened in polymer-like substrate. • Effect of applying a substrate bias on the APPJ irradiation area was investigated. - Abstract: An experimental study on the dynamic behaviour of microcapillary atmospheric pressure plasma jets (APPJs) with 5 μm tip size for surfaces of different conductivity is reported. Electrical and spatio-temporal characteristics of the APPJs are monitored using high voltage probe, current monitor and high speed intensified charge couple device camera. From these experimental results, we presented a simple model to understand the electrical discharge characteristics of the capillary APPJs with double electrodes, and estimated the velocity of the ionization fronts in the jet and the electron density to be 3.5–4.2 km/s and 2–7 × 10{sup 17} m{sup −3}. By analyzing the dynamics of the microcapillary APPJs for different substrate materials, it was found that the surface irradiation area strongly depended on the substrate conductivity and permittivity, especially in the case of polymer-like substrate, surface irradiation area was significantly broadened probably due to the repelling behaviour of the plasma jets from the accumulated electrical charges on the polymer surface. The effect of applying a substrate bias in the range from −900 V to +900 V on the plasma irradiation onto the substrates was also investigated. From the knowledge of the present results, it is helpful for choosing the substrate materials for microscale surface modification.

  10. Poloidal rotation driven by electron cyclotron resonance wave in tokamak plasmas

    Directory of Open Access Journals (Sweden)

    Qing Zhou

    2017-10-01

    Full Text Available The poloidal electric filed, which is the drive field of poloidal rotation, has been observed and increases obviously after the injection of electron cyclotron resonance wave in HL-2A experiment, and the amplitude of the poloidal electric field is in the order of 103 V/m. Through theoretical analysis using Stringer rotation model, the observed poloidal electric field is of the same order as the theoretical calculation value. In addition, the magnetic pump damping which would damp the poloidal rotation is calculated numerically and the calculation results show that the closer to the core plasmas, the stronger the magnetic pump damping will be. Meanwhile, according to the value of the calculated magnetic pump damping, the threshold of the poloidal electric field which could overcome magnetic pump damping and drive poloidal rotation in tokamak plasmas is given out. Finally, the poloidal rotation velocity over time at different minor radius is studied theoretically.

  11. Plasma-induced magnetic responses during nonlinear dynamics of magnetic islands due to resonant magnetic perturbations

    Energy Technology Data Exchange (ETDEWEB)

    Nishimura, Seiya, E-mail: n-seiya@kobe-kosen.ac.jp [Kobe City College of Technology, Kobe, Hyogo 651-2194 (Japan)

    2014-12-15

    Resonant magnetic perturbations (RMPs) produce magnetic islands in toroidal plasmas. Self-healing (annihilation) of RMP-induced magnetic islands has been observed in helical systems, where a possible mechanism of the self-healing is shielding of RMP penetration by plasma flows, which is well known in tokamaks. Thus, fundamental physics of RMP shielding is commonly investigated in both tokamaks and helical systems. In order to check this mechanism, detailed informations of magnetic island phases are necessary. In experiments, measurement of radial magnetic responses is relatively easy. In this study, based on a theoretical model of rotating magnetic islands, behavior of radial magnetic fields during the self-healing is investigated. It is confirmed that flips of radial magnetic fields are typically observed during the self-healing. Such behavior of radial magnetic responses is also observed in LHD experiments.

  12. Parallel ion flow velocity measurement using laser induced fluorescence method in an electron cyclotron resonance plasma

    International Nuclear Information System (INIS)

    Yoshimura, Shinji; Okamoto, Atsushi; Terasaka, Kenichiro; Ogiwara, Kohei; Tanaka, Masayoshi Y.; Aramaki, Mitsutoshi

    2010-01-01

    Parallel ion flow velocity along a magnetic field has been measured using a laser induced fluorescence (LIF) method in an electron cyclotron resonance (ECR) argon plasma with a weakly-diverging magnetic field. To measure parallel flow velocity in a cylindrical plasma using the LIF method, the laser beam should be injected along device axis; however, the reflection of the incident beam causes interference between the LIF emission of the incident and reflected beams. Here we present a method of quasi-parallel laser injection at a small angle, which utilizes the reflected beam as well as the incident beam to obtain the parallel ion flow velocity. Using this method, we observed an increase in parallel ion flow velocity along the magnetic field. The acceleration mechanism is briefly discussed on the basis of the ion fluid model. (author)

  13. Atmospheric pressure plasma surface modification of titanium for high temperature adhesive bonding

    NARCIS (Netherlands)

    Akram, M.; Jansen, K.M.B.; Ernst, L.J.; Bhowmik, S.

    2011-01-01

    In this investigation surface treatment of titanium is carried out by plasma ion implantation under atmospheric pressure plasma in order to increase the adhesive bond strength. Prior to the plasma treatment, titanium surfaces were mechanically treated by sand blasting. It is observed that the

  14. Focal Adhesion of Osteoblastic Cells on Titanium Surface with Amine Functionalities Formed by Plasma Polymerization

    Science.gov (United States)

    Song, Heesang; Jung, Sang Chul; Kim, Byung Hoon

    2012-08-01

    To enhance the focal adhesion of osteoblastic cells on a titanium surface, plasma polymerized allyl amine (AAm) thin films were deposited by plasma polymerization. This plasma polymer functionalization of titanium is advantageous for osteoblastic focal adhesion formation. Such Ti surfaces are useful for the fabrication of titanium-based dental implants for enhancement of osseointegration.

  15. Behavior of plasma facing surface in the large helical device

    International Nuclear Information System (INIS)

    Hino, T.; Nobuta, Y.; Sagara, A.

    2002-01-01

    Material probes have been installed at the inner walls along poloidal direction in LHD from the first experimental campaign. After each campaign, the impurity deposition and the gas retention have been examined to clarify the plasma surface interaction and the degree of wall cleaning. In the 2nd campaign, the entire wall was considerably cleaned by helium glow discharge conditionings. For the 3rd and 4th campaigns, graphite tiles were installed at entire divertor strike region, and then the wall condition significantly changed compared to the case of stainless steel wall. The erosion of graphite took place during the main discharges and the eroded carbon deposited on the entire wall. In particular, the deposition thickness was large at the wall far from the plasma. Since the entire wall was well carbonized, amount of retained discharge gas such as H and He became large. In particular, the helium retention was large at the position close to the anodes used for helium glow discharge cleanings. One characteristics of the LHD wall is a large retention of helium gas since the wall temperature is limited below 368 K. In order to reduce the recycling of discharge gas, the wall heating before the experimental campaign and the surface heating between the main discharge shots are planned. (author)

  16. Behavior of plasma facing surfaces in the large helical device

    International Nuclear Information System (INIS)

    Hino, T.; Nobuta, Y.; Sagara, A.

    2003-01-01

    Material probes have been installed at the inner walls along the poloidal direction in LHD from the first experimental campaign. After each campaign, the impurity deposition and the gas retention have been examined to clarify the plasma surface interaction and the degree of wall cleaning. In the 2nd campaign, the entire wall was thoroughly cleaned by helium glow discharge conditioning. For the 3rd and 4th campaigns, graphite tiles were installed over the entire divertor strike region, and then the wall condition was significantly changed compared to the case of a stainless steel wall. Graphite erosion took place during the main discharges and the eroded carbon was deposited on the entire wall. In particular, the deposition thickness was large at the wall far from the plasma. Since the entire wall was well carbonized, the amount of retained discharge gases such as H and He became large. In particular, the helium retention was large at the position close to the anodes used for helium glow discharge cleanings. One characteristic of the LHD wall is a large retention of helium gas since the wall temperature is limited to below 368 K. In order to reduce the recycling of discharge gas, wall heating before the experimental campaign and surface heating between the main discharge shots are planned. (author)

  17. Behavior of plasma facing surface in the large helical device

    International Nuclear Information System (INIS)

    Hino, T.; Nobuta, Y.; Sagara, A.

    2002-10-01

    Material probes have been installed at the inner walls along poloidal direction in LHD from the first experimental campaign. After each the campaign, the impurity deposition and the gas retention have been examined to clarify the plasma surface interaction and the degree of wall cleaning. In the 2nd campaign, the entire wall was considerably cleaned by helium glow discharge conditionings. For the 3rd and 4th campaigns, graphite tiles were installed at entire divertor strike region, and then the wall condition significantly changed compared to the case of stainless steel wall. The erosion of graphite took place during the main discharges and the eroded carbon deposited on the entire wall. In particular, the deposition thickness was large at the wall far from the plasma. Since the entire wall was well carbonized, amount of retained discharge gas such as H and He became large. In particular, the helium retention was large at the position close to the anodes used for helium glow discharge cleanings. One characteristics of the LHD wall is a large retention of helium gas since the wall temperature is limited below 368 K. In order to reduce the recycling of discharge gas, the wall heating before the experimental campaign and the surface heating between the main discharge shots are planned. (author)

  18. Behavior of plasma facing surface in the large helical device

    Energy Technology Data Exchange (ETDEWEB)

    Hino, T.; Nobuta, Y. [Hokkaido Univ., Dept. of Nuclear Engineering, Sapporo, Hokkaido (Japan); Sagara, A. [National Inst. for Fusion Science, Toki, Gifu (Japan)] [and others

    2002-11-01

    Material probes have been installed at the inner walls along poloidal direction in LHD from the first experimental campaign. After each campaign, the impurity deposition and the gas retention have been examined to clarify the plasma surface interaction and the degree of wall cleaning. In the 2nd campaign, the entire wall was considerably cleaned by helium glow discharge conditionings. For the 3rd and 4th campaigns, graphite tiles were installed at entire divertor strike region, and then the wall condition significantly changed compared to the case of stainless steel wall. The erosion of graphite took place during the main discharges and the eroded carbon deposited on the entire wall. In particular, the deposition thickness was large at the wall far from the plasma. Since the entire wall was well carbonized, amount of retained discharge gas such as H and He became large. In particular, the helium retention was large at the position close to the anodes used for helium glow discharge cleanings. One characteristics of the LHD wall is a large retention of helium gas since the wall temperature is limited below 368 K. In order to reduce the recycling of discharge gas, the wall heating before the experimental campaign and the surface heating between the main discharge shots are planned. (author)

  19. Liquid lithium limiter effects on tokamak plasmas and plasma-liquid surface interactions

    International Nuclear Information System (INIS)

    Kaita, R.; Majeski, R.; Doerner, R.

    2003-01-01

    We present results from the first experiments with a large area liquid lithium limiter in a magnetic fusion device, and its effect on improving plasma performance by reducing particle recycling. Using large area liquid metal surfaces in any major fusion device is unlikely before a test on a smaller scale. This has motivated its demonstration in the CDX-U spherical torus with a unique, fully toroidal lithium limiter. The highest current discharges were obtained with a liquid lithium limiter. There was a reduction in recycling, as indicated by a significant decrease in the deuterium-alpha emission and oxygen radiation. How these results might extrapolate to reactors is suggested in recycling/retention experiments with liquid lithium surfaces under high-flux deuterium and helium plasma bombardment in PISCES-B. Data on deuterium atoms retained in liquid lithium indicate retention of all incident ions until full volumetric conversion to lithium deuteride. The PISCES-B results also show a material loss mechanism that lowers the maximum operating temperature compared to that for the liquid surface equilibrium vapor pressure. This may restrict the lithium temperature in reactors. (author)

  20. Liquid Lithium Limiter Effects on Tokamak Plasmas and Plasma-Liquid Surface Interactions

    International Nuclear Information System (INIS)

    Kaita, R.; Majeski, R.; Doerner, R.; Antar, G.; Baldwin, M.; Conn, R.; Efthimion, P.; Finkenthal, M.; Hoffman, D.; Jones, B.; Krashenninikov, S.; Kugel, H.; Luckhardt, S.; Maingi, R.; Menard, J.; Munsat, T.; Stutman, D.; Taylor, G.; Timberlake, J.; Soukhanovskii, V.; Whyte, D.; Woolley, R.; Zakharov, L.

    2002-01-01

    We present results from the first experiments with a large area liquid lithium limiter in a magnetic fusion device, and its effect on improving plasma performance by reducing particle recycling. Using large area liquid metal surfaces in any major fusion device is unlikely before a test on a smaller scale. This has motivated its demonstration in the CDX-U spherical torus with a unique, fully toroidal lithium limiter. The highest current discharges were obtained with a liquid lithium limiter. There was a reduction in recycling, as indicated by a significant decrease in the deuterium-alpha emission and oxygen radiation. How these results might extrapolate to reactors is suggested in recycling/retention experiments with liquid lithium surfaces under high-flux deuterium and helium plasma bombardment in PISCES-B. Data on deuterium atoms retained in liquid lithium indicate retention of all incident ions until full volumetric conversion to lithium deuteride. The PISCES-B results also show a material loss mechanism that lowers the maximum operating temperature compared to that for the liquid surface equilibrium vapor pressure. This may restrict the lithium temperature in reactors

  1. Liquid Lithium Limiter Effects on Tokamak Plasmas and Plasma-Liquid Surface Interactions

    Energy Technology Data Exchange (ETDEWEB)

    R. Kaita; R. Majeski; R. Doerner; G. Antar; M. Baldwin; R. Conn; P. Efthimion; M. Finkenthal; D. Hoffman; B. Jones; S. Krashenninikov; H. Kugel; S. Luckhardt; R. Maingi; J. Menard; T. Munsat; D. Stutman; G. Taylor; J. Timberlake; V. Soukhanovskii; D. Whyte; R. Woolley; L. Zakharov

    2002-10-15

    We present results from the first experiments with a large area liquid lithium limiter in a magnetic fusion device, and its effect on improving plasma performance by reducing particle recycling. Using large area liquid metal surfaces in any major fusion device is unlikely before a test on a smaller scale. This has motivated its demonstration in the CDX-U spherical torus with a unique, fully toroidal lithium limiter. The highest current discharges were obtained with a liquid lithium limiter. There was a reduction in recycling, as indicated by a significant decrease in the deuterium-alpha emission and oxygen radiation. How these results might extrapolate to reactors is suggested in recycling/retention experiments with liquid lithium surfaces under high-flux deuterium and helium plasma bombardment in PISCES-B. Data on deuterium atoms retained in liquid lithium indicate retention of all incident ions until full volumetric conversion to lithium deuteride. The PISCES-B results also show a material loss mechanism that lowers the maximum operating temperature compared to that for the liquid surface equilibrium vapor pressure. This may restrict the lithium temperature in reactors.

  2. Double plasma resonance instability as a source of solar zebra emission

    Science.gov (United States)

    Benáček, J.; Karlický, M.

    2018-03-01

    Context. The double plasma resonance (DPR) instability plays a basic role in the generation of solar radio zebras. In the plasma, consisting of the loss-cone type distribution of hot electrons and much denser and colder background plasma, this instability generates the upper-hybrid waves, which are then transformed into the electromagnetic waves and observed as radio zebras. Aims: In the present paper we numerically study the double plasma resonance instability from the point of view of the zebra interpretation. Methods: We use a 3-dimensional electromagnetic particle-in-cell (3D PIC) relativistic model. We use this model in two versions: (a) a spatially extended "multi-mode" model and (b) a spatially limited "specific-mode" model. While the multi-mode model is used for detailed computations and verifications of the results obtained by the "specific-mode" model, the specific-mode model is used for computations in a broad range of model parameters, which considerably save computational time. For an analysis of the computational results, we developed software tools in Python. Results: First using the multi-mode model, we study details of the double plasma resonance instability. We show how the distribution function of hot electrons changes during this instability. Then we show that there is a very good agreement between results obtained by the multi-mode and specific-mode models, which is caused by a dominance of the wave with the maximal growth rate. Therefore, for computations in a broad range of model parameters, we use the specific-mode model. We compute the maximal growth rates of the double plasma resonance instability with a dependence on the ratio between the upper-hybrid ωUH and electron-cyclotron ωce frequency. We vary temperatures of both the hot and background plasma components and study their effects on the resulting growth rates. The results are compared with the analytical ones. We find a very good agreement between numerical and analytical growth

  3. 'Wall Lapping Plasma' with rotating helical resonant islands for impurity control and mechanical valves for ash exhaust in a reactor-grade tokamak without a divertor

    International Nuclear Information System (INIS)

    Tazima, Teruhiko; Sugihara, Masayoshi

    1979-09-01

    An alternative conception of the divertor, called ''Wall Lapping Plasma'' is proposed for impurity control and ash exhaust which are one of the most serious problems in reactor-grade tokamaks. Resonant helical islands formed in the boundary region rotate when we add rotating helical field by two sets of external helical coils whose current changes alternately. Consequently the plasna surface in contact with the wall by the islands rotates along the whole wall surface, so that the plasma contamination by evaporation of wall surfaces due to local heat deposition can be avoided. Plasma particles flow along the magnetic force lines intersecting the wall by islands. Intersecting angle is very small, so that mechanical valves with small height of opening located on the wall can exhaust ash easily, since backflow of neutralized helium is small because of the narrow opening. The necessary helical field is only 1/500 of the toroidal magnetic field, the total valve area is less than several percent of the wall surface area: besides the valves are easily repairable. ''Wall Lapping Plasma'' will be interesting as an alternative of the divertor because of the simple technology. (author)

  4. 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.

  5. Helicity injection with moving vacuum--plasma boundary with arbitrary flux surfaces

    International Nuclear Information System (INIS)

    Bellan, P.M.

    1988-01-01

    If a toroidal plasma has arbitrary nested magnetic flux surfaces and a moving plasma--vacuum interface, then any helicity injected by modulating the magnetic fields is simply consumed by an increase in helicity dissipation due to the modulated fields

  6. Controllable surface morphology and properties via mist polymerization on a plasma-treated polymethyl methacrylate surface.

    Science.gov (United States)

    Wan, S J; Wang, L; Xu, X J; Zhao, C H; Liu, X D

    2014-02-14

    Surface modification by grafting polymers on solid materials is an important strategy used to improve surface properties. This article reports that under appropriate conditions, very thin layers with desired morphologies may be constructed on a plasma-treated substrate by feeding a small quantity of a monomer with a mist stream carrying droplets produced from monomer solutions. We investigate the effects of process parameters that affect layer morphology, including exposure time to the mist stream, concentration of the monomer solution, and solvent selectivity. For a methyl methacrylate solution in ethanol, nanoparticles are uniformly grown with increasing monomer concentration or exposure time and finally form a porous layer at 3.65 mol L(-1) for 30 min. Decreasing solvent polarity not only affects surface morphology, but also increases hydrophobicity of the resulting surface. With 2,2,3,4,4,4-hexafluorobutyl methacrylate as the monomer, SEM and AFM micrographs indicated that mist polymerization results in numerous microspheres on the activated surface. These experimental results were interpreted by a mechanism in terms of an in situ polymerization accompanied by a phase transformation of the resulting polymer. Specifically, plasma treatment provides highly active cations and radicals to initiate very rapid polymerization, and the resulting polymers are consequently deposited from the liquid onto the surface under phase transition mechanisms.

  7. Biomimetic architectures by plasma processing fabrication and applications

    CERN Document Server

    Chattopadhyay, Surojit

    2014-01-01

    Photonic structures in the animal kingdom: valuable inspirations for bio-mimetic applications. Moth eye-type anti-reflecting nanostructures by an electron cyclotron resonance plasma. Plasma-processed biomimetic nano/microstructures. Wetting properties of natural and plasma processed biomimetic surfaces. Biomimetic superhydrophobic surface by plasma processing. Biomimetic interfaces of plasma modified titanium alloy.

  8. Plasma Surface Modification of Glass-Fibre-Reinforced Polyester Enhanced by Ultrasonic Irradiation

    DEFF Research Database (Denmark)

    Kusano, Yukihiro; Singh, Shailendra Vikram; Bardenshtein, Alexander

    2010-01-01

    .295, 0.385 and 0.447, respectively. This indicated that the plasma treatment oxidized and roughened the GFRP surface, and the ultrasonic irradiation further enhanced the oxidation. It is concluded that plasma treatment efficiency for adhesion improvement of GFRPs is enhanced by the ultrasonic irradiation.......During atmospheric pressure plasma treatment, reactive species generated in the plasma diffuse through a boundary gas layer which is adsorbed at the material surface. Many of the reactive species become inactivated before reaching the surface due to their short lifetime. The efficiency of plasma....... The surface characterizations were performed using contact angle measurements, X-ray photoelectron spectroscopy (XPS) and atomic force mictroscopy (AFM). O/C ratios at the GFRP surfaces before the treatments, after 30-s plasma treatment, and after 30-s plasma treatment with ultrasonic irradiation were 0...

  9. Injection and laser acceleration of ions based on the resonant surface photoionization

    International Nuclear Information System (INIS)

    Antsiferov, V.V.; Smirnov, G.I.; Telegin, G.G.

    1993-01-01

    The collective effects have been investigated of the injection and acceleration of the ion beams due to the resonant surface photoionization. The considered scheme of the laser accelerator allows to obtain positive ions with relativistic velocities. 11 refs., 2 figs

  10. Interfacing capillary electrophoresis and surface-enhanced resonance Raman spectroscopy for the determination of dye compounds

    NARCIS (Netherlands)

    Arraez Roman, D.; Efremov, E.V.; Ariese, F.; Segura Carretero, A.; Gooijer, C.

    2005-01-01

    The at-line coupling of capillary electrophoresis (CE) and surface-enhanced resonance Raman spectroscopy (SERRS) was optimized for the separation and subsequent spectroscopic identification of charged analytes (dye compounds). Raman spectra were recorded following deposition of the electropherogram

  11. Control of surface wettability for inkjet printing by combining hydrophobic coating and plasma treatment

    International Nuclear Information System (INIS)

    Park, Heung Yeol; Kang, Byung Ju; Lee, Dohyung; Oh, Je Hoon

    2013-01-01

    We have obtained a wide range of surface wettabilities of PI substrate for inkjet printing by combining hydrophobic solution coating and O 2 or Ar plasma treatments. Experiments were conducted to investigate the variation in inkjet-printed dot diameters with different surface treatments. The change in chemical and physical characteristics of treated surfaces was evaluated using static contact angle measurements, field emission scanning electron microscopy, atomic force microscopy, and X-ray photoelectron spectroscopy. Only hydrophobic coated surface produces the smallest dot diameter and the largest contact angle. Dot diameter increases and contact angle decreases as the plasma treatment time increases. Since the removal of hydrophobic layer from the surface occurs due to the etching effect of O 2 and Ar plasma during the plasma treatments, F/C ratio decreases with increasing the plasma treatment time. Surface roughness variations are also observed after plasma treatments. The ranges of printed dot sizes for O 2 and Ar plasma treatments are 38 μm–70 μm and 38 μm–92 μm, respectively. Ar plasma treatment shows a wider range of surface wettability because of higher removal rate of the hydrophobic layer. This combination of hydrophobic coating and plasma treatment can offer an effective way to obtain a wide range of surface wettabilities for high quality inkjet-printed patterns. - Highlights: • Hydrophobic coating and plasma treatments were used to control surface wettability. • Inkjet-printed dot diameters increase with O 2 or Ar plasma treatment time. • Contact angles of Ag ink agree well with the variation tendency of dot diameters. • The removal of hydrophobic layer occurs during the plasma treatments. • Ar plasma treatment shows a wider range of surface wettability than O 2 plasma

  12. Dual Electrolytic Plasma Processing for Steel Surface Cleaning and Passivation

    Science.gov (United States)

    Yang, L.; Zhang, P.; Shi, J.; Liang, J.; Tian, W. B.; Zhang, Y. M.; Sun, Z. M.

    2017-10-01

    To remove the rust on rebars and passivate the fresh surfaces, electrodes reversing electrolytic plasma processing (EPP) was proposed and conducted in a 10 wt.% Na2CO3 aqueous solution. The morphology and the composition of the surface were investigated by SEM and XPS. Experimental results show that the rust on the surface was removed effectively by cathode EPP, and a passive film containing Cr2O3 was achieved by the succeeding anode EPP treatment, by a simple operation of reversing the bias. The corrosion resistance was evaluated in a 3.5 wt.% NaCl aqueous solution using an electrochemical workstation. In comparison, the corrosion resistance was improved by the succeeding anode EPP treatment, which is evidenced by a positive shift of the open-circuit potential, an increase in the electrochemical impedance representing the inner layer by 76.8% and the decrease in the corrosion current density by 49.6%. This is an effective and environment-friendly technique to clean and passivate rebars and similar steel materials.

  13. Atmospheric-Pressure Plasma Jet Surface Treatment for Use in Improving Adhesion

    Energy Technology Data Exchange (ETDEWEB)

    Kuettner, Lindsey Ann [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-09-06

    Atmospheric-pressure plasma jets (APPJs) are a method of plasma treatment that plays an important role in material processing and modifying surface properties of materials, especially polymers. Gas plasmas react with polymer surfaces in numerous ways such as oxidation, radical formation, degradation, and promotion of cross-linking. Because of this, gas and plasma conditions can be explored for chosen processes to maximize desired properties. The purpose of this study is to investigate plasma parameters in order to modify surface properties for improved adhesion between aluminum and epoxy substrates using two types of adhesives. The background, results to date, and future work will be discussed.

  14. Influence of an External DC Electric Current on Plasma Cleaning Rate: an Application on the Enlarged Plasma-Surface Theory

    International Nuclear Information System (INIS)

    Xaplanteris, Constantine L.; Filippaki, Eleni D.

    2013-01-01

    During the last decades many researchers have been occupied with other plasma applications apart from the big challenge which the thermonuclear fusion poses. Many experiments have been carried out on the plasma behavior in contact with a solid surface; when the surface material consists of chemical compounds (e.g. oxides of metals), then the plasma chemistry takes place. The present paper contains the final experimental and theoretical work of Plasma Laboratory at “Demokritos , which consists of an elaboration of plasma sheath parameters adapted to experimental conditions, a suitable choice of plasma gases (either H 2 or N 2 ), and an electric potential current enforcement on objects. Additionally, a brief theory is given to explain the results, with a short reference to both boundary phenomena in thermonuclear reactors and low pressure plasma of glow discharges, so as to reveal the similarities and differences of these two cases. An extensive examination of the treated objects by X-ray diffraction method (XRD) gives results in agreement with the theoretical predictions. Using this improvement on plasma restoration system, (a combination of electric current on metallic object into suitable plasma), it is shown that better results can be achieved on the cleaning and conservation of archaeological objects. (plasma technology)

  15. Image potential resonances of the aluminum (100) surface; Bildpotentialresonanzen der Aluminium-(100)-Oberflaeche

    Energy Technology Data Exchange (ETDEWEB)

    Winter, Matthias

    2011-07-08

    Image-potential resonances on the (100) surface of pure Aluminum are investigated experimentally and theoretically. The experiments are conducted both energy- and time-resolved using the method of two-photon photoemission spectroscopy. The main attention of the theoretical examination and extensive numerical calculations is devoted to the interaction between surface and bulk states. Image-potential resonances on Al(100) are a system in which a complete series of discrete Rydberg states strongly couples to a continuum of states. As a simple metal it also provides a good opportunity to test theoretical models of the structure of the potential at metal surfaces. This work represents the first high-resolution investigation of image-potential resonances with such strong resonance character. For the first time, it is demonstrated experimentally that isolated image-potential resonances exist on an Aluminum surface. On the (100) surface of Aluminum the second through fifth image-potential resonance are resolved and both, their energies and lifetimes are measured. The binding energies of the image-potential resonances form a Rydberg series of states {epsilon}{sub n}=-(0,85 eV)/((n+a){sup 2}). Within the accuracy of the measurement it is not necessary to introduce a quantum defect a (a=0.022{+-}0.035). Using angle-resolved two-photon photoemission spectroscopy the effective mass of electrons in the second image-potential resonance is measured to 1.01{+-}0.11 electron masses. The lifetimes of the resonances increase as {tau}{sub n} = (1.0{+-}0.2)fs.n{sup 3} starting from n=2. Calculations using the density matrix formalism show that the experimentally observed lifetimes can be explained well by electrons decaying into the bulk. The effect of resonance trapping leads to extended lifetimes in the process. Contrary to common theoretical models of image-potential states at metal surfaces the first image-potential resonance cannot be observed in two-photon photoemission on Al(100

  16. Surface modification by preparation of buffer zone in glow-discharge plasma

    International Nuclear Information System (INIS)

    Cho, D.L.

    1986-01-01

    Reactive species, energetic particles, and uv radiation in the plasma created by a glow discharge strongly interact with solid surfaces under the influence of the plasma. As a result of the strong interaction, various physical and chemical reactions, unique and advantageous for the surface modification of solid materials, occur on the solid surfaces. The surface modification is carried out through formation of a thin buffering layer on the solid surface. The preparation of a buffer zone on solid surfaces for surface modification is described. Two kinds of a buffer zone are prepared by plasma polymerization, or simultaneous sputter deposition of electrode material with plasma polymerization: a transitional buffer zone and a graded buffer zone. Important factors for preparation of the buffer zone (pre-conditioning of a substrate surface, thin-film deposition, post-treatment of the film, magnetron discharge, energy input, geometry of a substrate and a plasma) are discussed

  17. Transience of plasma surface modification as an adhesion promoter for polychlorotrifluorethylene

    CERN Document Server

    Subramanian, S; Love, B J; Romand, M; Charbonnier, M

    2002-01-01

    Poly(chlorotrifluoroethylene) (PCTFE) and other fluoropolymers are increasingly used as inner layer dielectrics. However, these polymers have low surface energies and correspondingly poor adhesive properties. Results are presented on the use of a low-pressure ammonia plasma to enhance the surface bondability of PCTFE. The plasma modified PCTFE film surfaces were characterized by x-ray photoelectron spectroscopy and contact angle measurements. Surface modified films exhibited improved adhesion to electroless copper deposits (180 deg. peel test) compared to coated PCTFE controls and that underwent no plasma exposure. Annealing studies were conducted between 30 and 100 deg. C to examine the stability of the plasma-modified surfaces. For samples annealed below T sub g , contact angle measurements indicated that the plasma-introduced groups remained bound on the surface for four weeks. For specimens annealed above T sub g , the surface functionalities were absorbed within the bulk and surface rearrangement occurre...

  18. Correlation between the plasma characteristics and the surface chemistry of plasma-treated polymers through partial least-squares analysis.

    Science.gov (United States)

    Mavadat, Maryam; Ghasemzadeh-Barvarz, Massoud; Turgeon, Stéphane; Duchesne, Carl; Laroche, Gaétan

    2013-12-23

    We investigated the effect of various plasma parameters (relative density of atomic N and H, plasma temperature, and vibrational temperature) and process conditions (pressure and H2/(N2 + H2) ratio) on the chemical composition of modified poly(tetrafluoroethylene) (PTFE). The plasma parameters were measured by means of near-infrared (NIR) and UV-visible emission spectroscopy with and without actinometry. The process conditions of the N2-H2 microwave discharges were set at various pressures ranging from 100 to 2000 mTorr and H2/(N2+H2) gas mixture ratios between 0 and 0.4. The surface chemical composition of the modified polymers was determined by X-ray photoelectron spectroscopy (XPS). A mathematical model was constructed using the partial least-squares regression algorithm to correlate the plasma information (process condition and plasma parameters as determined by emission spectroscopy) with the modified surface characteristics. To construct the model, a set of data input variables containing process conditions and plasma parameters were generated, as well as a response matrix containing the surface composition of the polymer. This model was used to predict the composition of PTFE surfaces subjected to N2-H2 plasma treatment. Contrary to what is generally accepted in the literature, the present data demonstrate that hydrogen is not directly involved in the defluorination of the surface but rather produces atomic nitrogen and/or NH radicals that are shown to be at the origin of fluorine atom removal from the polymer surface. The results show that process conditions alone do not suffice in predicting the surface chemical composition and that the plasma characteristics, which cannot be easily correlated with these conditions, should be considered. Process optimization and control would benefit from plasma diagnostics, particularly infrared emission spectroscopy.

  19. Plasma conversion of methane into higher hydrocarbons at surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Sackinger, W.M.; Kamath, V.A. [Univ. of Alaska, Fairbanks, AK (United States)

    1995-12-31

    Natural gas is widely abundant, is easily withdrawn from reservoirs, is commonly produced as an associated gas along with crude oil production, and is found in many geologic settings as a resource separate from oil. A much larger fraction of the natural gas may be produced from a gas reservoir, as compared with a crude oil reservoir. However, natural gas is normally transported by pipeline, and the energy throughput of such a pipeline is perhaps only 20% to 30% of the throughput of an oil pipeline of the same size and cost. Gas is difficult to transport in moderate quantities at low cost, as it must either have a special pipeline or must be liquified into LNG, shipped in cryogenic LNG tankers, and regasified chemical stability of methane has made it difficult to convert it directly into conventional hydrocarbon fuel mixtures, and has also impeded its use as a feedstock for petrochemical production. Experiments are described in which a methane plasma is created, and the resulting methyl and hydrogen ions have been accelerated within a microchannel array so that they interact with neutral methane molecules on the inside surfaces of the microchannels. No catalysts are used, and the device operates at room temperature. Impact energies of the ions are in the range of 15 ev to greater than 100 ev, and the energy delivered in the interaction at the surfaces has caused the production of larger hydrocarbon molecules, such as C{sub 2}H{sub 2}, C{sub 2}H{sub 4}, and C{sub 2}H{sub 6}, along with C{sub 3}, C{sub 4}, C{sub 5}, C{sub 6}, C{sub 7}, and C{sub 8} molecules. Conversion effectiveness is greater at higher pressure, due to the increased ionic activity. The costs of production of the plasma conversion devices are projected to be quite low, and the technology appears to be commercially and economically feasible.

  20. Measurements of the anomalous RF surface resistance of niobium using a dielectric resonator

    International Nuclear Information System (INIS)

    Moffat, D.; Bolore, M.; Bonin, B.; Jacques, E.; Safa, H.

    1996-01-01

    The surface resistance of high and low residual resistance ratio (RRR) niobium plates at 4.2 K and 1.8 K has been measured as a function of many processing and testing parameters. A dielectric resonator was used instead of a resonant cavity. This resonator offered the ability to make many, sensitive measurements with an efficient use of time and helium. It was found that the surface resistance, R s , of RRR = 190 niobium increased noticeably from the theoretical value if the cooling rate was slower than ∼ 10 K/min. (author)

  1. Pellet injection into ohmically and additionally electron cyclotron resonance heated tokamak plasmas

    International Nuclear Information System (INIS)

    Drawin, H.W.; Geraud, A.

    1988-12-01

    Frozen H 2 and D 2 pellets injection into the electron cyclotron resonance heated plasmas of the Fontenay-aux-Roses tokamak are studied. Pellet injection with and without ECR heating are considered. In the first case, pellets penetration into the plasma is deeper than the neutral gas model predictions. In the second case, the position of the ECR layer had practically no influence on the penetration depth (reduced to a few centimeters). Only two-third of the pellet mass was found as ionized matter in the plasma, compared to the ohmic case. On the photographs the ablation clouds showed no particular structure when ECR heating was applied. Also the H β intensity was generally free of modulation. The enhanced ablation during ECRH can be simulated by a Parks and Turnbull formula. Perpendicular electron temperature of the hot electrons heated by the EC waves is by orders of magnitude larger than its parallel temperature. The resulting electron density profiles calculated by using the 1-D transport code MAKOKOT are in agreement with experiments, when suitable values of the anomalous radial convection velocity are chosen

  2. Plasma focus sources: Supplement to the neutron resonance radiography workshop proceedings

    International Nuclear Information System (INIS)

    Nardi, V.; Brzosko, J.

    1989-01-01

    Since their discovery, plasma focus discharges have been recognized as very intense pulsed sources of deuterium-deuterium (D-D) or deuterium-tritium (D-T) fusion-reaction neutrons, with outstanding capabilities. Specifically, the total neutron emission/shot, YN, and the rate of neutron emission, Y/sub n/, of an optimized plasma focus (PF) are higher than the corresponding quantities observed in any other type of pinched discharge at the same level of powering energy W 0 . Recent developments have led to the concept and experimental demonstration of an Advanced Plasma Focus System (APF) that consists of a Mather-geometry plasma focus in which field distortion elements (FDEs) are inserted in the inter-electrode gap for increasing the neutron yield/shot, Y/sub n/. The FDE-induced redistribution of the plasma current increases Y/sub n/ by a factor ≅5-10 above the value obtained without FDEs under otherwise identical conditions of operation of the plasma focus. For example, an APF that is fed by a fast capacitor bank with an energy, W 0 = 6kJ, and voltage, V 0 = 16.5 kV provides Y/sub n/ /congruent/ 4 /times/ 10 9 D-D neutrons/shot (pure D 2 filling) and Y/sub n/ = 4 /times/ 10 11 D-T neutrons/shot (filling is 50% deuterium and 50% tritium). The FDE-induced increase of Y/sub n/ for fixed values of (W 0 , V 0 ), the observed scaling law Y/sub n/ /proportional to/ W 0 2 for optimized plasma focus systems, and our experience with neutron scattering in bulk objects lead us to the conclusion that we can use an APF as a source of high-intensity neutron pulses (10 14 n/pulse) in the field off neutron radiography (surface and bulk) with a nanosecond or millisecond time resolution

  3. A portable blood plasma clot micro-elastometry device based on resonant acoustic spectroscopy.

    Science.gov (United States)

    Krebs, C R; Li, Ling; Wolberg, Alisa S; Oldenburg, Amy L

    2015-07-01

    Abnormal blood clot stiffness is an important indicator of coagulation disorders arising from a variety of cardiovascular diseases and drug treatments. Here, we present a portable instrument for elastometry of microliter volume blood samples based upon the principle of resonant acoustic spectroscopy, where a sample of well-defined dimensions exhibits a fundamental longitudinal resonance mode proportional to the square root of the Young's modulus. In contrast to commercial thromboelastography, the resonant acoustic method offers improved repeatability and accuracy due to the high signal-to-noise ratio of the resonant vibration. We review the measurement principles and the design of a magnetically actuated microbead force transducer applying between 23 pN and 6.7 nN, providing a wide dynamic range of elastic moduli (3 Pa-27 kPa) appropriate for measurement of clot elastic modulus (CEM). An automated and portable device, the CEMport, is introduced and implemented using a 2 nm resolution displacement sensor with demonstrated accuracy and precision of 3% and 2%, respectively, of CEM in biogels. Importantly, the small strains (<0.13%) and low strain rates (<1/s) employed by the CEMport maintain a linear stress-to-strain relationship which provides a perturbative measurement of the Young's modulus. Measurements of blood plasma CEM versus heparin concentration show that CEMport is sensitive to heparin levels below 0.050 U/ml, which suggests future applications in sensing heparin levels of post-surgical cardiopulmonary bypass patients. The portability, high accuracy, and high precision of this device enable new clinical and animal studies for associating CEM with blood coagulation disorders, potentially leading to improved diagnostics and therapeutic monitoring.

  4. Discrete surface state related to nitrogen-vacancy defect on plasma-treated GaN surfaces

    OpenAIRE

    Hashizume, Tamotsu; Nakasaki, Ryusuke

    2002-01-01

    Detailed studies on the defect-related surface states of plasma-exposed n-GaN surfaces were carried out. An anomalous flat portion appeared in the metal–insulator–semiconductor capacitance–voltage characteristics for the sample exposed to H2 plasma, corresponding to a localized peak at EC–0.5 eV in the surface state density distribution. Atomic-force microscope and x-ray photoemission studies revealed the formation of Ga droplets on H2-plasma-treated GaN surfaces, caused by the desorption of ...

  5. Study on surface modification of polymer films by using atmospheric plasma jet source

    International Nuclear Information System (INIS)

    Takemura, Yuichiro; Hara, Tamio; Yamaguchi, Naohiro

    2008-01-01

    Reactive gas plasma treatments of poly(ethylene terephthalate) (PET) and polyimide (Kapton) have been performed using an atmospheric plasmas jet source. Characteristics of surface modification have been examined by changing the distance between the plasma jet source and the treated sample, and by changing the working gas spaces. Simultaneously, each plasma jet source has been investigated by space-resolving spectroscopy in the UV/visible region. Polymer surfaces have been analyzed by X-ray photoelectron spectroscopy (XPS). A marked improvement in the hydrophilicity of the polymer surfaces has been made by using N 2 or O 2 plasma jet source with a very short exposure time of about 0.01 s, whereas the less improvement has been obtained using on air plasma jet source because of NO x compound production. Changes in the chemical states of C of the polymer surfaces have been observed in XPS spectra after N 2 plasma jet spraying. (author)

  6. Surface-enhanced Raman scattering (SERS) of riboflavin on nanostructured Ag surfaces: The role of excitation wavelength, plasmon resonance and molecular resonance

    Science.gov (United States)

    Šubr, Martin; Kuzminova, Anna; Kylián, Ondřej; Procházka, Marek

    2018-05-01

    Optimization of surface-enhanced Raman scattering (SERS)-based sensors for (bio)analytical applications has received much attention in recent years. For optimum sensitivity, both the nanostructure fabrication process and the choice of the excitation wavelength used with respect to the specific analyte studied are of crucial importance. In this contribution, detailed SERS intensity profiles were measured using gradient nanostructures with the localized surface-plasmon resonance (LSPR) condition varying across the sample length and using riboflavin as the model biomolecule. Three different excitation wavelengths (633 nm, 515 nm and 488 nm) corresponding to non-resonance, pre-resonance and resonance excitation with respect to the studied molecule, respectively, were tested. Results were interpreted in terms of a superposition of the enhancement provided by the electromagnetic mechanism and intrinsic properties of the SERS probe molecule. The first effect was dictated mainly by the degree of spectral overlap between the LSPR band, the excitation wavelength along with the scattering cross-section of the nanostructures, while the latter was influenced by the position of the molecular resonance with respect to the excitation wavelength. Our experimental findings contribute to a better understanding of the SERS enhancement mechanism.

  7. Bound and resonant surface states at the (110) surfaces of AlSb, AlAs, and AlP

    International Nuclear Information System (INIS)

    Beres, R.P.; Allen, R.E.; Buisson, J.P.; Bowen, M.A.; Blackwell, G.F.; Hjalmarson, H.P.; Dow, J.D.

    1982-01-01

    The dispersion curves E(k-bar) have been calculated for bound and resonant (110) surface states of AlSb, AlAs, and AlP. AlSb is predicted to have no surface states within the bulk fundamental band gap, but AlAs and AlP are predicted to have surface state band minima which are very near the conduction band edge, and could lie either within the gap or immediately above the edge

  8. Surface modification of polylactic acid films by atmospheric pressure plasma treatment

    Science.gov (United States)

    Kudryavtseva, V. L.; Zhuravlev, M. V.; Tverdokhlebov, S. I.

    2017-09-01

    A new approach for the modification of polylactic acid (PLA) materials using atmospheric pressure plasma (APP) is described. PLA films plasma exposure time was 20, 60, 120 s. The surface morphology and wettability of the obtained PLA films were investigated by atomic force microscopy (AFM) and the sitting drop method. The atmospheric pressure plasma increased the roughness and surface energy of PLA film. The wettability of PLA has been improved with the application of an atmospheric plasma surface treatment. It was shown that it is possible to obtain PLA films with various surface relief and tunable wettability. Additionally, we demonstrated that the use of cold atmospheric pressure plasma for surface activation allows for the immobilization of bioactive compounds like hyaluronic acid (HA) on the surface of obtained films. It was shown that composite PLA-HA films have an increased long-term hydrophilicity of the films surface.

  9. Plasma processing of the Si(0 0 1) surface for tuning SPR of Au/Si-based plasmonic nanostructures

    Energy Technology Data Exchange (ETDEWEB)

    Giangregorio, Maria M. [Institute of Inorganic Methodologies and of Plasmas, IMIP-CNR and INSTM sez. Bari, Via Orabona 4, 70125 Bari (Italy)]. E-mail: michelaria.giangregorio@ba.imip.cnr.it; Losurdo, Maria [Institute of Inorganic Methodologies and of Plasmas, IMIP-CNR and INSTM sez. Bari, Via Orabona 4, 70125 Bari (Italy); Sacchetti, Alberto [Institute of Inorganic Methodologies and of Plasmas, IMIP-CNR and INSTM sez. Bari, Via Orabona 4, 70125 Bari (Italy); Capezzuto, Pio [Institute of Inorganic Methodologies and of Plasmas, IMIP-CNR and INSTM sez. Bari, Via Orabona 4, 70125 Bari (Italy); Bruno, Giovanni [Institute of Inorganic Methodologies and of Plasmas, IMIP-CNR and INSTM sez. Bari, Via Orabona 4, 70125 Bari (Italy)

    2006-12-15

    Au nanoclusters have been deposited on Si(0 0 1) surfaces by sputtering of a metallic Au target using an Ar plasma. Different wet and dry treatments of the Si(0 0 1) surface, including dipping in HF solution and exposure to H{sub 2} and N{sub 2} plasmas, have been applied and the effects of these treatments on the Au nanoparticles/Si interface, the Au nanoclusters aspect ratio and the surface plasmon resonance (SPR) energy and amplitude are investigated exploiting spectroscopic ellipsometry and atomic force microscopy. It is found that the Au nanoclusters aspect ratio depends on the extent of the Au-Si intermixing. The thicker the Au-Si interface layer, the larger the Au nanoparticles aspect ratio and the red-shift of the SPR peak. Furthermore, SiO{sub 2} and the H{sub 2} plasma treatment inhibit the Si-Au intermixing, while HF-dipping and the N{sub 2} plasma treatment favour Au-Si intermixing, yielding silicide formation which increases the Si wetting by Au.

  10. Development of an Organosilicon-Based Superhydrophobic/Icephobic Surface Using an Atmospheric Pressure Plasma Jet =

    Science.gov (United States)

    Asadollahi, Siavash

    During the past few decades, plasma-based surface treatment methods have gained a lot of interest in various applications such as thin film deposition, surface etching, surface activation and/or cleaning, etc. Generally, in plasma-based surface treatment methods, high-energy plasma-generated species are utilized to modify the surface structure or the chemical composition of a substrate. Unique physical and chemical characteristics of the plasma along with the high controllability of the process makes plasma treatment approaches very attractive in several industries. Plasma-based treatment methods are currently being used or investigated for a number of practical applications, such as adhesion promotion in auto industry, wound management and cancer treatment in biomedical industry, and coating development in aerospace industry. In this study, a two-step procedure is proposed for the development of superhydrophobic/icephobic coatings based on atmospheric-pressure plasma treatment of aluminum substrates using air and nitrogen plasma. The effects of plasma parameters on various surface properties are studied in order to identify the optimum conditions for maximum coating efficiency against icing and wetting. In the first step, the interactions between air or nitrogen plasma and the aluminum surface are studied. It is shown that by reducing jet-to-substrate distance, air plasma treatment, unlike nitrogen plasma treatment, is capable of creating micro-porous micro-roughened structures on the surface, some of which bear a significant resemblance to the features observed in laser ablation of metals with short and ultra-short laser pulses. The formation of such structures in plasma treatment is attributed to a transportation of energy from the jet to the surface over a very short period of time, in the range of picoseconds to microseconds. This energy transfer is shown to occur through a streamer discharge from the rotating arc source in the jet body to a close proximity of

  11. Surface chemical changes of atmospheric pressure plasma treated rabbit fibres important for felting process

    International Nuclear Information System (INIS)

    Štěpánová, Vlasta; Slavíček, Pavel; Stupavská, Monika; Jurmanová, Jana; Černák, Mirko

    2015-01-01

    Graphical abstract: - Highlights: • Rabbit fibres plasma treatment is an effective method for fibres modification. • Atmospheric pressure plasma treatment is able to affect fibres properties. • Surface changes on fibres after plasma treatment were analysed via SEM, ATR-FTIR, XPS. • Significant increase of fibres wettability after plasma treatment was observed. • Plasma treatment at atmospheric pressure can replace the chemical treatment of fibres. - Abstract: We introduce the atmospheric pressure plasma treatment as a suitable procedure for in-line industrial application of rabbit fibres pre-treatment. Changes of rabbit fibre properties due to the plasma treatment were studied in order to develop new technology of plasma-based treatment before felting. Diffuse Coplanar Surface Barrier Discharge (DCSBD) in ambient air at atmospheric pressure was used for plasma treatment. Scanning electron microscopy was used for determination of the fibres morphology before and after plasma treatment. X-ray photoelectron spectroscopy and attenuated total reflectance-Fourier transform infrared spectroscopy were used for evaluation of reactive groups. The concentration of carbon decreased and conversely the concentration of nitrogen and oxygen increased after plasma treatment. Aging effect of plasma treated fibres was also investigated. Using Washburn method the significant increase of fibres wettability was observed after plasma treatment. New approach of pre-treatment of fibres before felting using plasma was developed. Plasma treatment of fibres at atmospheric pressure can replace the chemical method which consists of application of strong acids on fibres.

  12. Surface chemical changes of atmospheric pressure plasma treated rabbit fibres important for felting process

    Energy Technology Data Exchange (ETDEWEB)

    Štěpánová, Vlasta, E-mail: vstepanova@mail.muni.cz [Department of Physical Electronics, Faculty of Science Masaryk University, Kotlářská 2, 611 37 Brno (Czech Republic); Slavíček, Pavel; Stupavská, Monika; Jurmanová, Jana [Department of Physical Electronics, Faculty of Science Masaryk University, Kotlářská 2, 611 37 Brno (Czech Republic); Černák, Mirko [Department of Physical Electronics, Faculty of Science Masaryk University, Kotlářská 2, 611 37 Brno (Czech Republic); Department of Experimental Physics, Faculty of Mathematics, Physics and Informatics, Comenius University, Mlynská dolina F2, 842 48 Bratislava (Slovakia)

    2015-11-15

    Graphical abstract: - Highlights: • Rabbit fibres plasma treatment is an effective method for fibres modification. • Atmospheric pressure plasma treatment is able to affect fibres properties. • Surface changes on fibres after plasma treatment were analysed via SEM, ATR-FTIR, XPS. • Significant increase of fibres wettability after plasma treatment was observed. • Plasma treatment at atmospheric pressure can replace the chemical treatment of fibres. - Abstract: We introduce the atmospheric pressure plasma treatment as a suitable procedure for in-line industrial application of rabbit fibres pre-treatment. Changes of rabbit fibre properties due to the plasma treatment were studied in order to develop new technology of plasma-based treatment before felting. Diffuse Coplanar Surface Barrier Discharge (DCSBD) in ambient air at atmospheric pressure was used for plasma treatment. Scanning electron microscopy was used for determination of the fibres morphology before and after plasma treatment. X-ray photoelectron spectroscopy and attenuated total reflectance-Fourier transform infrared spectroscopy were used for evaluation of reactive groups. The concentration of carbon decreased and conversely the concentration of nitrogen and oxygen increased after plasma treatment. Aging effect of plasma treated fibres was also investigated. Using Washburn method the significant increase of fibres wettability was observed after plasma treatment. New approach of pre-treatment of fibres before felting using plasma was developed. Plasma treatment of fibres at atmospheric pressure can replace the chemical method which consists of application of strong acids on fibres.

  13. Influence of the electron cyclotron resonance plasma confinement on reducing the bremsstrahlung production of an electron cyclotron resonance ion source with metal-dielectric structures

    International Nuclear Information System (INIS)

    Schachter, L.; Dobrescu, S.; Stiebing, K. E.

    2009-01-01

    The influence of metal-dielectric (MD) layers (MD structures) inserted into the plasma chamber of an electron cyclotron resonance ion source (ECRIS) onto the production of electron bremsstrahlung radiation has been studied in a series of dedicated experiments at the 14 GHz ECRIS of the Institut fuer Kernphysik der Universitaet Frankfurt. The IKF-ECRIS was equipped with a MD liner, covering the inner walls of the plasma chamber, and a MD electrode, covering the plasma-facing side of the extraction electrode. On the basis of similar extracted currents of highly charged ions, significantly reduced yields of bremsstrahlung radiation for the 'MD source' as compared to the standard (stainless steel) source have been measured and can be explained by the significantly better plasma confinement in a MD source as compared to an ''all stainless steel'' ECRIS.

  14. Three-dimensional modeling of plasma edge transport and divertor fluxes during application of resonant magnetic perturbations on ITER

    Czech Academy of Sciences Publication Activity Database

    Schmitz, O.; Becoulet, M.; Cahyna, Pavel; Evans, T.E.; Feng, Y.; Frerichs, H.; Loarte, A.; Pitts, R.A.; Reiser, D.; Fenstermacher, M.E.; Harting, D.; Kirschner, A.; Kukushkin, A.; Lunt, T.; Saibene, G.; Reiter, D.; Samm, U.; Wiesen, S.

    2016-01-01

    Roč. 56, č. 6 (2016), č. článku 066008. ISSN 0029-5515 Institutional support: RVO:61389021 Keywords : resonant magnetic perturbations * plasma edge physics * 3D modeling * neutral particle physics * ITER * divertor heat and particle loads * ELM control Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 3.307, year: 2016 http://iopscience.iop.org/article/10.1088/0029-5515/56/6/066008/meta

  15. Surface Plasmon Resonance Imaging biosensor for cystatin determination based on the application of bromelain, ficin and chymopapain

    Directory of Open Access Journals (Sweden)

    Anna Sankiewicz

    2012-04-01

    Full Text Available A Surface Plasmon Resonance Imaging (SPRI sensor based on bromelain or chymopapain or ficin has been developed for specific cystatin determination. Cystatin was captured from a solution by immobilized bromelain or chymopapain or ficin due to the formation of an enzyme-inhibitor complex on the biosensor surface. The influence of bromelain, chymopapain or ficin concentration, as well as the pH of the interaction on the SPRI signal, was investigated and optimized. Sensor dynamic response range is between 0–0.6 μg/ml and the detection limit is equal to 0.1 μg/ml. In order to demonstrate the sensor potential, cystatin was determined in blood plasma, urine and saliva, showing good agreement with the data reported in the literature.

  16. Curling probe measurement of a large-volume pulsed plasma with surface magnetic confinement

    Science.gov (United States)

    Pandey, A.; Tashiro, H.; Sakakibara, W.; Nakamura, K.; Sugai, H.

    2016-12-01

    A curling probe (CP) based on microwave resonance is applied to the measurement of electron density in a pulsed DC glow discharge under surface magnetic confinement (SMC) provided by a number of permanent magnets on a chamber wall. Owing to the SMC effects, a 1 m scale large-volume plasma is generated by a relatively low voltage (~1 kV) at low pressure (~1 Pa) in various gases (Ar, CH4, and C2H2). Temporal variation of the electron density is measured for pulse frequency f  =  0.5-25 kHz for various discharge-on times (T ON) with a high resolution time (~0.2 µs), using the on-point mode. In general, the electron density starts to increase at time t  =  0 after turn-on of the discharge voltage, reaches peak density at t  =  T ON, and then decreases after turn-off. The peak electron density is observed to increase with the pulse frequency f for constant T ON owing to the residual plasma. This dependence is successfully formulated using a semi-empirical model. The spatio-temporal evolution of the cathode sheath in the pulsed discharge is revealed by a 1 m long movable CP. The measured thickness of the high-voltage cathode fall in a steady state coincides with the value of the so-called Child-Langmuir sheath.

  17. Modification of glassy carbon surfaces by atmospheric pressure cold plasma torch

    DEFF Research Database (Denmark)

    Mortensen, Henrik Junge; Kusano, Yukihiro; Leipold, Frank

    2006-01-01

    The effect of plasma treatment on glassy carbon (GC) surfaces was studied with adhesion improvement in mind. A newly constructed remote plasma source was used to treat GC plates. Pure He and a dilute NH3/He mixture were used as feed gases. Optical emission spectroscopy was performed for plasma...

  18. The effect of surface plasmon resonance on optical response in ...

    Indian Academy of Sciences (India)

    By increasing the shell radius and therefore increasing the metal content the SPR at the outer surface shifts to higher energy and the weaker peak (at inner surface) shifts to lower energy. Also, depending on the metal shell materials SPR occurs in different energy regions and therefore can be tuned the SP frequency at ...

  19. Improved localized surface plasmon resonance index sensitivity based on chemically-synthesized gold nanoparticles on indium tin oxide surfaces

    Science.gov (United States)

    Zhu, Jin; Li, Xiaolong; Zheng, Wei; Wang, Biao; Tian, Yubo

    2018-02-01

    The results of this reported work indicated that gold nanoparticle arrays self-assembled on indium tin oxide (ITO) glasses can obtain broader localized surface plasmon resonance (LSPR) wavelength range and higher sensitivity than the bare quartz. The results of surface electric field calculated using finite difference time domain showed that the electric field of nanoparticles on ITO glasses is enhanced and the repulsive forces within each particle is weakened. According to the dipolar interaction mechanism, a weakened repulsive forces within each particle lead to a lower resonance frequency and a strong redshift of the LSPR spectra.

  20. Emission spectroscopic analysis of oxygen-plasma reaction on polymer surface: Effective polyacrylonitrile treatment by the plasma

    International Nuclear Information System (INIS)

    Kobayashi, Takaomi; Sasama, Tomonori; Wada, Hiroshi; Fujii, Nobuyuki

    2001-01-01

    Emission spectroscopy was applied to observe decomposed species of polyacrylonitrile (PAN) exposed with oxygen (O 2 ) plasma, which was generated by microwave discharge with 8x10 -2 dm 3 /s flow rate in the range of 1.8-4.7 Torr. As O 2 plasma was exposed to the polymer, the surface was etched and a violet emission was observed on the surface. The strong emission assigned to CN(B 2 Σ-X 2 Π) transition appeared near 340-460 nm and also CH(A 2 Δ-X 2 Π) at 431 nm. These results indicated that the PAN sample was decomposed by the plasma etching and the decomposed species emitted the violet light on the surface. The time dependence of the emission intensities was also investigated. When the discharge time of O 2 plasma increased, the emission intensities of the CN and CH transitions increased and then gradually decreased. Evidence was presented by infrared measurements that a hetrocyclic nitrile group was formed on the treated surface. Furthermore, the polymer surface decomposition in O 2 plasma was compared with that observed in nitrogen (N 2 ) and air plasma. The N 2 and air discharge showed less PAN decomposition than observed in O 2 discharge

  1. Atmospheric plasma inactivation of foodborne pathogens on fresh produce surfaces.

    Science.gov (United States)

    Critzer, Faith J; Kelly-Wintenberg, Kimberly; South, Suzanne L; Golden, David A

    2007-10-01

    A study was conducted to determine the effect of one atmosphere uniform glow discharge plasma (OAUGDP) on inactivation of Escherichia coli O157:H7, Salmonella, and Listeria monocytogenes on apples, cantaloupe, and lettuce, respectively. A five-strain mixture of cultured test organisms was washed, suspended in phosphate buffer, and spot inoculated onto produce (7 log CFU per sample). Samples were exposed inside a chamber affixed to the OAUGDP blower unit operated at a power of 9 kV and frequency of 6 kHz. This configuration allows the sample to be placed outside of the plasma generation unit while allowing airflow to carry the antimicrobial active species, including ozone and nitric oxide, onto the food sample. Cantaloupe and lettuce samples were exposed for 1, 3, and 5 min, while apple samples were exposed for 30 s, 1 min, and 2 min. After exposure, samples were pummeled in 0.1% peptone water-2% Tween 80, diluted, and plated in duplicate onto selective media and tryptic soy agar and incubated as follows: E. coli O157:H7 (modified eosin methylene blue) and Salmonella (xylose lysine tergitol-4) for 48 h at 37 degrees C, and L. monocytogenes (modified Oxford medium) at 48 h for 32 degrees C. E. coli O157:H7 populations were reduced by >1 log after 30-s and 1-min exposures and >2 log after a 2-min exposure. Salmonella populations were reduced by >2 log after 1 min. Three- and 5-min exposure times resulted in >3-log reduction. L. monocytogenes populations were reduced by 1 log after 1 min of exposure. Three- and 5-min exposure times resulted in >3- and >5-log reductions, respectively. This process has the capability of serving as a novel, nonthermal processing technology to be used for reducing microbial populations on produce surfaces.

  2. Surface modification with a remote atmospheric pressure plasma: dc glow discharge and surface streamer regime

    International Nuclear Information System (INIS)

    Temmerman, Eef; Akishev, Yuri; Trushkin, Nikolay; Leys, Christophe; Verschuren, Jo

    2005-01-01

    A remote atmospheric pressure discharge working with ambient air is used for the near room temperature treatment of polymer foils and textiles of varying thickness. The envisaged plasma effect is an increase in the surface energy of the treated material, leading, e.g., to a better wettability or adhesion. Changes in wettability are examined by measuring the contact angle or the liquid absorptive capacity. Two regimes of the remote atmospheric pressure discharge are investigated: the glow regime and the streamer regime. These regimes differ mainly in power density and in the details of the electrode design. The results show that this kind of discharge makes up a convenient non-thermal plasma source to be integrated into a treatment installation working at atmospheric pressure

  3. Surface ion implantation induced by laser-generated plasmas

    Czech Academy of Sciences Publication Activity Database

    Giuffrida, L.; Torrisi, L.; Gammino, S.; Wolowski, J.; Ullschmied, Jiří

    2010-01-01

    Roč. 165, 6-10 (2010), s. 534-542 ISSN 1042-0150. [International Workshop on Pulsed Plasma Laser Ablation (PPLA)/4./. Monte Pieta, Messina, 18.06.2009-20.06.2009] Institutional support: RVO:61389021 Keywords : laser ablation * laser plasma * ion implantation * RBS analysis Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 0.660, year: 2010

  4. Development and experimental evaluation of theoretical models for ion cyclotron resonance frequency heating of tokamak plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Mantsinen, M. [Helsinki Univ. of Technology, Espoo (Finland). Dept. of Technical Physics

    1999-06-01

    Heating with electromagnetic waves in the ion cyclotron range of frequencies (ICRF) is a well-established method for auxiliary heating of present-day tokamak plasmas and is envisaged as one of the main heating techniques for the International Thermonuclear Experimental Reactor (ITER) and future reactor plasmas. In order to predict the performance of ICRF heating in future machines, it is important to benchmark present theoretical modelling with experimental results on present tokamaks. This thesis reports on development and experimental evaluation of theoretical models for ICRF heating at the Joint European Torus (JET). Several ICRF physics effects and scenarios have been studied. Direct importance to the ITER is the theoretical analysis of ICRF heating experiments with deuterium-tritium (D-T) plasmas. These experiments clearly demonstrate the potential of ICRF heating for auxiliary heating of reactor plasmas. In particular, scenarios with potential for good bulk ion heating and enhanced D-T fusion reactivity have been identified. Good bulk ion heating is essential for reactor plasmas in order to obtain a high ion temperature and a high fusion reactivity. In JET good bulk ion heating with ICRF waves has been achieved in high-performance discharges by adding ICRF heating to neutral beam injection. In these experiments, as in other JET discharges where damping at higher harmonics of the ion cyclotron frequency takes place, so-called finite Larmor radius (FLR) effects play an important role. Due to FLR effects, the resonating ion velocity distribution function can have a strong influence on the power deposition. Evidence for this effect has been obtained from the third harmonic deuterium heating experiments. Because of FLR effects, the wave-particle interaction can also become weak at certain ion energies, which prevents resonating ions from reaching higher energies. When interacting with the wave, an ion receives not only a change in energy but also a change in

  5. Field emission studies of silver nanoparticles synthesized by electron cyclotron resonance plasma

    International Nuclear Information System (INIS)

    Purohit, Vishwas; Mazumder, Baishakhi; Bhise, A.B.; Poddar, Pankaj; Joag, D.S.; Bhoraskar, S.V.

    2011-01-01

    Field emission has been studied for silver nanoparticles (25-200 nm), deposited within a cylindrical silver target in an electron cyclotron resonance (ECR) plasma. Particle size distribution was controlled by optimum biasing voltages between the chamber and the target. Presence of non-oxidized silver was confirmed from the X-Ray diffraction analysis; however, thin protective layer of oxide was identified from the selective area electron diffraction pattern obtained with transmission electron microscopy. The silver nanoparticles were seen to exhibit hilly pointed like structures when viewed under the atomic force microscopy (AFM). The emissive properties of these particles were investigated by field emission microscopy. It is found that this technique of deposition is ideal for formation of nanoparticles films on different substrate geometries with size controllability as well as its application to emission devices.

  6. H-Nuclear Magnetic Resonance-Based Plasma Metabolic Profiling of Dairy Cows with Fatty Liver

    Directory of Open Access Journals (Sweden)

    Chuang Xu

    2016-02-01

    Full Text Available Fatty liver is a common metabolic disorder of dairy cows during the transition period. Historically, the diagnosis of fatty liver has involved liver biopsy, biochemical or histological examination of liver specimens, and ultrasonographic imaging of the liver. However, more convenient and noninvasive methods would be beneficial for the diagnosis of fatty liver in dairy cows. The plasma metabolic profiles of dairy cows with fatty liver and normal (control cows were investigated to identify new biomarkers using 1H nuclear magnetic resonance. Compared with the control group, the primary differences in the fatty liver group included increases in β-hydroxybutyric acid, acetone, glycine, valine, trimethylamine-N-oxide, citrulline, and isobutyrate, and decreases in alanine, asparagine, glucose, γ-aminobutyric acid glycerol, and creatinine. This analysis revealed a global profile of endogenous metabolites, which may present potential biomarkers for the diagnosis of fatty liver in dairy cows.

  7. Surface plasmon resonance imaging based multiplex biosensor: Integration of biomolecular screening, detection and kinetics estimation.

    NARCIS (Netherlands)

    Krishnamoorthy, G.; Carlen, Edwin; van den Berg, Albert; Schasfoort, Richardus B.M.

    2010-01-01

    We present a multiplex biosensing method to simultaneously screen targets of interest in a multiple target analyte sample and to extract the binding affinities of all interactant pairs from a single sensor surface using a commercial surface plasmon resonance imaging system. For demonstration, we

  8. Label-free screening of foodborne Salmonella using surface plasmon resonance imaging

    Science.gov (United States)

    Since 15 pathogens cause approximately 95% of the foodborne infections, it is desirable to develop rapid and simultaneous screening methods for these major pathogens. In this study, we developed an immunoassay for Salmonella based on surface plasmon resonance imaging (SPRi). The sensor surface modif...

  9. A surface plasmon resonance immunosensor for detecting a dioxin precursor using a gold binding polypeptide

    DEFF Research Database (Denmark)

    Soh, N; Tokuda, T.; Watanabe, T.

    2003-01-01

    A surface plasmon resonance (SPR) based biosensor was developed for monitoring 2,4-dichlorophenol, a known dioxin precursor, using an indirect competitive immunoassay. The SPR sensor was fabricated by immobilizing a gold-thin layer on the surface of an SPR sensor chip with an anti-(2...

  10. Surface plasmon resonance is an analytically sensitive method for antigen profiling of extracellular vesicles

    NARCIS (Netherlands)

    Gool, Elmar L.; Stojanovic, Ivan; Schasfoort, Richardus B.M.; Sturk, Auguste; Van Leeuwen, Ton G.; Nieuwland, Rienk; Terstappen, Leon W.M.M.; Coumans, Frank A.W.

    2017-01-01

    BACKGROUND: Identification, enumeration, and characterization of extracellular vesicles (EVs) are hampered by the small size of EVs, a low refractive index, and low numbers of antigens on their surface. METHODS: We investigated the potential of a 48- multiplex surface plasmon resonance imaging

  11. Surface Plasmon Resonance is an Analytically Sensitive Method for Antigen Profiling of Extracellular Vesicles

    NARCIS (Netherlands)

    Gool, Elmar L.; Stojanovic, Ivan; Schasfoort, Richard B. M.; Sturk, Auguste; van Leeuwen, Ton G.; Nieuwland, Rienk; Terstappen, Leon W. M. M.; Coumans, Frank A. W.

    2017-01-01

    Identification, enumeration, and characterization of extracellular vesicles (EVs) are hampered by the small size of EVs, a low refractive index, and low numbers of antigens on their surface. We investigated the potential of a 48-multiplex surface plasmon resonance imaging (SPRi) system to perform EV

  12. Electron emission induced by resonant coherent ion-surface interaction at grazing incidence

    International Nuclear Information System (INIS)

    Garcia de Abajo, F.J.; Ponce, V.H.; Echenique, P.M.

    1992-01-01

    A new spectroscopy based on the resonant coherently induced electron loss to the continuum in ion-surface scattering under grazing incidence is proposed. A series of peaks, corresponding to the energy differences determined by the resonant interaction with the rows of atoms in the surface, is predicted to appear in the energy distribution of electrons emitted from electronic states bound to the probe. Calculations for MeV He + ions scattered at a W(001) surface along the left-angle 100 right-angle direction with a glancing angle of 0--2 mrad show a total yield close to 1

  13. Study of a continuous plasma generated by electron bombardment and its mixing with a laser induced plasma. Influence of collisions on resonance cone phenomenon

    International Nuclear Information System (INIS)

    Besuelle, E.

    1997-01-01

    This thesis deals with three different fields of plasma physics. In the first part, we studied free expansion of an ionised uranium vapour generated in an electron beam evaporator. The electron temperature and the electron density of the expanding plasma have been measured by a Langmuir probe. The experimental results have been compared with the ones obtained by numerical simulation using a fluid code. The calculated points are in the error bars. We observe that there are two electron populations with different temperatures, which undergo a mixing during the plasma expansion. The neutral density influence on the electron temperature by collisional relaxation is also studied. The second part deals with a plasma diagnostic which can replace Langmuir probe in the case of a cold magnetized plasma: the resonance cone phenomenon. After recalling the wave propagation theory in a cold plasma, we introduce a new calculation of the potential radiated by an antenna in a collisional magnetized plasma. The domain where the resonance cone exists in considerably reduced because of collisions. More of that, the cone angle is reduced by this phenomenon too. The experiments performed show that we must take into account a wave turbulence phenomenon to explain the High collision frequency that we observe. The third part is about the study of the expansion of a plasma into another one. We solve this problem with fluid codes and Particle-In-Cell (PIC) code. THe electron families have a counter stream motion locally. Then, we study the electrostatic extraction of two plasmas-one pulsed, one continuous-in which we observe electron unfurling. (author)

  14. Bactericidal effects of plasma-modified surface chemistry of silicon nanograss

    Science.gov (United States)

    Ostrikov, Kola; Macgregor-Ramiasa, Melanie; Cavallaro, Alex; (Ken Ostrikov, Kostya; Vasilev, Krasimir

    2016-08-01

    The surface chemistry and topography of biomaterials regulate the adhesion and growth of microorganisms in ways that are still poorly understood. Silicon nanograss structures prepared via inductively coupled plasma etching were coated with plasma deposited nanometer-thin polymeric films to produce substrates with controlled topography and defined surface chemistry. The influence of surface properties on Staphylococcus aureus proliferation is demonstrated and explained in terms of nanograss substrate wetting behaviour. With the combination of the nanograss topography; hydrophilic plasma polymer coatings enhanced antimicrobial activity while hydrophobic coatings reduced it. This study advances the understanding of the effects of surface wettability on the bactericidal properties of reactive nano-engineered surfaces.

  15. Bactericidal effects of plasma-modified surface chemistry of silicon nanograss

    International Nuclear Information System (INIS)

    Ostrikov, Kola; Macgregor-Ramiasa, Melanie; Cavallaro, Alex; Ostrikov, Kostya; Vasilev, Krasimir

    2016-01-01

    The surface chemistry and topography of biomaterials regulate the adhesion and growth of microorganisms in ways that are still poorly understood. Silicon nanograss structures prepared via inductively coupled plasma etching were coated with plasma deposited nanometer-thin polymeric films to produce substrates with controlled topography and defined surface chemistry. The influence of surface properties on Staphylococcus aureus proliferation is demonstrated and explained in terms of nanograss substrate wetting behaviour. With the combination of the nanograss topography; hydrophilic plasma polymer coatings enhanced antimicrobial activity while hydrophobic coatings reduced it. This study advances the understanding of the effects of surface wettability on the bactericidal properties of reactive nano-engineered surfaces. (paper)

  16. Stability of Atmospheric-Pressure Plasma Induced Changes on Polycarbonate Surfaces

    Science.gov (United States)

    Sharma, Rajesh; Holcomb, Edward; Trigwell, Steve

    2006-01-01

    Polycarbonate films are subjected to plasma treatment in a number of applications such as improving adhesion between polycarbonate and silicon alloy in protective and optical coatings. The changes in surface chemistry due to plasma treatment have tendency to revert back. Thus stability of the plasma induced changes on polymer surfaces over desired time period is very important. The objective of this study was to examine the effect of ageing on atmospheric pressure helium-plasma treated polycarbonate (PC) sample as a function of treatment time. The ageing effects were studied over a period of 10 days. The samples were plasma treated for 0.5, 2, 5 and 10 minutes. Contact angle measurements were made to study surface energy changes. Modification of surface chemical structure was examined using, X-ray Photoelectron Spectroscopy (XPS). Contact angle measurements on untreated and plasma treated surfaces were made immediately, 24, 48, 72 and 96 hrs after treatment. Contact angle decreased from 93 deg for untreated sample to 30 deg for sample plasma treated for 10 minutes. After 10 days the contact angles for the 10 minute plasma treated sample increased to 67 deg, but it never reverted back to that of untreated surface. Similarly the O/C ratio increased from 0.136 for untreated sample to 0.321 for 10 minute plasma treated sample indication increase in surface energy.

  17. Nonlinear radiation of waves at combination frequencies due to radiation-surface wave interaction in plasmas

    International Nuclear Information System (INIS)

    El Naggar, I.A.; Hussein, A.M.; Khalil, Sh.M.

    1992-09-01

    Electromagnetic waves radiated with combination frequencies from a semi-bounded plasma due to nonlinear interaction of radiation with surface wave (both of P-polarization) has been investigated. Waves are radiated both into vacuum and plasma are found to be P-polarized. We take into consideration the continuity at the plasma boundary of the tangential components of the electric field of the waves. The case of normal incidence of radiation and rarefield plasma layer is also studied. (author). 7 refs

  18. Surface Modification of Ferritic Stainless Steel by Active Screen Plasma Nitriding

    OpenAIRE

    NII, Hiroaki; NISHIMOTO, Akio

    2012-01-01

    Plasma nitriding is a surface modification process with a low environmental impact. Active screen plasma nitriding (ASPN) is one of the new plasma nitriding technologies, and can eliminate problems related to conventional direct current plasma nitriding (DCPN). In this study, ferritic stainless steel SUS430 samples were treated by ASPN to increase their wear resistance without decreasing their corrosion resistance. ASPN was performed in a nitrogen-hydrogen atmosphere with 25%N2 + 75%H2 for 18...

  19. Non-destructive plasma frequency measurement for a semiconductor thin film using broadband surface plasmon polaritons

    Science.gov (United States)

    Yang, Tao; Ge, Jia-cheng; Li, Xing-ao; Stantchev, Rayko Ivanov; Zhu, Yong-yuan; Zhou, Yuan; Huang, Wei

    2018-03-01

    Measurement of the plasma frequency of a semiconductor film using broadband surface plasmon is demonstrated in this paper. We theoretically deduce a formula about the relation between plasma frequency and characteristic surface plasmon frequency. The characteristic surface plasmon frequency can be captured from the cut-off frequency of the transmission spectra of the broadband surface plasmon, which is used to measure the plasma frequency indirectly. The plasma frequencies of an intrinsic indium antimonide with and without optical illuminance are measured with a THz time-domain spectrometer at room temperature. The experimental measured plasma frequencies fit well with theoretical and simulation results. Compared with other methods, the proposed method has a special advantage on measuring the plasma frequency for a thin semiconductor film coated on other materials.

  20. Effect of atmospheric oxidative plasma treatments on polypropylenic fibers surface: Characterization and reaction mechanisms

    International Nuclear Information System (INIS)

    Nisticò, Roberto; Magnacca, Giuliana; Faga, Maria Giulia; Gautier, Giovanna; D’Angelo, Domenico; Ciancio, Emanuele; Lamberti, Roberta; Martorana, Selanna

    2013-01-01

    Atmospheric pressure plasma-dielectric barrier discharge (APP-DBD, open chamber configuration) was used to functionalize polypropylene (PP) fibers surface in order to generate oxidized-reactive groups such as hydroperoxides, alcohols and carbonyl species (i.e. ketones and others). Such a species increased the surface polarity, without causing material degradation. Three different types of plasma mixture (He, He/O 2 , He/O 2 /H 2 O) under three different values of applied power (750, 1050, 1400 W) were investigated. The formed plasma species (O 2 + , O single atom and OH radical) and their distribution were monitored via optical emission spectrometry (OES) measurements, and the plasma effects on PP surface species formation were followed by X-ray photoemission spectroscopy (XPS). Results allowed to better understand the reaction pathways between plasma phase and PP fibers. In fact, two reaction mechanisms were proposed, the first one concerning the plasma phase reactions and the second one involving material surface modifications.

  1. Cleaning of niobium surface by plasma of diffuse discharge at atmospheric pressure

    Science.gov (United States)

    Tarasenko, V. F.; Erofeev, M. V.; Shulepov, M. A.; Ripenko, V. S.

    2017-07-01

    Elements composition of niobium surface before and after plasma treatment by runaway electron preionized diffuse discharge was investigated in atmospheric pressure nitrogen flow by means of an Auger electron spectroscopy. Surface characterizations obtained from Auger spectra show that plasma treatment by diffuse discharge after exposure of 120000 pulses provides ultrafine surface cleaning from carbon contamination. Moreover, the surface free energy of the treated specimens increased up to 3 times, that improve its adhesion property.

  2. Plasma transport in stochastic magnetic field caused by vacuum resonant magnetic perturbations at diverted tokamak edge

    International Nuclear Information System (INIS)

    Park, G.; Chang, C. S.; Joseph, I.; Moyer, R. A.

    2010-01-01

    A kinetic transport simulation for the first 4 ms of the vacuum resonant magnetic perturbations (RMPs) application has been performed for the first time in realistic diverted DIII-D tokamak geometry [J. Luxon, Nucl. Fusion 42, 614 (2002)], with the self-consistent evaluation of the radial electric field and the plasma rotation. It is found that, due to the kinetic effects, the stochastic parallel thermal transport is significantly reduced when compared to the standard analytic model [A. B. Rechester and M. N. Rosenbluth, Phys. Rev. Lett. 40, 38 (1978)] and the nonaxisymmetric perpendicular radial particle transport is significantly enhanced from the axisymmetric level. These trends agree with recent experimental result trends [T. E. Evans, R. A. Moyer, K. H. Burrell et al., Nat. Phys. 2, 419 (2006)]. It is also found, as a side product, that an artificial local reduction of the vacuum RMP fields in the vicinity of the magnetic separatrix can bring the kinetic simulation results to a more detailed agreement with experimental plasma profiles.

  3. Temperature dependence of the cosphi conductance in Josephson tunnel junctions determined from plasma resonance experiments

    International Nuclear Information System (INIS)

    Pedersen, N.F.; Soerensen, O.H.; Mygind, J.

    1978-01-01

    The microwave response at 9 GHz of Sn-O-Sn tunnel-junction current biased at zero dc voltage has been measured just below the critical temperature T/sub c/ of the Sn films. The temperature dependence of the cosphi conductance is determined from the resonant response at the junction plasma frequency f/sub p/ as the temperature is decreased from T/sub c/. We used three different schemes for observation of the plasma oscillations: (a) second-harmonic generation (excitation at approx. 4.5 GHz, f/sub p/ approx. 4.5 GHz); (b) mixing (excitations at approx. 9 and approx. 18 GHz, f/sub p/ approx. 9 GHz); (c) parametric half-harmonic oscillation (excitation at approx. 18 GHz, f/sub p/ approx. 9 GHz). Measurements were possible in two temperature intervals; 0.994 or = T/T/sub c/ > or = 0.930, with the result that as the temperature was decreased the cosphi amplitude first increased from about zero to positive values and then at lower temperatures decreased approaching -1 at the lowest temperatures of the experiment

  4. Optical fiber sensor based on surface plasmon resonance for rapid detection of avian influenza virus subtype H6: Initial studies.

    Science.gov (United States)

    Zhao, Xihong; Tsao, Yu-Chia; Lee, Fu-Jung; Tsai, Woo-Hu; Wang, Ching-Ho; Chuang, Tsung-Liang; Wu, Mu-Shiang; Lin, Chii-Wann

    2016-07-01

    A side-polished fiber optic surface plasmon resonance (SPR) sensor was fabricated to expose the core surface and then deposited with a 40 nm thin gold film for the near surface sensing of effective refractive index changes with surface concentration or thickness of captured avian influenza virus subtype H6. The detection surface of the SPR optical fiber sensor was prepared through the plasma modification method for binding a self-assembled monolayer of isopropanol chemically on the gold surface of the optical fiber. Subsequently, N-(3-dimethylaminopropyl)-N'-ethylcarbodiimide/N-hydroxysuccinimide was activated to enable EB2-B3 monoclonal antibodies to capture A/chicken/Taiwan/2838V/00 (H6N1) through a flow injection system. The detection limit of the fabricated optical fiber sensor for A/chicken/Taiwan/2838V/00 was 5.14 × 10(5) EID50/0.1 mL, and the response time was 10 min on average. Moreover, the fiber optic sensor has the advantages of a compact size and low cost, thus rendering it suitable for online and remote sensing. The results indicated that the optical fiber sensor can be used for epidemiological surveillance and diagnosing of avian influenza subtype H6 rapidly. Copyright © 2016 Elsevier B.V. All rights reserved.

  5. Microwave resonators from YBa2Cu3O(7-delta) thin films made by plasma-enhanced metalorganic chemical vapor deposition

    Science.gov (United States)

    Young, K. H.; Robinson, Mcd.; Negrete, G. V.; Zhao, J.; Chern, C. S.; Li, Y. Q.; Norris, P. E.

    1992-08-01

    Epitaxial YBa2Cu3O(7-delta) thin films on LaAlO3 deposited by plasma-enhanced metalorganic chemical vapor deposition were tested in a 100 GHz microwave cavity and as patterned 5.6 GHz resonators. Two films, both having high critical temperature and high critical current density, exhibited low-power Q's of 5400 and 8000 as 5.6 GHz microstrip resonators when operated at 77 K. The equivalent surface resistances at 10 GHz are 1.7 and 1 m-Omega, respectively. Despite the fact that these films are thinner than typical laser ablation films, the results are within a factor of 2 of the best laser ablation prepared YBa2Cu3O(7-delta) films.

  6. Effects of group velocity and multiplasmon resonances on the modulation of Langmuir waves in a degenerate plasma.

    Science.gov (United States)

    Misra, Amar P; Chatterjee, Debjani; Brodin, Gert

    2017-11-01

    We study the nonlinear wave modulation of Langmuir waves (LWs) in a fully degenerate plasma. Using the Wigner-Moyal equation coupled to the Poisson equation and the multiple scale expansion technique, a modified nonlocal nonlinear Schrödinger (NLS) equation is derived which governs the evolution of LW envelopes in degenerate plasmas. The nonlocal nonlinearity in the NLS equation appears due to the group velocity and multiplasmon resonances, i.e., resonances induced by the simultaneous particle absorption of multiple wave quanta. We focus on the regime where the resonant velocity of electrons is larger than the Fermi velocity and thereby the linear Landau damping is forbidden. As a result, the nonlinear wave-particle resonances due to the group velocity and multiplasmon processes are the dominant mechanisms for wave-particle interaction. It is found that in contrast to classical or semiclassical plasmas, the group velocity resonance does not necessarily give rise the wave damping in the strong quantum regime where ℏk∼mv_{F} with ℏ denoting the reduced Planck's constant, m the electron mass, and v_{F} the Fermi velocity; however, the three-plasmon process plays a dominant role in the nonlinear Landau damping of wave envelopes. In this regime, the decay rate of the wave amplitude is also found to be higher compared to that in the modest quantum regime where the multiplasmon effects are forbidden.

  7. Surface modification of chromatography adsorbents by low temperature low pressure plasma

    DEFF Research Database (Denmark)

    Arpanaei, Ayyoob; Winther-Jensen, Bjørn; Theodosiou, E.

    2010-01-01

    a purpose-designed rotating reactor, plasmas were employed to either: (i) remove anion exchange ligands at or close to the exterior surface of Q HyperZ, and replace them with polar oxygen containing functions (‘plasma etching and oxidation’); or (ii) bury the same surface exposed ligands beneath thin...

  8. Atmospheric-pressure plasma activation and surface characterization on polyethylene membrane separator

    Science.gov (United States)

    Tseng, Yu-Chien; Li, Hsiao-Ling; Huang, Chun

    2017-01-01

    The surface hydrophilic activation of a polyethylene membrane separator was achieved using an atmospheric-pressure plasma jet. The surface of the atmospheric-pressure-plasma-treated membrane separator was found to be highly hydrophilic realized by adjusting the plasma power input. The variations in membrane separator chemical structure were confirmed by Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy. Chemical analysis showed newly formed carbonyl-containing groups and high surface concentrations of oxygen-containing species on the atmospheric-pressure-plasma-treated polymeric separator surface. It also showed that surface hydrophilicity primarily increased from the polar component after atmospheric-pressure plasma treatment. The surface and pore structures of the polyethylene membrane separator were examined by scanning electron microscopy, revealing a slight alteration in the pore structure. As a result of the incorporation of polar functionalities by atmospheric-pressure plasma activation, the electrolyte uptake and electrochemical impedance of the atmospheric-pressure-plasma-treated membrane separator improved. The investigational results show that the separator surface can be controlled by atmospheric-pressure plasma surface treatment to tailor the hydrophilicity and enhance the electrochemical performance of lithium ion batteries.

  9. Study of plasma formation in CW CO2 laser beam-metal surface interaction

    Science.gov (United States)

    Azharonok, V. V.; Vasilchenko, Zh V.; Golubev, Vladimir S.; Gresev, A. N.; Zabelin, Alexandre M.; Chubrik, N. I.; Shimanovich, V. D.

    1994-04-01

    An interaction of the cw CO2 laser beam and a moving metal surface has been studied. The pulsed and thermodynamical parameters of the surface plasma were investigated by optical and spectroscopical methods. The subsonic radiation wave propagation in the erosion plasma torch has been studied.

  10. Cholera toxin binding affinity and specificity for gangliosides determined by surface plasmon resonance

    Energy Technology Data Exchange (ETDEWEB)

    Kuziemko, G.M.; Stroh, M.; Stevens, R.C. [Univ. of California, Berkeley, CA (United States)]|[Lawrence Berkeley National Lab., CA (United States)

    1996-05-21

    The present study determines the affinity of cholera toxin for the ganglioside series GM1, GM2, GM3, GD1A, GD1B, GT1B, asialo GM1, globotriosyl ceramide, and lactosyl ceramide using real time biospecific interaction analysis (surface plasmon resonance, SPR). SPR shows that cholera toxin preferably binds to gangliosides in the following sequence: GM1 > GM2 > GD1A > GM3 > GT1B > GD1B > asialo-GM1. The measured binding affinity of cholera toxin for the ganglioside sequence ranges from 4.61 {times} 10{sup {minus}12} M for GM1 to 1.88 {times} 10{sup {minus}10} M for asialo GM1. The picomolar values obtained by surface plasmon resonance are similar to K{sub d} values determined with whole-cell binding assays. Both whole-cell assays ans SPR measurements on synthetic membranes are higher than free solution measurements by several orders of magnitude. This difference may be caused by the effects of avidity and charged lipid head-groups, which may play a major role in the binding between cholera toxin, the receptor, and the membrane surface. The primary difference between free solution binding studies and surface plasmon resonance studies is that the latter technique is performed on surfaces resembling the cell membrane. Surface plasmon resonance has the further advantage of measuring apparent kinetic association and dissociation rates in real time, providing direct information about binding events at the membrane surface. 34 refs., 8 figs., 2 tabs.

  11. Adhesion enhancement of Al coatings on carbon/epoxy composite surfaces by atmospheric plasma

    International Nuclear Information System (INIS)

    Coulon, J.F.; Tournerie, N.; Maillard, H.

    2013-01-01

    Adhesion strengths between aluminium thin film coatings and manufactured carbon/epoxy composite surfaces were measured by assessing fracture tensile strengths using pull-off tests. The effect of the substrate roughness (nm to μm) of these composite surfaces on adhesion was studied by examining the surface free energies and adhesion strengths. The adhesion strengths of the coatings varied significantly. To improve the coating adhesion, each composite surface was treated with atmospheric plasma prior to deposition, which resulted in an increase in the surface free energy from approximately 40 mJ/m 2 to 70 mJ/m 2 because the plasma pretreatment led to the formation of hydrophilic C-O and C=O bonds on the composite surfaces, as demonstrated by X-ray photoelectron spectroscopy analyses. The adhesion strengths of the coatings were enhanced for all surface roughnesses studied. In our study, the effect of mechanical adhesion due to roughness was separated from the effect of modifying the chemical bonds with plasma activation. The adhesion ability of the pure resin was relatively weak. Increasing the surface roughness largely improved the adhesion of the resin surface. Plasma treatment of the pure resin also increased the surface adhesion. Our study shows that plasma activation effectively enhances the adhesion of manufactured composites, even when the surface roughness is on the order of microns. The ageing of the surface activation was also investigated, and the results demonstrate that atmospheric plasma has potential for use in the pretreatment of composite materials.

  12. Nano-structuring of PTFE surface by plasma treatment, etching, and sputtering with gold

    International Nuclear Information System (INIS)

    Reznickova, Alena; Kolska, Zdenka; Hnatowicz, Vladimir; Svorcik, Vaclav

    2011-01-01

    Properties of pristine, plasma modified, and etched (by water and methanol) polytetrafluoroethylene (PTFE) were studied. Gold nanolayers sputtered on this modified PTFE have been also investigated. Contact angle, measured by goniometry, was studied as a function of plasma exposure and post-exposure aging times. Degradation of polymer chains was examined by etching of plasma modified PTFE in water or methanol. The amount of ablated and etched layer was measured by gravimetry. In the next step the pristine, plasma modified, and etched PTFE was sputtered with gold. Changes in surface morphology were observed using atomic force microscopy. Chemical structure of modified polymers was characterized by X-ray photoelectron spectroscopy (XPS). Surface chemistry of the samples was investigated by electrokinetic analysis. Sheet resistance of the gold layers was measured by two-point technique. The contact angle of the plasma modified PTFE decreases with increasing exposure time. The PTFE amount, ablated by the plasma treatment, increases with the plasma exposure time. XPS measurements proved that during the plasma treatment the PTFE macromolecular chains are degraded and oxidized and new –C–O–C–, –C=O, and –O–C=O groups are created in modified surface layer. Surface of the plasma modified PTFE is weakly soluble in methanol and intensively soluble in water. Zeta potential and XPS shown dramatic changes in PTFE surface chemistry after the plasma exposure, water etching, and gold deposition. When continuous gold layer is formed a rapid decrease of the sheet resistance of the gold layer is observed.

  13. The relationship between cellular adhesion and surface roughness in polystyrene modified by microwave plasma radiation

    Directory of Open Access Journals (Sweden)

    Biazar E

    2011-03-01

    Full Text Available Esmaeil Biazar1, Majid Heidari2, Azadeh Asefnezhad2, Naser Montazeri11Department of Chemistry, Islamic Azad University, Tonekabon Branch, Mazandaran; 2Department of Biomaterial Engineering, Faculty of Biomedical Engineering, Science and Research Branch, Islamic Azad University, Tehran, IranBackground: Surface modification of medical polymers can improve biocompatibility. Pure polystyrene is hydrophobic and cannot provide a suitable environment for cell cultures. The conventional method for surface modification of polystyrene is treatment with plasma. In this study, conventional polystyrene was exposed to microwave plasma treatment with oxygen and argon gases for 30, 60, and 180 seconds.Methods and results: Attenuated total reflection Fourier transform infrared spectra investigations of irradiated samples indicated clearly the presence of functional groups. Atomic force microscopic images of samples irradiated with inert and active gases indicated nanometric surface topography. Samples irradiated with oxygen plasma showed more roughness (31 nm compared with those irradiated with inert plasma (16 nm at 180 seconds. Surface roughness increased with increasing duration of exposure, which could be due to reduction of the contact angle of samples irradiated with oxygen plasma. Contact angle analysis showed reduction in samples irradiated with inert plasma. Samples irradiated with oxygen plasma showed a lower contact angle compared with those irradiated by argon plasma.Conclusion: Cellular investigations with unrestricted somatic stem cells showed better adhesion, cell growth, and proliferation for samples radiated by oxygen plasma with increasing duration of exposure than those of normal samples.Keywords: surface topography, polystyrene, plasma treatment, argon, oxygen

  14. INSTRUMENTS AND METHODS OF INVESTIGATION: Generation of high-order harmonics of high-power lasers in plasmas produced under irradiation of solid target surfaces by a prepulse

    Science.gov (United States)

    Ganeev, Rashid A.

    2009-01-01

    Research on high-order harmonic generation in laser-produced plasmas is reviewed. We analyze the conditions for the generation of harmonics (up to the 101st order, λ = 7.9 nm) in the propagation of laser radiation through a weakly ionized plasma prepared by irradiating the surfaces of different targets with a laser prepulse. We discuss the findings of investigations into the resonance intensity enhancement of individual harmonics in a number of plasma formations, which have demonstrated a substantial increase in the conversion efficiency in the plateau region of the harmonic-order distribution (in particular, of the 13th harmonic in indium plasmas with the efficiency 10-4). We review the results of investigations of harmonic generation in nanoparticle-containing plasmas. Different techniques for increasing the intensity and order of the generated harmonics are discussed.

  15. Enhancement of Biocompatibility on Bioactive Titanium Surface by Low-Temperature Plasma Treatment

    Science.gov (United States)

    Lin, Chia-Cheng; Cheng, Hsin-Chung; Huang, Chiung-Fang; Lin, Che-Tong; Lee, Sheng-Yang; Chen, Chin-Sung; Ou, Keng-Liang

    2005-12-01

    The surface of implantable biomaterials directly contacts the host tissue and is critical in determining biocompatibility. To improve implant integration, interfacial reactions must be controlled to minimize nonspecific adsorption of proteins, and tissue-healing phenomena can be controlled. The purpose of this study was to develop a new method of functionalizing titanium surfaces by plasma treatment. The covalent immobilization of bioactive organic molecules and the bioactivities in vitro were assessed by transmission electron microscopy (TEM), atomic force spectroscopy (AFM), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), and 3-(4,5-dimethylthiazole-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay as indices of cellular cytotoxicity. Argon plasma removed all of the adsorbed contaminants and impurities. Plasma-cleaned titanium surfaces showed better bioactive performances than untreated titanium surfaces. The analytical results reveal that plasma-cleaned titanium surfaces provide a clean and reproducible starting condition for further plasma treatments to create well-controlled surface layers. Allylamine was ionized by plasma treatment, and acted as a medium to link albumin. Cells demonstrated a good spread, and a wide attachment was attained on the Albu-Ti plate. Cell attachment and growth were shown to be influenced by the surface properties. The plasma treatment process plays an important role in facilitating tissue healing. This process not only provides a clean titanium surface, but also leads to surface amination on plasma-treated titanium surfaces. Surface cleaning by ion bombardment and surface modification by plasma polymerization are believed to remove contamination on titanium surfaces and thus promote tissue healing.

  16. Resonator structures on AlN ceramics surface treated by laser radiation

    Science.gov (United States)

    Koziol, Pawel E.; Antonczak, Arkadiusz J.; Stepak, Bogusz; Gorski, Przemyslaw A.; Walczakowski, Michal; Palka, Norbert; Abramski, Krzysztof M.

    2014-03-01

    In this paper a method for producing resonant structures using laser micromachining is presented. In the spot of laser beam impact on AlN ceramics surface a conductive aluminum layer is formed. Compilation of process parameters allows for the fabrication of structures with resistance at Rs ~ 0.01Ω/Rs. It has been also found out that the maximum value of resistance for which spiral resonator structures manifest their unique properties is at the level of Rs = 1.43 Ω. Furthermore, the occurrence of mutual capacity which value is dependent on the arrangement of individual SR structures with respect to each other was observed and examined. Based on satisfactory results for SR structures, it has been attempted to produce a resonant structures dedicated to the THz range based on the process of direct metallization of AlN ceramics surface. As a result, the Split Ring Resonator structure whose properties were verified by using the THz -TDS method was manufactured. In case of the field E perpendicular to SRR structure and one resonance area for 0.50 THz with field E parallel to the structure, two characteristic resonant dips for 0.22 THz and 0.46 THz were obtained. The studies confirmed that the method of direct metallization of AlN ceramics allows to produce resonant structures in the THz range.

  17. Localized surface plasmon polariton resonance in holographically structured Al-doped ZnO

    Energy Technology Data Exchange (ETDEWEB)

    George, David; Lowell, David; Mao, Michelle; Hassan, Safaa; Philipose, Usha [Department of Physics and Center for Advanced Research and Technology, University of North Texas, Denton, Texas 76203 (United States); Li, Li; Jiang, Yan; Cui, Jingbiao [Department of Physics and Materials Science, University of Memphis, Memphis, Tennessee 38152 (United States); Ding, Jun; Zhang, Hualiang [Department of Electrical and Computer Engineering, University of Massachusetts Lowell, Lowell, Massachusetts 01854 (United States); Lin, Yuankun [Department of Physics and Center for Advanced Research and Technology, University of North Texas, Denton, Texas 76203 (United States); Department of Electrical Engineering, University of North Texas, Denton, Texas 76203 (United States)

    2016-07-28

    In this paper, we studied the localized surface plasmon polariton (SPP) resonance in hole arrays in transparent conducting aluminum-doped zinc oxide (AZO). CMOS-compatible fabrication process was demonstrated for the AZO devices. The localized SPP resonance was observed and confirmed by electromagnetic simulations. Using a standing wave model, the observed SPP was dominated by the standing-wave resonance along (1,1) direction in square lattices. This research lays the groundwork for a fabrication technique that can contribute to the core technology of future integrated photonics through its extension into tunable conductive materials.

  18. Plasma diagnostics of low pressure high power impulse magnetron sputtering assisted by electron cyclotron wave resonance plasma

    Czech Academy of Sciences Publication Activity Database

    Straňák, V.; Herrendorf, A.-P.; Drache, S.; Čada, Martin; Hubička, Zdeněk; Bogdanowicz, R.; Tichý, M.; Hippler, R.

    2012-01-01

    Roč. 112, č. 9 (2012), "093305-1"-"093305-9" ISSN 0021-8979 R&D Projects: GA TA ČR TA01010517; GA ČR(CZ) GAP205/11/0386 Institutional research plan: CEZ:AV0Z10100522 Keywords : Langmuir probes * mass spectroscopy * plasma density * plasma diagnostics * plasma materials processing * plasma pressure * plasma radiofrequency heating Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 2.210, year: 2012 http://jap.aip.org/resource/1/japiau/v112/i9/p093305_s1

  19. Localized surface plate modes via flexural Mie resonances

    KAUST Repository

    Farhat, M.

    2017-05-11

    Surface-plasmon polaritons are naturally generated upon excitation of metals with high-frequency electromagnetic waves. However, the concept of spoof plasmons has made it possible to generate plasmoniclike effects in microwave electrodynamics, magnetics, and even acoustics. Similarly, in this paper, the concept of localized surface plate modes (SPMs) is introduced. It is demonstrated that SPMs can be generated on a two-dimensional (clamped or stress-free) cylindrical surface with subwavelength corrugations, which resides on a thin elastic plate, under excitation by an incident flexural plane wave. Numerical characterization of this corrugated rigid structure shows that it is elastically equivalent to a cylindrical scatterer with dispersive but uniformly negative flexural rigidity. This, indeed, suggests that plasmoniclike elastic materials can be engineered with potential applications in various areas including earthquake sensing and elastic imaging and cloaking.

  20. Comparison of SF₆ and CF₄ Plasma Treatment for Surface Hydrophobization of PET Polymer.

    Science.gov (United States)

    Resnik, Matic; Zaplotnik, Rok; Mozetic, Miran; Vesel, Alenka

    2018-02-21

    The fluorination of the polymer polyethylene terephthalate in plasma created from SF₆ or CF₄ gas at various pressures was investigated. The surface was analysed by X-ray photoelectron spectroscopy and water contact angle measurements, whereas the plasma was characterized by optical emission spectroscopy. The extent of the polymer surface fluorination was dependent on the pressure. Up to a threshold pressure, the amount of fluorine on the polymer surface and the surface hydrophobicity were similar, which was explained by the full dissociation of the SF₆ and CF₄ gases, leading to high concentrations of fluorine radicals in the plasma and thus causing the saturation of the polymer surface with fluorine functional groups. Above the threshold pressure, the amount of fluorine on the polymer surface significantly decreased, whereas the oxygen concentration increased, leading to the formation of the hydrophilic surface. This effect, which was more pronounced for the SF₆ plasma, was explained by the electronegativity of both gases.

  1. Comparison of SF6 and CF4 Plasma Treatment for Surface Hydrophobization of PET Polymer

    Science.gov (United States)

    Mozetic, Miran

    2018-01-01

    The fluorination of the polymer polyethylene terephthalate in plasma created from SF6 or CF4 gas at various pressures was investigated. The surface was analysed by X-ray photoelectron spectroscopy and water contact angle measurements, whereas the plasma was characterized by optical emission spectroscopy. The extent of the polymer surface fluorination was dependent on the pressure. Up to a threshold pressure, the amount of fluorine on the polymer surface and the surface hydrophobicity were similar, which was explained by the full dissociation of the SF6 and CF4 gases, leading to high concentrations of fluorine radicals in the plasma and thus causing the saturation of the polymer surface with fluorine functional groups. Above the threshold pressure, the amount of fluorine on the polymer surface significantly decreased, whereas the oxygen concentration increased, leading to the formation of the hydrophilic surface. This effect, which was more pronounced for the SF6 plasma, was explained by the electronegativity of both gases. PMID:29466293

  2. Hybrid surface platform for the simultaneous detection of proteins and DNA using a surface plasmon resonance (SPR) imaging sensor

    Czech Academy of Sciences Publication Activity Database

    Homola, Jiří; Piliarik, Marek; Ladd, J.; Taylor, A.; Shaoyi, J.

    2008-01-01

    Roč. 80, č. 11 (2008), s. 4231-4236 ISSN 0003-2700 R&D Projects: GA AV ČR KAN200670701 Institutional research plan: CEZ:AV0Z20670512 Keywords : Surface plasmon resonance imaging * DNA -directed immobilization * protein array Subject RIV: JB - Sensors, Measurment, Regulation Impact factor: 5.712, year: 2008

  3. Surface functionalization for self-referencing surface plasmon resonance /SPR/ biosensors by multi-step self assembly

    Czech Academy of Sciences Publication Activity Database

    Boozer, C.; Yu, Q.; Chen, S.; Lee, Ch.-Y.; Homola, Jiří; Yee, S. S.; Jiang, S.

    2003-01-01

    Roč. 90, 1/3 (2003), s. 22-30 ISSN 0925-4005 Institutional research plan: CEZ:AV0Z2067918 Keywords : biosensors * surface plasmon resonance * optical sensors Subject RIV: JB - Sensors, Measurment, Regulation Impact factor: 2.391, year: 2003

  4. Angular scanning and variable wavelength surface plasmon resonance allowing free sensor surface selection for optimum material- and bio-sensing

    NARCIS (Netherlands)

    Lakayan, Dina; Tuppurainen, Jussipekka; Albers, Martin; van Lint, Matthijs J.; van Iperen, Dick J.; Weda, Jelmer J.A.; Kuncova-Kallio, Johana; Somsen, Govert W.; Kool, Jeroen

    2018-01-01

    A variable-wavelength Kretschmann configuration surface plasmon resonance (SPR) apparatus with angle scanning is presented. The setup provides the possibility of selecting the optimum wavelength with respect to the properties of the metal layer of the sensorchip, sample matrix, and biomolecular

  5. Plasma-oxidation of Ge(100)-surfaces characterized by MIES, UPS and XPS

    Energy Technology Data Exchange (ETDEWEB)

    Wegewitz, Lienhard; Dahle, Sebastian; Maus-Friedrichs, Wolfgang [Institut fuer Energieforschung und Physikalische Technologien, Technische Universitaet Clausthal, Leibnizstr. 4, 38678 Clausthal-Zellerfeld (Germany); Hoefft, Oliver; Endres, Frank [Institut fuer Mechanische Verfahrenstechnik, Technische Universitaet Clausthal, Arnold-Sommerfeld-Str. 6, 38678 Clausthal-Zellerfeld (Germany); Vioel, Wolfgang [HAWK Goettingen, Fakultaet Naturwissenschaften und Technik, Von-Ossietzky-Str. 99, 37085 Goettingen (Germany)

    2011-07-01

    Cleaning and passivation of Germanium surfaces is of tremendous technological interest. Germanium has various applications, for example in complementary metal-oxide-semiconductor elements. It turned out to be difficult to prepare contamination free Germanium surfaces by methods of wet chemistry. Several attempts have been made preparing such surfaces by different plasma treatments. We report cleaning and passivation of Ge(100)-surfaces by dielectric barrier discharge plasma at ambient temperature in oxygen and in air studied by Metastable Induced Electron Spectroscopy (MIES) and Photoelectron Spectroscopy (UPS(He I) and XPS). The plasma treatment is carried out in a special high-vacuum chamber which operates up to ambient pressure and is directly connected to the ultra-high vacuum chamber including the analysis equipment. In summary the air plasma treatment as well as the oxygen plasma treatment result in contamination free GeO{sub 2} covered surfaces.

  6. Surface roughness effects on plasma near a divertor plate and local impact angle

    Directory of Open Access Journals (Sweden)

    Wanpeng Hu

    2017-08-01

    Full Text Available The impact of rough surface topography on the electric potential and electric field is generally neglected due to the small scale of surface roughness compared to the width of the plasma sheath. However, the distributions of the electric potential and field on rough surfaces are expected to influence the characteristics of edge plasma and the local impact angle. The distributions of plasma sheath and local impact angle on rough surfaces are investigated by a two dimension-in-space and three dimension-in-velocity (2d3v Particle-In-Cell (PIC code. The influences of the plasma temperature andsurface morphology on the plasma sheath, local impact angle and resulting physical sputtering yield on rough surfaces are investigated.

  7. Surface modification of fluorosilicone acrylate RGP contact lens via low-temperature argon plasma

    International Nuclear Information System (INIS)

    Yin Shiheng; Wang Yingjun; Ren Li; Zhao Lianna; Kuang Tongchun; Chen Hao; Qu Jia

    2008-01-01

    A fluorosilicone acrylate rigid gas permeable (RGP) contact lens was modified via argon plasma to improve surface hydrophilicity and resistance to protein deposition. The influence of plasma treatment on surface chemical structure, hydrophilicity and morphology of RGP lens was investigated by X-ray photoelectron spectrometer (XPS), contact angle measurements and scanning electron microscope (SEM), respectively. The contact angle results showed that the hydrophilicity of the contact lens was improved after plasma treatment. XPS results indicated that the incorporation of oxygen-containing groups on surface and the transformation of silicone into hydrophilic silicate after plasma treatment are the main reasons for the surface hydrophilicity improvement. SEM results showed that argon plasma with higher power could lead to surface etching

  8. Surface plasmon resonance spectroscopy for analysis of influenza vaccines

    Science.gov (United States)

    The hemagglutinin (HA) compounds are surface glycoproteins of a virus that can initiate an immune response from a host organism. Hemagglutinin and the related neuraminidase (NA) compounds are the basis for virus strain classification and have become part of the accepted HN taxonomy. These compounds ...

  9. Tuning Acoustic Wave Properties by Mechanical Resonators on a Surface

    DEFF Research Database (Denmark)

    Dühring, Maria Bayard; Laude, Vincent; Khelif, Abdelkrim

    Vibrations generated by high aspects ratio electrodes are studied by the finite element method. It is found that the modes are combined of a surface wave and vibration in the electrodes. For increasing aspect ratio most of the mechanical energy is confined to the electrodes which act as mechanical...

  10. Improved adhesion of Ag NPs to the polyethylene terephthalate surface via atmospheric plasma treatment and surface functionalization

    Science.gov (United States)

    Shen, Tao; Liu, Yong; Zhu, Yan; Yang, De-Quan; Sacher, Edward

    2017-07-01

    Ag nanoparticles (NPs) have been widely applied, as important antibacterial materials, on textile and polymer surfaces. However, their adhesion to nonreactive polymer surfaces is generally too weak for many applications. Here, we propose a two-step process, atmospheric plasma treatment followed by a surface chemical modification process, which enhances their adhesion to polyethylene terephthalate (PET) surfaces. We found that, compared to either plasma treatments or surface chemical functionalizations, alone, this combination greatly enhanced their adhesion. The plasma treatment resulted in an increase of active sites (sbnd OH, sbnd CHdbnd O and COOH) at the PET surface, permitting increased bonding to 3-aminopropyltriethoxysilane (APTES), whose sbnd NH2 groups were then able to form a bonding complex with the Ag NPs.

  11. Sticking non-stick: Surface and Structure control of Diamond-like Carbon in Plasma Enhanced Chemical Vapour Deposition

    Science.gov (United States)

    Jones, B. J.; Nelson, N.

    2016-10-01

    This short review article explores the practical use of diamond-like carbon (DLC) produced by plasma enhanced chemical vapour deposition (PECVD). Using as an example issues relating to the DLC coating of a hand-held surgical device, we draw on previous works using atomic force microscopy, X-ray photoelectron spectroscopy, Raman spectroscopy, scanning electron microscopy, tensiometry and electron paramagnetic resonance. Utilising data from these techniques, we examine the surface structure, substrate-film interface and thin film microstructure, such as sp2/sp3 ratio (graphitic/diamond-like bonding ratio) and sp2 clustering. We explore the variations in parameters describing these characteristics, and relate these to the final device properties such as friction, wear resistance, and diffusion barrier integrity. The material and device characteristics are linked to the initial plasma and substrate conditions.

  12. ITO induced tunability of surface plasmon resonance of silver thin film

    Energy Technology Data Exchange (ETDEWEB)

    Hong, Ruijin; Wang, Xianhai; Ji, Jialin; Tao, Chunxian [Engineering Research Center of Optical Instrument and System, Ministry of Education and Shanghai Key Lab of Modern Optical System, University of Shanghai for Science and Technology, No. 516 Jungong Road, Shanghai 200093 (China); Zhang, Daohua [School of Electrical and Electronic Engineering, Nanyang Technological University, Singapore 639798 (Singapore); Zhang, Dawei, E-mail: dwzhang@usst.edu.cn [Engineering Research Center of Optical Instrument and System, Ministry of Education and Shanghai Key Lab of Modern Optical System, University of Shanghai for Science and Technology, No. 516 Jungong Road, Shanghai 200093 (China)

    2015-11-30

    Highlights: • The localized surface plasmon resonance of silver thin film was generated by ITO buffer layer. • The tunability of surface plasmon resonance wavelength was realized by varying silver thin film thickness. • Raman scattering intensity varies with silver layer thickness. • FDTD calculation results of electronic field distribution are consistent with those of experiments. - Abstract: A series of silver films with various thicknesses were deposited on ITO covered silica substrates by magnetron sputtering at room temperature. The tunability of the surface plasmon resonance wavelength was realized by varying the thickness of silver thin film. By adjusting the silver layer thickness from 5 to 40 nm, the resonance wavelength shows a blueshift, which is due to a change in the electromagnetic field coupling strength from the localized surface plasmons excited between the silver thin film and ITO layer. In contrast, when the ITO layer is absent from the system, no noticeable shift in the resonance wavelength is observed upon varying the silver thin film thickness.

  13. Breaking the black-body limit with resonant surfaces

    Directory of Open Access Journals (Sweden)

    Valagiannopoulos Constantinos A.

    2017-01-01

    Full Text Available The speed with which electromagnetic energy can be wirelessly transferred from a source to the user is a crucial indicator for the performance of a large number of electronic and photonic devices. We expect that energy transfer can be enhanced using special materials. In this paper, we determine the constituent parameters of a medium which can support theoretically infinite energy concentration close to its boundary; such a material combines properties of Perfectly Matched Layers (PML and Double-Negative (DNG media. It realizes conjugate matching with free space for every possible mode including, most importantly, all evanescent modes; we call this medium Conjugate Matched Layer (CML. Sources located outside such layer deliver power to the conjugate-matched body exceptionally effectively, impressively overcoming the black-body absorption limit which takes into account only propagating waves. We also expand this near-field concept related to the infinitely fast absorption of energy along the air-medium interface to enhance the far-field radiation. This becomes possible with the use of small particles randomly placed along the boundary; the induced currents due to the extremely high-amplitude resonating fields can play the role of emission “vessels”, by sending part of the theoretically unlimited near-field energy far away from the CML structure.

  14. Surface modification and stability of detonation nanodiamonds in microwave gas discharge plasma

    International Nuclear Information System (INIS)

    Stanishevsky, Andrei V.; Walock, Michael J.; Catledge, Shane A.

    2015-01-01

    Graphical abstract: - Highlights: • Single and binary gas plasma modification of nanodiamond powders studied. • Temperature-dependent effect of N 2 and N 2 /H 2 plasma reported for the first time. • Role of H 2 in H 2 /N 2 and H 2 /O 2 plasma modification of nanodiamond discussed. - Abstract: Detonation nanodiamonds (DND), with low hydrogen content, were exposed to microwave plasma generated in pure H 2 , N 2 , and O 2 gases and their mixtures, and investigated using X-ray diffraction (XRD), Fourier Transform Infrared (FTIR), Raman, and X-ray photoelectron spectroscopies. Considerable alteration of the DND surface was observed under the plasma conditions for all used gases, but the diamond structure of the DND particle core was preserved in most cases. The stabilizing effect of H 2 in H 2 /N 2 and H 2 /O 2 binary gas plasmas on the DND structure and the temperature-dependent formation of various CNH x surface groups in N 2 and H 2 /N 2 plasmas were observed and discussed for the first time. DND surface oxidation and etching were the main effects of O 2 plasma, whereas the N 2 plasma led to DND surfaces rich in amide groups below 1073 K and nitrile groups at higher temperatures. Noticeable graphitization of the DND core structure was detected only in N 2 plasma when the substrate temperature was above 1103 K.

  15. Localized surface plasmon resonance mercury detection system and methods

    Science.gov (United States)

    James, Jay; Lucas, Donald; Crosby, Jeffrey Scott; Koshland, Catherine P.

    2016-03-22

    A mercury detection system that includes a flow cell having a mercury sensor, a light source and a light detector is provided. The mercury sensor includes a transparent substrate and a submonolayer of mercury absorbing nanoparticles, e.g., gold nanoparticles, on a surface of the substrate. Methods of determining whether mercury is present in a sample using the mercury sensors are also provided. The subject mercury detection systems and methods find use in a variety of different applications, including mercury detecting applications.

  16. Surface characterization of polyethylene terephthalate films treated by ammonia low-temperature plasma

    International Nuclear Information System (INIS)

    Zheng Zhiwen; Ren Li; Feng Wenjiang; Zhai Zhichen; Wang Yingjun

    2012-01-01

    In order to study the surface characterization and protein adhesion behavior of polyethylene terephthalate film, low temperature ammonia plasma was used to modify the film. Effects of plasma conditions of the surface structures and properties were investigated. Results indicated that surface hydrophilicity of polyethylene terephthalate was significantly improved by ammonia plasma treatment. Ammonia plasma played the role more important than air treatment in the process of modification. Furthermore, by Fourier Transform Infrared spectra some new bonds such as -N=O and N-H which could result in the improvement of the surface hydrophilicity were successfully grafted on the film surface. Atom force microscope experiments indicated that more protein adsorbed on hydrophobic surfaces than hydrophilic ones, and the blobs arranged in a straight line at etching surface by plasma. Modified membrane after ammonia plasma treatment had a good cell affinity and could be effective in promoting the adhesion and growth of cells on the material surface. Timeliness experiments showed that the plasma treatment gave the material a certain performance only in a short period of time and the hydrophobicity recovered after 12 days.

  17. Resonance

    DEFF Research Database (Denmark)

    Petersen, Nils Holger

    2014-01-01

    A chapter in a book about terminology within the field of medievalism: the chapter discusses the resonance of medieval music and ritual in modern (classical) music culture and liturgical practice.......A chapter in a book about terminology within the field of medievalism: the chapter discusses the resonance of medieval music and ritual in modern (classical) music culture and liturgical practice....

  18. A solid-state nuclear magnetic resonance study of post-plasma reactions in organosilicone microwave plasma-enhanced chemical vapor deposition (PECVD) coatings.

    Science.gov (United States)

    Hall, Colin J; Ponnusamy, Thirunavukkarasu; Murphy, Peter J; Lindberg, Mats; Antzutkin, Oleg N; Griesser, Hans J

    2014-06-11

    Plasma-polymerized organosilicone coatings can be used to impart abrasion resistance and barrier properties to plastic substrates such as polycarbonate. Coating rates suitable for industrial-scale deposition, up to 100 nm/s, can be achieved through the use of microwave plasma-enhanced chemical vapor deposition (PECVD), with optimal process vapors such as tetramethyldisiloxane (TMDSO) and oxygen. However, it has been found that under certain deposition conditions, such coatings are subject to post-plasma changes; crazing or cracking can occur anytime from days to months after deposition. To understand the cause of the crazing and its dependence on processing plasma parameters, the effects of post-plasma reactions on the chemical bonding structure of coatings deposited with varying TMDSO-to-O2 ratios was studied with (29)Si and (13)C solid-state magic angle spinning nuclear magnetic resonance (MAS NMR) using both single-pulse and cross-polarization techniques. The coatings showed complex chemical compositions significantly altered from the parent monomer. (29)Si MAS NMR spectra revealed four main groups of resonance lines, which correspond to four siloxane moieties (i.e., mono (M), di (D), tri (T), and quaternary (Q)) and how they are bound to oxygen. Quantitative measurements showed that the ratio of TMDSO to oxygen could shift the chemical structure of the coating from 39% to 55% in Q-type bonds and from 28% to 16% for D-type bonds. Post-plasma reactions were found to produce changes in relative intensities of (29)Si resonance lines. The NMR data were complemented by Fourier transform infrared (FTIR) spectroscopy. Together, these techniques have shown that the bonding environment of Si is drastically altered by varying the TMDSO-to-O2 ratio during PECVD, and that post-plasma reactions increase the cross-link density of the silicon-oxygen network. It appears that Si-H and Si-OH chemical groups are the most susceptible to post-plasma reactions. Coatings produced at a

  19. Polymer masks for structured surface and plasma etching

    International Nuclear Information System (INIS)

    Vital, Alexane; Vayer, Marylène; Sinturel, Christophe; Tillocher, Thomas; Lefaucheux, Philippe; Dussart, Rémi

    2015-01-01

    Graphical abstract: - Highlights: • Sub-micrometric silicon structures were prepared by cryogenic plasma etching. • Polymer templates based on phase-separated films of PS/PLA were used. • Silica structured masks were prepared by filling the polymer templates. • Etching of underlying silicon through silica templates gave original structures. - Abstract: Silica and silicon structures have been prepared at the sub-micrometer length-scale, using laterally phase-separated thin films of poly(styrene) (PS) and poly(lactic acid) (PLA) homopolymer blends. The selective removal of one polymer and the filling of the released space by silica precursor solution led, after calcination, to silica structures on silicon such as arrays of bowl-shape features or pillars, layers with through or non-through cylindrical holes, which has not been observed for some of them. The control of the morphology of the initial polymer film was a key point to achieve such type of structures. Particularly relevant was the use of solvent vapor annealing (vs thermal annealing) of the initial spin-coated films that favored and stabilized laterally phase-separated morphologies. Characteristic dimension of the domains were shown to be coupled with the thickness of the film, thinner films giving smaller domain sizes. Despite a relatively high incompatibility of the two polymers, a macro-phase separation was prevented in all the studied conditions. Sub-micrometric domains were formed, and for the thinner films, nanometric domains as small as 74 nm in size can be obtained. The silica structures formed by the infiltration of the polymer templates were used as hard masks for the cryogenic etching of underlying silicon. New structured surfaces, arrays of silicon pillars which can be plain or hollow at the upper part or arrays of cylindrical holes were formed. A selectivity as high as 21 was obtained using this type of mask for 1.5 μm deep holes having a typical diameter of 200 nm

  20. Cancer cell uptake behavior of Au nanoring and its localized surface plasmon resonance induced cell inactivation

    Science.gov (United States)

    Chu, Che-Kuan; Tu, Yi-Chou; Chang, Yu-Wei; Chu, Chih-Ken; Chen, Shih-Yang; Chi, Ting-Ta; Kiang, Yean-Woei; Yang, Chih-Chung

    2015-02-01

    Au nanorings (NRIs), which have the localized surface plasmon resonance (LSPR) wavelength around 1058 nm, either with or without linked antibodies, are applied to SAS oral cancer cells for cell inactivation through the LSPR-induced photothermal effect when they are illuminated by a laser of 1065 nm in wavelength. Different incubation times of cells with Au NRIs are considered for observing the variations of cell uptake efficiency of Au NRI and the threshold laser intensity for cell inactivation. In each case of incubation time, the cell sample is washed for evaluating the total Au NRI number per cell adsorbed and internalized by the cells based on inductively coupled plasma mass spectrometry measurement. Also, the Au NRIs remaining on cell membrane are etched with KI/I2 solution to evaluate the internalized Au NRI number per cell. The threshold laser intensities for cell inactivation before washout, after washout, and after KI/I2 etching are calibrated from the circular area sizes of inactivated cells around the illuminated laser spot center with various laser power levels. By using Au NRIs with antibodies, the internalized Au NRI number per cell increases monotonically with incubation time up to 24 h. However, the number of Au NRI remaining on cell membrane reaches a maximum at 12 h in incubation time. The cell uptake behavior of an Au NRI without antibodies is similar to that with antibodies except that the uptake NRI number is significantly smaller and the incubation time for the maximum NRI number remaining on cell membrane is delayed to 20 h. By comparing the threshold laser intensities before and after KI/I2 etching, it is found that the Au NRIs remaining on cell membrane cause more effective cancer cell inactivation, when compared with the internalized Au NRIs.

  1. Cancer cell uptake behavior of Au nanoring and its localized surface plasmon resonance induced cell inactivation

    International Nuclear Information System (INIS)

    Chu, Che-Kuan; Tu, Yi-Chou; Chang, Yu-Wei; Chu, Chih-Ken; Chen, Shih-Yang; Chi, Ting-Ta; Kiang, Yean-Woei; Yang, Chih-Chung

    2015-01-01

    Au nanorings (NRIs), which have the localized surface plasmon resonance (LSPR) wavelength around 1058 nm, either with or without linked antibodies, are applied to SAS oral cancer cells for cell inactivation through the LSPR-induced photothermal effect when they are illuminated by a laser of 1065 nm in wavelength. Different incubation times of cells with Au NRIs are considered for observing the variations of cell uptake efficiency of Au NRI and the threshold laser intensity for cell inactivation. In each case of incubation time, the cell sample is washed for evaluating the total Au NRI number per cell adsorbed and internalized by the cells based on inductively coupled plasma mass spectrometry measurement. Also, the Au NRIs remaining on cell membrane are etched with KI/I 2 solution to evaluate the internalized Au NRI number per cell. The threshold laser intensities for cell inactivation before washout, after washout, and after KI/I 2 etching are calibrated from the circular area sizes of inactivated cells around the illuminated laser spot center with various laser power levels. By using Au NRIs with antibodies, the internalized Au NRI number per cell increases monotonically with incubation time up to 24 h. However, the number of Au NRI remaining on cell membrane reaches a maximum at 12 h in incubation time. The cell uptake behavior of an Au NRI without antibodies is similar to that with antibodies except that the uptake NRI number is significantly smaller and the incubation time for the maximum NRI number remaining on cell membrane is delayed to 20 h. By comparing the threshold laser intensities before and after KI/I 2 etching, it is found that the Au NRIs remaining on cell membrane cause more effective cancer cell inactivation, when compared with the internalized Au NRIs. (paper)

  2. Method for atmospheric pressure reactive atom plasma processing for surface modification

    Science.gov (United States)

    Carr, Jeffrey W [Livermore, CA

    2009-09-22

    Reactive atom plasma processing can be used to shape, polish, planarize and clean the surfaces of difficult materials with minimal subsurface damage. The apparatus and methods use a plasma torch, such as a conventional ICP torch. The workpiece and plasma torch are moved with respect to each other, whether by translating and/or rotating the workpiece, the plasma, or both. The plasma discharge from the torch can be used to shape, planarize, polish, and/or clean the surface of the workpiece, as well as to thin the workpiece. The processing may cause minimal or no damage to the workpiece underneath the surface, and may involve removing material from the surface of the workpiece.

  3. Quantum effects on propagation of bulk and surface waves in a thin quantum plasma film

    Energy Technology Data Exchange (ETDEWEB)

    Moradi, Afshin, E-mail: a.moradi@kut.ac.ir [Department of Engineering Physics, Kermanshah University of Technology, Kermanshah (Iran, Islamic Republic of); Department of Nano Sciences, Institute for Studies in Theoretical Physics and Mathematics (IPM), Tehran (Iran, Islamic Republic of)

    2015-06-19

    The propagation of bulk and surface plasma waves in a thin quantum plasma film is investigated, taking into account the quantum effects. The generalized bulk and surface plasma dispersion relation due to quantum effects is derived, using the quantum hydrodynamic dielectric function and applying appropriate additional boundary conditions. The quantum mechanical and film geometric effects on the bulk and surface modes are discussed. It is found that quantum effects become important for a thin film of small thickness. - Highlights: • New bulk and surface plasma dispersion relations due to quantum effects are derived, in a thin quantum plasma film. • It is found that quantum effects become important for a thin quantum film of small thickness.

  4. Novel spectral fiber optic sensor based on surface plasmon resonance

    Czech Academy of Sciences Publication Activity Database

    Slavík, Radan; Homola, Jiří; Čtyroký, Jiří; Brynda, Eduard

    B74, 1/3 (2001), s. 106-111 ISSN 0925-4005. [European Conference on Optical Chemical Sensors and Biosensors EUROPT(R)ODE /5./. Lyon-Villeurbanne, 16.04.2000-19.04.2000] R&D Projects: GA ČR GA102/99/M057; GA ČR GA102/99/0549; GA ČR GA102/00/1536 Institutional research plan: CEZ:AV0Z2067918 Keywords : fibre optic sensors * surface plasmons Subject RIV: JB - Sensors, Measurment, Regulation Impact factor: 1.440, year: 2001

  5. Plasma surface modification as a new approach to protect urinary catheter against Escherichia coli biofilm formation

    OpenAIRE

    Taheran, Leila; Zarrini, Gholamreza; Khorram, Sirous; Zakerhamidi, Mohammad Sadegh

    2016-01-01

    Background and Objectives: Biomaterials are widely used in medical devices such as urinary catheters. One of the main problems associated with long term using of the urinary catheters is biofilm formation on their surfaces. Many techniques have been presented to reduce the biofilm formation. One of the most revolutionary techniques allowing such surface fictionalization is plasma surface modification. Materials and Methods: In this study, a glow discharge plasma (GDP) effect on Escherichia co...

  6. A new facility for studying plasma interacting with flowing liquid lithium surface

    International Nuclear Information System (INIS)

    Cao, X.; Ou, W.; Tian, S.; Wang, C.; Zhu, Z.; Wang, J.; Gou, F.; Yang, D.; Chen, S.

    2014-01-01

    A new facility to study plasmas interacting with flowing liquid lithium surface was designed and is constructing in Sichuan University. The integrated setup includes the liquid lithium circulating part and linear high density plasma generator. The circulating part is consisted of main loop, on-line monitor system, lithium purification system and temperature programmed desorption system. In our group a linear high density plasma generator was built in 2012. Three coils were mounted along the vessel to produce an axial magnetic field inside. The magnetic field strength is up to 0.45 T and work continuously. Experiments on plasmas interacting with free flowing liquid lithium surface will be performed

  7. HARDENING OF CRANE RAILS BY PLASMA DISCRETE-TIME SURFACE TREATMENT

    Directory of Open Access Journals (Sweden)

    S. S. Samotugin

    2017-01-01

    Full Text Available Crane wheels and rails are subjected to intensive wear in the process of operation. Therefore, improvement of these components’ performance can be considered a task of high importance. A promising direction in this regard is surface treatment by highly concentrated energy flows such as laser beams or plasma jets. This thesis suggests that the use of gradient plasma surface treatment can improve the performance of crane rails. A research was conducted, according to which hardened zones were deposited on crane rails under different treatment modes. Microhardness was measured both at the surface and in depth using custom-made microsections. The article includes the results of study of plasma surface hardening effects on wear resistance of crane rails. Change of plasma surface treatment parameters (current, plasma torch movement speed, argon gas flow rate allows for desired steel hardness and structure, while the choice of optimal location for hardened zones makes it possible to significantly improve wear resistance and crack resistance. As a result of plasma surface hardening, the fine-grained martensite structure is obtained with mainly lamellar morphology and higher hardness rate compared toinduction hardening or overlaying. Wear test of carbon steels revealed that plasma surfacing reduces abrasive wear rate compared to the irinitial state by 2 to 3 times. Enough sharp boundary between hardened and non-hardened portions has a positive effect on the performance of parts under dynamic loads, contributing to the inhibition of cracks during the transition from solid to a soft metal. For carbon and low alloy rail steels, the properties achieved by plasma surface hardening can effectively replace induction hardening or overlaying.The mode range for plasma surface treatment that allow sobtaining a surface layer with certain operating properties has been determined.

  8. Creation of fluorocarbon barriers on surfaces of starch-based products through cold plasma treatment

    Science.gov (United States)

    Han, Yousoo

    Two kinds of starch foam trays (starch and aspen-starch foam trays) were produced using a lab model baking machine. Surfaces of the trays were treated with CF4 and SF6 plasma to create fluorine-rich layers on the surfaces, which might show strong water resistance. The plasma parameters, such like RF power, gas pressure and reaction time, were varied to evaluate the effects of each parameter on fluorination of surfaces. The atomic concentrations of fluorine, oxygen and carbon on samples' surfaces were earned from ESCA (electron spectroscopy for chemical analysis) and contact angles of sample surfaces were measured for hydrophobicity. For water resistance of plasma treated surfaces, liquid water uptake and water vapor uptake test were performed. Also, equilibrium moisture contents of unmodified and plasma treated samples were measured to evaluate biodegradability of plasma treated samples. Fluorine-rich barriers were created on sample surfaces treated with CF 4 and SF6 plasma. The fluorine atomic concentrations of treated sample surfaces were ranged from 34.4% to 64.4% (CF4 treatment) and 43.6% to 57.9% (SF6 treatment). It was found at both plasma gases that plasma parameters affected total fluorine concentration and carbon-peak shapes in ESCA surveys, which imply different distributions of mono- or multi-fluoro carbon's contents. In various reaction times, it was found that total fluorine contents were decreased after a critical point as the reaction time was prolonged, which may imply that a dominant mechanism has been changed from deposition or functionalization to etching. Oxygen atomic concentration was decreased at sample surfaces treated by both plasmas. In the case of SF6 plasma, it was proved that the removal of oxygen surely occurred because there was no addition of sulfur species. Plasma treated sample surfaces had high contact angles with distilled water up to 150° and the high values of angles have been kept constant up to for 15 minutes. Fluorine

  9. Surface Plasma Arc by Radio-Frequency Control Study (SPARCS)

    International Nuclear Information System (INIS)

    Ruzic, David N.

    2013-01-01

    This paper is to summarize the work carried out between April 2012 and April 2013 for development of an experimental device to simulate interactions of o-normal detrimental events in a tokamak and ICRF antenna. The work was mainly focused on development of a pulsed plasma source using theta pinch and coaxial plasma gun. This device, once completed, will have a possible application as a test stand for high voltage breakdown of an ICRF antenna in extreme events in a tokamak such as edge-localized modes or disruption. Currently, DEVeX does not produce plasma with high temperature enough to requirement for an ELM simulator. However, theta pinch is a good way to produce high temperature ions. The unique characteristic of plasma heating by a theta pinch is advantageous for an ELM simulator due to its effective ion heating. The objective of the proposed work, therefore, is to build a test facility using the existing theta pinch facility in addition to a coaxial plasma gun. It is expected to produce a similar pulsed-plasma heat load to the extreme events in tokamaks and to be applied for studying interactions of hot plasma and ICRF antennas

  10. Effects of air dielectric barrier discharge plasma treatment time on surface properties of PBO fiber

    International Nuclear Information System (INIS)

    Wang Qian; Chen Ping; Jia Caixia; Chen, Mingxin; Li Bin

    2011-01-01

    In this paper, the effects of air dielectric barrier discharge (DBD) plasma treatment time on surface properties of poly(p-phenylene benzobisoxazole) (PBO) fiber were investigated. The surface characteristics of PBO fiber before and after the plasma treatments were analyzed by dynamic contact angle (DCA) analysis, scanning electron microscopy (SEM), atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS). DCA measurements indicated that the surface wettability of PBO fiber was improved significantly by increasing the fiber surface free energy via air DBD plasma treatments. The results were confirmed by the improvement of adhesion of a kind of thermoplastic resin to PBO fiber which was observed by SEM, showing that more resin was adhering evenly to the fiber surface. AFM measurement revealed that the surface topography of PBO fiber became more complicated and the surface roughness was greatly enhanced after the plasma treatments, and XPS analysis showed that some new polar groups (e.g. -O-C=O) were introduced on plasma treated PBO fiber surface. The results of this study also showed that the surface properties of PBO fiber changed with the elongation of plasma treatment time.

  11. Hydrophilic surface modification of coronary stent using an atmospheric pressure plasma jet for endothelialization.

    Science.gov (United States)

    Shim, Jae Won; Bae, In-Ho; Park, Dae Sung; Lee, So-Youn; Jang, Eun-Jae; Lim, Kyung-Seob; Park, Jun-Kyu; Kim, Ju Han; Jeong, Myung Ho

    2018-03-01

    The first two authors contributed equally to this study. Bioactivity and cell adhesion properties are major factors for fabricating medical devices such as coronary stents. The aim of this study was to evaluate the advantages of atmospheric-pressure plasma jet in enhancing the biocompatibility and endothelial cell-favorites. The experimental objects were divided into before and after atmospheric-pressure plasma jet treatment with the ratio of nitrogen:argon = 3:1, which is similar to air. The treated surfaces were basically characterized by means of a contact angle analyzer for the activation property on their surfaces. The effect of atmospheric-pressure plasma jet on cellular response was examined by endothelial cell adhesion and XTT analysis. It was difficult to detect any changeable morphology after atmospheric-pressure plasma jet treatment on the surface. The roughness was increased after atmospheric-pressure plasma jet treatment compared to nonatmospheric-pressure plasma jet treatment (86.781 and 7.964 nm, respectively). The X-ray photoelectron spectroscopy results showed that the surface concentration of the C-O groups increased slightly from 6% to 8% after plasma activation. The contact angle dramatically decreased in the atmospheric-pressure plasma jet treated group (22.6 ± 15.26°) compared to the nonatmospheric-pressure plasma jet treated group (72.4 ± 15.26°) ( n = 10, p atmospheric-pressure plasma jet on endothelial cell migration and proliferation was 85.2% ± 12.01% and 34.2% ± 2.68%, respectively, at 7 days, compared to the nonatmospheric-pressure plasma jet treated group (58.2% ± 11.44% in migration, n = 10, p atmospheric-pressure plasma jet method. Moreover, the atmospheric-pressure plasma jet might affect re-endothelialization after stenting.

  12. Fourier Transform Surface Plasmon Resonance (FTSPR) with Gyromagnetic Plasmonic Nanorods.

    Science.gov (United States)

    Jung, Insub; Yoo, Haneul; Jang, Hee-Jeong; Cho, Sanghyun; Lee, Kyungeun; Hong, Seunghun; Park, Sungho

    2018-02-12

    An unprecedented active and dynamic sensing platform based on a LSPR configuration that is modulated by using an external magnetic field is reported. Electrochemically synthesized Au/Fe/Au nanorods exhibited plasmonically active behavior through plasmonic coupling, and the middle ferromagnetic Fe block responded to a magnetic impetus, allowing the nanorods to be modulated. The shear force variation induced by the specific binding events between antigens and antibodies on the nanorod surface is used to enhance the sensitivity of detection of antigens in the plasmonics-based sensor application. As a proof-of-concept, influenza A virus (HA1) was used as a target protein. The limit of detection was enhanced by two orders of magnitude compared to that of traditional LSPR sensing. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Surface Plasmon Resonance Evaluation of Colloidal Metal Aerogel Filters

    Science.gov (United States)

    Smith, David D.; Sibille, Laurent; Cronise, Raymond J.; Noever, David A.

    1997-01-01

    We have fabricated aerogels containing gold, silver, and platinum nanoparticles for gas catalysis applications. By applying the concept of an average or effective dielectric constant to the heterogeneous interlayer surrounding each particle, we extend the technique of immersion spectroscopy to porous or heterogeneous media. Specifically, we apply the predominant effective medium theories for the determination of the average fractional composition of each component in this inhomogeneous layer. Hence, the surface area of metal available for catalytic gas reaction is determined. The technique is satisfactory for statistically random metal particle distributions but needs further modification for aggregated or surfactant modified systems. Additionally, the kinetics suggest that collective particle interactions in coagulated clusters are perturbed during silica gelation resulting in a change in the aggregate geometry.

  14. Improved adhesion of Ag NPs to the polyethylene terephthalate surface via atmospheric plasma treatment and surface functionalization

    Energy Technology Data Exchange (ETDEWEB)

    Shen, Tao [Faculty of Materials Science and Engineering, Kunming University of Science and Technology, 253 Xuefu Rd, Kunming, Yunnan, 650093 (China); Liu, Yong [Faculty of Materials Science and Engineering, Kunming University of Science and Technology, 253 Xuefu Rd, Kunming, Yunnan, 650093 (China); Solmont Technology Wuxi Co., Ltd. 228 Linghu Blvd. Tianan Tech Park, A1-602, Xinwu District, Wuxi, Jiangsu 214135 (China); Zhu, Yan, E-mail: zhuyan@kmust.edu.cn [Faculty of Materials Science and Engineering, Kunming University of Science and Technology, 253 Xuefu Rd, Kunming, Yunnan, 650093 (China); Yang, De-Quan, E-mail: dequan.yang@gmail.com [Faculty of Materials Science and Engineering, Kunming University of Science and Technology, 253 Xuefu Rd, Kunming, Yunnan, 650093 (China); Solmont Technology Wuxi Co., Ltd. 228 Linghu Blvd. Tianan Tech Park, A1-602, Xinwu District, Wuxi, Jiangsu 214135 (China); Sacher, Edward [Regroupement Québécois de Matériaux de Pointe, Department of Engineering Physics, École Polytechnique de Montréal, Case Postale 6079, succursale Centre-Ville, Montréal, Québec H3C 3A7 (Canada)

    2017-07-31

    Highlights: • A two-step process has been developed to enhance the adhesion of immobilized Ag NPs to the PET surface. • The method is simple, easy to use and low-cost for mass production. • The increased density of active sites (−OH, −CH=O and COOH) at the PET surface, after plasma treatment, permits increased reaction with 3-aminopropyltriethoxysilane (APTES). • The presence of APTES with high surface density permits −NH{sub 2}-Ag complex formation, increasing the adhesion of the Ag NPs. - Abstract: Ag nanoparticles (NPs) have been widely applied, as important antibacterial materials, on textile and polymer surfaces. However, their adhesion to nonreactive polymer surfaces is generally too weak for many applications. Here, we propose a two-step process, atmospheric plasma treatment followed by a surface chemical modification process, which enhances their adhesion to polyethylene terephthalate (PET) surfaces. We found that, compared to either plasma treatments or surface chemical functionalizations, alone, this combination greatly enhanced their adhesion. The plasma treatment resulted in an increase of active sites (−OH, −CH=O and COOH) at the PET surface, permitting increased bonding to 3-aminopropyltriethoxysilane (APTES), whose −NH{sub 2} groups were then able to form a bonding complex with the Ag NPs.

  15. Resonances

    DEFF Research Database (Denmark)

    an impetus or drive to that account: change, innovation, rupture, or discontinuity. Resonances: Historical Essays on Continuity and Change explores the historiographical question of the modes of interrelation between these motifs in historical narratives. The essays in the collection attempt to realize...... theoretical consciousness through historical narrative ‘in practice’, by discussing selected historical topics from Western cultural history, within the disciplines of history, literature, visual arts, musicology, archaeology, philosophy, and theology. The title Resonances indicates the overall perspective...... of the book: how connotations of past meanings may resonate through time, in new contexts, assuming new meanings without surrendering the old....

  16. Evidence on a link between the intensity of Schumann resonance and global surface temperature

    Directory of Open Access Journals (Sweden)

    M. Sekiguchi

    2006-08-01

    Full Text Available A correlation is investigated between the intensity of the global electromagnetic oscillations (Schumann resonance with the planetary surface temperature. The electromagnetic signal was monitored at Moshiri (Japan, and temperature data were taken from surface meteorological observations. The series covers the period from November 1998 to May 2002. The Schumann resonance intensity is found to vary coherently with the global ground temperature in the latitude interval from 45° S to 45° N: the relevant cross-correlation coefficient reaches the value of 0.9. It slightly increases when the high-latitude temperature is incorporated. Correspondence among the data decreases when we reduce the latitude interval, which indicates the important role of the middle-latitude lightning in the Schumann resonance oscillations. We apply the principal component (or singular spectral analysis to the electromagnetic and temperature records to extract annual, semiannual, and interannual variations. The principal component analysis (PCA clarifies the links between electromagnetic records and meteorological data.

  17. Scattering properties of vein induced localized surface plasmon resonances on a gold disk

    KAUST Repository

    Amin, Muhammad

    2011-12-01

    It is demonstrated via simulations that a gold nano-disk with a non-concentric cavity supports localized surface plasmon resonances over a frequency band that includes the visible and the near-infrared parts of the spectrum. The charge distribution on the disk indicates that the two distinct peaks in the scattering cross section are due to the (hybridized) higher-order plasmon modes; plasmon hybridization that involves the dipole modes of the disk and the cavity enforces the "coupling" of the plane-wave excitation to the originally-dark higher-order modes. It is further demonstrated that the resonance frequencies can be tuned by varying the radius of the embedded non-concentric cavity. The near-field enhancement observed at these two tunable resonance frequencies suggests that the proposed structure can be used as a substrate in surface enhanced spectroscopy applications. © 2011 IEEE.

  18. Catastrophic instabilities of modified DA-DC hybrid surface waves in a semi-bounded plasma system

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Myoung-Jae [Department of Physics and Research Institute for Natural Sciences, Hanyang University, Seoul 04763 (Korea, Republic of); Jung, Young-Dae, E-mail: ydjung@hanyang.ac.kr [Department of Applied Physics and Department of Bionanotechnology, Hanyang University, Ansan, Kyunggi-Do 15588, South Korea and Department of Physics, Applied Physics, and Astronomy, Rensselaer Polytechnic Institute, 110 8th Street, Troy, New York 12180-3590 (United States)

    2016-06-15

    We find the catastrophic instabilities and derive the growth rates for the dust-cyclotron resonance (DCR) and dust-rotation resonance (DRR) modes of the modified dust-acoustic and dust-cyclotron (DA-DC) hybrid surface waves propagating at the plasma–vacuum interface where the plasma is semi-bounded and composed of electrons and rotating dust grains. The effects of magnetic field and dust rotation frequency on the DCR- and DDR-modes are also investigated. We find that the dust rotation frequency enhances the growth rate of DCR-mode and the effect of dust rotation on this resonance mode decreases with an increase of the wave number. We also find that an increase of magnetic field strength enhances the DCR growth rate, especially, for the short wavelength regime. In the case of DRR-mode, the growth rate is found to be decreased less sensitively with an increase of the wave number compared with the case of DCR, but much significantly enhanced by an increase of dust rotation frequency. The DRR growth rate also decreases with an increase of the magnetic field strength, especially in the long wavelength regime. Interestingly, we find that catastrophic instabilities occur for both DCR- and DRR-modes of the modified DA-DC hybrid surface waves when the rotational frequency is close to the dust-cyclotron frequency. Both modes can also be excited catastrophically due to the cooperative interaction between the DCR-mode and the DRR-mode.

  19. Synthesis methods of gold nanoparticles for Localized Surface Plasmon Resonance (LSPR sensor applications

    Directory of Open Access Journals (Sweden)

    Samsuri Nurul Diyanah

    2017-01-01

    Full Text Available Gold nanoparticles (GNPs have been known as an excellent characteristic for Local Surface Plasmon Resonance (LSPR sensors due to their sensitive spectral response to the local environment of the nanoparticle surface and ease of monitoring the light signal due to their strong scattering or absorption. Prior the technologies, GNPs based LSPR has been commercialized and have become a central tool for characterizing and quantifying in various field. In this review, we presented a brief introduction on the history of surface plasmon, the theory behind the surface plasmon resonance (SPR and the principles of LSPR. We also reported on the synthetization as well of the properties of the GNPs and the applications in current LSPR sensors.

  20. Spectrally resolved surface plasmon resonance dispersion using half-ball optics

    Science.gov (United States)

    Dehmel, Raphael; Baumberg, Jeremy J.; Steiner, Ullrich; Wilts, Bodo D.

    2017-11-01

    In this work, a variant of a Kretschmann-type surface plasmon resonance (SPR) sensor is introduced. k-space imaging is combined with half-ball glass optics to facilitate the measurement of SPRs across the visible spectral range. In contrast to current state-of-the-art techniques, which are widely utilized in commercially available systems, the presented method allows single-shot-acquisition of the full angular reflection without any moving parts, as well as mapping of the surface plasmon dispersion by scanning across the entire visible wavelength range. Measurements on various thin metallic films demonstrate the sensitivity of the system towards minute changes of the metal surface and its close vicinity. The fast and precise measurement of surface plasmon resonances paves the way for improved detection in applications such as immunoassays or gas-sensors, especially for real-time in situ measurements.

  1. Surface-nitriding treatment of steels using microwave-induced nitrogen plasma at atmospheric pressure

    International Nuclear Information System (INIS)

    Sato, Shigeo; Arai, Yuuki; Yamashita, Noboru; Kojyo, Atsushi; Kodama, Kenji; Ohtsu, Naofumi; Okamoto, Yukio; Wagatsuma, Kazuaki

    2012-01-01

    A rapid surface-nitriding system using microwave-induced nitrogen plasma at atmospheric pressure was developed for modifying iron and steel surfaces. Since the conventional plasma nitriding technique requires a low-pressure atmosphere in the treatment chamber, the population of excited nitrogen molecules in the plasma is limited. Accordingly, several hours are required for nitriding treatment. By contrast, the developed nitriding system can use atmospheric-pressure plasma through application of the Okamoto cavity for excitation of nitrogen plasma. The high population of excited nitrogen molecules induced by the atmospheric-pressure plasma allowed the formation of a nitriding layer that was several micrometers thick within 1 min and produced an expanded austenite iron phase with a high nitrogen concentration close to the solubility limit on the iron substrate. In addition, the nitriding treatment on high-chromium steel was performed by introducing a reducing gas such as NH 3 and H 2 into the treatment chamber. While the nitriding reaction did not proceed in a simple N 2 atmosphere due to surface oxidation, the surface reduction induced by the NH 3 or H 2 gas promoted the nitriding reaction at the surface. These nitriding phenomena characteristics of the atmospheric-pressure plasma are discussed in this paper based on the effects of the specimen temperature and plasma atmosphere on the thickness, the chemical states, and the nitride compounds of the nitrided layer as investigated by X-ray diffraction, glow-discharge optical emission spectroscopy, and X-ray photoelectron spectroscopy.

  2. Effect of plasma-induced surface charging on catalytic processes: application to CO2 activation

    Science.gov (United States)

    Bal, Kristof M.; Huygh, Stijn; Bogaerts, Annemie; Neyts, Erik C.

    2018-02-01

    Understanding the nature and effect of the multitude of plasma–surface interactions in plasma catalysis is a crucial requirement for further process development and improvement. A particularly intriguing and rather unique property of a plasma-catalytic setup is the ability of the plasma to modify the electronic structure, and hence chemical properties, of the catalyst through charging, i.e. the absorption of excess electrons. In this work, we develop a quantum chemical model based on density functional theory to study excess negative surface charges in a heterogeneous catalyst exposed to a plasma. This method is specifically applied to investigate plasma-catalytic CO2 activation on supported M/Al2O3 (M = Ti, Ni, Cu) single atom catalysts. We find that (1) the presence of a negative surface charge dramatically improves the reductive power of the catalyst, strongly promoting the splitting of CO2 to CO and oxygen, and (2) the relative activity of the investigated transition metals is also changed upon charging, suggesting that controlled surface charging is a powerful additional parameter to tune catalyst activity and selectivity. These results strongly point to plasma-induced surface charging of the catalyst as an important factor contributing to the plasma-catalyst synergistic effects frequently reported for plasma catalysis.

  3. Ambient plasma treatment of silicon wafers for surface passivation recovery

    Science.gov (United States)

    Ge, Jia; Prinz, Markus; Markert, Thomas; Aberle, Armin G.; Mueller, Thomas

    2017-08-01

    In this work, the effect of an ambient plasma treatment powered by compressed dry air on the passivation quality of silicon wafers coated with intrinsic amorphous silicon sub-oxide is investigated. While long-time storage deteriorates the effective lifetime of all samples, a short ambient plasma treatment improves their passivation qualities. By studying the influence of the plasma treatment parameters on the passivation layers, an optimized process condition was identified which even boosted the passivation quality beyond its original value obtained immediately after deposition. On the other hand, the absence of stringent requirement on gas precursors, vacuum condition and longtime processing makes the ambient plasma treatment an excellent candidate to replace conventional thermal annealing in industrial heterojunction solar cell production.

  4. Two Contemporary Problems in Magnetized Plasmas: the ion-ion hybrid resonator and MHD stability in a snowflake divertor

    Energy Technology Data Exchange (ETDEWEB)

    Farmer, William Anthony [Univ. of California, Los Angeles, CA (United States)

    2014-01-01

    The rst part of the dissertation investigates the e ects of multiple-ions on the propagation of shear Alfv en waves. It is shown that the presence of a second ion-species allows for the formation of an ion-ion hybrid resonator in the presence of a magnetic well. A fullwave description is shown to explain the measured eigenfrequencies and spatial form of the resonator modes identi ed in experiments in the Large Plasma Device (LAPD) at UCLA. However, it is determined that neither electron collisions or radial convection of the mode due to coupling to either the compressional or ion-Bernstein wave can explain the observed dissipation.

  5. Evaporation of water drop on a plasma-irradiated hydrophilic surface

    Energy Technology Data Exchange (ETDEWEB)

    Takata, Y.; Hidaka, S.; Yamashita, A.; Yamamoto, H

    2004-04-01

    Experimental study has been performed on evaporation of water droplet on stainless steel, copper, and aluminum surfaces. These surfaces are exposed by the plasma irradiation to increase the wettability. We obtained the relation between the plasma irradiation and contact angle first, and then measured the evaporation time, the wetting limit temperature and the Leidenfrost temperature, increasing the surface temperature. The effect of plasma irradiation on evaporation curve has been examined. It is found that the evaporation time decreases and the wetting limit and the Leidenfrost temperatures increase as the contact angle decreases.

  6. Problems of surface morphology and layer deposition during plasma etching processes. 2

    International Nuclear Information System (INIS)

    Tiller, H.-J.; Krausse, J.; Voigt, R.

    1982-01-01

    The plasma etching of Si in CF 4 -, CF 4 /O 2 - and CF 4 /H 2 plasmas was investigated in dependence on the etching gas, the plasma conditions (pressure, power density) and etching time in different reactors. A roughening of the surface and the formation of a 'semi-amorphous' surface layer with a powder-like morphology was detected by TEM-and RHEED methods. It is supposed that the surface layer has a fundamental consequence as an intermediate state in the etching mechanism. (author)

  7. Surface characterization of alloy Ti-6Al-7Nb treated plasma

    International Nuclear Information System (INIS)

    Moura, J.K.L.; Macedo, H.R.A.; Brito, E.M.; Brandim, A.S.

    2014-01-01

    Plasma surface modifications are subject of numerous studies to improve the quality of a given material. Titanium and its alloys are widely used in biomedical applications and plasma treatment technique is increasingly used to improve the surface properties thereof. The research have a objective in the comparative analysis of the change in microstructure of Ti-6Al-7Nb alloys after treatment of plasma nitriding. The technical are: nitriding with cathode cage (NGC) and planar discharge. The characterization was obtained by MEV (Scanning Electronic Microscope) and hardness. The results was compared about the better surface modification that meets future prospects of the biocompatibility of the alloy.(author)

  8. Self-calibrated dynamical optical biochip system using surface plasmon resonance imaging: application to genotyping

    Science.gov (United States)

    Hottin, Jérôme; Moreau, Julien; Spadavecchia, Jolanda; Bellemain, Alain; Lecerf, Laure; Goossens, Michel; Canva, Michael

    2008-04-01

    The present paper summarizes some of our work in the field of genetic diagnosis using Surface Plasmon Resonance Imaging. The optical setup and its capability are presented, as well as the gold surface functionalization used. Results obtained with oligonucleotides targets, specific to Cystic Fibrosis disease, in high and low concentration are shown. The self-calibration method we have developed to reduce data dispersion in genetic diagnosis applications is described.

  9. Multiplex surface plasmon resonance imaging platform for label-free detection of foodborne pathogens

    Science.gov (United States)

    Salmonellae are among the leading causes of foodborne outbreaks in the United States, and more rapid and efficient detection methods are needed. Surface plasmon resonance imaging (SPRi) is an emerging optical technique, which allows for rapid and label-free screening of multiple targets simultaneous...

  10. Detection of mycotoxins using imaging surface plasmon resonance (iSPR)

    Science.gov (United States)

    Significant progress has been made in the development of biosensors that can be used to detect mycotoxins. One technology that has been extensively tested is surface plasmon resonance (SPR). In 2003 a multi-toxin method was reported that detected aflatoxin B1 (AFB1), zearalenone (ZEA), fumonisin B1 ...

  11. Surface plasmon resonance imaging for label-free detection of foodborne pathogens and toxins

    Science.gov (United States)

    More rapid and efficient detection methods for foodborne pathogenic bacteria and toxins are needed to address the long assay time and limitations in multiplex capacity. Surface plasmon resonance imaging (SPRi) is an emerging optical technique, which allows for rapid and label-free screening of multi...

  12. Detection of egg yolk antibodies reflecting Salmonella enteritidis infections using a surface plasmon resonance biosensor

    NARCIS (Netherlands)

    Thomas, M.E.; Bouma, A.; Eerden, van E.; Landman, W.J.M.; Knapen, van F.; Stegeman, J.A.; Bergwerff, A.A.

    2006-01-01

    A surface plasmon resonance (SPR) biosensor assay was developed on the basis of a lipopolysaccharide antigen of Salmonella enterica serovar enteritidis (S. enterica serovar enteritidis) to detect egg yolk antibodies against S. enterica serovar enteritidis. This biosensor assay was compared to two

  13. Applicability of surface-enhanced resonance Raman scattering for the direct discrimination of ballpoint pen inks

    NARCIS (Netherlands)

    Seifar, R.M.; Verheul, J.M.; Ariese, F.; Brinkman, U.A.T.; Gooijer, C.

    2001-01-01

    In situ surface-enhanced resonance Raman spectroscopy (SERRS) with excitation at 685 nm is suitable for the direct discrimination of blue and black ballpoint pen inks on paper. For black inks, shorter excitation wavelengths can also be used. For blue inks, SERRS at 514.5 and 457.9 nm does not

  14. Detection of benzimidazole carbamates and amino metabolites in liver by surface plasmon resonance-biosensor

    Science.gov (United States)

    Two surface plasmon resonance (SPR) biosensor screening assays were developed and validated to detect 11 benzimidazole carbamate (BZT) and four amino-benzimidazole veterinary drug residues in liver tissue. The assays used polyclonal antibodies, raised in sheep, to detect BZTs and amino-benzimidazole...

  15. Surface plasmon resonance sensor for detection of bisphenol A in drinking water

    Czech Academy of Sciences Publication Activity Database

    Hegnerová, Kateřina; Homola, Jiří

    2010-01-01

    Roč. 151, č. 1 (2010), s. 177-179 ISSN 0925-4005 R&D Projects: GA AV ČR KAN200670701 Institutional research plan: CEZ:AV0Z20670512 Keywords : surface plasmon resonance biosensor * bisphenol A * drinking water Subject RIV: JB - Sensors, Measurment, Regulation Impact factor: 3.368, year: 2010

  16. Surface plasmon resonance biosensor for the detection of VEGFR-1-a protein marker of myelodysplastic syndromes

    Czech Academy of Sciences Publication Activity Database

    Pimková, K.; Bocková, Markéta; Hegnerová, Kateřina; Suttnar, J.; Čermák, J.; Homola, Jiří; Dyr, J. E.

    2012-01-01

    Roč. 402, č. 1 (2012), s. 381-387 ISSN 1618-2642 R&D Projects: GA AV ČR KAN200670701 Institutional research plan: CEZ:AV0Z20670512 Keywords : surface plasmon resonance * myelodysplastic syndromes * vascular endothelial growth factor Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering Impact factor: 3.659, year: 2012

  17. Collective acceleration of ions on the basis of resonance surface photoionization

    International Nuclear Information System (INIS)

    Antsiferov, V.V.; Smirnov, G.I.; Telegin, G.G.

    1994-01-01

    The effects of ion beam shaping and collective acceleration on the basis of resonance surface ionization are discussed. The principle diagram of the device for collective acceleration of positive ions is given. The method suggested for positive ion acceleration provides the efficiency increase, the design simplification, the size decrease and the increase in the frequency of the collective laser ion accelerator pulses

  18. Surface Plasmon Resonance Biosensor for Rapid Label-Free Detection of Microribonucleic Acid at Subfemtomole Level

    Czech Academy of Sciences Publication Activity Database

    Šípová, Hana; Zhang, S.-Ch.; Dudley, A.M.; Galas, D.; Wang, K.; Homola, Jiří

    2010-01-01

    Roč. 82, č. 24 (2010), s. 10110-10115 ISSN 0003-2700 R&D Projects: GA AV ČR KAN200670701 Institutional research plan: CEZ:AV0Z20670512 Keywords : surface plasmon resonance * microRNA * cancer diagnostics * biosensor Subject RIV: JB - Sensors, Measurment, Regulation Impact factor: 5.874, year: 2010

  19. Surface-enhanced resonance Raman spectroscopy as an identification tool in column liquid chromatography

    NARCIS (Netherlands)

    Seifar, R.M.; Altelaar, M.A.F.; Dijkstra, R.J.; Ariese, F.; Brinkman, U.A.T.; Gooijer, C.

    2000-01-01

    The compatibility of ion-pair reversed-phase column liquid chromatography and surface-enhanced resonance Raman spectroscopy (SERRS) for separation and identification of anionic dyes has been investigated, with emphasis on the at-line coupling via a thin-layer chromatography (TLC) plate. SERR spectra

  20. Detection of bisphenol A using a novel surface plasmon resonance biosensor

    Czech Academy of Sciences Publication Activity Database

    Hegnerová, Kateřina; Piliarik, Marek; Šteinbachová, M.; Flegelová, Z.; Černohorská, H.; Homola, Jiří

    2010-01-01

    Roč. 398, č. 5 (2010), s. 1963-1966 ISSN 1618-2642 R&D Projects: GA AV ČR KAN200670701; GA MŠk OC09058 Institutional research plan: CEZ:AV0Z20670512 Keywords : surface plasmon resonance biosensor * bisphenol A * endocrine disruptor Subject RIV: JB - Sensors, Measurment, Regulation Impact factor: 3.841, year: 2010

  1. Reflection-based fibre-optic refractive index sensor using surface plasmon resonance

    Czech Academy of Sciences Publication Activity Database

    Hlubina, P.; Kadulová, M.; Ciprian, D.; Sobota, Jaroslav

    2014-01-01

    Roč. 9, August 19 (2014), 14033:1-5 ISSN 1990-2573 R&D Projects: GA MŠk(CZ) LO1212 Keywords : surface plasmon resonance * fibre -optic sensor * spectral interrogation technique * aqueous solutions of ethanol * refractive index Subject RIV: BH - Optics, Masers, Lasers Impact factor: 1.231, year: 2014

  2. Preliminary results of endorectal surface coil magnetic resonance imaging for local staging of prostate cancer

    NARCIS (Netherlands)

    Jager, G. J.; Barentsz, J. O.; de la Rosette, J. J.; Rosenbusch, G.

    1994-01-01

    To evaluate the effectiveness of endorectal surface coil (ERC) magnetic resonance imaging (MRI) in the local staging of adenocarcinoma of the prostate (ACP). A total of 23 patients who were considered candidates for radical prostatectomy because of clinically localized ACP were examined by ERC-MRI.

  3. Detection of apoptosis in cancer cell lines using Surface Plasmon Resonance imaging

    NARCIS (Netherlands)

    Stojanović, I.; van Hal, Y.; van der Velden, T.J.G.; Schasfoort, Richardus B.M.; Terstappen, Leonardus Wendelinus Mathias Marie

    2016-01-01

    Induction of apoptosis in cancer cells by therapeutic agents is an important event to detect the potential effectiveness of therapies. Here we explore the potential of Surface Plasmon Resonance imaging (SPRi) to assess apoptosis in cancer cells exposed to therapeutic agents by measuring the

  4. A selectively coated photonic crystal fiber based surface plasmon resonance sensor

    DEFF Research Database (Denmark)

    Yu, X; Zhang, Y.; Pan, S.S.

    2010-01-01

    We propose a novel design for a photonic crystal fiber based surface plasmonic resonance sensor. The sensor consists of selectively metal-coated air holes containing analyte channels, which enhance the phase matching between the plasmonic mode and the core-guided mode. Good refractive index sensi...

  5. Rapid Determination of Phytophthora infestans sporangia Using a Surface Plasmon Resonance Immunosensor

    DEFF Research Database (Denmark)

    Skottrup, Peter; Nicolaisen, Mogens; Justesen, Annemarie Fejer

    2007-01-01

    Phytophthora infestans is the cause of late blight disease in potato and is an economically important pathogen worldwide. Early disease detection is important to implement disease control measures. In this study a surface plasmon resonance (SPR) immunosensor for detection of P. infestans sporangia...

  6. Theoretical analysis of a fiber optic surface plasmon resonance sensor utilizing a Bragg grating

    Czech Academy of Sciences Publication Activity Database

    Špačková, Barbora; Homola, Jiří

    2009-01-01

    Roč. 17, č. 25 (2009), s. 23254-23264 ISSN 1094-4087 Institutional research plan: CEZ:AV0Z20670512 Keywords : Surface plasmon resonance * Fiber optic * Bragg grating * Biosensor * Coupled mode theory Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering Impact factor: 3.278, year: 2009

  7. Novel concept of multi-channel fiber optic surface plasmon resonance sensor

    Czech Academy of Sciences Publication Activity Database

    Špačková, Barbora; Piliarik, Marek; Kvasnička, Pavel; Rajarajan, M.; Homola, Jiří

    2009-01-01

    Roč. 139, č. 1 (2009), s. 199-203 ISSN 0925-4005 R&D Projects: GA AV ČR KAN200670701 Institutional research plan: CEZ:AV0Z20670512 Keywords : . Surface plasmon resonance * Fiber optic * Bragg grating * Biosensor Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering Impact factor: 3.083, year: 2009

  8. Electromagnetic wave energy flow control with a tunable and reconfigurable coupled plasma split-ring resonator metamaterial: A study of basic conditions and configurations

    Energy Technology Data Exchange (ETDEWEB)

    Kourtzanidis, Konstantinos, E-mail: kkourt@utexas.edu; Pederson, Dylan M.; Raja, Laxminarayan L. [Department of Aerospace Engineering and Engineering Mechanics, The University of Texas at Austin, Austin, Texas 78712-1221 (United States)

    2016-05-28

    We propose and study numerically a tunable and reconfigurable metamaterial based on coupled split-ring resonators (SRRs) and plasma discharges. The metamaterial couples the magnetic-electric response of the SRR structure with the electric response of a controllable plasma slab discharge that occupies a volume of the metamaterial. Because the electric response of a plasma depends on its constitutive parameters (electron density and collision frequency), the plasma-based metamaterial is tunable and active. Using three-dimensional numerical simulations, we analyze the coupled plasma-SRR metamaterial in terms of transmittance, performing parametric studies on the effects of electron density, collisional frequency, and the position of the plasma slab with respect to the SRR array. We find that the resonance frequency can be controlled by the plasma position or the plasma-to-collision frequency ratio, while transmittance is highly dependent on the latter.

  9. Aqueous reactive species induced by a PCB surface micro-discharge air plasma device: a quantitative study

    Science.gov (United States)

    Chen, Chen; Li, Fanying; Chen, Hai-Lan; Kong, Michael G.

    2017-11-01

    This paper presents a quantitative investigation on aqueous reactive species induced by air plasma generated from a printed circuit board surface micro-discharge (SMD) device. Under the conditions amenable for proliferation of mammalian cells, concentrations of ten types of reactive oxygen and nitrogen species (RONS) in phosphate buffering solution (PBS) are measured by chemical fluorescent assays and electron spin resonance spectroscopy (ESR). Results show that concentrations of several detected RNS (NO2- , NO3- , peroxynitrites, and NO2\\centerdot ) are higher than those of ROS (H2O2, O2\\centerdot - , and 1O2) in the air plasma treated solution. Concentrations of NO3- can reach 150 times of H2O2 with 60 s plasma treatment. For short-lived species, the air plasma generates more copious peroxynitrite than other RONS including NO2\\centerdot , O2\\centerdot - , 1O2, and N{{O}\\centerdot } in PBS. In addition, the existence of reaction between H2O2 and NO2- /HNO2 to produce peroxynitrite is verified by the chemical scavenger experiments. The reaction relations between detected RONS are also discussed.

  10. Science Court on ICRH [ion cyclotron resonance heating] modeling of tokamak plasmas

    International Nuclear Information System (INIS)

    Hively, L.M.; Sadowski, W.L.

    1987-10-01

    The Applied Plasma Physics (APP) Theory program in the Office of Fusion Energy is charged with supporting the development of advanced physics models for fusion research. One such effort is ion cyclotron resonance heating (ICRH), which has seen substantial progress recently. However, due to serious questions about the adequacy of present models for CIT (Compact Ignition Tokamak), a Science Court was formed to assess ICRH models, including: validity of theoretical and computational approximations; underlying physics assumptions and corresponding limits on the results; self-consistency; any subsidiary issues needing resolution (e.g., new computer tools); adequacy of the models in simulating experiments (especially CIT); and new or improved experiments to validate and refine the models. The Court did not review work by specific individuals, institutions, or programs, thereby avoiding any biases along these lines. Rather, the Science Court was carefully structured as a technical review of ICRH theory and modeling in the US. This paper discusses the Science Court process, findings, and conclusions

  11. Preparation of Al O N Films by Electron Cyclotron Resonance Plasma-Assisted Chemical Vapor Deposition

    Science.gov (United States)

    Goto, Takashi; Zhang, Wei; Hirai, Toshio

    1999-06-01

    Al O N films were prepared by electron cyclotron resonance plasma-assisted chemical vapor deposition (ECR PACVD) using an AlBr3 N2O N2 Ar H2 gas system. The structure, composition, deposition rate and optical properties were investigated. The compositions were controlled by changing the N2O/(N2O+N2) flow rate ratio (R). The refractive index was varied from 1.60 to 2.10, and the cutoff photon energy at 10% transmittance (Eg/10) from 5.1 to 7.0 eV as the R changed from 0 to 1.0. The Al O N films were composed mainly of a mixture of Al2O3 and AlN. An aluminum oxynitride phase was also identified at R=0.2 to 0.53. The Al O N films contained a (001)-oriented hexagonal AlN phase at R=0.025, and the films were amorphous at R>0.05.

  12. Two-ion hybrid resonances and ion cyclotron absorption in tokamak plasmas

    International Nuclear Information System (INIS)

    Brambilla, M.; Ottaviani, M.

    1983-11-01

    The behaviour of IC waves near resonances in tokamak geometry is investigated in details. For this purpose, a one-dimensional model is proposed, which takes into account the orientation of the incident wavefronts with respect both to the singular layer and to the magnetic surfaces. The differential equations describing the waves are derived again from Vlasov-Maxwell equations in the finite Larmor radius approximation; they are shown to conserve the wave power flux in the absence of dissipation, and to reproduce the local dispersion relation in the WKB limit. These equations are solved exactly in some important situations, and with the Green-function technique in the general case. The amount of power coupled to Bernstein waves and absorbed by cyclotron damping is explicitly evaluated. (orig.)

  13. Surface treatment of aramid fiber by air dielectric barrier discharge plasma at atmospheric pressure

    International Nuclear Information System (INIS)

    Jia Caixia; Chen Ping; Liu Wei; Li Bin; Wang Qian

    2011-01-01

    Aramid fiber samples are treated by air dielectric barrier discharge (DBD) plasma at atmospheric pressure; the plasma treatment time is investigated as the major parameter. The effects of this treatment on the fiber surface physical and chemical properties are studied by using surface characterization techniques. Scanning electron microscopy (SEM) is performed to determine the surface morphology changes, X-ray photoelectron spectroscopy (XPS) is analyzed to reveal the surface chemical composition variations and dynamic contact angle analysis (DCAA) is used to examine the changes of the fiber surface wettability. In addition, the wetting behavior of a kind of thermoplastic resin, poly(phthalazinone ether sulfone ketone) (PPESK), on aramid fiber surface is also observed by SEM photos. The study shows that there seems to be an optimum treatment condition for surface modification of aramid fiber by the air DBD plasma. In this paper, after the 12 s, 27.6 W/cm 3 plasma treatment the aramid fiber surface roughness is significantly improved, some new oxygen-containing groups such as C-O, C=O and O=C-O are generated on the fiber surface and the fiber surface wettability is greatly enhanced, which results in the better wetting behavior of PPESK resin on the plasma-treated aramid fiber.

  14. Apparent Surface Free Energy of Polymer/Paper Composite Material Treated by Air Plasma

    Directory of Open Access Journals (Sweden)

    Konrad Terpiłowski

    2017-01-01

    Full Text Available Surface plasma treatment consists in changes of surface properties without changing internal properties. In this paper composite polymer/paper material is used for production of packaging in cosmetic industry. There are problems with bonding this material at the time of packaging production due to its properties. Composite surface was treated by air plasma for 1, 10, 20, and 30 s. The advancing and receding contact angles of water, formamide, and diiodomethane were measured using both treated and untreated samples. Apparent surface free energy was estimated using the hysteresis (CAH and Van Oss, Good, Chaudhury approaches (LWAB. Surface roughness was investigated using optical profilometry and identification of after plasma treatment emerging chemical groups was made by means of the XPS (X-ray photoelectron spectroscopy technique. After plasma treatment the values of contact angles decreased which is particularly evident for polar liquids. Apparent surface free energy increased compared to that of untreated samples. Changes of energy value are due to the electron-donor parameter of energy. This parameter increases as a result of adding polar groups at the time of surface plasma activation. Changes of surface properties are combination of increase of polar chemical functional groups, increase on the surface, and surface roughness increase.

  15. Influence of atmospheric pressure plasma treatment on surface properties of PBO fiber

    International Nuclear Information System (INIS)

    Zhang Ruiyun; Pan Xianlin; Jiang Muwen; Peng Shujing; Qiu Yiping

    2012-01-01

    Highlights: ► PBO fibers were treated with atmospheric pressure plasmas. ► When 1% of oxygen was added to the plasma, IFSS increased 130%. ► Increased moisture regain could enhance plasma treatment effect on improving IFSS with long treatment time. - Abstract: In order to improve the interfacial adhesion property between PBO fiber and epoxy, the surface modification effects of PBO fiber treated by atmospheric pressure plasma jet (APPJ) in different time, atmosphere and moisture regain (MR) were investigated. The fiber surface morphology, functional groups, surface wettability for control and plasma treated samples were analyzed by scanning electron microscope (SEM), X-ray photoelectron spectroscopy (XPS) and water contact angle measurements, respectively. Meanwhile, the fiber interfacial shear strength (IFSS), representing adhesion property in epoxy, was tested using micro-bond pull-out test, and single fiber tensile strength was also tested to evaluate the mechanical performance loss of fibers caused by plasma treatment. The results indicated that the fiber surface was etched during the plasma treatments, the fiber surface wettability and the IFSS between fiber and epoxy had much improvement due to the increasing of surface energy after plasma treatment, the contact angle decreased with the treatment time increasing, and the IFSS was improved by about 130%. The processing atmosphere could influence IFSS significantly, and moisture regains (MR) of fibers also played a positive role on improving IFSS but not so markedly. XPS analysis showed that the oxygen content on fiber surface increased after treatment, and C=O, O-C=O groups were introduced on fiber surface. On the other hand, the observed loss of fiber tensile strength caused by plasma treatment was not so remarkable to affect the overall performance of composite materials.

  16. Coupled resonances allow studying the aging of adhesive contacts between a QCM surface and single, micrometer-sized particles.

    Science.gov (United States)

    Peschel, Astrid; Langhoff, Arne; Johannsmann, Diethelm

    2015-12-04

    Interparticle contacts and contacts between particles and surfaces are known to change over time. The contact area, the contact stiffness, and the contact strength usually increase as the contact ages. Contact aging is mostly driven by capillary forces, but also by plastic deformation. Making use of acoustic resonators, we have studied the stiffness of contacts between the surface of a quartz crystal microbalance (QCM) and individual, micrometer-sized particles adsorbed to the resonator surface. Studying single particles avoids ensemble-averaging. Central to the analysis is the coupled resonance, occurring when a surface-attached particle together with the link forms a resonator of its own. If the frequency of this second resonator comes close to one of the crystal's overtones, plots of shifts in resonance bandwidth versus overtone order display a resonance curve. This secondary resonance is caused by the coupling between the particle's resonance and the main resonance. One can read the frequency of the coupled resonance from this plot. Similarly, resonance curves are observed in plots of frequency and bandwidth versus time, if the contact stiffness varies smoothly with time. Because the coupled resonance is a characteristic feature, it is easily identified even in cases where frequency shifts of some other origin are superimposed onto the data. For the cases studied here, the links stiffened while they dried. Interestingly, the efficiency of coupling between the particle resonance and the main resonance decreased at the same time. This can be explained with an increase in the link's bending stiffness. The analysis highlights that a QCM experiment amounts to vibrational spectroscopy on surface-attached particles. Among the application examples is the adsorption and drying of a lycopodium spore. Clearly, the technique is also applicable to problems of bioadhesion.

  17. Surface modification of polyester fabric with plasma pretreatment and carbon nanotube coating for antistatic property improvement

    Energy Technology Data Exchange (ETDEWEB)

    Wang, C.X., E-mail: cxwang@mail.dhu.edu.cn [College of Textiles and Clothing, Yancheng Institute of Technology, Jiangsu 224051 (China); Collaborative Innovation Center for Ecological Building Materials and Environmental Protection Equipments, Jiangsu 224051 (China); Key Laboratory for Advanced Technology in Environmental Protection, Jiangsu 224051 (China); Lv, J.C. [College of Textiles and Clothing, Yancheng Institute of Technology, Jiangsu 224051 (China); Ren, Y. [School of Textile and Clothing, Nantong University, Jiangsu 226019 (China); Zhi, T.; Chen, J.Y.; Zhou, Q.Q. [College of Textiles and Clothing, Yancheng Institute of Technology, Jiangsu 224051 (China); Lu, Z.Q.; Gao, D.W. [College of Textiles and Clothing, Yancheng Institute of Technology, Jiangsu 224051 (China); Collaborative Innovation Center for Ecological Building Materials and Environmental Protection Equipments, Jiangsu 224051 (China); Key Laboratory for Advanced Technology in Environmental Protection, Jiangsu 224051 (China); Jin, L.M. [Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201204 (China)

    2015-12-30

    Graphical abstract: - Highlights: • PET was finished by plasma treatment and SWCNT coating to improve antistatic property. • Plasma modification had a positive effect on SWCNT coating on PET fiber surface. • O{sub 2} plasma was more effective in SWCNT coating than Ar plasma in the shorter time. • Antistatic enhanced and then declined with enhancing treatment time and output power. • Antistatic increased with increasing concentration, curing time, curing temperature. - Abstract: This study introduced a green method to prepare antistatic polyester (PET) fabrics by plasma pretreatment and single-walled carbon nanotube (SWCNT) coating. The influences of plasma conditions and SWCNT coating parameters on antistatic property of PET fabrics were investigated. PET fabrics were pretreated under various plasma conditions such as different treatment times, output powers and working gases, and then SWCNT coating on the plasma treated PET fabrics was carried out by coating-dry-cure using various coating parameters including different SWCNT concentrations, curing times and curing temperatures. PET fabrics were characterized by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and volume resistivity. SEM and XPS analysis of the plasma treated PET fabrics revealed the increase in surface roughness and oxygen/nitrogen containing groups on the PET fiber surface. SEM and XPS analysis of the plasma treated and SWCNT coated PET fabrics indicated the SWCNT coating on PET fiber surface. The plasma treated and SWCNT coated PET fabrics exhibited a good antistatic property, which increased and then decreased with the increasing plasma treatment time and output power. The antistatic property of the O{sub 2} plasma treated and SWCNT coated PET fabric was better and worse than that of N{sub 2} or Ar plasma treated and SWCNT coated PET fabric in the shorter treatment time and the longer treatment time, respectively. In addition, the antistatic property of the

  18. Surface modification of polyester fabric with plasma pretreatment and carbon nanotube coating for antistatic property improvement

    International Nuclear Information System (INIS)

    Wang, C.X.; Lv, J.C.; Ren, Y.; Zhi, T.; Chen, J.Y.; Zhou, Q.Q.; Lu, Z.Q.; Gao, D.W.; Jin, L.M.

    2015-01-01

    Graphical abstract: - Highlights: • PET was finished by plasma treatment and SWCNT coating to improve antistatic property. • Plasma modification had a positive effect on SWCNT coating on PET fiber surface. • O 2 plasma was more effective in SWCNT coating than Ar plasma in the shorter time. • Antistatic enhanced and then declined with enhancing treatment time and output power. • Antistatic increased with increasing concentration, curing time, curing temperature. - Abstract: This study introduced a green method to prepare antistatic polyester (PET) fabrics by plasma pretreatment and single-walled carbon nanotube (SWCNT) coating. The influences of plasma conditions and SWCNT coating parameters on antistatic property of PET fabrics were investigated. PET fabrics were pretreated under various plasma conditions such as different treatment times, output powers and working gases, and then SWCNT coating on the plasma treated PET fabrics was carried out by coating-dry-cure using various coating parameters including different SWCNT concentrations, curing times and curing temperatures. PET fabrics were characterized by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and volume resistivity. SEM and XPS analysis of the plasma treated PET fabrics revealed the increase in surface roughness and oxygen/nitrogen containing groups on the PET fiber surface. SEM and XPS analysis of the plasma treated and SWCNT coated PET fabrics indicated the SWCNT coating on PET fiber surface. The plasma treated and SWCNT coated PET fabrics exhibited a good antistatic property, which increased and then decreased with the increasing plasma treatment time and output power. The antistatic property of the O 2 plasma treated and SWCNT coated PET fabric was better and worse than that of N 2 or Ar plasma treated and SWCNT coated PET fabric in the shorter treatment time and the longer treatment time, respectively. In addition, the antistatic property of the plasma treated

  19. Surface modification of carbon nanohorns by helium plasma and ozone treatments

    Science.gov (United States)

    Lin, Zaw; Iijima, Toru; Selvam Karthik, Paneer; Yoshida, Mitsunobu; Hada, Masaki; Nishikawa, Takeshi; Hayashi, Yasuhiko

    2017-01-01

    In this paper, we describe the effects of helium plasma and ozone treatments on the dispersibility of carbon nanohorns (CNHs) in water. The experimental setups have been designed to efficiently generate helium plasma and ozone by dielectric barrier discharge at atmospheric pressure. After being treated with ozone, the oxygen-containing functional groups were introduced to the surface of CNHs, and are responsible for better dispersion. Helium plasma treatment was performed separately and it resulted in hydroxyl functional groups on the surface of CNHs. It was also found that the sizes of CNHs in water were smaller after ozone treatment. However, plasma-treated CNHs were bigger than ozone treated CNHs. The dispersed CNHs modified by ozone treatment were stable for more than three months without precipitation. In contrast, though helium plasma treatment introduced hydroxyl groups to the surface of CNHs, the dispersibility decreased and the flocculation of CNHs was observed in a few minutes.

  20. Evaluation of mechanism of non-thermal plasma effect on the surface of polypropylene films for enhancement of adhesive and hemo compatible properties

    Energy Technology Data Exchange (ETDEWEB)

    Navaneetha Pandiyaraj, K., E-mail: dr.knpr@gmail.com [Surface Engineering Laboratory, Department of Physics, Sri Shakthi Institute of Engineering and Technology, L& T by pass, Chinniyam Palayam (post), Coimbatore-641062 (India); Deshmukh, R.R. [Department of Physics, Institute of Chemical Technology, Matunga, Mumbai-400 019 (India); Arunkumar, A.; Ramkumar, M.C. [Surface Engineering Laboratory, Department of Physics, Sri Shakthi Institute of Engineering and Technology, L& T by pass, Chinniyam Palayam (post), Coimbatore-641062 (India); Ruzybayev, I.; Ismat Shah, S. [Department of Physics and Astronomy, Department of Materials Science and Engineering, University of Delaware, 208 Dupont Hall, Newark (United States); Su, Pi-Guey [Department of Chemistry, Chinese Culture University, Taipei 111, Taiwan (China); Periayah, Mercy Halleluyah; Halim, A.S. [School of Medical Sciences, Health Campus, Universiti Sains Malaysia, 16150 Kubang Kerian, Kelantan (Malaysia)

    2015-08-30

    Highlights: • Investigated the mechanism of effect of various gaseous plasma treatments on the surface properties of Polypropylene (PP) films. • The improvement in surface energy is basically due to the incorporation of polar functional groups onto the PP films. • The extent of surface modification and hydrophobic recovery depends upon the type of plasma forming gas. • Due to the significant morphological and chemical changes induced by the gaseous plasma treatment, improved the blood compatibility as well as adhesive strength of the PP films. - Abstract: The hydro-carbon based polymers have attracted attention of scientists for its use in bio-medical field as various implants due to inherent flexibility. However, they have poor surface properties; particularly they have low surface energy (SE). Hence, blood components (platelets, blood proteins, etc.)-polymer surface interaction is the major concern when it comes in contact with blood. Thus, surface modification is required to develop the perfect antithrombogenic property without affecting the materials bulk. The present study describes the improvement in adhesive and blood compatible properties of polypropylene (PP) by low temperature (non-thermal) plasma of various gases such as Ar, O{sub 2}, air and Ar + O{sub 2} for biomedical applications. The changes in surface morphological, chemical and hydrophilic modification induced by the gaseous plasma treatment were analyzed by atomic force microscopy (AFM), X-ray photo electron spectroscopy (XPS), electron spin resonance (ESR) spectroscopy and contact angle measurements, respectively. Moreover, the stability of plasma effect was also studied for the different storage conditions. Variation in adhesive strength of the plasma treated PP film was studied by T-Peel and Lap-Shear strength tests. The blood compatibility of the surface modified PP films was investigated by in vitro analysis. It was found that gaseous plasma treatment improved the blood compatibility