Dynamic Response of a Magnetized Plasma to AN External Source: Application to Space and Solid State Plasmas

NASA Astrophysics Data System (ADS)

Zhou, Huai-Bei

This dissertation examines the dynamic response of a magnetoplasma to an external time-dependent current source. To achieve this goal a new method which combines analytic and numerical techniques to study the dynamic response of a 3-D magnetoplasma to a time-dependent current source imposed across the magnetic field was developed. The set of the cold electron and/or ion plasma equations and Maxwell's equations are first solved analytically in (k, omega)^ace; inverse Laplace and 3 -D complex Fast Fourier Transform (FFT) techniques are subsequently used to numerically transform the radiation fields and plasma currents from the (k, omega) ^ace to the (r, t) space. The dynamic responses of the electron plasma and of the compensated two-component plasma to external current sources are studied separately. The results show that the electron plasma responds to a time -varying current source imposed across the magnetic field by exciting whistler/helicon waves and forming of an expanding local current loop, induced by field aligned plasma currents. The current loop consists of two anti-parallel field-aligned current channels concentrated at the ends of the imposed current and a cross-field current region connecting these channels. The latter is driven by an electron Hall drift. A compensated two-component plasma responds to the same current source as following: (a) For slow time scales tau > Omega_sp{i}{-1} , it generates Alfven waves and forms a non-local current loop in which the ion polarization currents dominate the cross-field current; (b) For fast time scales tau < Omega_sp{i}{-1} , the dynamic response of the compensated two-component plasma is the same as that of the electron plasma. The characteristics of the current closure region are determined by the background plasma density, the magnetic field and the time scale of the current source. This study has applications to a diverse range of space and solid state plasma problems. These problems include current closure in emf inducing tethered satellite systems (TSS), generation of ELF/VLF waves by ionospheric heating, current closure and quasineutrality in thin magnetopause transitions, and short electromagnetic pulse generation in solid state plasmas. The cross-field current in TSS builds up on a time scale corresponding to the whistler waves and results in local current closure. Amplitude modulated HF ionospheric heating generates ELF/VLF waves by forming a horizontal magnetic dipole. The dipole is formed by the current closure in the modified region. For thin transition the time-dependent cross-field polarization field at the magnetopause could be neutralized by the formation of field aligned current loops that close by a cross-field electron Hall current. A moving current source in a solid state plasma results in microwave emission if the speed of the source exceeds the local phase velocity of the helicon or Alfven waves. Detailed analysis of the above problems is presented in the thesis.

QUARTERLY PROGRESS REPORT NO. 83,

DTIC Science & Technology

Topics included are: microwave spectroscopy; radio astronomy; solid-state microwave electronics; optical and infrared spectroscopy; physical electronics and surface physics; physical acoustics; plasma physics; gaseous electronics; plasmas and controlled nuclear fusion ; energy conversion research; statistical communication theory; linguistics; cognitive information processing; communications biophysics; neurophysiology; computation research.

Solid State Division progress report, September 30, 1981

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1982-04-01

Progress made during the 19 months from March 1, 1980, through September 30, 1981, is reported in the following areas: theoretical solid state physics (surfaces, electronic and magnetic properties, particle-solid interactions, and laser annealing); surface and near-surface properties of solids (plasma materials interactions, ion-solid interactions, pulsed laser annealing, and semiconductor physics and photovoltaic conversion); defects in solids (radiation effects, fracture, and defects and impurities in insulating crystals); transport properties of solids (fast-ion conductors, superconductivity, and physical properties of insulating materials); neutron scattering (small-angle scattering, lattice dynamics, and magnetic properties); crystal growth and characterization (nuclear waste forms, ferroelectric mateirals, high-temperature materials,more » and special materials); and isotope research materials. Publications and papers are listed. (WHK)« less

Sorptive thin film microextraction followed by direct solid state spectrofluorimetry: A simple, rapid and sensitive method for determination of carvedilol in human plasma.

PubMed

Karimi, Shima; Talebpour, Zahra; Adib, Noushin

2016-06-14

A poly acrylate-ethylene glycol (PA-EG) thin film is introduced for the first time as a novel polar sorbent for sorptive extraction method coupled directly to solid-state spectrofluorimetry without the necessity of a desorption step. The structure, polarity, fluorescence property and extraction performance of the developed thin film were investigated systematically. Carvedilol was used as the model analyte to evaluate the proposed method. The entire procedure involved one-step extraction of carvedilol from plasma using PA-EG thin film sorptive phase without protein precipitation. Extraction variables were studied in order to establish the best experimental conditions. Optimum extraction conditions were the followings: stirring speed of 1000 rpm, pH of 6.8, extraction temperature of 60 °C, and extraction time of 60 min. Under optimal conditions, extraction of carvedilol was carried out in spiked human plasma; and the linear range of calibration curve was 15-300 ng mL(-1) with regression coefficient of 0.998. Limit of detection (LOD) for the method was 4.5 ng mL(-1). The intra- and inter-day accuracy and precision of the proposed method were evaluated in plasma sample spiked with three concentration levels of carvedilol; yielding a recovery of 91-112% and relative standard deviation of less than 8%, respectively. The established procedure was successfully applied for quantification of carvedilol in plasma sample of a volunteer patient. The developed PA-EG thin film sorptive phase followed by solid-state spectrofluorimetric method provides a simple, rapid and sensitive approach for the analysis of carvedilol in human plasma. Copyright © 2016 Elsevier B.V. All rights reserved.

Tunable Solid-State Quantum Memory Using Rare-Earth-Ion-Doped Crystal, Nd(3+):GaN

DTIC Science & Technology

2017-04-01

by plasma-assisted molecular beam epitaxy in a modular Gen II reactor using liquid gallium, solid Nd, and a nitrogen plasma. The photoluminescence (PL...provide a tunable memory. To vary the applied field, we designed and grew a series of Nd-doped GaN p-i-n structures, strain- balanced superlattice...27 Fig. 23 Electric field vs. GaN well/ AlxGa(1-x)N barrier thickness for strain- balanced superlattice (SBSL) structures with

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

NASA Astrophysics Data System (ADS)

Totsuji, Hiroo

2008-07-01

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

Helicons in Unbounded Plasmas.

PubMed

Stenzel, R L; Urrutia, J M

2015-05-22

Helicons are whistler modes with helical phase fronts. They have been studied in solid state plasmas and in discharge tubes where boundaries and nonuniformities are ever present. The present work shows that helicons also exist in unbounded and uniform plasmas, thereby bridging the fields of laboratory and space plasma physics. First measurements of helicon field lines in three dimensional space are presented. Helicons with negative and positive mode numbers can propagate with equal amplitudes.

Nanoscale femtosecond imaging of transient hot solid density plasmas with elemental and charge state sensitivity using resonant coherent diffraction

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kluge, T., E-mail: t.kluge@hzdr.de; Bussmann, M.; Huang, L. G., E-mail: lingen.huang@hzdr.de

Here, we propose to exploit the low energy bandwidth, small wavelength, and penetration power of ultrashort pulses from XFELs for resonant Small Angle Scattering (SAXS) on plasma structures in laser excited plasmas. Small angle scattering allows to detect nanoscale density fluctuations in forward scattering direction. Typically, the SAXS signal from laser excited plasmas is expected to be dominated by the free electron distribution. We propose that the ionic scattering signal becomes visible when the X-ray energy is in resonance with an electron transition between two bound states (resonant coherent X-ray diffraction). In this case, the scattering cross-section dramatically increases somore » that the signal of X-ray scattering from ions silhouettes against the free electron scattering background which allows to measure the opacity and derived quantities with high spatial and temporal resolution, being fundamentally limited only by the X-ray wavelength and timing. Deriving quantities such as ion spatial distribution, charge state distribution, and plasma temperature with such high spatial and temporal resolution will make a vast number of processes in shortpulse laser-solid interaction accessible for direct experimental observation, e.g., hole-boring and shock propagation, filamentation and instability dynamics, electron transport, heating, and ultrafast ionization dynamics.« less

Raman Scattering in the Magnetized Semiconductor Plasma

NASA Astrophysics Data System (ADS)

Jankauskas, Zigmantas; Kvedaras, Vygaudas; Balevičius, Saulius

2005-04-01

Radio frequency (RF) magnetoplasmic waves known as helicons will propagate in solid-state plasmas when a strong magnetic field is applied. In our device the helicons were excited by RFs (the range 100-2000 MHz) much higher than the helicon generation frequency (the main peak at 20 MHz). The excitation of helicons in this case may be described by the effect similar to the Combination Scattering (Raman effect) when a part of the high RF wave energy that passes through the active material is absorbed and re-emitted by the magnetized solid-state plasma. It is expedient to call this experimental device a Helicon Maser (HRM) and the higher frequency e/m field - a pumping field. In full analogy with the usual Raman maser (or laser) the magnetized semiconductor sample plays the role of active material and the connecting cable - the role of high quality external resonator.

Raman Scattering in the Magnetized Semiconductor Plasma

NASA Astrophysics Data System (ADS)

Jankauskas, Zigmantas; Kvedaras, Vygaudas; Balevičius, Saulius

Radio frequency (RF) magnetoplasmic waves known as helicons will propagate in solid-state plasmas when a strong magnetic field is applied. In our device the helicons were excited by RFs (the range 100-2000 MHz) much higher than the helicon generation frequency (the main peak at 20 MHz). The excitation of helicons in this case may be described by the effect similar to the Combination Scattering (Raman effect) when a part of the high RF wave energy that passes through the active material is absorbed and re-emitted by the magnetized solid-state plasma. It is expedient to call this experimental device a Helicon Maser (HRM) and the higher frequency e/m field - a pumping field. In full analogy with the usual Raman maser (or laser) the magnetized semiconductor sample plays the role of active material and the connecting cable - the role of high quality external resonator.

Diagnostics of ion beam generated from a Mather type plasma focus device

NASA Astrophysics Data System (ADS)

Lim, L. K.; Ngoi, S. K.; Wong, C. S.; Yap, S. L.

2014-03-01

Diagnostics of ion beam emission from a 3 kJ Mather-type plasma focus device have been performed for deuterium discharge at low pressure regime. Deuterium plasma focus was found to be optimum at pressure of 0.2 mbar. The energy spectrum and total number of ions per shot from the pulsed ion beam are determined by using biased ion collectors, Faraday cup, and solid state nuclear track detector CR-39. Average energy of the ion beam obtained is about 60 keV. Total number of the ions has been determined to be in the order of 1011 per shot. Solid state nuclear track detectors (SSNTD) CR39 are employed to measure the particles at all angular direction from end on (0°) to side on (90°). Particle tracks are registered by SSNTD at 30° to 90°, except the one at the end-on 0°.

International Conference on Vacuum Ultraviolet Radiation Physics, 8th, Lunds Universitet, Sweden, Aug. 4-8, 1986, Proceedings

NASA Technical Reports Server (NTRS)

Nilsson, Per-Olof (Editor); Nordgren, Joseph (Editor)

1987-01-01

The interactions of VUV radiation with solids are explored in reviews and reports of recent theoretical and experimental investigations from the fields of atomic and molecular physics, solid-state physics, and VUV instrumentation. Topics examined include photoabsorption and photoionization, multiphoton processes, plasma physics, VUV lasers, time-resolved spectroscopy, synchrotron radiation centers, solid-state spectroscopy, and dynamical processes involving localized levels. Consideration is given to the fundamental principles of photoemission, spin-polarized photoemission, inverse photoemission, semiconductors, organic materials, and adsorbates.

Ionization potential depression in an atomic-solid-plasma picture

NASA Astrophysics Data System (ADS)

Rosmej, F. B.

2018-05-01

Exotic solid density matter such as heated hollow crystals allow extended material studies while their physical properties and models such as the famous ionization potential depression are presently under renewed controversial discussion. Here we develop an atomic-solid-plasma (ASP) model that permits ionization potential depression studies also for single and multiple core hole states. Numerical calculations show very good agreement with recently available data not only in absolute values but also for Z-scaled properties while currently employed methods fail. For much above solid density compression, the ASP model predicts increased K-edge energies that are related to a Fermi surface rising. This is in good agreement with recent quantum molecular dynamics simulations. For hot dense matter a quantum number dependent optical electron finite temperature ion sphere model is developed that fits well with line shift and line disappearance data from dense laser produced plasma experiments. Finally, the physical transparency of the ASP picture allows a critical discussion of current methods.

Shunting arc plasma source for pure carbon ion beam.

PubMed

Koguchi, H; Sakakita, H; Kiyama, S; Shimada, T; Sato, Y; Hirano, Y

2012-02-01

A plasma source is developed using a coaxial shunting arc plasma gun to extract a pure carbon ion beam. The pure carbon ion beam is a new type of deposition system for diamond and other carbon materials. Our plasma device generates pure carbon plasma from solid-state carbon material without using a hydrocarbon gas such as methane gas, and the plasma does not contain any hydrogen. The ion saturation current of the discharge measured by a double probe is about 0.2 mA∕mm(2) at the peak of the pulse.

Shunting arc plasma source for pure carbon ion beam

DOE Office of Scientific and Technical Information (OSTI.GOV)

Koguchi, H.; Sakakita, H.; Kiyama, S.

2012-02-15

A plasma source is developed using a coaxial shunting arc plasma gun to extract a pure carbon ion beam. The pure carbon ion beam is a new type of deposition system for diamond and other carbon materials. Our plasma device generates pure carbon plasma from solid-state carbon material without using a hydrocarbon gas such as methane gas, and the plasma does not contain any hydrogen. The ion saturation current of the discharge measured by a double probe is about 0.2 mA/mm{sup 2} at the peak of the pulse.

Classical molecular dynamics simulations for non-equilibrium correlated plasmas

NASA Astrophysics Data System (ADS)

Ferri, S.; Calisti, A.; Talin, B.

2017-03-01

A classical molecular dynamics model was recently extended to simulate neutral multi-component plasmas where various charge states of the same atom and electrons coexist. It is used to investigate the plasma effects on the ion charge and on the ionization potential in dense plasmas. Different simulated statistical properties will show that the concept of isolated particles is lost in such correlated plasmas. The charge equilibration is discussed for a carbon plasma at solid density and investigation on the charge distribution and on the ionization potential depression (IPD) for aluminum plasmas is discussed with reference to existing experiments.

2011 NRL REVIEW

DTIC Science & Technology

2011-01-01

other mechanism ? What accelerates the solar wind? What are the near- Sun plasma properties (particle density, magnetic field)? Does the solar wind come...microstructure character iza tion, elec tronic ceramics, solid-state physics, fiber optics, electro-optics, microelectronics, fracture mechan ics...computational fluid mechanics , experi mental structural mechanics , solid me chan ics, elastic/plastic fracture mechanics , materials, finite-element

Temperature effect on laser-induced breakdown spectroscopy spectra of molten and solid salts

NASA Astrophysics Data System (ADS)

Hanson, Cynthia; Phongikaroon, Supathorn; Scott, Jill R.

2014-07-01

Laser-induced breakdown spectroscopy (LIBS) has been investigated as a potential analytical tool to improve operations and safeguards for electrorefiners, such as those used in processing spent nuclear fuel. This study set out to better understand the effect of sample temperature and physical state on LIBS spectra of molten and solid salts by building calibration curves of cerium and assessing self-absorption, plasma temperature, electron density, and local thermal equilibrium (LTE). Samples were composed of a LiCl-KCl eutectic salt, an internal standard of MnCl2, and varying concentrations of CeCl3 (0.1, 0.3, 0.5, 0.8, and 1.0 wt.% Ce) under different temperatures (773, 723, 673, 623, and 573 K). Analysis of salts in their molten form is preferred as plasma plumes from molten samples experienced less self-absorption, less variability in plasma temperature, and higher clearance of the minimum electron density required for local thermal equilibrium. These differences are attributed to plasma dynamics as a result of phase changes. Spectral reproducibility was also better in the molten state due to sample homogeneity.

Deposition stress effects on thermal barrier coating burner rig life

NASA Technical Reports Server (NTRS)

Watson, J. W.; Levine, S. R.

1984-01-01

A study of the effect of plasma spray processing parameters on the life of a two layer thermal barrier coating was conducted. The ceramic layer was plasma sprayed at plasma arc currents of 900 and 600 amps onto uncooled tubes, cooled tubes, and solid bars of Waspalloy in a lathe with 1 or 8 passes of the plasma gun. These processing changes affected the residual stress state of the coating. When the specimens were tested in a Mach 0.3 cyclic burner rig at 1130 deg C, a wide range of coating lives resulted. Processing factors which reduced the residual stress state in the coating, such as reduced plasma temperature and increased heat dissipation, significantly increased coating life.

Deposition stress effects on the life of thermal barrier coatings on burner rigs

NASA Technical Reports Server (NTRS)

Watson, J. W.; Levine, S. R.

1984-01-01

A study of the effect of plasma spray processing parameters on the life of a two layer thermal barrier coating was conducted. The ceramic layer was plasma sprayed at plasma arc currents of 900 and 600 amps onto uncooled tubes, cooled tubes, and solid bars of Waspalloy in a lathe with 1 or 8 passes of the plasma gun. These processing changes affected the residual stress state of the coating. When the specimens were tested in a Mach 0.3 cyclic burner rig at 1130 deg C, a wide range of coating lives resulted. Processing factors which reduced the residual stress state in the coating, such as reduced plasma temperature and increased heat dissipation, significantly increased coating life.

Conceptual design of 100 TW solid state laser system

DOE Office of Scientific and Technical Information (OSTI.GOV)

McMordie, J.A.

1995-12-31

Currently the main solid state laser facilities used for plasma physics research in the United Kingdom are the VULCAN laser at the Rutherford Appleton Laboratory and the HELEN facility at the Atomic Weapons Establishment. In the future it is proposed to replace HELEN with a new 100 TW facility to come on line early in the next century. A brief review is given of the VULCAN and HELEN. Then the authors discuss the design for the HELEN replacement.

Determination of the Unstable States of the Solid State Plasma in Semiconductor Devices

DTIC Science & Technology

1988-05-01

of the carrier moving through the lattice potentials, which alter the carrier’s response to an external electromag- netic field. so If the average...see quantum mechanical affects from the lattice potentials and a spread in carrier momentums due to the Heisenburg Uncertainty Principle. We can...us to account for the quantum mechanical source of the plasma. That source is the lattice . At values of the quantum compression parameter near unity

Diagnostics of ion beam generated from a Mather type plasma focus device

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lim, L. K., E-mail: yapsl@um.edu.my; Ngoi, S. K., E-mail: yapsl@um.edu.my; Wong, C. S., E-mail: yapsl@um.edu.my

Diagnostics of ion beam emission from a 3 kJ Mather-type plasma focus device have been performed for deuterium discharge at low pressure regime. Deuterium plasma focus was found to be optimum at pressure of 0.2 mbar. The energy spectrum and total number of ions per shot from the pulsed ion beam are determined by using biased ion collectors, Faraday cup, and solid state nuclear track detector CR-39. Average energy of the ion beam obtained is about 60 keV. Total number of the ions has been determined to be in the order of 10{sup 11} per shot. Solid state nuclear trackmore » detectors (SSNTD) CR39 are employed to measure the particles at all angular direction from end on (0°) to side on (90°). Particle tracks are registered by SSNTD at 30° to 90°, except the one at the end-on 0°.« less

Stabilization of a supersaturated solution of mefenamic acid from a solid dispersion with EUDRAGIT(®) EPO.

PubMed

Kojima, Taro; Higashi, Kenjirou; Suzuki, Toyofumi; Tomono, Kazuo; Moribe, Kunikazu; Yamamoto, Keiji

2012-10-01

The stabilization mechanism of a supersaturated solution of mefenamic acid (MFA) from a solid dispersion with EUDRAGIT(®) EPO (EPO) was investigated. The solid dispersions were prepared by cryogenic grinding method. Powder X-ray diffractometry, in vitro dissolution test, in vivo oral absorption study, infrared spectroscopy, and solid- and solution-state NMR spectroscopies were used to characterize the solid dispersions. Dissolution tests in acetate buffer (pH 5.5) revealed that solid dispersion showed > 200-fold higher concentration of MFA. Supersaturated solution was stable over 1 month and exhibited improved oral bioavailability of MFA in rats, with a 7.8-fold higher area under the plasma concentration-versus-time curve. Solid-state (1)H spin-lattice relaxation time (T(1)) measurement showed that MFA was almost monomolecularly dispersed in the EPO polymer matrix. Intermolecular interaction between MFA and EPO was indicated by solid-state infrared and (13)C-T(1) measurements. Solution-state (1)H-NMR measurement demonstrated that MFA existed in monomolecular state in supersaturated solution. (1)H-T(1) and difference nuclear Overhauser effect measurements indicated that cross relaxation occurred between MFA and EPO due to the small distance between them. The formation and high stability of the supersaturated solution were attributable to the specifically formed intermolecular interactions between MFA and EPO.

Lab- and space-based researchers discuss plasma experiments

NASA Astrophysics Data System (ADS)

Baker, D. N.; Yamada, M.

Plasma physics provides a common language and set of approaches that tie together all scientists who study the acceleration, transport, and loss processes of the plasma state. Some years ago, researchers from the laboratory and space research communities suggested a workshop to bring together the diverse researchers in the respective fields. A series of workshops on the “Interrelationship between Plasma Experiments in the Laboratory and Space” (IPELS) was established, and the third meeting was held July 24-28, 1995, in the beautiful and historic town of Pitlochry in the Scottish Highlands.The conference reestablished the critical point that plasma physics is an important but surprisingly diversified research discipline. Meetings attendees discussed a number of new approaches to plasma research, including novel diagnostic techniques for use in space, such as active antennas and electric field sounding devices. Detailed discussions covered spacecraft-plasma environment interactions, including vehicle charging and neutral gas release; fundamental aspects of industrial application of dusty plasmas and waves in dusty plasmas; a very distinctive phase transition of coulomb crystals (from solid state to liquid state) in dusty plasmas; and terrella experiments to simulate and study chaotic transport in the ionosphere.

Solid expellant plasma generator

NASA Technical Reports Server (NTRS)

Stone, Nobie H. (Inventor); Poe, Garrett D. (Inventor); Rood, Robert (Inventor)

2010-01-01

An improved solid expellant plasma generator has been developed. The plasma generator includes a support housing, an electrode rod located in the central portion of the housing, and a mass of solid expellant material that surrounds the electrode rod within the support housing. The electrode rod and the solid expellant material are made of separate materials that are selected so that the electrode and the solid expellant material decompose at the same rate when the plasma generator is ignited. This maintains a point of discharge of the plasma at the interface between the electrode and the solid expellant material.

Pulsed plasma polymerization for controlling shrinkage and surface composition of nanopores

NASA Astrophysics Data System (ADS)

Asghar, Waseem; Ilyas, Azhar; Deshmukh, Rajendra R.; Sumitsawan, Sulak; Timmons, Richard B.; Iqbal, Samir M.

2011-07-01

Solid-state nanopores have emerged as sensors for single molecules and these have been employed to examine the biophysical properties of an increasingly large variety of biomolecules. Herein we describe a novel and facile approach to precisely adjust the pore size, while simultaneously controlling the surface chemical composition of the solid-state nanopores. Specifically, nanopores fabricated using standard ion beam technology are shrunk to the requisite molecular dimensions via the deposition of highly conformal pulsed plasma generated thin polymeric films. The plasma treatment process provides accurate control of the pore size as the conformal film deposition depends linearly on the deposition time. Simultaneously, the pore and channel chemical compositions are controlled by appropriate selection of the gaseous monomer and plasma conditions employed in the deposition of the polymer films. The controlled pore shrinkage is characterized with high resolution AFM, and the film chemistry of the plasma generated polymers is analyzed with FTIR and XPS. The stability and practical utility of this new approach is demonstrated by successful single molecule sensing of double-stranded DNA. The process offers a viable new advance in the fabrication of tailored nanopores, in terms of both the pore size and surface composition, for usage in a wide range of emerging applications.

Equation of state for two-dimensional dusty plasma liquids and its applications

NASA Astrophysics Data System (ADS)

Feng, Yan

2017-10-01

Laboratory dusty plasma consists of free electrons, free ions, and micro-sized dust particles with thousands of negative elementary charges. Due to their extremely low charge-to-mass ratio, these dust particles are strongly coupled, arranging themselves like atoms in liquids or solids. Due to the shielding effects of electrons and ions, dust particles interact with each other through the Yukawa potential, so that simulations of Yukawa liquids or solids are used to study properties of dusty plasmas. In the past two decades, the properties of liquid 2D dusty plasmas have been widely studied from experiments to theories and simulations. However, from our literature search, we have not found a quantitative and comprehensive study of properties of 2D liquid dusty plasmas over a wide range of plasma conditions. Here, from molecular-dynamics simulations of Yukawa liquids, we have obtained a concise equation of state (EOS) for the 2D liquid dusty plasmas from empirical fitting, which contains three quantities of the internal pressure, the coupling parameter, and the screening parameter. From this EOS, different thermodynamical processes can be directly derived, such as isotherms, isobars and isochores. Also, various physical properties of 2D liquid dusty plasmas, like the bulk modulus of elasticity, can be analytically derived, so that the sound speeds can be obtained. Finally, an analytical expression of the specific heat for 2D liquid dusty plasmas has been achieved. Work supported by the National Natural Science Foundation of China under Grant No. 11505124, the 1000 Youth Talents Plan, and the startup funds from Soochow University.

An ecotoxic risk assessment of residue materials produced by the plasma pyrolysis/vitrification (PP/V) process.

PubMed

Lapa, N; Santos, Oliveira J F; Camacho, S L; Circeo, L J

2002-01-01

Plasma is the fourth state of matter, following the three states of solid, liquid and gas. Experience has amply demonstrated that solids exposed to the oxygen-deficient plasma flame are converted to liquid, and liquid exposed to the same flame is converted to gas. A low amount of vitrified solid residue material usually remains at the end of this process. Plasma pyrolysis/vitrification (PP/V) has been demonstrated as a safe, efficient, cost-effective technology for the treatment of wastes, including hazardous wastes. Besides the low amounts of gaseous byproducts that PP/V produces, the solid vitrified residue presents a low leachability of pollutants. Studies have been performed in many countries in order to assess the leachability of chemical substances. But from the results of identified studies, none has reported results on the ecotoxicological properties of the leachates. The aim of this study was to contribute to the assessment of ecotoxic risk of four different vitrified materials. Vitrified samples of contaminated soils, municipal solid wastes, and incinerator bottom ashes were submitted to the European leaching pre-standard test number prEN 12457-2. The leachates were analyzed for 22 chemical parameters. The biological characterization comprised the assessment of bioluminescence inhibition of Photobacterium phosphoreum bacterium, growth inhibition of Pseudokirchneriella subcapitata algae and the germination inhibition of Lactuca sativa vegetable. The chemical and ecotoxicological results were analyzed according to the French proposal of Criteria on the Evaluation Methods of Waste Toxicity (CEMWT) and a Toxicity Classification System (TCS). The chemical and ecotoxicological results indicated a low leachability of pollutants and a low toxicity level of leachates. All samples studied were as below the TCS class 1 level (no significant toxicity observed) and as non-ecotoxic for CEMWT. Therefore, the environmental ecotoxic risk of the analyzed vitrified samples was determined to be very low.

20 kA PFN capacitor bank with solid-state switching. [pulse forming network for plasma studies

NASA Technical Reports Server (NTRS)

Posta, S. J.; Michels, C. J.

1973-01-01

A compact high-current pulse-forming network capacitor bank using paralleled silicon controlled rectifiers as switches is described. The maximum charging voltage of the bank is 1kV and maximum load current is 20 kA. The necessary switch equalization criteria and performance with dummy load and an arc plasma generator are described.

Hepatoprotective Effect of Wheat-Based Solid-State Fermented Antrodia cinnamomea in Carbon Tetrachloride-Induced Liver Injury in Rat

PubMed Central

Chiu, Huan-Wen; Hua, Kuo-Feng

2016-01-01

Antrodia cinnamomea (A. cinnamomea) is an indigenous medical fungus in Taiwan and has multiple biological functions, including hepatoprotective and immune-modulatory effects. Currently, the commercially available A. cinnamomea are mainly liquid- and solid-state fermented A. cinnamomea. However, the hepatoprotective effect of solid-state fermented A. cinnamomea has never been reported. Here we evaluate the ability of air-dried, ground and non-extracted wheat-based solid-state fermented A. cinnamomea (WFAC) to protect against carbon tetrachloride (CCl4)-induced hepatic injury in vivo. The results showed that oral administration of WFAC dose dependently (180, 540 and 1080 mg/kg) ameliorated the increase in plasma aspartate aminotransferase and alanine aminotransferase levels caused by chronic repeated CCl4 intoxication in rats. WFAC significantly reduced the CCl4-induced increase in hepatic lipid peroxidation levels and hydroxyproline contents, as well as reducing the spleen weight and water content of the liver. WFAC also restored the hepatic soluble protein synthesis and plasma albumin concentration in CCl4-intoxicated rats, but it did not affect the activities of superoxide dismutase, catalase, or glutathione peroxidase. In addition, a hepatic morphological analysis showed that the hepatic fibrosis and necrosis induced by CCl4 were significantly ameliorated by WFAC. Furthermore, the body weights of control rats and WFAC-administered rats were not significantly different, and no adverse effects were observed in WFAC-administered rats. These results indicate that WFAC is a nontoxic hepatoprotective agent against chronic CCl4-induced hepatic injury. PMID:27046059

A novel experimental setup for energy loss and charge state measurements in dense moderately coupled plasma using laser-heated hohlraum targets

NASA Astrophysics Data System (ADS)

Ortner, A.; Schumacher, D.; Cayzac, W.; Frank, A.; Basko, M. M.; Bedacht, S.; Blazevic, A.; Faik, S.; Kraus, D.; Rienecker, T.; Schaumann, G.; Tauschwitz, An.; Wagner, F.; Roth, M.

2016-03-01

We report on a new experimental setup for ion energy loss measurements in dense moderately coupled plasma which has recently been developed and tested at GSI Darmstadt. A partially ionized, moderately coupled carbon plasma (ne ≤ 0.8• 1022 cm-3, Te = 15 eV, z = 2.5, Γ = 0.5) is generated by volumetrical heating of two thin carbon foils with soft X-rays. This plasma is then probed by a bunched heavy ion beam. For that purpose, a special double gold hohlraum target of sub-millimeter size has been developed which efficiently converts intense laser light into thermal radiation and guarantees a gold-free interaction path for the ion beam traversing the carbon plasma. This setup allows to do precise energy loss measurements in non-ideal plasma at the level of 10 percent solid-state density.

Correlations between plasma variables and the deposition process of Si films from chlorosilanes in low pressure RF plasma of argon and hydrogen

NASA Technical Reports Server (NTRS)

Avni, R.; Carmi, U.; Grill, A.; Manory, R.; Grossman, E.

1984-01-01

The dissociation of chlorosilanes to silicon and its deposition on a solid substrate in a RF plasma of mixtures of argon and hydrogen were investigated as a function of the macrovariables of the plasma. The dissociation mechanism of chlorosilanes and HCl as well as the formation of Si in the plasma state were studied by sampling the plasma with a quadrupole mass spectrometer. Macrovariables such as pressure, net RF power input and locations in the plasma reactor strongly influence the kinetics of dissociation. The deposition process of microcrystalline silicon films and its chlorine contamination were correlated to the dissociation mechanism of chlorosilanes and HCl.

Experiment and Theory for Nuclear Reactions in Nano-Materials Show e14 - e16 Solid-State Fusion Reactions

NASA Astrophysics Data System (ADS)

George, Russ

2005-03-01

Nano-lattices of deuterium loving metals exhibit coherent behavior by populations of deuterons (d's) occupying a Bloch state. Therein, coherent d-overlap occurs wherein the Bloch condition reduces the Coulomb barrier.Overlap of dd pairs provides a high probability fusion will/must occur. SEM photo evidence showing fusion events is now revealed by laboratories that load or flux d into metal nano-domains. Solid-state dd fusion creates an excited ^4He nucleus entangled in the large coherent population of d's.This contrasts with plasma dd fusion in collision space where an isolated excited ^4He nucleus seeks the ground state via fast particle emission. In momentum limited solid state fusion,fast particle emission is effectively forbidden.Photographed nano-explosive events are beyond the scope of chemistry. Corroboration of the nuclear nature derives from photographic observation of similar events on spontaneous fission, e.g. Cf. We present predictive theory, heat production, and helium isotope data showing reproducible e14 to e16 solid-state fusion reactions.

Entanglement of solid vortex matter: a boomerang-shaped reduction forced by disorder in interlayer phase coherence in Bi2Sr2CaCu2O8+y.

PubMed

Kato, T; Shibauchi, T; Matsuda, Y; Thompson, J R; Krusin-Elbaum, L

2008-07-11

We present evidence for entangled solid vortex matter in a glassy state in a layered superconductor Bi2Sr2CaCu2O8+y containing randomly splayed linear defects. The interlayer phase coherence--probed by the Josephson plasma resonance--is enhanced at high temperatures, reflecting the recoupling of vortex liquid by the defects. At low temperatures in the vortex solid state, the interlayer coherence follows a boomerang-shaped reentrant temperature path with an unusual low-field decrease in coherence, indicative of meandering vortices. We uncover a distinct temperature scaling between in-plane and out-of-plane critical currents with opposing dependencies on field and time, consistent with the theoretically proposed "splayed-glass" state.

Plasma-Enhanced Copolymerization of Amino Acid and Synthetic Monomers

DTIC Science & Technology

2011-12-16

Langmuir 2012, 28, 1833−18451839 The final copolymerization study utilizing a liquid inorganic component, titanium isopropoxide , and solid L-tyrosine was...conducted with the two monomers being vaporized and exposed to the plasma simultaneously. Titanium isopropoxide was heated in a liquid state to...hydroxyethyl methacrylate (HEMA), and titanium tetraiso- propoxide (TTIP). The organic and inorganic functional monomers used were chosen to demonstrate the

Enhanced Multiferroic Properties of YMnO3 Ceramics Fabricated by Spark Plasma Sintering Along with Low-Temperature Solid-State Reaction

PubMed Central

Wang, Meng; Wang, Ting; Song, Shenhua; Ravi, Muchakayala; Liu, Renchen; Ji, Shishan

2017-01-01

Based on precursor powders with a size of 200–300 nm prepared by the low-temperature solid-state reaction method, phase-pure YMnO3 ceramics are fabricated using spark plasma sintering (SPS). X-ray diffraction (XRD) and scanning electron microscopy (SEM) reveal that the high-purity YMnO3 ceramics can be prepared by SPS at 1000 °C for 5 minutes with annealing at 800 °C for 2 h. The relative density of the sample is as high as 97%, which is much higher than those of the samples sintered by other methods. The present dielectric and magnetic properties are much better than those of the samples fabricated by conventional methods and SPS with ball-milling precursors, and the ferroelectric loops at room temperature can be detected. These findings indicate that the YMnO3 ceramics prepared by the low temperature solid reaction method and SPS possess excellent dielectric lossy ferroelectric properties at room temperature, and magnetic properties at low temperature (10 K), making them suitable for potential multiferroic applications. PMID:28772832

Synthesis mechanism and preparation of LaMgAl11O19 powder for plasma spraying

NASA Astrophysics Data System (ADS)

He, Mingtao; Meng, Huimin; Wang, Yuchao; Ren, Pengwei

2018-06-01

Lanthanide magnesium hexaaluminate (LaMgAl11O19) powders were successfully synthesized by the solid-state reaction method. The objective of this study was to investigate the synthesis mechanism of LaMgAl11O19 and prepare LaMgAl11O19 powders suitable for plasma spraying. The results show that LaAlO3 reacts with MgAl2O4 and Al2O3 to form LaMgAl11O19 at approximately 1300 °C. Single-phase LaMgAl11O19 powders were prepared successfully by solid-state reaction at a synthesis temperature of 1600 °C for 6 h. Unlike the particles in the synthesized powders, those of the centrifugally spray-dried powders have a spherical shape with uniform granularity and good flowability, density, and particle size distribution, making them suitable for plasma spraying. The synthesized powders and centrifugally spray-dried powders remained as a single phase after heat treatment at 1300 °C for 100 h, indicating that LaMgAl11O19 has excellent high-temperature stability.

Transient lattice contraction in the solid-to-plasma transition

PubMed Central

Ferguson, Ken R.; Bucher, Maximilian; Gorkhover, Tais; Boutet, Sébastien; Fukuzawa, Hironobu; Koglin, Jason E.; Kumagai, Yoshiaki; Lutman, Alberto; Marinelli, Agostino; Messerschmidt, Marc; Nagaya, Kiyonobu; Turner, Jim; Ueda, Kiyoshi; Williams, Garth J.; Bucksbaum, Philip H.; Bostedt, Christoph

2016-01-01

In condensed matter systems, strong optical excitations can induce phonon-driven processes that alter their mechanical properties. We report on a new phenomenon where a massive electronic excitation induces a collective change in the bond character that leads to transient lattice contraction. Single large van der Waals clusters were isochorically heated to a nanoplasma state with an intense 10-fs x-ray (pump) pulse. The structural evolution of the nanoplasma was probed with a second intense x-ray (probe) pulse, showing systematic contraction stemming from electron delocalization during the solid-to-plasma transition. These findings are relevant for any material in extreme conditions ranging from the time evolution of warm or hot dense matter to ultrafast imaging with intense x-ray pulses or, more generally, any situation that involves a condensed matter-to-plasma transition. PMID:27152323

Thermal Properties of Matter

NASA Astrophysics Data System (ADS)

Khachan, Joe

2018-02-01

The ancient Greeks believed that all matter was composed of four elements: earth, water, air, and fire. By a remarkable coincidence (or perhaps not), today we know that there are four states of matter: solids (e.g. earth), liquids (e.g. water), gasses (e.g. air) and plasma (e.g. ionized gas produced by fire). The plasma state is beyond the scope of this book and we will only look at the first three states. Although on the microscopic level all matter is made from atoms or molecules, everyday experience tells us that the three states have very different properties. The aim of this book is to examine some of these properties and the underlying physics.

A summary of the research program in the broad field of electronics

NASA Technical Reports Server (NTRS)

1972-01-01

Summary reports of research projects covering solid state materials, semiconductors and devices, quantum electronics, plasmas, applied electromagnetics, electrical engineering systems to include control communication, computer and power systems, biomedical engineering and mathematical biosciences.

Intensity-dependent resonant transmission of x-rays in solid-density aluminum plasma

NASA Astrophysics Data System (ADS)

Cho, M. S.; Chung, H.-K.; Cho, B. I.

2018-05-01

X-ray free-electron lasers (XFELs) provide unique opportunities to generate and investigate dense plasmas. The absorption and transmission properties of x-ray photons in dense plasmas are important in characterizing the state of the plasmas. Experimental evidence shows that the transmission of x-ray photons through dense plasmas depends greatly on the incident XFEL intensity. Here, we present a detailed analysis of intensity-dependent x-ray transmission in solid-density aluminum using collisional-radiative population kinetics calculations. Reverse saturable absorption (RSA), i.e., an increase in x-ray absorption with intensity has been observed for photon energies below the K-absorption edge and in the intensity range of 1016-1017 W/cm2 for XFEL photons with 1487 eV. At higher intensities, a transition from RSA to saturable absorption (SA) is predicted; thus, the x-ray absorption decreases with intensity above a threshold value. For XFEL photon energies of 1501 eV and 1515 eV, the transition from RSA to SA occurs at XFEL intensities between 1017-1018 W/cm2. Electron temperatures are predicted to be in the range of 30-50 eV for the given experimental conditions. Detailed population kinetics of the charge states explains the intensity-dependent absorption of x-ray photons and the fast modulation of XFEL pulses for both RSA and SA.

Porous Organic Nanolayers for Coating of Solid-state Devices

PubMed Central

2011-01-01

Background Highly hydrophobic surfaces can have very low surface energy and such low surface energy biological interfaces can be obtained using fluorinated coatings on surfaces. Deposition of biocompatible organic films on solid-state surfaces is attained with techniques like plasma polymerization, biomineralization and chemical vapor deposition. All these require special equipment or harsh chemicals. This paper presents a simple vapor-phase approach to directly coat solid-state surfaces with biocompatible films without any harsh chemical or plasma treatment. Hydrophilic and hydrophobic monomers were used for reaction and deposition of nanolayer films. The monomers were characterized and showed a very consistent coating of 3D micropore structures. Results The coating showed nano-textured surface morphology which can aid cell growth and provide rich molecular functionalization. The surface properties of the obtained film were regulated by varying monomer concentrations, reaction time and the vacuum pressure in a simple reaction chamber. Films were characterized by contact angle analysis for surface energy and with profilometer to measure the thickness. Fourier Transform Infrared Spectroscopy (FTIR) analysis revealed the chemical composition of the coated films. Variations in the FTIR results with respect to different concentrations of monomers showed the chemical composition of the resulting films. Conclusion The presented approach of vapor-phase coating of solid-state structures is important and applicable in many areas of bio-nano interface development. The exposure of coatings to the solutions of different pH showed the stability of the coatings in chemical surroundings. The organic nanocoating of films can be used in bio-implants and many medical devices. PMID:21569579

Plasma-based beam combiner for very high fluence and energy

DOE PAGES

Kirkwood, R. K.; Turnbull, D. P.; Chapman, T.; ...

2017-10-02

Extreme optical fluences, much beyond the damage threshold of conventional optics, are of interest for a range of high-energy-density physics applications. Nonlinear interactions of multiple beams in plasmas have the potential to produce optics that operate at much higher intensity and fluence than is possible in solids. In inertial confinement fusion experiments indirectly driven with lasers, many beams overlap in the plasma inside a hohlraum, and cross-beam energy transfer by Brillouin scattering has been employed to redistribute energy between laser beams within the target. Here in this paper, we show that in a hot, under-dense plasma the energy of manymore » input beams can be combined into a single well-collimated beam. The emerging beam has an energy of 4 kJ (over 1 ns) that is more than triple that of any incident beam, and a fluence that is more than double. Because the optic produced is plasma, and is diffractive, it is inherently capable of generating higher fluences in a single beam than solid-state refractive or reflective optics.« less

ICPP: Charge and Density Coupling in Nonideal Plasmas

NASA Astrophysics Data System (ADS)

Fortov, V. E.

2000-10-01

Plasmas with Strong Coulomb Interaction (SCI) are found in astrophysics, planetary physics, inertial confinement fusion, advanced energetics and elsewhere[1]. SCI plasmas can be achieved in: I Dusty plasmas, II Shock-compressed plasmas. I. SCI in low-density dusty (colloidal) plasmas arises from the high charge of micron-size macroparticles[2]. Experiments use glow and inductive RF discharges, combustion flames of gas and solid propellant, ultraviolet light beams, and radioactive decay fluxes. Liquid- and solid-like structures are seen, and phase diagrams and transitions investigated by experiment and simulation. Zero-g experiments on space station Mir and in aircraft clarified the gravity effect on plasma crystal formation. II. Plasma SCI can arise in shock compression of solid and porous metals, noble gases, hydrogen, sulphur, and iodine at megabar pressures [3,4], using high explosive drive. Phase diagram regions were examined, where thermal and pressure ionization exist. Multiple-shock-compressed hydrogen can show metal-like conductivity from pressure ionization. The ``metal-to-dielectric" transition in shock-compressed lithium at 0.5 Mbar was detected and analyzed. Thermodynamics, equation of state, plasma composition, electrical and radiative properties show SCI suppression of discrete electron spectra and strong lowering of ionization potentials, evoking the ``confined-atom" model[5] for SCI and other models[6]. [1] V.E.Fortov, I.T.Yakubov, Physics of Nonideal Plasmas, Hemisphere, N.Y.-London (1989). [2] V.E.Fortov, A.P.Nefedov, O.F.Petrov, Soviet Physics-Uspekhy, 167(1997)1215. [3] V.Gryaznov, I.Iosilevsky, V.Fortov, Contrib. Plasma Physics, 39(1999)89. [4] V.Ya.Temovoi, A.S. Filimonov, V.E.Fortov et al. Proc. XXXVI EHPRG Meeting, Catania, Italy (1998). [5] V.K.Gryaznov, M.V.Zhernokletov et al. Zh. Exp. Teor. Fiz. (Soviet JETP) 78(1980) 573. [6] V.Ebeling, A.Foerster, V.Fortov et al. Thermodynamical Properties of Hot Dense Plasmas, Teubner Verlaggeselschaft , Berlin-Stuttgart, 1991.

Women in Physics.

ERIC Educational Resources Information Center

Roth, Laura M.; O'Fallon, Nancy M.

This booklet presents information about career opportunities for women in physics. Included are summaries of research areas in physics (optical physics, solid-state physics, materials science, nuclear physics, high-energy physics, astrophysics, cryogenics, plasma physics, biophysics, atmospheric physics) and differences between theory and…

Investigation of Singly Ionized Iodine Spectroscopy in Support of Electrostatic Propulsion Diagnostics Development

DTIC Science & Technology

2012-07-02

from complex user interactions due to the use of liquid lasing medium with finite lifetime. Solid state lasers such as titanium sapphire (Ti:Sapphire...transitions for laser -induced fluorescence of an accelerated atomic iodine singly charged ion (I+). While the second spectrum of iodine has been analyzed...diagnostics tools, such as laser -induced fluorescence (LIF), to examine the plasma acceleration within an electro-static plasma propulsion thruster. While

Computational study of hot electron generation and energy transport in intense laser produced hot dense matter

NASA Astrophysics Data System (ADS)

Mishra, Rohini

Present ultra high power lasers are capable of producing high energy density (HED) plasmas, in controlled way, with a density greater than solid density and at a high temperature of keV (1 keV ˜ 11,000,000° K). Matter in such extreme states is particularly interesting for (HED) physics such as laboratory studies of planetary and stellar astrophysics, laser fusion research, pulsed neutron source etc. To date however, the physics in HED plasma, especially, the energy transport, which is crucial to realize applications, has not been understood well. Intense laser produced plasmas are complex systems involving two widely distinct temperature distributions and are difficult to model by a single approach. Both kinetic and collisional process are equally important to understand an entire process of laser-solid interaction. By implementing atomic physics models, such as collision, ionization, and radiation damping, self consistently, in state-of-the-art particle-in-cell code (PICLS) has enabled to explore the physics involved in the HED plasmas. Laser absorption, hot electron transport, and isochoric heating physics in laser produced hot dense plasmas are studied with a help of PICLS simulations. In particular, a novel mode of electron acceleration, namely DC-ponderomotive acceleration, is identified in the super intense laser regime which plays an important role in the coupling of laser energy to a dense plasma. Geometric effects on hot electron transport and target heating processes are examined in the reduced mass target experiments. Further, pertinent to fast ignition, laser accelerated fast electron divergence and transport in the experiments using warm dense matter (low temperature plasma) is characterized and explained.

Kinetic Modeling of Ultraintense X-Ray Laser-Matter Interactions

NASA Astrophysics Data System (ADS)

Royle, Ryan; Sentoku, Yasuhiko; Mancini, Roberto; Johzaki, Tomoyuki

2015-11-01

High-intensity XFELs have become a novel way of creating and studying hot dense plasmas. The LCLS at Stanford can deliver a millijoule of energy with more than 1012 photons in a ~ 100 femtosecond pulse. By tightly focusing the beam to a micron-scale spot size, the XFEL can be intensified to more than 1018 W/cm2, making it possible to heat solid matter isochorically beyond a million degrees (>100 eV). Such extreme states of matter are of considerable interest due to their relevance to astrophysical plasmas. Additionally, they will allow novel ways of studying equation-of-state and opacity physics under Gbar pressure and strong fields. Photoionization is the dominant x-ray absorption mechanism and triggers the heating processes. A photoionization model that takes into account the subshell cross-sections has been developed in a kinetic plasma simulation code, PICLS, that solves the x-ray transport self-consistently. The XFEL-matter interaction with several elements, including solid carbon, aluminum, and iron, is studied with the code, and the results are compared with recent LCLS experiments. This work was supported by the DOE/OFES under Contract No. DE-SC0008827.

Repetitively Pulsed High Power RF Solid-State System

NASA Astrophysics Data System (ADS)

Bowman, Chris; Ziemba, Timothy; Miller, Kenneth E.; Prager, James; Quinley, Morgan

2017-10-01

Eagle Harbor Technologies, Inc. (EHT) is developing a low-cost, fully solid-state architecture for the generation of the RF frequencies and power levels necessary for plasma heating and diagnostic systems at validation platform experiments within the fusion science community. In Year 1 of this program, EHT has developed a solid-state RF system that combines an inductive adder, nonlinear transmission line (NLTL), and antenna into a single system that can be deployed at fusion science experiments. EHT has designed and optimized a lumped-element NLTL that will be suitable RF generation near the lower-hybrid frequency at the High Beta Tokamak (HBT) located at Columbia University. In Year 2, EHT will test this system at the Helicity Injected Torus at the University of Washington and HBT at Columbia. EHT will present results from Year 1 testing and optimization of the NLTL-based RF system. With support of DOE SBIR.

Spent nuclear fuel recycling with plasma reduction and etching

DOEpatents

Kim, Yong Ho

2012-06-05

A method of extracting uranium from spent nuclear fuel (SNF) particles is disclosed. Spent nuclear fuel (SNF) (containing oxides of uranium, oxides of fission products (FP) and oxides of transuranic (TRU) elements (including plutonium)) are subjected to a hydrogen plasma and a fluorine plasma. The hydrogen plasma reduces the uranium and plutonium oxides from their oxide state. The fluorine plasma etches the SNF metals to form UF₆ and PuF₄. During subjection of the SNF particles to the fluorine plasma, the temperature is maintained in the range of 1200-2000 deg K to: a) allow any PuF₆ (gas) that is formed to decompose back to PuF₄ (solid), and b) to maintain stability of the UF₆. Uranium (in the form of gaseous UF₆) is easily extracted and separated from the plutonium (in the form of solid PuF₄). The use of plasmas instead of high temperature reactors or flames mitigates the high temperature corrosive atmosphere and the production of PuF₆ (as a final product). Use of plasmas provide faster reaction rates, greater control over the individual electron and ion temperatures, and allow the use of CF₄ or NF₃ as the fluorine sources instead of F₂ or HF.

Gas-phase detection of solid-state fission product complexes for post-detonation nuclear forensic analysis

DOE PAGES

Stratz, S. Adam; Jones, Steven A.; Oldham, Colton J.; ...

2016-06-27

This study presents the first known detection of fission products commonly found in post-detonation nuclear debris samples using solid sample introduction and a uniquely coupled gas chromatography inductively-coupled plasma time-of-flight mass spectrometer. Rare earth oxides were chemically altered to incorporate a ligand that enhances the volatility of the samples. These samples were injected (as solids) into the aforementioned instrument and detected for the first time. Repeatable results indicate the validity of the methodology, and this capability, when refined, will prove to be a valuable asset for rapid post-detonation nuclear forensic analysis.

Gas-phase detection of solid-state fission product complexes for post-detonation nuclear forensic analysis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stratz, S. Adam; Jones, Steven A.; Oldham, Colton J.

This study presents the first known detection of fission products commonly found in post-detonation nuclear debris samples using solid sample introduction and a uniquely coupled gas chromatography inductively-coupled plasma time-of-flight mass spectrometer. Rare earth oxides were chemically altered to incorporate a ligand that enhances the volatility of the samples. These samples were injected (as solids) into the aforementioned instrument and detected for the first time. Repeatable results indicate the validity of the methodology, and this capability, when refined, will prove to be a valuable asset for rapid post-detonation nuclear forensic analysis.

Highly Sensitive and Wide-Band Tunable Terahertz Response of Plasma Waves Based on Graphene Field Effect Transistors

PubMed Central

Wang, Lin; Chen, Xiaoshuang; Yu, Anqi; Zhang, Yang; Ding, Jiayi; Lu, Wei

2014-01-01

Terahertz (THz) technology is becoming a spotlight of scientific interest due to its promising myriad applications including imaging, spectroscopy, industry control and communication. However, one of the major bottlenecks for advancing this field is due to lack of well-developed solid-state sources and detectors operating at THz gap which serves to mark the boundary between electronics and photonics. Here, we demonstrate exceptionally wide tunable terahertz plasma-wave excitation can be realized in the channel of micrometer-level graphene field effect transistors (FET). Owing to the intrinsic high propagation velocity of plasma waves (>~108 cm/s) and Dirac band structure, the plasma-wave graphene-FETs yield promising prospects for fast sensing, THz detection, etc. The results indicate that the multiple guide-wave resonances in the graphene sheets can lead to the deep sub-wavelength confinement of terahertz wave and with Q-factor orders of magnitude higher than that of conventional 2DEG system at room temperature. Rooted in this understanding, the performance trade-off among signal attenuation, broadband operation, on-chip integrability can be avoided in future THz smart photonic network system by merging photonics and electronics. The unique properties presented can open up the exciting routes to compact solid state tunable THz detectors, filters, and wide band subwavelength imaging based on the graphene-FETs. PMID:24969065

10 CFR Appendix A to Part 605 - The Energy Research Program Office Descriptions

Code of Federal Regulations, 2010 CFR

2010-01-01

... inorganic chemistry; chemical physics; atomic physics; photochemistry; radiation chemistry; thermodynamics... is comprised of the subfields metallurgy, ceramics, solid state physics, materials chemistry, and... listed below. (a) Applied Plasma Physics (APP) This Division seeks to develop that body of physics...

Effects of the Physical Characteristics of Cerium Oxide on Plasma-Enhanced Tetraethylorthosiliate Removal Rate of Chemical Mechanical Polishing for Shallow Trench Isolation

NASA Astrophysics Data System (ADS)

Kim, Sang-Kyun; Paik, Ungyu; Oh, Seong-Geun; Park, Yong-Kook; Katoh, Takeo; Park, Jea-Gun

2003-03-01

Ceria powders were synthesized by two different methods, solid-state displacement reaction and wet chemical precipitation, and the influence of the physical characteristics of cerium oxide on the removal rate of plasma-enhanced tetraethylorthosilicate (PETEOS) and chemical vapor deposition (CVD) nitride films in chemical mechanical planarization (CMP) was investigated. The fundamental physicochemical property and electrokinetic behavior of ceria particles in aqueous suspending media were investigated to identify the correlation between the colloidal property of ceria and the CMP performance. The surface potentials of two different ceria particles are found to have different isoelectric point (pHiep) values and differences in physical properties of ceria particles such as porosity and density were found to be the key parameters in CMP of PETEOS films. Ceria powders synthesized by the solid-state displacement reaction method yielded a higher removal rate of PETEOS and higher selectivity than powders synthesized by the wet chemical precipitation method.

On fast solid-body rotation of the solar core and differential (liquid-like) rotation of the solar surface

NASA Astrophysics Data System (ADS)

Pashitskii, E. A.

2017-07-01

On the basis of a two-component (two-fluid) hydrodynamic model, it is shown that the probable phenomenon of solar core rotation with a velocity higher than the average velocity of global rotation of the Sun, discovered by the SOHO mission, can be related to fast solid-body rotation of the light hydrogen component of the solar plasma, which is caused by thermonuclear fusion of hydrogen into helium inside the hot dense solar core. Thermonuclear fusion of four protons into a helium nucleus (α-particle) creates a large free specific volume per unit particle due to the large difference between the densities of the solar plasma and nuclear matter. As a result, an efficient volumetric sink of one of the components of the solar substance—hydrogen—forms inside the solar core. Therefore, a steady-state radial proton flux converging to the center should exist inside the Sun, which maintains a constant concentration of hydrogen as it burns out in the solar core. It is demonstrated that such a converging flux of hydrogen plasma with the radial velocity v r ( r) = -β r creates a convective, v r ∂ v φ/∂ r, and a local Coriolis, v r v φ/ r,φ nonlinear hydrodynamic forces in the solar plasma, rotating with the azimuthal velocity v φ. In the absence of dissipation, these forces should cause an exponential growth of the solid-body rotation velocity of the hydrogen component inside the solar core. However, friction between the hydrogen and helium components of the solar plasma due to Coulomb collisions of protons with α-particles results in a steady-state regime of rotation of the hydrogen component in the solar core with an angular velocity substantially exceeding the global rotational velocity of the Sun. It is suggested that the observed differential (liquid-like) rotation of the visible surface of the Sun (photosphere) with the maximum angular velocity at the equator is caused by sold-body rotation of the solar plasma in the radiation zone and strong turbulence in the tachocline layer, where the turbulent viscosity reaches its maximum value at the equator. There, the tachocline layer exerts the most efficient drag on the less dense outer layers of the solar plasma, which are slowed down due to the interaction with the ambient space plasma (solar wind).

QCL seeded, ns-pulse, multi-line, CO2 laser oscillator for laser-produced-plasma extreme-UV source

NASA Astrophysics Data System (ADS)

Nowak, Krzysztof Michał; Suganuma, Takashi; Kurosawa, Yoshiaki; Ohta, Takeshi; Kawasuji, Yasufumi; Nakarai, Hiroaki; Saitou, Takashi; Fujimoto, Junichi; Mizoguchi, Hakaru; Sumitani, Akira; Endo, Akira

2017-01-01

Successful merger of state-of-the-art, semiconductor quantum-cascade lasers (QCL), with the mature CO2 laser technology, resulted in a delivery of highly-desired qualities of CO2 laser output that were not available previously without much effort. These qualities, such as multi-line operation, excellent spectro-temporal stability and pulse waveform control, became available from a single device of moderate complexity. This paper describes the operation principle and the unique properties of the solid{state seeded CO2 laser, invented for an application in laser-produced-plasma (LPP), extreme-UV (EUV) light source.

Reference hematologic and plasma chemistry values of brown tree snakes (Boiga irregularis).

PubMed

Lamirande, E W; Bratthauer, A D; Fischer, D C; Nichols, D K

1999-12-01

Reference hematologic and plasma chemistry values were determined from 103 blood samples collected from 53 clinically healthy brown tree snakes (Boiga irregularis). Female snakes had significantly higher mean plasma values for total solids, total protein, calcium (Ca), phosphorus (P), uric acid, and blood monocyte percentage than did males, whereas males had significantly higher mean plasma fibrinogen values. The variances for hematocrit, monocyte percentage, azurophil percentage, plasma total solids, plasma total protein, albumin, Ca, and P also differed significantly between sexes. The higher mean values and greater variances for plasma total protein, plasma total solids, Ca, and P in the female snakes were probably associated with yolk synthesis and accumulation.

Physics in the Twentieth Century

ERIC Educational Resources Information Center

Weisskopf, Victor F.

1970-01-01

Provides a review of the great discoveries, theoretical concepts and development of physics in the 20th century. The growth and significance of diverse fields such as quantum theory, relativity theory, atomic physics, molecular physics, the physics of the solid state, nuclear physics, astrophysics, plasma physics, and particle physics are…

Optical spectroscopy of laser-produced plasmas for standoff isotopic analysis

NASA Astrophysics Data System (ADS)

Harilal, S. S.; Brumfield, B. E.; LaHaye, N. L.; Hartig, K. C.; Phillips, M. C.

2018-06-01

Rapid, in-field, and non-contact isotopic analysis of solid materials is extremely important to a large number of applications, such as nuclear nonproliferation monitoring and forensics, geochemistry, archaeology, and biochemistry. Presently, isotopic measurements for these and many other fields are performed in laboratory settings. Rapid, in-field, and non-contact isotopic analysis of solid material is possible with optical spectroscopy tools when combined with laser ablation. Laser ablation generates a transient vapor of any solid material when a powerful laser interacts with a sample of interest. Analysis of atoms, ions, and molecules in a laser-produced plasma using optical spectroscopy tools can provide isotopic information with the advantages of real-time analysis, standoff capability, and no sample preparation requirement. Both emission and absorption spectroscopy methods can be used for isotopic analysis of solid materials. However, applying optical spectroscopy to the measurement of isotope ratios from solid materials presents numerous challenges. Isotope shifts arise primarily due to variation in nuclear charge distribution caused by different numbers of neutrons, but the small proportional nuclear mass differences between nuclei of various isotopes lead to correspondingly small differences in optical transition wavelengths. Along with this, various line broadening mechanisms in laser-produced plasmas and instrumental broadening generated by the detection system are technical challenges frequently encountered with emission-based optical diagnostics. These challenges can be overcome by measuring the isotope shifts associated with the vibronic emission bands from molecules or by using the techniques of laser-based absorption/fluorescence spectroscopy to marginalize the effect of instrumental broadening. Absorption and fluorescence spectroscopy probe the ground state atoms existing in the plasma when it is cooler, which inherently provides narrower lineshapes, as opposed to emission spectroscopy which requires higher plasma temperatures to be able to detect thermally excited emission. Improvements in laser and detection systems and spectroscopic techniques have allowed for isotopic measurements to be carried out at standoff distances under ambient atmospheric conditions, which have expanded the applicability of optical spectroscopy-based isotopic measurements to a variety of scientific fields. These technological advances offer an in-situ measurement capability that was previously not available. This review will focus on isotope detection through emission, absorption, and fluorescence spectroscopy of atoms and molecules in a laser-produced plasma formed from a solid sample. A description of the physics behind isotope shifts in atoms and molecules is presented, followed by the physics behind solid sampling of laser ablation plumes, optical methods for isotope measurements, the suitable physical conditions of laser-produced plasma plumes for isotopic analysis, and the current status. Finally, concluding remarks will be made on the existing knowledge/technological gaps identified from the current literature and suggestions for the future work.

Pulsed plasma solid propellant microthruster for the synchronous meteorological satellite. Task 4: Engineering model fabrication and test report

NASA Technical Reports Server (NTRS)

Guman, W. J. (Editor)

1972-01-01

Two flight prototype solid propellant pulsed plasma microthruster propulsion systems for the SMS satellite were fabricated, assembled and tested. The propulsion system is a completely self contained system requiring only three electrical inputs to operate: a 29.4 volt power source, a 28 volt enable signal and a 50 millsec long command fire signal that can be applied at any rate from 50 ppm to 110 ppm. The thrust level can be varied over a range 2.2 to 1 at constant impulse bit amplitude. By controlling the duration of the 28 volt enable either steady state thrust or a series of discrete impulse bits can be generated. A new technique of capacitor charging was implemented to reduce high voltage stress on energy storage capacitors.

Diagnostic Tools for Plasma Wind Tunnels and Reentry Vehicles at the IRS

DTIC Science & Technology

2000-04-01

activ n e pronte . pwindkanal", Dissertation, Universittit Stuttgart, 1998. A mass spectrometer probe can be used with low [A.9] Auweter-Kurtz, M., Laure...obtained ffrom experiments at a plasma state with a mass flowFig. B2.28: RtooOISobandfrom dintensities in a 3D -view rate of 2 g/s air and an ambient...spectrometer work is based on the estimations either in solid food stuffs or organic chopped-light (AC) principle which is illustrated in materials ( e.g

Scattering of Microwaves by Steady-State Plasma Slabs, Columns, and Layers at Atmospheric Pressure

DTIC Science & Technology

1998-03-01

permeability unity is- (Fig 0) SÖ$ftS?S5 Pressure Plasmas Y=J7(er) . 2071 (1) where y is the complex propagation coefficient, w is the wave...a phase dependence expjtot-Yxl to a i„ ., permeability nnTty,^ J ’°SSy med’Um °f reIat<- ■j^r)^ • (1) where y is the complex propagation...preservation is an. issue. Some examples are food (solid or liquid) sterilization, pharmaceutical applications, and environmental applications ( soil

Point Source X-Ray Lithography System for Sub-0.15 Micron Design Rules

DTIC Science & Technology

1998-05-22

consist of a SAL developed stepper, an SRL developed Dense Plasma Focus , (DPF), X-Ray source, and a CXrL developed beam line. The system will be...existing machine that used spark gap switching, SRL has developed an all solid state driver and improved head electrode assembly for their dense plasma ... focus X-Ray source. Likewise, SAL has used their existing Model 4 stepper installed at CXrL as a design starting point, and has developed an advanced

The Structure and Properties of Plasma Sprayed Iron Oxide Doped Manganese Cobalt Oxide Spinel Coatings for SOFC Metallic Interconnectors

NASA Astrophysics Data System (ADS)

Puranen, Jouni; Lagerbom, Juha; Hyvärinen, Leo; Kylmälahti, Mikko; Himanen, Olli; Pihlatie, Mikko; Kiviaho, Jari; Vuoristo, Petri

2011-01-01

Manganese cobalt oxide spinel doped with Fe2O3 was studied as a protective coating on ferritic stainless steel interconnects. Chromium alloying causes problems at high operation temperatures in such oxidizing conditions where chromium compounds evaporate and poison the cathode active area, causing the degradation of the solid oxide fuel cell. In order to prevent chromium evaporation, these interconnectors need a protective coating to block the chromium evaporation and to maintain an adequate electrical conductivity. Thermal spraying is regarded as a promising way to produce dense and protective layers. In the present work, the ceramic Mn-Co-Fe oxide spinel coatings were produced by using the atmospheric plasma spray process. Coatings with low thickness and low amount of porosity were produced by optimizing deposition conditions. The original spinel structure decomposed because of the fast transformation of solid-liquid-solid states but was partially restored by using post-annealing treatment.

An ultra-high gain and efficient amplifier based on Raman amplification in plasma

DOE Office of Scientific and Technical Information (OSTI.GOV)

Vieux, G.; Cipiccia, S.; Grant, D. W.

Raman amplification arising from the excitation of a density echelon in plasma could lead to amplifiers that significantly exceed current power limits of conventional laser media. Here we show that 1–100 J pump pulses can amplify picojoule seed pulses to nearly joule level. The extremely high gain also leads to significant amplification of backscattered radiation from “noise”, arising from stochastic plasma fluctuations that competes with externally injected seed pulses, which are amplified to similar levels at the highest pump energies. The pump energy is scattered into the seed at an oblique angle with 14 J sr -1, and net gainsmore » of more than eight orders of magnitude. The maximum gain coefficient, of 180 cm -1, exceeds high-power solid-state amplifying media by orders of magnitude. The observation of a minimum of 640 J sr -1 directly backscattered from noise, corresponding to ≈10% of the pump energy in the observation solid angle, implies potential overall efficiencies greater than 10%.« less

An ultra-high gain and efficient amplifier based on Raman amplification in plasma

DOE PAGES

Vieux, G.; Cipiccia, S.; Grant, D. W.; ...

2017-05-25

Raman amplification arising from the excitation of a density echelon in plasma could lead to amplifiers that significantly exceed current power limits of conventional laser media. Here we show that 1–100 J pump pulses can amplify picojoule seed pulses to nearly joule level. The extremely high gain also leads to significant amplification of backscattered radiation from “noise”, arising from stochastic plasma fluctuations that competes with externally injected seed pulses, which are amplified to similar levels at the highest pump energies. The pump energy is scattered into the seed at an oblique angle with 14 J sr -1, and net gainsmore » of more than eight orders of magnitude. The maximum gain coefficient, of 180 cm -1, exceeds high-power solid-state amplifying media by orders of magnitude. The observation of a minimum of 640 J sr -1 directly backscattered from noise, corresponding to ≈10% of the pump energy in the observation solid angle, implies potential overall efficiencies greater than 10%.« less

Extending laser plasma accelerators into the mid-IR spectral domain with a next-generation ultra-fast CO 2 laser

DOE PAGES

Pogorelsky, I. V.; Babzien, M.; Ben-Zvi, I.; ...

2016-01-20

Here we discuss how expanding the scope of relativistic plasma research to wavelengths longer than λ/≈0.8₋1.1μm covered by conventional mode-locked solid-state lasers would offer attractive opportunities due to the quadratic scaling of the ponderomotive electron energy and critical plasma density with λ. Answering this quest, a next-generation mid-IR laser project is being advanced at the BNL ATF as a part of the user facility upgrade. We discuss the technical approach to this conceptually new 100 TW, 100 fs, λ=9₋11 μm CO 2 laser BESTIA (Brookhaven Experimental Supra-Terawatt Infrared at ATF) that encompasses several innovations applied for the first time tomore » molecular gas lasers. BESTIA will enable new regimes of laser plasma accelerators. One for example is shock-wave ion acceleration from gas jets. We review ongoing efforts to achieve stable, monoenergetic proton acceleration by dynamically shaping the plasma density profile from a hydrogen gas target with laser-produced blast waves. At its full power, 100 TW BESTIA promises to achieve proton beams at energy exceeding 200 MeV. In addition to ion acceleration in over-critical plasma, the ultra-intense mid-IR laser BESTIA will open new opportunities in driving wakefields in tenuous plasmas, expanding the landscape of Laser Wake Field Accelerator (LWFA) studies into unexplored long-wavelength spectral domain. Simple wavelength scaling suggests that a 100-TW CO2 laser beam will be capable to efficiently generate plasma “bubbles” thousand times bigger in volume compared to a near-IR solid state laser of an equivalent power. Combined with a femtosecond electron linac available at the ATF, this wavelength scaling will facilitate study of external seeding and staging of LWFA.« less

Local thermodynamic equilibrium in a laser-induced plasma evidenced by blackbody radiation

NASA Astrophysics Data System (ADS)

Hermann, Jörg; Grojo, David; Axente, Emanuel; Craciun, Valentin

2018-06-01

We show that the plasma produced by laser ablation of solid materials in specific conditions has an emission spectrum that is characterized by the saturation of the most intense spectral lines at the blackbody radiance. The blackbody temperature equals the excitation temperature of atoms and ions, proving directly and unambiguously a plasma in local thermodynamic equilibrium. The present investigations take benefit from the very rich and intense emission spectrum generated by ablation of a nickel-chromium-molybdenum alloy. This alternative and direct proof of the plasma equilibrium state re-opens the perspectives of quantitative material analyses via calibration-free laser-induced breakdown spectroscopy. Moreover, the unique properties of this laser-produced plasma promote its use as radiation standard for intensity calibration of spectroscopic instruments.

Physics: A Career for You?

ERIC Educational Resources Information Center

American Inst. of Physics, New York, NY.

Information is provided for students who may be interested in pursuing a career in physics. This information includes the type of work done and areas studied by physicists in the following areas: nuclear physics, solid-state physics, elementary-particle physics, atomic/molecular/electron physics, fluid/plasma physics, space/planetary physics,…

Dynamics of bulk electron heating and ionization in solid density plasmas driven by ultra-short relativistic laser pulses

DOE Office of Scientific and Technical Information (OSTI.GOV)

Huang, L. G., E-mail: lingen.huang@hzdr.de; Kluge, T.; Cowan, T. E.

The dynamics of bulk heating and ionization is investigated both in simulations and theory, which determines the crucial plasma parameters such as plasma temperature and density in ultra-short relativistic laser-solid target interactions. During laser-plasma interactions, the solid density plasma absorbs a fraction of laser energy and converts it into kinetic energy of electrons. A portion of the electrons with relativistic kinetic energy goes through the solid density plasma and transfers energy into the bulk electrons, which results in bulk electron heating. The bulk electron heating is finally translated into the processes of bulk collisional ionization inside the solid target. Amore » simple model based on the Ohmic heating mechanism indicates that the local and temporal profile of bulk return current is essential to determine the temporal evolution of bulk electron temperature. A series of particle-in-cell simulations showing the local heating model is robust in the cases of target with a preplasma and without a preplasma. Predicting the bulk electron heating is then benefit for understanding the collisional ionization dynamics inside the solid targets. The connection of the heating and ionization inside the solid target is further studied using Thomas-Fermi model.« less

Innovative design and material solutions of thermal contact layers for high heat flux applications in fusion devices

DOE Office of Scientific and Technical Information (OSTI.GOV)

Federici, G.; Matera, R.; Chiocchio, S.

1994-11-01

One difficulty associated with the design and development of sacrificial plasma facing components that have to handle the high heat and particle fluxes in ITER is achieving the necessary contact conductance between the plasma protection material and the high-conductivity substrate in contact with the coolant. This paper presents a novel bond idea which is proposed as one of the options for the sacrificial energy dump targets located at the bottom of the divertor legs. The bonded joint in this design concept provides thermal and electrical contact between the armour and the cooled sub-structure while promoting remote, in-situ maintenance repair andmore » an easy replaceability of the armour part without disturbing the cooling pipes or rewelding neutron irradiated materials. To provide reliable and demountable adhesion, the bond consists of a metal alloy, treated in the semi-solid phase so that it leads to a fine dispersion of a globular solid phase into a liquid matrix (rheocast process). This thermal bond layer would normally operate in the solid state but could be brought reversibly to the semi-solid state during the armour replacement simply by heating it slightly above its solidus temperature. Material and design options are discussed in this paper. Possible methods of installation and removal are described, and lifetime considerations are addressed. In order to validate this concept within the ITER time-frame, a R&D programme must be rapidly implemented.« less

Plasma shape control by pulsed solenoid on laser ion source

NASA Astrophysics Data System (ADS)

Sekine, M.; Ikeda, S.; Romanelli, M.; Kumaki, M.; Fuwa, Y.; Kanesue, T.; Hayashizaki, N.; Lambiase, R.; Okamura, M.

2015-09-01

A Laser ion source (LIS) provides high current heavy ion beams with a very simple mechanical structure. Plasma is produced by a pulsed laser ablation of a solid state target and ions are extracted by an electric field. However, it was difficult to manipulate the beam parameters of a LIS, since the plasma condition could only be adjusted by the laser irradiation condition. To enhance flexibility of LIS operation, we employed a pulsed solenoid in the plasma drift section and investigated the effect of the solenoid field on singly charged iron beams. The experimentally obtained current profile was satisfactorily controlled by the pulsed magnetic field. This approach may also be useful to reduce beam emittance of a LIS.

Laser Irradiated Foam Targets: Absorption and Radiative Properties

NASA Astrophysics Data System (ADS)

Salvadori, Martina; Luigi Andreoli, Pier; Cipriani, Mattia; Consoli, Fabrizio; Cristofari, Giuseppe; De Angelis, Riccardo; di Giorgio, Giorgio; Giulietti, Danilo; Ingenito, Francesco; Gus'kov, Sergey Yu.; Rupasov, Alexander A.

2018-01-01

An experimental campaign to characterize the laser radiation absorption of foam targets and the subsequent emission of radiation from the produced plasma was carried out in the ABC facility of the ENEA Research Center in Frascati (Rome). Different targets have been used: plastic in solid or foam state and aluminum targets. The activated different diagnostics allowed to evaluate the plasma temperature, the density distribution, the fast particle spectrum and the yield of the X-Ray radiation emitted by the plasma for the different targets. These results confirm the foam homogenization action on laser-plasma interaction, mainly attributable to the volume absorption of the laser radiation propagating in such structured materials. These results were compared with simulation absorption models of the laser propagating into a foam target.

Plasma shape control by pulsed solenoid on laser ion source

DOE PAGES

Sekine, M.; Ikeda, S.; Romanelli, M.; ...

2015-05-28

A Laser ion source (LIS) provides high current heavy ion beams with a very simple mechanical structure. Plasma is produced by a pulsed laser ablation of a solid state target and ions are extracted by an electric field. It was difficult to manipulate the beam parameters of a LIS, since the plasma condition could only be adjusted by the laser irradiation condition. To enhance flexibility of LIS operation, we employed a pulsed solenoid in the plasma drift section and investigated the effect of the solenoid field on singly charged iron beams. The experimentally obtained current profile was satisfactorily controlled bymore » the pulsed magnetic field. Thus, this approach may also be useful to reduce beam emittance of a LIS.« less

Decomposition of poly(amide-imide) film enameled on solid copper wire using atmospheric pressure non-equilibrium plasma.

PubMed

Sugiyama, Kazuo; Suzuki, Katsunori; Kuwasima, Shusuke; Aoki, Yosuke; Yajima, Tatsuhiko

2009-01-01

The decomposition of a poly(amide-imide) thin film coated on a solid copper wire was attempted using atmospheric pressure non-equilibrium plasma. The plasma was produced by applying microwave power to an electrically conductive material in a gas mixture of argon, oxygen, and hydrogen. The poly(amide-imide) thin film was easily decomposed by argon-oxygen mixed gas plasma and an oxidized copper surface was obtained. The reduction of the oxidized surface with argon-hydrogen mixed gas plasma rapidly yielded a metallic copper surface. A continuous plasma heat-treatment process using a combination of both the argon-oxygen plasma and argon-hydrogen plasma was found to be suitable for the decomposition of the poly(amide-imide) thin film coated on the solid copper wire.

Spark Plasma Sintering As a Solid-State Recycling Technique: The Case of Aluminum Alloy Scrap Consolidation

PubMed Central

Paraskevas, Dimos; Vanmeensel, Kim; Vleugels, Jef; Dewulf, Wim; Deng, Yelin; Duflou, Joost R.

2014-01-01

Recently, “meltless” recycling techniques have been presented for the light metals category, targeting both energy and material savings by bypassing the final recycling step of remelting. In this context, the use of spark plasma sintering (SPS) is proposed in this paper as a novel solid-state recycling technique. The objective is two-fold: (I) to prove the technical feasibility of this approach; and (II) to characterize the recycled samples. Aluminum (Al) alloy scrap was selected to demonstrate the SPS effectiveness in producing fully-dense samples. For this purpose, Al alloy scrap in the form of machining chips was cold pre-compacted and sintered bellow the solidus temperature at 490 °C, under elevated pressure of 200 MPa. The dynamic scrap compaction, combined with electric current-based joule heating, achieved partial fracture of the stable surface oxides, desorption of the entrapped gases and activated the metallic surfaces, resulting in efficient solid-state chip welding eliminating residual porosity. The microhardness, the texture, the mechanical properties, the microstructure and the density of the recycled specimens have been investigated. An X-ray computed tomography (CT) analysis confirmed the density measurements, revealing a void-less bulk material with homogeneously distributed intermetallic compounds and oxides. The oxide content of the chips incorporated within the recycled material slightly increases its elastic properties. Finally, a thermal distribution simulation of the process in different segments illustrates the improved energy efficiency of this approach. PMID:28788153

Spark Plasma Sintering As a Solid-State Recycling Technique: The Case of Aluminum Alloy Scrap Consolidation.

PubMed

Paraskevas, Dimos; Vanmeensel, Kim; Vleugels, Jef; Dewulf, Wim; Deng, Yelin; Duflou, Joost R

2014-08-06

Recently, "meltless" recycling techniques have been presented for the light metals category, targeting both energy and material savings by bypassing the final recycling step of remelting. In this context, the use of spark plasma sintering (SPS) is proposed in this paper as a novel solid-state recycling technique. The objective is two-fold: (I) to prove the technical feasibility of this approach; and (II) to characterize the recycled samples. Aluminum (Al) alloy scrap was selected to demonstrate the SPS effectiveness in producing fully-dense samples. For this purpose, Al alloy scrap in the form of machining chips was cold pre-compacted and sintered bellow the solidus temperature at 490 °C, under elevated pressure of 200 MPa. The dynamic scrap compaction, combined with electric current-based joule heating, achieved partial fracture of the stable surface oxides, desorption of the entrapped gases and activated the metallic surfaces, resulting in efficient solid-state chip welding eliminating residual porosity. The microhardness, the texture, the mechanical properties, the microstructure and the density of the recycled specimens have been investigated. An X-ray computed tomography (CT) analysis confirmed the density measurements, revealing a void-less bulk material with homogeneously distributed intermetallic compounds and oxides. The oxide content of the chips incorporated within the recycled material slightly increases its elastic properties. Finally, a thermal distribution simulation of the process in different segments illustrates the improved energy efficiency of this approach.

Generation of shock waves and formation of craters in a solid material irradiated by a short laser pulse

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gus'kov, Sergei Yu; Borodziuk, S; Kasperczuk, A

2004-11-30

The results of investigations are presented which are concerned with laser radiation absorption in a target, the plasma state of its ablated material, the energy transfer to the solid target material, the characteristics of the shock wave and craters on the target surface. The investigation involved irradiation of a planar target by a subnanosecond plasma-producing laser pulse. The experiments were carried out with massive aluminium targets using the PALS iodine laser, whose pulse duration (0.4 ns) was much shorter than the shock wave attenuation and on-target crater formation times (50-200 ns). The investigations were conducted for a laser radiation energymore » of 100 J at two wavelengths of 0.438 and 1.315 {mu}m. For a given pulse energy, the irradiation intensity was varied in a broad range (10{sup 13}-10{sup 16} W cm{sup -2}) by varying the radius of the laser beam. The efficiency of laser radiation-to-shock energy transfer was determined as a function of the intensity and wavelength of laser radiation; also determined were the characteristics of the plasma plume and the shock wave propagating in the solid target, including the experimental conditions under which two-dimensional effects are highly significant. (invited paper)« less

Plasma Processing of Model Residential Solid Waste

NASA Astrophysics Data System (ADS)

Messerle, V. E.; Mossé, A. L.; Nikonchuk, A. N.; Ustimenko, A. B.; Baimuldin, R. V.

2017-09-01

The authors have tested the technology of processing of model residential solid waste. They have developed and created a pilot plasma unit based on a plasma chamber incinerator. The waste processing technology has been tested and prepared for commercialization.

System and process for dissolution of solids

DOEpatents

Liezers, Martin; Farmer, III, Orville T.

2017-10-10

A system and process are disclosed for dissolution of solids and "difficult-to-dissolve" solids. A solid sample may be ablated in an ablation device to generate nanoscale particles. Nanoparticles may then swept into a coupled plasma device operating at atmospheric pressure where the solid nanoparticles are atomized. The plasma exhaust may be delivered directly into an aqueous fluid to form a solution containing the atomized and dissolved solids. The composition of the resulting solution reflects the composition of the original solid sample.

Thermal Stir Welding Development at Marshall Space Flight Center

NASA Technical Reports Server (NTRS)

Ding, Robert J.

2008-01-01

Solid state welding processes have become the focus of welding process development at NASA's Marshall Space Flight Center. Unlike fusion weld processes such as tungsten inert gas (TIG), variable polarity plasma arc (VPPA), electron beam (EB), etc., solid state welding processes do not melt the material during welding. The resultant microstructure can be characterized as a dynamically recrystallized morphology much different than the casted, dentritic structure typical of fusion weld processes. The primary benefits of solid state processes over fusion weld processes include superior mechanic properties and the elimination of thermal distortion and residual stresses. These solid state processes attributes have profoundly influenced the direction of advanced welding research and development within the NASA agency. Thermal Stir Welding (TSW) is a new solid state welding process being developed at the Marshall Space Flight Center. Unlike friction stir welding, the heating, stirring and forging elements of the weld process can be decoupled for independent control. An induction coil induces energy into a workpiece to attain a desired plastic temperature. An independently controlled stir rod, captured within non-rotating containment plates, then stirs the plasticized material followed by forging plates/rollers that work the stirred weld joint. The independent control (decoupling) of heating, stirring and forging allows, theoretically, for the precision control of microstructure morphology. The TSW process is being used to evaluate the solid state joining of Haynes 230 for ARES J-2X applications. It is also being developed for 500-in (12.5 mm) thick commercially pure grade 2 titanium for navy applications. Other interests include Inconel 718 and stainless steel. This presentation will provide metallurgical and mechanical property data for these high melting temperature alloys.

An Overview of Recent PISCES Program PMI Results

NASA Astrophysics Data System (ADS)

Tynan, George; Doerner, Russell; Abe, Shota; Baldwin, Matthew; Barton, Joseph; Chen, Renkun; Gosselin, Jordan; Hollmann, Eric; Nishijima, Daisuke; Simmonds, Michael; Wang, Yong; Yu, Jonathan

2015-11-01

The PISCES Program is focused on fundamental PMI studies of Be and W-based solid plasma facing components under steady-state and transient conditions. We will show results from studies in W, Be and mixed W-Be material systems. Topics of investigation include formation of near-surface nanobubbles from He plasma ion implantation, growth of W-fuzz from these bubbles in steady-state and transient conditions, D retention in Be and W and development of a D-retention model for both H/D isotope exchange and displacement damage experiments. Initial studies of PMI in displacement damaged W are also presented, showing the effect of damage and exposure temperature on D retention, D diffusion, W thermal conductivity. Be-based results include morphology evolution under high plasma flux exposure, Be erosion mechanisms, and retention in Be-based materials. Future plans and connections to fusion energy system requirements will be discussed. This work supported by grant DE-FG02-07ER54912.

Low-velocity ion stopping in a dense and low-temperature plasma target

NASA Astrophysics Data System (ADS)

Deutsch, Claude; Popoff, Romain

2007-07-01

We investigate the stopping specificities involved in the heating of thin foils irradiated by intense ion beams in the 0.3-3 MeV/amu energy range and in close vicinity of the Bragg peak. Considering a swiftly ionized target to eV temperatures before expansion while retaining solid-state density, a typical warm dense matter (WDM) situation thus arises. We stress low Vp stopping through ion diffusion in the given target plasma. This allows to include the case of a strongly magnetized target in a guiding center approximation. We also demonstrate that the ion projectile penetration depth in target is significantly affected by multiple scattering on target electrons. The given plasma target is taken weakly coupled with Maxwell electron either with no magnetic field ( B=0) or strongly magnetized ( B≠0). Dynamical coupling between ion projectiles energy losses and projectiles charge state will also be addressed.

Itraconazole solid dispersion prepared by a supercritical fluid technique: preparation, in vitro characterization, and bioavailability in beagle dogs.

PubMed

Yin, Xuezhi; Daintree, Linda Sharon; Ding, Sheng; Ledger, Daniel Mark; Wang, Bing; Zhao, Wenwen; Qi, Jianping; Wu, Wei; Han, Jiansheng

2015-01-01

This research aimed to develop a supercritical fluid (SCF) technique for preparing a particulate form of itraconazole (ITZ) with good dissolution and bioavailability characteristics. The ITZ particulate solid dispersion was formulated with hydroxypropyl methylcellulose, Pluronic F-127, and L-ascorbic acid. Aggregated particles showed porous structure when examined by scanning electron microscopy. Powder X-ray diffraction and Fourier transform infrared spectra indicated an interaction between ITZ and excipients and showed that ITZ existed in an amorphous state in the composite solid dispersion particles. The solid dispersion obtained by the SCF process improved the dissolution of ITZ in media of pH 1.0, pH 4.5, and pH 6.8, compared with a commercial product (Sporanox(®)), which could be ascribed to the porous aggregated particle shape and amorphous solid state of ITZ. While the solid dispersion did not show a statistical improvement (P=0.50) in terms of oral bioavailability of ITZ compared with Sporanox(®), the C max (the maximum plasma concentration of ITZ in a pharmacokinetic curve) of ITZ was raised significantly (P=0.03) after oral administration. Thus, the SCF process has been shown to be an efficient, single step process to form ITZ-containing solid dispersion particles with good dissolution and oral bioavailability characteristics.

Exciton fission in monolayer transition metal dichalcogenide semiconductors.

PubMed

Steinhoff, A; Florian, M; Rösner, M; Schönhoff, G; Wehling, T O; Jahnke, F

2017-10-27

When electron-hole pairs are excited in a semiconductor, it is a priori not clear if they form a plasma of unbound fermionic particles or a gas of composite bosons called excitons. Usually, the exciton phase is associated with low temperatures. In atomically thin transition metal dichalcogenide semiconductors, excitons are particularly important even at room temperature due to strong Coulomb interaction and a large exciton density of states. Using state-of-the-art many-body theory, we show that the thermodynamic fission-fusion balance of excitons and electron-hole plasma can be efficiently tuned via the dielectric environment as well as charge carrier doping. We propose the observation of these effects by studying exciton satellites in photoemission and tunneling spectroscopy, which present direct solid-state counterparts of high-energy collider experiments on the induced fission of composite particles.

Synthesis of the flavonoid 3',4',5'-trimethoxyflavonol and its determination in plasma and tissues of mice by HPLC with fluorescence detection.

PubMed

Britton, Robert G; Fong, Isabel; Saad, Shaban; Brown, Karen; Steward, William P; Gescher, Andreas; Sale, Stewart

2009-04-01

3',4',5'-Trimethoxyflavonol (TMFol) was synthesized as a potential colorectal cancer chemopreventive agent. An HPLC method for determination for TMFol in murine plasma and tissues was developed and validated using human plasma. Analyte was separated (C(18) column; fluorescence detection 330nm excitation, 440nm emission) using 69% methanol and 0.1M ammonium acetate buffer (pH 5.1) as mobile phase. The method was linear for 50-2500ng/ml plasma and 0.05-10microg/g tissue (r>0.99). TMFol was recovered from plasma or tissues using solid phase columns or organic solvent protein precipitation, respectively. Recovery at low, medium and high concentrations was 97.6-107.3%, with inter- and intra-day coefficients of variation of <10%. The lower limit of quantitation for plasma was 50ng/ml. The method was applied to measure steady-state TMFol plasma and tissue levels in mice which received dietary TMFol (0.2%).

A solid-state nuclear magnetic resonance study of post-plasma reactions in organosilicone microwave plasma-enhanced chemical vapor deposition (PECVD) coatings.

PubMed

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 low TMDSO-to-oxygen ratio had little to no singly substituted moieties, displayed a highly cross-linked structure, and showed less post-plasma reactions. However, these chemically more stable coatings are less compatible mechanically with plastic substrates, because of their high stiffness.

BADGER v1.0: A Fortran equation of state library

NASA Astrophysics Data System (ADS)

Heltemes, T. A.; Moses, G. A.

2012-12-01

The BADGER equation of state library was developed to enable inertial confinement fusion plasma codes to more accurately model plasmas in the high-density, low-temperature regime. The code had the capability to calculate 1- and 2-T plasmas using the Thomas-Fermi model and an individual electron accounting model. Ion equation of state data can be calculated using an ideal gas model or via a quotidian equation of state with scaled binding energies. Electron equation of state data can be calculated via the ideal gas model or with an adaptation of the screened hydrogenic model with ℓ-splitting. The ionization and equation of state calculations can be done in local thermodynamic equilibrium or in a non-LTE mode using a variant of the Busquet equivalent temperature method. The code was written as a stand-alone Fortran library for ease of implementation by external codes. EOS results for aluminum are presented that show good agreement with the SESAME library and ionization calculations show good agreement with the FLYCHK code. Program summaryProgram title: BADGERLIB v1.0 Catalogue identifier: AEND_v1_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEND_v1_0.html Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.html No. of lines in distributed program, including test data, etc.: 41 480 No. of bytes in distributed program, including test data, etc.: 2 904 451 Distribution format: tar.gz Programming language: Fortran 90. Computer: 32- or 64-bit PC, or Mac. Operating system: Windows, Linux, MacOS X. RAM: 249.496 kB plus 195.630 kB per isotope record in memory Classification: 19.1, 19.7. Nature of problem: Equation of State (EOS) calculations are necessary for the accurate simulation of high energy density plasmas. Historically, most EOS codes used in these simulations have relied on an ideal gas model. This model is inadequate for low-temperature, high-density plasma conditions; the gaseous and liquid phases; and the solid phase. The BADGER code was developed to give more realistic EOS data in these regimes. Solution method: BADGER has multiple, user-selectable models to treat the ions, average-atom ionization state and electrons. Ion models are ideal gas and quotidian equation of state (QEOS), ionization models are Thomas-Fermi and individual accounting method (IEM) formulation of the screened hydrogenic model (SHM) with l-splitting, electron ionization models are ideal gas and a Helmholtz free energy minimization method derived from the SHM. The default equation of state and ionization models are appropriate for plasmas in local thermodynamic equilibrium (LTE). The code can calculate non-LTE equation of state (EOS) and ionization data using a simplified form of the Busquet equivalent-temperature method. Restrictions: Physical data are only provided for elements Z=1 to Z=86. Multiple solid phases are not currently supported. Liquid, gas and plasma phases are combined into a generalized "fluid" phase. Unusual features: BADGER divorces the calculation of average-atom ionization from the electron equation of state model, allowing the user to select ionization and electron EOS models that are most appropriate to the simulation. The included ion ideal gas model uses ground-state nuclear spin data to differentiate between isotopes of a given element. Running time: Example provided only takes a few seconds to run.

Phase Transformation of Droplets into Particles and Nucleation in Atmospheric Pressure Discharges

NASA Astrophysics Data System (ADS)

Iqbal, M. M.; Stallard, C. P.; Dowling, D. P.; Turner, M. M.

2013-09-01

We investigate the mechanism of phase transformation of liquid precursor droplets into nano-particulates in an atmospheric pressure discharge (APD). This phase transformation is possible when the solid to a liquid mass ratio of slurry droplet reaches a threshold value. The behaviour of phase transformation of a single slurry droplet of HMDSO is described by developing a numerical model under the saturation condition of evaporation. It is observed from the temporal evolution of inner radius (Ri) of a single slurry droplet that its value approaches zero before the entire shifting of a liquid phase and which explains with an expansion in the crust thickness (Ro - Ri) . The solid traces of nano-particles are observed experimentally on the surface coating depositions because the time for transferring the slurry droplet of HMDSO into solid state is amplified with an increment in the radii of droplets and the entire phase transition occurs within residence time for the nano-sized liquid droplets. The GDE coupled with discharge plasma is numerically solved to describe the mechanism of nucleation of nano-sized particles in APD plasma under similar conditions of the experiment. The growth of nucleation in APD plasma depends on the type of liquid precursor, such as HMDSO, TEOS and water, which is verified with a sharp peak in the nucleation rate and saturation ratio. Science Foundation Ireland under Grant No. 08/SRC/I1411.

Hydrogen recovery from the thermal plasma gasification of solid waste.

PubMed

Byun, Youngchul; Cho, Moohyun; Chung, Jae Woo; Namkung, Won; Lee, Hyeon Don; Jang, Sung Duk; Kim, Young-Suk; Lee, Jin-Ho; Lee, Carg-Ro; Hwang, Soon-Mo

2011-06-15

Thermal plasma gasification has been demonstrated as one of the most effective and environmentally friendly methods for solid waste treatment and energy utilization in many of studies. Therefore, the thermal plasma process of solid waste gasification (paper mill waste, 1.2 ton/day) was applied for the recovery of high purity H(2) (>99.99%). Gases emitted from a gasification furnace equipped with a nontransferred thermal plasma torch were purified using a bag-filter and wet scrubber. Thereafter, the gases, which contained syngas (CO+H(2)), were introduced into a H(2) recovery system, consisting largely of a water gas shift (WGS) unit for the conversion of CO to H(2) and a pressure swing adsorption (PSA) unit for the separation and purification of H(2). It was successfully demonstrated that the thermal plasma process of solid waste gasification, combined with the WGS and PSA, produced high purity H(2) (20 N m(3)/h (400 H(2)-Nm(3)/PMW-ton), up to 99.99%) using a plasma torch with 1.6 MWh/PMW-ton of electricity. The results presented here suggest that the thermal plasma process of solid waste gasification for the production of high purity H(2) may provide a new approach as a future energy infrastructure based on H(2). Copyright © 2011 Elsevier B.V. All rights reserved.

Toxin-induced conformational changes in a potassium channel revealed by solid-state NMR

NASA Astrophysics Data System (ADS)

Lange, Adam; Giller, Karin; Hornig, Sönke; Martin-Eauclaire, Marie-France; Pongs, Olaf; Becker, Stefan; Baldus, Marc

2006-04-01

The active site of potassium (K+) channels catalyses the transport of K+ ions across the plasma membrane-similar to the catalytic function of the active site of an enzyme-and is inhibited by toxins from scorpion venom. On the basis of the conserved structures of K+ pore regions and scorpion toxins, detailed structures for the K+ channel-scorpion toxin binding interface have been proposed. In these models and in previous solution-state nuclear magnetic resonance (NMR) studies using detergent-solubilized membrane proteins, scorpion toxins were docked to the extracellular entrance of the K+ channel pore assuming rigid, preformed binding sites. Using high-resolution solid-state NMR spectroscopy, here we show that high-affinity binding of the scorpion toxin kaliotoxin to a chimaeric K+ channel (KcsA-Kv1.3) is associated with significant structural rearrangements in both molecules. Our approach involves a combined analysis of chemical shifts and proton-proton distances and demonstrates that solid-state NMR is a sensitive method for analysing the structure of a membrane protein-inhibitor complex. We propose that structural flexibility of the K+ channel and the toxin represents an important determinant for the high specificity of toxin-K+ channel interactions.

Making Pure Fine-Grained Inorganic Powder

NASA Technical Reports Server (NTRS)

Wood, C.

1985-01-01

Sustained arc plasma chemical reactor fabricates very-fine-grained inorganic solids having low thermal conductivity. Powder fabrication method, based on plasma tube technique produces pure solids without contamination commonly produced by grinding.

Fabrication of copper-based anodes via atmosphoric plasma spraying techniques

DOEpatents

Lu, Chun [Monroeville, PA

2012-04-24

A fuel electrode anode (18) for a solid oxide fuel cell is made by presenting a solid oxide fuel cell having an electrolyte surface (15), mixing copper powder with solid oxide electrolyte in a mixing step (24, 44) to provide a spray feedstock (30,50) which is fed into a plasma jet (32, 52) of a plasma torch to melt the spray feed stock and propel it onto an electrolyte surface (34, 54) where the spray feed stock flattens into lamellae layer upon solidification, where the layer (38, 59) is an anode coating with greater than 35 vol. % based on solids volume.

Plasma membranes modified by plasma treatment or deposition as solid electrolytes for potential application in solid alkaline fuel cells.

PubMed

Reinholdt, Marc; Ilie, Alina; Roualdès, Stéphanie; Frugier, Jérémy; Schieda, Mauricio; Coutanceau, Christophe; Martemianov, Serguei; Flaud, Valérie; Beche, Eric; Durand, Jean

2012-07-30

In the highly competitive market of fuel cells, solid alkaline fuel cells using liquid fuel (such as cheap, non-toxic and non-valorized glycerol) and not requiring noble metal as catalyst seem quite promising. One of the main hurdles for emergence of such a technology is the development of a hydroxide-conducting membrane characterized by both high conductivity and low fuel permeability. Plasma treatments can enable to positively tune the main fuel cell membrane requirements. In this work, commercial ADP-Morgane® fluorinated polymer membranes and a new brand of cross-linked poly(aryl-ether) polymer membranes, named AMELI-32®, both containing quaternary ammonium functionalities, have been modified by argon plasma treatment or triallylamine-based plasma deposit. Under the concomitant etching/cross-linking/oxidation effects inherent to the plasma modification, transport properties (ionic exchange capacity, water uptake, ionic conductivity and fuel retention) of membranes have been improved. Consequently, using plasma modified ADP-Morgane® membrane as electrolyte in a solid alkaline fuel cell operating with glycerol as fuel has allowed increasing the maximum power density by a factor 3 when compared to the untreated membrane.

Plasma Membranes Modified by Plasma Treatment or Deposition as Solid Electrolytes for Potential Application in Solid Alkaline Fuel Cells

PubMed Central

Reinholdt, Marc; Ilie, Alina; Roualdès, Stéphanie; Frugier, Jérémy; Schieda, Mauricio; Coutanceau, Christophe; Martemianov, Serguei; Flaud, Valérie; Beche, Eric; Durand, Jean

2012-01-01

In the highly competitive market of fuel cells, solid alkaline fuel cells using liquid fuel (such as cheap, non-toxic and non-valorized glycerol) and not requiring noble metal as catalyst seem quite promising. One of the main hurdles for emergence of such a technology is the development of a hydroxide-conducting membrane characterized by both high conductivity and low fuel permeability. Plasma treatments can enable to positively tune the main fuel cell membrane requirements. In this work, commercial ADP-Morgane® fluorinated polymer membranes and a new brand of cross-linked poly(aryl-ether) polymer membranes, named AMELI-32®, both containing quaternary ammonium functionalities, have been modified by argon plasma treatment or triallylamine-based plasma deposit. Under the concomitant etching/cross-linking/oxidation effects inherent to the plasma modification, transport properties (ionic exchange capacity, water uptake, ionic conductivity and fuel retention) of membranes have been improved. Consequently, using plasma modified ADP-Morgane® membrane as electrolyte in a solid alkaline fuel cell operating with glycerol as fuel has allowed increasing the maximum power density by a factor 3 when compared to the untreated membrane. PMID:24958295

Soft lithography of ceramic microparts using wettability-tunable poly(dimethylsiloxane) (PDMS) molds

NASA Astrophysics Data System (ADS)

Su, Bo; Zhang, Aijun; Meng, Junhu; Zhang, Zhaozhu

2016-07-01

Green alumina microparts were fabricated from a high solid content aqueous suspension by microtransfer molding using air plasma-treated poly(dimethylsiloxane) (PDMS) molds. The wettability of the air plasma-treated PDMS molds spontaneously changed between the hydrophilic and hydrophobic states during the process. Initial hydrophilicity of the air plasma-treated PDMS molds significantly improved the flowability of the concentrated suspension. Subsequent hydrophobic recovery of the air plasma-treated PDMS molds enabled a perfect demolding of the green microparts. Consequently, defect-free microchannel parts of 60 μm and a micromixer with an area of several square centimeters were successfully fabricated. In soft lithography, tuning the wetting behavior of PDMS molds has a great effect on the quality of ceramic microparts. Using wettability-tunable PDMS molds has great potential in producing complex-shaped and large-area ceramic microparts and micropatterns.

Space plasma physics at the Applied Physics Laboratory over the past half-century

NASA Technical Reports Server (NTRS)

Potemra, Thomas A.

1992-01-01

An overview is given of space-plasma experiments conducted at the Applied Physics Laboratory (APL) at Johns Hopkins University including observational campaigns and the instrumentation developed. Specific space-plasma experiments discussed include the study of the radiation environment in the Van Allen radiation belt with solid-state proton detectors. Also described are the 5E-1 satellites which acquired particle and magnetic-field data from earth orbit. The Triad satellite and its magnetometer system were developed for high-resolution studies of the earth's magnetic field, and APL contributions to NASA's Interplanetary Monitoring Platforms are listed. The review mentions the International Ultraviolet Explorer, the Atmosphere Explorer mission, and the Active Magnetic Particle Tracer Explorers mission. Other recent programs reviewed include a high-latitude satellite, contributions to the Voyager mission, and radar studies of space plasmas.

Exact periodic cross-kink wave solutions for the new (2+1)-dimensional KdV equation in fluid flows and plasma physics.

PubMed

Liu, Jian-Guo; Du, Jian-Qiang; Zeng, Zhi-Fang; Ai, Guo-Ping

2016-10-01

The Korteweg-de Vries (KdV)-type models have been shown to describe many important physical situations such as fluid flows, plasma physics, and solid state physics. In this paper, a new (2 + 1)-dimensional KdV equation is discussed. Based on the Hirota's bilinear form and a generalized three-wave approach, we obtain new exact solutions for the new (2 + 1)-dimensional KdV equation. With the help of symbolic computation, the properties for some new solutions are presented with some figures.

A phonon thermodynamics approach of gold nanofluids synthesized in solution plasma

DOE Office of Scientific and Technical Information (OSTI.GOV)

Heo, YongKang, E-mail: yk@rd.numse.nagoya-u.ac.jp; Aburaya, Daiki, E-mail: daiki@rd.numse.nagoya-u.ac.jp; Antoaneta Bratescu, Maria, E-mail: maria@rd.numse.nagoya-u.ac.jp

2014-03-17

The phonon thermodynamics theory for liquids was applied to explain the thermal characteristics of gold nanofluids synthesized by a simple, one-step, and chemical-free method using an electrical discharge in a liquid environment termed solution plasma process. The specific heat capacity of nanofluids was measured with a differential scanning calorimeter using the ratio between the differential heat flow rate and the heating rate. The decrease of the specific heat capacity with 10% of gold nanofluids relative to water was explained by the decrease of Frenkel relaxation time with 22%, considering a solid-like state model of liquids.

Plasma ignition thresholds in UV laser ablation plumes

NASA Astrophysics Data System (ADS)

Clarke, P.; Dyer, P. E.; Key, P. H.; Snelling, H. V.

Ultraviolet (UV) laser thresholds for plasma ignition on solid targets predicted from electron-neutral collisional heating are generally much higher than those observed experimentally. This inconsistency was reconciled by Rosen, et al. [2], who showed that excited-state photoionization played a key role in long-pulse UV laser breakdown. Here we develop a related model but with emphasis on pulses of 10 ns duration. Experimental results are also reported for titanium, copper, silicon, and ferulic acid targets in vacuum, irradiated with combinations of the XeF, KrF, and ArF lasers for comparison with predictions.

Atmospheric Pressure Non-Equilibrium Plasma as a Green Tool to Crosslink Gelatin Nanofibers

NASA Astrophysics Data System (ADS)

Liguori, Anna; Bigi, Adriana; Colombo, Vittorio; Focarete, Maria Letizia; Gherardi, Matteo; Gualandi, Chiara; Oleari, Maria Chiara; Panzavolta, Silvia

2016-12-01

Electrospun gelatin nanofibers attract great interest as a natural biomaterial for cartilage and tendon repair despite their high solubility in aqueous solution, which makes them also difficult to crosslink by means of chemical agents. In this work, we explore the efficiency of non-equilibrium atmospheric pressure plasma in stabilizing gelatin nanofibers. We demonstrate that plasma represents an innovative, easy and environmentally friendly approach to successfully crosslink gelatin electrospun mats directly in the solid state. Plasma treated gelatin mats display increased structural stability and excellent retention of fibrous morphology after immersion in aqueous solution. This method can be successfully applied to induce crosslinking both in pure gelatin and genipin-containing gelatin electrospun nanofibers, the latter requiring an even shorter plasma exposure time. A complete characterization of the crosslinked nanofibres, including mechanical properties, morphological observations, stability in physiological solution and structural modifications, has been carried out in order to get insights on the occurring reactions triggered by plasma.

Mechanism of solid-state plasma-induced dewetting for formation of copper and gold nanoparticles.

PubMed

Kwon, Soon-Ho; Choe, Han Joo; Lee, Hyo-Chang; Chung, Chin-Wook; Lee, Jung-Joong

2013-09-01

Cu and Au nanoparticles were fabricated by plasma treatment on Cu and Au films at 653 K. The nanoparticles were formed by dewetting the metallic films using plasma. Scanning electron microscopy and transmission electron microscopy investigations showed that the plasma-induced dewetting of the Cu and Au films proceeded through heterogeneous hole nucleation and growth along the grain boundaries to lower the surface energy. The amount of energy transferred to surface atoms by one Ar ion was calculated to be 16.1 eV, which was sufficient for displacing Cu and Au atoms. Compared to thermally activated dewetting, more uniform particles could be obtained by plasma-induced dewetting because a much larger number of holes with smaller sizes was generated. The plasma dewetting process is less sensitive to the oxidation of metallic films compared to the annealing process. As a result, Cu nanoparticles could be fabricated at 653 K, whereas the thermally activated dewetting was not possible.

Clocking Femtosecond Collisional Dynamics via Resonant X-Ray Spectroscopy

NASA Astrophysics Data System (ADS)

van den Berg, Q. Y.; Fernandez-Tello, E. V.; Burian, T.; Chalupský, J.; Chung, H.-K.; Ciricosta, O.; Dakovski, G. L.; Hájková, V.; Hollebon, P.; Juha, L.; Krzywinski, J.; Lee, R. W.; Minitti, M. P.; Preston, T. R.; de la Varga, A. G.; Vozda, V.; Zastrau, U.; Wark, J. S.; Velarde, P.; Vinko, S. M.

2018-02-01

Electron-ion collisional dynamics is of fundamental importance in determining plasma transport properties, nonequilibrium plasma evolution, and electron damage in diffraction imaging applications using bright x-ray free-electron lasers (FELs). Here we describe the first experimental measurements of ultrafast electron impact collisional ionization dynamics using resonant core-hole spectroscopy in a solid-density magnesium plasma, created and diagnosed with the Linac Coherent Light Source x-ray FEL. By resonantly pumping the 1 s →2 p transition in highly charged ions within an optically thin plasma, we have measured how off-resonance charge states are populated via collisional processes on femtosecond time scales. We present a collisional cross section model that matches our results and demonstrates how the cross sections are enhanced by dense-plasma effects including continuum lowering. Nonlocal thermodynamic equilibrium collisional radiative simulations show excellent agreement with the experimental results and provide new insight on collisional ionization and three-body-recombination processes in the dense-plasma regime.

The results of the study of compact gas-puff and vacuum spark plasma sources of SXR with Glass-Capillary Converters (GCC)

NASA Astrophysics Data System (ADS)

Shlyaptseva, Alla; Kantsyrev, Victor; Inozemtsev, Andrei; Petrukhin, Oleg

1994-06-01

The results are presented dealing with the working out and study of the SXR compact plasma source. The experimental set up included a compact new 'gas-puff' source with parameters being better than the traditional ones and a new type of SXR source - low-inductance vacuum spark (LIVS) with glass-capillary converters (GCC) of SXR. The compact plasma 'gas-puff' source had the high value of the z approx. (1-2) 10(exp -2) (conversion coefficient of initial energy supply into SXR); a small effective size of emission region and greater resource. The characteristics of LIVS with GCC were studied. GCC consisting of about several hundreds of glass capillaries allowed us to focus SXR, to change the cross section of SXR beams to plasma sources, and to change SXR spectrum. The possibility was shown of using of GCC in plasma diagnostics of powerful plasma devices: for X-ray microscopy and to study the influence of SXR on the solid state surface.

Clocking Femtosecond Collisional Dynamics via Resonant X-Ray Spectroscopy

DOE PAGES

van den Berg, Q. Y.; Fernandez-Tello, E. V.; Burian, T.; ...

2018-02-01

Electron-ion collisional dynamics is of fundamental importance in determining plasma transport properties, nonequilibrium plasma evolution, and electron damage in diffraction imaging applications using bright x-ray free-electron lasers (FELs). Here in this paper, we describe the first experimental measurements of ultrafast electron impact collisional ionization dynamics using resonant core-hole spectroscopy in a solid-density magnesium plasma, created and diagnosed with the Linac Coherent Light Source x-ray FEL. By resonantly pumping the 1s → 2p transition in highly charged ions within an optically thin plasma, we have measured how off-resonance charge states are populated via collisional processes on femtosecond time scales. We presentmore » a collisional cross section model that matches our results and demonstrates how the cross sections are enhanced by dense-plasma effects including continuum lowering. Nonlocal thermodynamic equilibrium collisional radiative simulations show excellent agreement with the experimental results and provide new insight on collisional ionization and three-body-recombination processes in the dense-plasma regime.« less

Linear dependence of surface expansion speed on initial plasma temperature in warm dense matter

DOE PAGES

Bang, Woosuk; Albright, Brian James; Bradley, Paul Andrew; ...

2016-07-12

Recent progress in laser-driven quasi-monoenergetic ion beams enabled the production of uniformly heated warm dense matter. Matter heated rapidly with this technique is under extreme temperatures and pressures, and promptly expands outward. While the expansion speed of an ideal plasma is known to have a square-root dependence on temperature, computer simulations presented here show a linear dependence of expansion speed on initial plasma temperature in the warm dense matter regime. The expansion of uniformly heated 1–100 eV solid density gold foils was modeled with the RAGE radiation-hydrodynamics code, and the average surface expansion speed was found to increase linearly withmore » temperature. The origin of this linear dependence is explained by comparing predictions from the SESAME equation-of-state tables with those from the ideal gas equation-of-state. In conclusion, these simulations offer useful insight into the expansion of warm dense matter and motivate the application of optical shadowgraphy for temperature measurement.« less

Metastable States Arising from the Ablation of Solid Copper

NASA Astrophysics Data System (ADS)

Andrejeva, Anna; Harris, Joe; Wright, Tim

2014-06-01

Laser ablation is a popular method for generating metal atoms so that metal clusters, complexes, and molecules may be investigated in gas phase spectroscopic studies. However, the initial production of a highly energetic metal plasma from the surface of a solid metal target can produce atoms which are not in their ground electronic state, and consequently atomic spectra can become quite complicated due to transitions arising from metastable atomic excited states which remain populated on the experimental timescale. Presented herein are details of the laser vaporisation source in use by our group. Spectra of atomic copper are presented, recorded via (1+1') and (2+1) resonance enhanced multiphoton ionisation (REMPI) spectroscopy. The energetic regions examined are expected to correspond to the (4s24p) 2P ← 2S and the (4s2nd) 2D ← 2S Rydberg series respectively, but the observed spectra also exhibit many additional contributions which are found to arise from electronically excited states, and these will be discussed.

Solid coatings deposited from liquid methyl methacrylate via Plasma Polymerization

NASA Astrophysics Data System (ADS)

Wurlitzer, Lisa; Maus-Friedrichs, Wolfgang; Dahle, Sebastian

2016-09-01

The polymerization of methyl methacrylate via plasma discharges is well known today. Usually, plasma-enhanced chemical vapor deposition (PECVD) is used to deposit polymer coatings. Solid coatings are formed out of the liquid phase from methyl methacrylate via dielectric barrier discharge. The formation of the coating proceeds in the gas and the liquid phase. To learn more about the reactions in the two phases, the coatings from MMA monomer will be compared to those from MMA resin. Finally, attenuated total reflection infrared spectroscopy, confocal laser scanning microscopy and X-ray photoelectron spectroscopy are employed to characterize the solid coatings. In conclusion, the plasma enhanced chemical solution deposition is compared to the classical thermal polymerization of MMA.

The investigation of solid slag obtained by neutralization of sewage sludge.

PubMed

Kavaliauskas, Zydrunas; Valincius, Vitas; Stravinskas, Giedrius; Milieska, Mindaugas; Striugas, Nerijus

2015-11-01

The purpose of this research is to investigate the feasibility of utilizing the slag collected after gasification of organic fuel combined with sewage sludge. The residue left after gasification process is likely usable as raw material for production of supercondensers. The sewage sludge neutralization system consists of a dosing system (fuel tank), gasifier, plasma reactor, electrostatic filter, and heat exchangers. For the gasification process, dried solid sewage is supplied in proportion of 70% to biomass 30% by weight. The slag is collected in a specially designed chamber beneath the gasifier. A scanning electron microscope (SEM) was used to evaluate surface morphology of the samples. Elemental analysis of the sewage sludge slag was performed using the energy-dispersive spectroscopy (EDS) method, which showed different solid-state elements contained in the porous structure of the solid phase: carbon 29%, aluminum 26%, potassium 20%, chlorine 1%, and others. The specific surface area of the sewage sludge slag is 6.15 m(2)/g as the BET analysis shows. In order to use the slag as a secondary raw material, detailed analysis of the structure and properties is necessary for a decision on whether the slag left after gasification of sewage sludge is suitable for any further usages. Initial results indicate that the slag may be used for production of electrodes for supercapacitors. Every year thousands of tons of sewage sludge are formed in Lithuania. Sewage sludge consists of organic and inorganic compounds. Partial combustion, plasma decomposition, and other methods are used to neutralize the sewage sludge. The incineration of sewage sludge results in generation of solid-phase slag. In this paper the material structure and composition of a solid slag (formed during neutralization of sewage sludge) is considered. Also, the impact the ambient temperature on structure and composition of solid slag is analyzed.

Specular Reflectivity and Hot-Electron Generation in High-Contrast Relativistic Laser-Plasma Interactions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kemp, Gregory Elijah

2013-01-01

Ultra-intense laser (> 1018 W/cm2) interactions with matter are capable of producing relativistic electrons which have a variety of applications in state-of-the-art scientific and medical research conducted at universities and national laboratories across the world. Control of various aspects of these hot-electron distributions is highly desired to optimize a particular outcome. Hot-electron generation in low-contrast interactions, where significant amounts of under-dense pre-plasma are present, can be plagued by highly non-linear relativistic laser-plasma instabilities and quasi-static magnetic field generation, often resulting in less than desirable and predictable electron source characteristics. High-contrast interactions offer more controlled interactions but often at the costmore » of overall lower coupling and increased sensitivity to initial target conditions. An experiment studying the differences in hot-electron generation between high and low-contrast pulse interactions with solid density targets was performed on the Titan laser platform at the Jupiter Laser Facility at Lawrence Livermore National Laboratory in Livermore, CA. To date, these hot-electrons generated in the laboratory are not directly observable at the source of the interaction. Instead, indirect studies are performed using state-of-the-art simulations, constrained by the various experimental measurements. These measurements, more-often-than-not, rely on secondary processes generated by the transport of these electrons through the solid density materials which can susceptible to a variety instabilities and target material/geometry effects. Although often neglected in these types of studies, the specularly reflected light can provide invaluable insight as it is directly influenced by the interaction. In this thesis, I address the use of (personally obtained) experimental specular reflectivity measurements to indirectly study hot-electron generation in the context of high-contrast, relativistic laser-plasma interactions.« less

Path Integral Monte Carlo Simulations of Warm Dense Matter and Plasmas

DOE Office of Scientific and Technical Information (OSTI.GOV)

Militzer, Burkhard

2018-01-13

New path integral Monte Carlo simulation (PIMC) techniques will be developed and applied to derive the equation of state (EOS) for the regime of warm dense matter and dense plasmas where existing first-principles methods cannot be applied. While standard density functional theory has been used to accurately predict the structure of many solids and liquids up to temperatures on the order of 10,000 K, this method is not applicable at much higher temperature where electronic excitations become important because the number of partially occupied electronic orbitals reaches intractably large numbers and, more importantly, the use of zero-temperature exchange-correlation functionals introducesmore » an uncontrolled approximation. Here we focus on PIMC methods that become more and more efficient with increasing temperatures and still include all electronic correlation effects. In this approach, electronic excitations increase the efficiency rather than reduce it. While it has commonly been assumed such methods can only be applied to elements without core electrons like hydrogen and helium, we recently showed how to extend PIMC to heavier elements by performing the first PIMC simulations of carbon and water plasmas [Driver, Militzer, Phys. Rev. Lett. 108 (2012) 115502]. Here we propose to continue this important development to extend the reach of PIMC simulations to yet heavier elements and also lower temperatures. The goal is to provide a robust first-principles simulation method that can accurately and efficiently study materials with excited electrons at solid-state densities in order to access parts of the phase diagram such the regime of warm dense matter and plasmas where so far only more approximate, semi-analytical methods could be applied.« less

Nonlinear propagation of light in Dirac matter.

PubMed

Eliasson, Bengt; Shukla, P K

2011-09-01

The nonlinear interaction between intense laser light and a quantum plasma is modeled by a collective Dirac equation coupled with the Maxwell equations. The model is used to study the nonlinear propagation of relativistically intense laser light in a quantum plasma including the electron spin-1/2 effect. The relativistic effects due to the high-intensity laser light lead, in general, to a downshift of the laser frequency, similar to a classical plasma where the relativistic mass increase leads to self-induced transparency of laser light and other associated effects. The electron spin-1/2 effects lead to a frequency upshift or downshift of the electromagnetic (EM) wave, depending on the spin state of the plasma and the polarization of the EM wave. For laboratory solid density plasmas, the spin-1/2 effects on the propagation of light are small, but they may be significant in superdense plasma in the core of white dwarf stars. We also discuss extensions of the model to include kinetic effects of a distribution of the electrons on the nonlinear propagation of EM waves in a quantum plasma.

Method for producing metallic nanoparticles

DOEpatents

Phillips, Jonathan; Perry, William L.; Kroenke, William J.

2004-02-10

Method for producing metallic nanoparticles. The method includes generating an aerosol of solid metallic microparticles, generating non-oxidizing plasma with a plasma hot zone at a temperature sufficiently high to vaporize the microparticles into metal vapor, and directing the aerosol into the hot zone of the plasma. The microparticles vaporize in the hot zone to metal vapor. The metal vapor is directed away from the hot zone and to the plasma afterglow where it cools and condenses to form solid metallic nanoparticles.

100 Years of the Physics of Diodes

NASA Astrophysics Data System (ADS)

Luginsland, John

2013-10-01

The Child-Langmuir Law (CL), discovered 100 years ago, gives the maximum current that can be transported across a planar diode in the steady state. As a quintessential example of the impact of space-charge shielding near a charged surface, it is central to the studies of high current diodes, such as high power microwave sources, vacuum microelectronics, electron and ion sources, and high current drivers used in high-energy density physics experiments. CL remains a touchstone of fundamental sheath physics, including contemporary studies of nano-scale quantum diodes and plasmonic devices. Its solid state analog is the Mott-Gurney law, governing the maximum charge injection in solids, such as organic materials and other dielectrics, which is important to energy devices, such as solar cells and light-emitting diodes. This paper reviews the important advances in the physics of diodes since the discovery of CL, including virtual cathode formation and extension of CL to multiple dimensions, to the quantum regime, and to ultrafast processes. We will review the influence of magnetic fields, multiple species in bipolar flow, electromagnetic and time dependent effects in both short pulse and high frequency THz limits, and single electron regimes. Transitions from various emission mechanisms (thermionic, field, and photo-emission) to the space charge limited state (CL) will be addressed, especially highlighting important simulation and experimental developments in selected contemporary areas of study. This talk will stress the fundamental physical links between the physics of beams to limiting currents in other areas, such as low temperature plasmas, laser plasmas, and space propulsion. Also emphasized is the role of non-equilibrium phenomena associated with materials and plasmas in close contact. Work supported by the Air Force Office of Scientific Research.

Analyzing the adsorption of blood plasma components by means of fullerene-containing silica gels and NMR spectroscopy in solids

NASA Astrophysics Data System (ADS)

Melenevskaya, E. Yu.; Mokeev, M. V.; Nasonova, K. V.; Podosenova, N. G.; Sharonova, L. V.; Gribanov, A. V.

2012-10-01

The results from studying the adsorption of blood plasma components (e.g., protein, triglycerides, cholesterol, and lipoproteins of low and high density) using silica gels modified with fullerene molecules (in the form of C60 or the hydroxylated form of C60(OH) x ) and subjected to hydration (or, alternatively, dehydration) are presented. The conditions for preparing adsorbents that allow us to control the adsorption capacity of silica gel and the selectivity of adsorption toward the components of blood plasma, are revealed. The nature and strength of the interactions of the introduced components (fullerene molecules and water) with functional groups on the silica surface are studied by means of solid state NMR spectroscopy (NMR-SS). Conclusions regarding the nature of the centers that control adsorption are drawn on the basis of NMR-SS spectra in combination with direct measurements of adsorption. The interaction of the oxygen of the hydroxyl group of silica gel with fullerene, leading to the formation of electron-donor complexes of C60-H, C60-OH, or C60-OSi type, is demonstrated by the observed changes in the NMR-SS spectra of silica gels in the presence of fullerene.

Quantitative ionspray liquid chromatographic/tandem mass spectrometric determination of reserpine in equine plasma.

PubMed

Anderson, M A; Wachs, T; Henion, J D

1997-02-01

A method based on ionspray liquid chromatography/tandem mass spectrometry (LC/MS/MS) was developed for the determination of reserpine in equine plasma. A comparison was made of the isolation of reserpine from plasma by liquid-liquid extraction and by solid-phase extraction. A structural analog, rescinnamine, was used as the internal standard. The reconstituted extracts were analyzed by ionspray LC/MS/MS in the selected reaction monitoring (SRM) mode. The calibration graph for reserpine extracted from equine plasma obtained using liquid-liquid extraction was linear from 10 to 5000 pg ml-1 and that using solid-phase extraction from 100 to 5000 pg ml-1. The lower level of quantitation (LLQ) using liquid-liquid and solid-phase extraction was 50 and 200 pg ml-1, respectively. The lower level of detection for reserpine by LC/MS/MS was 10 pg ml-1. The intra-assay accuracy did not exceed 13% for liquid-liquid and 12% for solid-phase extraction. The recoveries for the LLQ were 68% for liquid-liquid and 58% for solid-phase extraction.

Megajoule Dense Plasma Focus Solid Target Experiments

NASA Astrophysics Data System (ADS)

Podpaly, Y. A.; Falabella, S.; Link, A.; Povilus, A.; Higginson, D. P.; Shaw, B. H.; Cooper, C. M.; Chapman, S.; Bennett, N.; Sipe, N.; Olson, R.; Schmidt, A. E.

2016-10-01

Dense plasma focus (DPF) devices are plasma sources that can produce significant neutron yields from beam into gas interactions. Yield increases, up to approximately a factor of five, have been observed previously on DPFs using solid targets, such as CD2 and D2O ice. In this work, we report on deuterium solid-target experiments at the Gemini DPF. A rotatable target holder and baffle arrangement were installed in the Gemini device which allowed four targets to be deployed sequentially without breaking vacuum. Solid targets of titanium deuteride were installed and systematically studied at a variety of fill pressures, bias voltages, and target positions. Target holder design, experimental results, and comparison to simulations will be presented. Prepared by LLNL under Contract DE-AC52-07NA27344.

Observations of strong ion-ion correlations in dense plasmas

DOE PAGES

Ma, T.; Fletcher, L.; Pak, A.; ...

2014-04-24

Using simultaneous spectrally, angularly, and temporally resolved x-ray scattering, we measure the pronounced ion-ion correlation peak in a strongly coupled plasma. Laser-driven shock-compressed aluminum at ~3× solid density is probed with high-energy photons at 17.9 keV created by molybdenum He-α emission in a laser-driven plasma source. The measured elastic scattering feature shows a well-pronounced correlation peak at a wave vector of k=4Å –1. The magnitude of this correlation peak cannot be described by standard plasma theories employing a linear screened Coulomb potential. Advanced models, including a strong short-range repulsion due to the inner structure of the aluminum ions are howevermore » in good agreement with the scattering data. These studies have demonstrated a new highly accurate diagnostic technique to directly measure the state of compression and the ion-ion correlations. Furthermore, we have since applied this new method in single-shot wave-number resolved S(k) measurements to characterize the physical properties of dense plasmas.« less

Simulation of Plasma Jet Merger and Liner Formation within the PLX- α Project

NASA Astrophysics Data System (ADS)

Samulyak, Roman; Chen, Hsin-Chiang; Shih, Wen; Hsu, Scott

2015-11-01

Detailed numerical studies of the propagation and merger of high Mach number argon plasma jets and the formation of plasma liners have been performed using the newly developed method of Lagrangian particles (LP). The LP method significantly improves accuracy and mathematical rigor of common particle-based numerical methods such as smooth particle hydrodynamics while preserving their main advantages compared to grid-based methods. A brief overview of the LP method will be presented. The Lagrangian particle code implements main relevant physics models such as an equation of state for argon undergoing atomic physics transformation, radiation losses in thin optical limit, and heat conduction. Simulations of the merger of two plasma jets are compared with experimental data from past PLX experiments. Simulations quantify the effect of oblique shock waves, ionization, and radiation processes on the jet merger process. Results of preliminary simulations of future PLX- alpha experiments involving the ~ π / 2 -solid-angle plasma-liner configuration with 9 guns will also be presented. Partially supported by ARPA-E's ALPHA program.

Polymerization of phenol by using discharged plasma under hydrothermal state

NASA Astrophysics Data System (ADS)

Mitsugi, M.; Yoshida, A.; Watanabe, H.; Kiyan, T.; Takade, M.; Miyaji, K.; Namihira, T.; Kuwahara, Y.; Akiyama, H.; Hara, M.; Sasaki, M.; Goto, M.

2010-03-01

Supercritical fluid with plasma is a type of green processing media because this technique does not use catalyst and toxic solvents. In this study, we carried out experiments of organic materials in the presence of discharged plasma in sub- and supercritical water to evaluate the possibility for new reactions. For this purpose, we used SUS316 reactor that generates plasma at temperature and pressure up to 573K and 30MPa, respectively. 100 mmol/L aqueous phenol solution was used as starting material. The reactions were carried out at temperature of 523K and under pressure of 25MPa. After a series of reactions, water-soluble, water-insoluble (oily products), solid residue and gaseous product were obtained. For the analysis of these products, HPLC, GC-MS, TOC, GC-TCD and TOF-MS were used. The highest phenol conversion was 16.96% obtained at 523K, 25MPa and with 4000 times discharged plasma. Polymerized phenol was obtained as a product.

Method for producing metal oxide nanoparticles

DOEpatents

Phillips, Jonathan [Santa Fe, NM; Mendoza, Daniel [Santa Fe, NM; Chen, Chun-Ku [Albuquerque, NM

2008-04-15

Method for producing metal oxide nanoparticles. The method includes generating an aerosol of solid metallic microparticles, generating plasma with a plasma hot zone at a temperature sufficiently high to vaporize the microparticles into metal vapor, and directing the aerosol into the hot zone of the plasma. The microparticles vaporize in the hot zone into metal vapor. The metal vapor is directed away from the hot zone and into the cooler plasma afterglow where it oxidizes, cools and condenses to form solid metal oxide nanoparticles.

Disordered multihyperuniformity derived from binary plasmas

NASA Astrophysics Data System (ADS)

Lomba, Enrique; Weis, Jean-Jacques; Torquato, Salvatore

2018-01-01

Disordered multihyperuniform many-particle systems are exotic amorphous states that allow exquisite color sensing capabilities due to their anomalous suppression of density fluctuations for distinct subsets of particles, as recently evidenced in photoreceptor mosaics in avian retina. Motivated by this biological finding, we present a statistical-mechanical model that rigorously achieves disordered multihyperuniform many-body systems by tuning interactions in binary mixtures of nonadditive hard-disk plasmas. We demonstrate that multihyperuniformity competes with phase separation and stabilizes a clustered phase. Our work provides a systematic means to generate disordered multihyperuniform solids, and hence lays the groundwork to explore their potentially unique photonic, phononic, electronic, and transport properties.

Design of a new electron cyclotron resonance ion source at Oshima National College of Maritime Technology

DOE Office of Scientific and Technical Information (OSTI.GOV)

Asaji, T., E-mail: asaji@oshima-k.ac.jp; Hirabara, N.; Izumihara, T.

A new electron cyclotron resonance ion/plasma source has been designed and will be built at Oshima National College of Maritime Technology by early 2014. We have developed an ion source that allows the control of the plasma parameters over a wide range of electron temperatures for material research. A minimum-B magnetic field composed of axial mirror fields and radial cusp fields was designed using mainly Nd-Fe-B permanent magnets. The axial magnetic field can be varied by three solenoid coils. The apparatus has 2.45 GHz magnetron and 2.5–6.0 GHz solid-state microwave sources.

Improvement of Characteristics of Laser Source of Ions Using Two-Element Targets

DOE Office of Scientific and Technical Information (OSTI.GOV)

Khaydarov, R. T.

2006-12-04

Two-element plasma ions generated from porous (Ho2O3) and solid (PbMg) targets were studied depending on the target density {rho} and on the fraction of light (Mg) component of the target, using a mass-spectrometer. Oxygen ions with maximal charge is observed for small values of {rho}, while the heavy component of the target Ho has maximal charge for larger values of {rho}. The influence of {rho} to the energy spectra and intensity of plasma ions is also investigated. In the case of solid (PbMg) target the increase of the fraction of Mg leads to the widening of the energy spectra ofmore » Pb ions by more than a factor of two, while the intensity of Pb ions of all charge states does not depend on the Mg fraction. These effects are explained by the friction existing between light and heavy ions during their expansion away from the target.« less

Simulations of Neon Pellets for Plasma Disruption Mitigation in Tokamaks

NASA Astrophysics Data System (ADS)

Bosviel, Nicolas; Samulyak, Roman; Parks, Paul

2017-10-01

Numerical studies of the ablation of neon pellets in tokamaks in the plasma disruption mitigation parameter space have been performed using a time-dependent pellet ablation model based on the front tracking code FronTier-MHD. The main features of the model include the explicit tracking of the solid pellet/ablated gas interface, a self-consistent evolving potential distribution in the ablation cloud, JxB forces, atomic processes, and an improved electrical conductivity model. The equation of state model accounts for atomic processes in the ablation cloud as well as deviations from the ideal gas law in the dense, cold layers of neon gas near the pellet surface. Simulations predict processes in the ablation cloud and pellet ablation rates and address the sensitivity of pellet ablation processes to details of physics models, in particular the equation of state.

Detailed energy distributions in laser-produced plasmas of solid gold and foam gold planar targets

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dong, Yunsong; Department of Engineering Physics, Tsinghua University, Beijing 100084; Zhang, Lu

Foam gold was proposed to increase the laser to x-ray conversion efficiency due to its important applications. To understand the mechanism of x-ray enhancement, the detailed energy distributions and plasma profiles for laser-irradiated solid gold and foam gold targets were studied comparatively by hydrodynamic simulations using the code Multi-1D. It is confirmed that the radiation heat wave is subsonic for the normal solid gold target, while supersonic for the foam gold target. The shock wave, which is behind the supersonic radiation heat wave for the foam gold target, generates a plasma temperature gradient with high temperature near the shock wavemore » front to produce an additional net outward radiation for enhancement of the x-ray emission. Much larger inward plasma velocity is also driven by the shock wave as an initial plasma velocity for the laser deposition and electron thermal conduct zone, which decreases the expanding plasma kinetic energy loss and helps to increase the x-ray radiation.« less

New equation of state models for hydrodynamic applications

NASA Astrophysics Data System (ADS)

Young, David A.; Barbee, Troy W.; Rogers, Forrest J.

1998-07-01

Two new theoretical methods for computing the equation of state of hot, dense matter are discussed. The ab initio phonon theory gives a first-principles calculation of lattice frequencies, which can be used to compare theory and experiment for isothermal and shock compression of solids. The ACTEX dense plasma theory has been improved to allow it to be compared directly with ultrahigh pressure shock data on low-Z materials. The comparisons with experiment are good, suggesting that these models will be useful in generating global EOS tables for hydrodynamic simulations.

LINE-1 methylation in plasma DNA as a biomarker of activity of DNA methylation inhibitors in patients with solid tumors.

PubMed

Aparicio, Ana; North, Brittany; Barske, Lindsey; Wang, Xuemei; Bollati, Valentina; Weisenberger, Daniel; Yoo, Christine; Tannir, Nizar; Horne, Erin; Groshen, Susan; Jones, Peter; Yang, Allen; Issa, Jean-Pierre

2009-04-01

Multiple clinical trials are investigating the use of the DNA methylation inhibitors azacitidine and decitabine for the treatment of solid tumors. Clinical trials in hematological malignancies have shown that optimal activity does not occur at their maximum tolerated doses but selection of an optimal biological dose and schedule for use in solid tumor patients is hampered by the difficulty of obtaining tumor tissue to measure their activity. Here we investigate the feasibility of using plasma DNA to measure the demethylating activity of the DNA methylation inhibitors in patients with solid tumors. We compared four methods to measure LINE-1 and MAGE-A1 promoter methylation in T24 and HCT116 cancer cells treated with decitabine treatment and selected Pyrosequencing for its greater reproducibility and higher signal to noise ratio. We then obtained DNA from plasma, peripheral blood mononuclear cells, buccal mucosa cells and saliva from ten patients with metastatic solid tumors at two different time points, without any intervening treatment. DNA methylation measurements were not significantly different between time point 1 and time point 2 in patient samples. We conclude that measurement of LINE-1 methylation in DNA extracted from the plasma of patients with advanced solid tumors, using Pyrosequencing, is feasible and has low within patient variability. Ongoing studies will determine whether changes in LINE-1 methylation in plasma DNA occur as a result of treatment with DNA methylation inhibitors and parallel changes in tumor tissue DNA.

A simplified radiometabolite analysis procedure for PET radioligands using a solid phase extraction with micellar medium.

PubMed

Nakao, Ryuji; Halldin, Christer

2013-07-01

A solid phase extraction method has been developed for simple and high-speed direct determination of PET radioligands in plasma. This methodology makes use of a micellar medium and a solid-phase extraction cartridge for displacement of plasma protein bound radioligand and separation of PET radioligands from their radiometabolites without significant preparation. The plasma samples taken from monkey or human during PET measurements were mixed with a micellar eluent containing an anionic surfactant sodium dodecyl sulphate and loaded onto SPE cartridges. The amount of radioactivity corresponding to parent radioligand (retained on the cartridge) and its radioactive metabolites (eluted with micellar eluent) was measured. Under the optimized conditions, excellent separation of target PET radioligands from their radiometabolites was achieved with a single elution and short run-time of 1 min. This method was successfully applied to study the metabolism for (11)C-labelled radioligands in human or monkey plasma. The amount of parent PET radioligands estimated by micellar solid phase extraction strongly corresponded with that determined by radio-LC. The improved throughput permitted the analysis of a large number of plasma samples (up to 13 samples per one PET study) for accurate estimation of metabolite-corrected input function during quantitative PET imaging studies. Solid phase extraction together with micellar medium is fast, sensitive and easy to use, and therefore it is an attractive alternative method to determine relative composition of PET radioligands in plasma. Copyright © 2013 Elsevier Inc. All rights reserved.

Ultrafast Thermal Plasma Preparation of Solid Si Films with Potential Application in Photovoltaic Cells: A Parametric Study

NASA Astrophysics Data System (ADS)

Mostajeran Goortani, Behnam; Gitzhofer, François; Bouyer, Etienne; Mousavi, Mehdi

2009-03-01

An innovative method, namely ultrafast plasma surface melting, is developed to fabricate solid films of silicon with very high rates (150 cm2/min). The method is composed of preparing a suspension of solid particles in a volatile solvent and spreading it on a refractory substrate such as Mo. After solvent evaporation, the resulting porous layer is exposed to the flame tale of inductively coupled RF plasma to sinter and melt the surface particles and to prepare a solid film of silicon. It is shown that by controlling the flow dynamics and heat transfer around the substrate, and managing the kinetic parameters (i.e., exposure time, substrate transport speed, and reaction kinetics) in the reactor, we can produce solid crystalline Si films with the potential applications in photovoltaic cells industry. The results indicate that the optimum formation conditions with a film thickness of 250-700 μm is when the exposure time in the plasma is in the range of 5-12.5 s for a 100 × 50 mm large layer. By combining the Fourier’s law of conduction with the experimental measurements, we obtained an effective heat diffusivity and developed a model to obtain heat diffusion in the porous layer exposed to the plasma. The model further predicts the minimum and maximum exposure time for the substrate in the plasma flame as a function of material properties, the porous layer thickness and of the imposed heat flux.

Computational challenges in magnetic-confinement fusion physics

NASA Astrophysics Data System (ADS)

Fasoli, A.; Brunner, S.; Cooper, W. A.; Graves, J. P.; Ricci, P.; Sauter, O.; Villard, L.

2016-05-01

Magnetic-fusion plasmas are complex self-organized systems with an extremely wide range of spatial and temporal scales, from the electron-orbit scales (~10-11 s, ~ 10-5 m) to the diffusion time of electrical current through the plasma (~102 s) and the distance along the magnetic field between two solid surfaces in the region that determines the plasma-wall interactions (~100 m). The description of the individual phenomena and of the nonlinear coupling between them involves a hierarchy of models, which, when applied to realistic configurations, require the most advanced numerical techniques and algorithms and the use of state-of-the-art high-performance computers. The common thread of such models resides in the fact that the plasma components are at the same time sources of electromagnetic fields, via the charge and current densities that they generate, and subject to the action of electromagnetic fields. This leads to a wide variety of plasma modes of oscillations that resonate with the particle or fluid motion and makes the plasma dynamics much richer than that of conventional, neutral fluids.

Reducing wall plasma expansion with gold foam irradiated by laser

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, Lu; Ding, Yongkun, E-mail: ding-yk@vip.sina.com; Jiang, Shaoen, E-mail: jiangshn@vip.sina.com

The experimental study on the expanding plasma movement of low-density gold foam (∼1% solid density) irradiated by a high power laser is reported in this paper. Experiments were conducted using the SG-III prototype laser. Compared to solid gold with 19.3 g/cc density, the velocities of X-ray emission fronts moving off the wall are much smaller for gold foam with 0.3 g/cc density. Theoretical analysis and MULTI 1D simulation results also show less plasma blow-off, and that the density contour movement velocities of gold foam are smaller than those of solid gold, agreeing with experimental results. These results indicate that foam walls havemore » advantages in symmetry control and lowering plasma fill when used in ignition hohlraum.« less

Protein Hydrolysates/Peptides in Animal Nutrition

NASA Astrophysics Data System (ADS)

McCalla, Jeff; Waugh, Terry; Lohry, Eric

The use of protein hydrolysates as an important nutrient for growth and maintenance has been increasing in animal nutrition. Although animal proteins and protein hydrolysates are widely used however, recently vegetable protein hydrolysates are gaining importance. This chapter reviews the use of protein hydrolysates developed by enzyme hydrolysis and by solid state fermentation process in animal nutrition especially for piglets and compares it with the standard products such as plasma and fishmeal.

Application of atmospheric-pressure plasma jet processed carbon nanotubes to liquid and quasi-solid-state gel electrolyte supercapacitors

NASA Astrophysics Data System (ADS)

Kuok, Fei-Hong; Kan, Ken-Yuan; Yu, Ing-Song; Chen, Chieh-Wen; Hsu, Cheng-Che; Cheng, I.-Chun; Chen, Jian-Zhang

2017-12-01

We use a dc-pulse nitrogen atmospheric-pressure plasma jet (APPJ) to calcine carbon nanotubes (CNTs) pastes that are screen-printed on carbon cloth. 30-s APPJ treatment can efficiently oxidize and vaporize the organic binders, thereby forming porous structures. As indicated by X-ray photoelectron spectroscopy (XPS) and electron probe microanalysis (EPMA), the oxygen content decreases after APPJ treatment owing to the oxidation and vaporization of ethyl cellulose, terpineol, and ethanol. Nitrogen doping was introduced to the materials by the nitrogen APPJ. APPJ-calcination improves the wettability of the CNTs printed on carbon cloth, as evidenced by water contact angle measurement. Raman spectroscopy indicates that reactive species of nitrogen APPJ react violently with CNTs in only 30-s APPJ processing time and introduce defects and/or surface functional groups on CNTs. Carbon cloths with calcined CNT layers are used as electrodes for liquid and quasi-solid-state electrolyte supercapacitors. Under a cyclic voltammetry test with a 2 mV/s potential scan rate, the specific capacitance is 73.84 F/g (areal capacitance = 5.89 mF/cm2) with a 2 M KCl electrolyte and 66.47 F/g (areal capacitance = 6.10 mF/cm2) with a H2SO4/polyvinyl alcohol (PVA) gel electrolyte.

Microwave induced plasma for solid fuels and waste processing: A review on affecting factors and performance criteria.

PubMed

Ho, Guan Sem; Faizal, Hasan Mohd; Ani, Farid Nasir

2017-11-01

High temperature thermal plasma has a major drawback which consumes high energy. Therefore, non-thermal plasma which uses comparatively lower energy, for instance, microwave plasma is more attractive to be applied in gasification process. Microwave-induced plasma gasification also carries the advantages in terms of simplicity, compactness, lightweight, uniform heating and the ability to operate under atmospheric pressure that gains attention from researchers. The present paper synthesizes the current knowledge available for microwave plasma gasification on solid fuels and waste, specifically on affecting parameters and their performance. The review starts with a brief outline on microwave plasma setup in general, and followed by the effect of various operating parameters on resulting output. Operating parameters including fuel characteristics, fuel injection position, microwave power, addition of steam, oxygen/fuel ratio and plasma working gas flow rate are discussed along with several performance criteria such as resulting syngas composition, efficiency, carbon conversion, and hydrogen production rate. Based on the present review, fuel retention time is found to be the key parameter that influences the gasification performance. Therefore, emphasis on retention time is necessary in order to improve the performance of microwave plasma gasification of solid fuels and wastes. Copyright © 2017 Elsevier Ltd. All rights reserved.

Diffusion and reactivity of ground-state nitrogen atoms N(4S) between 3 and 15 K: application to the hydrogen abstraction reaction from methane under non-energetic conditions

NASA Astrophysics Data System (ADS)

Nourry, Sendres; Krim, Lahouari

2015-07-01

We have characterized the CH4 + N(4S) reaction in solid phase, at very low temperature, under non-energetic conditions and where the CH4 and N reactants are in their ground states. A microwave-driven atomic source has been used to generate ground-state nitrogen atoms N(4S), and experiments have been carried out at temperatures as low as 3 K to reduce the mobility of the trapped species in solid phase and hence to freeze the first step of the CH4 + N reaction pathway. Leaving the formed solid sample in the dark for a while allows all trapped reactants to relax to the ground state, specifically radicals and excited species streaming from the plasma discharge. Such a method could be the only possibility of proving that the CH4 + N reaction occurs between CH4 and N reactants in their ground states without any additional energy to initiate the chemical process. The appearance of the CH3 reaction product, just by inducing the mobility of N atoms between 3 and 11 K, translates that a hydrogen abstraction reaction from methane, under non-energetic conditions, will start occurring at very low temperature. The formation of methyl radical, under these experimental conditions, is due to recombination processes N(4S)-N(4S) of ground-state nitrogen atoms without any contribution of cosmic ray particles or high-energy photons.

Thermal Stir Welding: A New Solid State Welding Process

NASA Technical Reports Server (NTRS)

Ding, R. Jeffrey

2003-01-01

Thermal stir welding is a new welding process developed at NASA's Marshall Space Flight Center in Huntsville, AL. Thermal stir welding is similar to friction stir welding in that it joins similar or dissimilar materials without melting the parent material. However, unlike friction stir welding, the heating, stirring and forging elements of the process are all independent of each other and are separately controlled. Furthermore, the heating element of the process can be either a solid-state process (such as a thermal blanket, induction type process, etc), or, a fusion process (YG laser, plasma torch, etc.) The separation of the heating, stirring, forging elements of the process allows more degrees of freedom for greater process control. This paper introduces the mechanics of the thermal stir welding process. In addition, weld mechanical property data is presented for selected alloys as well as metallurgical analysis.

Thermal Stir Welding: A New Solid State Welding Process

NASA Technical Reports Server (NTRS)

Ding, R. Jeffrey; Munafo, Paul M. (Technical Monitor)

2002-01-01

Thermal stir welding is a new welding process developed at NASA's Marshall Space Flight Center in Huntsville, AL. Thermal stir welding is similar to friction stir welding in that it joins similar or dissimilar materials without melting the parent material. However, unlike friction stir welding, the heating, stirring and forging elements of the process are all independent of each other and are separately controlled. Furthermore, the heating element of the process can be either a solid-state process (such as a thermal blanket, induction type process, etc), or, a fusion process (YG laser, plasma torch, etc.) The separation of the heating, stirring, forging elements of the process allows more degrees of freedom for greater process control. This paper introduces the mechanics of the thermal stir welding process. In addition, weld mechanical property data is presented for selected alloys as well as metallurgical analysis.

100 years of the physics of diodes

NASA Astrophysics Data System (ADS)

Zhang, Peng; Valfells, Ágúst; Ang, L. K.; Luginsland, J. W.; Lau, Y. Y.

2017-03-01

The Child-Langmuir Law (CL), discovered a century ago, gives the maximum current that can be transported across a planar diode in the steady state. As a quintessential example of the impact of space charge shielding near a charged surface, it is central to the studies of high current diodes, such as high power microwave sources, vacuum microelectronics, electron and ion sources, and high current drivers used in high energy density physics experiments. CL remains a touchstone of fundamental sheath physics, including contemporary studies of nanoscale quantum diodes and nano gap based plasmonic devices. Its solid state analog is the Mott-Gurney law, governing the maximum charge injection in solids, such as organic materials and other dielectrics, which is important to energy devices, such as solar cells and light emitting diodes. This paper reviews the important advances in the physics of diodes since the discovery of CL, including virtual cathode formation and extension of CL to multiple dimensions, to the quantum regime, and to ultrafast processes. We review the influence of magnetic fields, multiple species in bipolar flow, electromagnetic and time dependent effects in both short pulse and high frequency THz limits, and single electron regimes. Transitions from various emission mechanisms (thermionic-, field-, and photoemission) to the space charge limited state (CL) will be addressed, especially highlighting the important simulation and experimental developments in selected contemporary areas of study. We stress the fundamental physical links between the physics of beams to limiting currents in other areas, such as low temperature plasmas, laser plasmas, and space propulsion.

Rayleigh-Taylor and Richtmyer-Meshkov Instabilities in Turbulent Regime

NASA Astrophysics Data System (ADS)

Dimonte, G.

1998-11-01

The Rayleigh-Taylor instability (RTI) and its shock driven analog, the Richtmyer-Meshkov instability (RMI), affect a wide variety of important phenomena from sub-terrainian to astrophysical environments. The ``fluids" are equally varied from plasmas and magnetic fields to elastic-plastic solids. In most applications, the instabilities occur with a complex acceleration history and evolve to a highly nonlinear state, making the theoretical description formidable. We will link the fluid and plasma regimes while describing the theoretical issues and basic experiments in different venues to isolate key physics issues. RMI experiments on the Nova laser investigate the affects of compressibility with strong radiatively driven shocks (Mach > 10) in near solid density plasmas of sub-millimeter scale. The growth of single sinusoidal and random 3-D perturbations are measured using backlit radiography. RTI experiments with the Linear Electric Motor (LEM) are conducted with a variety of acceleration (<< 10^4 m/s^2) histories and fluids of 10 cm scale. Turbulent RTI experiments with high Reynolds number liquids show self-similar growth which is characterized with laser induced fluorescence. LEM experiments with an elastic-plastic material (yogurt) exhibit a critical wavelength and amplitude for instability. The experimental results will be compared with linear and nonlinear theories and hydrodynamic simulations.

Improved di-p-xylylene polymer and apparatus and method for making the same

DOEpatents

Jahn, R.K.; Liepins, R.

Solid di-para-xylyene dimer is sublimed in a sublimation furnace at approximately 100 to 200/sup 0/C and subsequently conducted to a pyrolysis furnace where it is pyrolyzed to the diradical p-xylylene monomer while in the vapor state at approximately 600 degrees C. The diradical monomer is then introduced into a deposition chamber for deposition onto a suitable substrate. The deposition chamber includes electrodes for producing a low pressure plasma through which the diradical monomer passes prior to deposition. The interaction of the diradical monomer with the low pressure plasma results in the formation of poly-p-xylyene film which is exceptionally hard and thermally stable.

ASCA X-ray observations of pre-main-sequence stars

NASA Technical Reports Server (NTRS)

Skinner, S. L.; Walter, F. M.; Yamauchi, S.

1996-01-01

The results of recent Advanced Satellite for Cosmology and Astrophysics (ASCA) X-ray observations of two pre-main sequence stars are presented: the weak emission line T Tauri star HD 142361, and the Herbig Ae star HD 104237. The solid state imaging spectrometer spectra for HD 142361 shows a clear emission line from H-like Mg 7, and spectral fits reveal a multiple temperature plasma with a hot component of at least 16 MK. The spectra of HD 104237 show a complex temperature structure with the hottest plasma at temperatures of greater than 30 MK. It is concluded that mechanisms that predict only soft X-ray emission can be dismissed for Herbig Ae stars.

Thermomechanical and chemical properties of porous W/liquid Li hybrid systems as plasma-facing self-healing surfaces

NASA Astrophysics Data System (ADS)

Kapat, Aveek; Lang, Eric; Neff, Anton; Allain, Jean Paul

2017-10-01

The environmental conditions at the plasma-material interface of a future nuclear fusion reactor interacting will be extreme. The incident plasma will carry heat fluxes of the order of 100's of MWm-2 and particle fluxes that can average 1024 m-2s-1. The fusion reactor wall would need to operate at high temperatures near 800 C and the incident energy of particles will vary from a few eV ions to MeV neutrons. A hybrid system, inspired by self-healing solid-state concepts, combines the ductile phase of liquid Li within a solid phase porous W. The liquid Li serves to control hydrogen retention and provide vapor shielding, within the framework of a tunable porosity to optimize edge plasma conditions [2]. Additionally, the porous interface can also provide for effective defect sinks for high duty cycle neutron damage. The surface chemistry of liquid Li on a porous surface varied with D irradiation is studied and its effect on retention. Prior results with refractory alloys have demonstrated effective wetting properties [3]. These hybrid systems, as well as traditional W samples, are bombarded with 500eV D2+and Ar+ at 230oC and 300oC. The Li, O, and C XPS peaks were examined and compared to controls. Additionally, the porous W is characterized for thermo-mechanical properties. Work supported by USDOE Contract DE- DE-SC0014267.

In vitro and in vivo studies on a novel solid dispersion of repaglinide using polyvinylpyrrolidone as the carrier.

PubMed

Yin, Li-Fang; Huang, Shi-Jing; Zhu, Chun-Li; Zhang, Shu-Hui; Zhang, Qiang; Chen, Xi-Jing; Liu, Qing-Wang

2012-11-01

In order to improve the dissolution and absorption of the water insoluble drug repaglinide, a solid dispersion was developed by solvent method using polyvinylpyrrolidone K30 (PVP K30) as the hydrophilic carrier for the first time. Studies indicated that both solubility and the dissolution rate of repaglinide were significantly increased in the solid dispersion system compared with that of repaglinide raw material or physical mixtures. The repaglinide solid dispersions with PVP K30 solid state was characterized by polarizing microscopy, differential scanning calorimetry (DSC), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FT-IR). DSC and XRD studies indicated that repaglinide existed in an amorphous form in the solid dispersion. FT-IR analysis demonstrated the presence of intermolecular hydrogen bonding between repaglinide and PVP K30 in the solid dispersion. In the in situ gastrointestinal perfusion experiment, solid dispersion was shown to remarkably enhance the absorption of repaglinide in stomach and all segments of intestine. In vivo pharmacokinetic study in rats showed that immediate and complete release of repaglinide from the solid dispersion resulted in rapid absorption that significantly increased the bioavailability and the maximum plasma concentration over repaglinide raw material. These results demonstrated PVP K30 was an appropriate carrier for solid dispersion of repaglinide, with increased dissolution and oral absorption.

XFEL resonant photo-pumping of dense plasmas and dynamic evolution of autoionizing core hole states

NASA Astrophysics Data System (ADS)

Rosmej, F. B.; Moinard, A.; Renner, O.; Galtier, E.; Lee, J. J.; Nagler, B.; Heimann, P. A.; Schlotter, W.; Turner, J. J.; Lee, R. W.; Makita, M.; Riley, D.; Seely, J.

2016-03-01

Similarly to the case of LIF (Laser-Induced Fluorescence), an equally revolutionary impact to science is expected from resonant X-ray photo-pumping. It will particularly contribute to a progress in high energy density science: pumped core hole states create X-ray transitions that can escape dense matter on a 10 fs-time scale without essential photoabsorption, thus providing a unique possibility to study matter under extreme conditions. In the first proof of principle experiment at the X-ray Free Electron Laser LCLS at SCLAC [Seely, J., Rosmej, F.B., Shepherd, R., Riley, D., Lee, R.W. Proposal to Perform the 1st High Energy Density Plasma Spectroscopic Pump/Probe Experiment”, approved LCLS proposal L332 (2010)] we have successfully pumped inner-shell X-ray transitions in dense plasmas. The plasma was generated with a YAG laser irradiating solid Al and Mg targets attached to a rotating cylinder. In parallel to the optical laser beam, the XFEL was focused into the plasma plume at different delay times and pump energies. Pumped X-ray transitions have been observed with a spherically bent crystal spectrometer coupled to a Princeton CCD. By using this experimental configuration, we have simultaneously achieved extremely high spectral (λ/δλ ≈ 5000) and spatial resolution (δx≈70 μm) while maintaining high luminosity and a large spectral range covered (6.90 - 8.35 Å). By precisely measuring the variations in spectra emitted from plasma under action of XFEL radiation, we have successfully demonstrated transient X- ray pumping in a dense plasma.

Structuring in fast-quenched ferrite compositions under plasma spraying

NASA Astrophysics Data System (ADS)

Lepeshev, A. A.; Karpov, I. V.; Ushakov, A. V.; Nagibin, G. E.; Dorozhkina, E. A.; Karpova, O. N.; Demin, V. G.; Shaikhadinov, A. A.

2017-06-01

The influence of the quench rate on structuring in spinel ferrites has been studied. It has been found that, when the quench rate is increased, the equilibrium spinel structure gradually becomes disordered. At the first stage, the statistically homogeneous (or almost homogeneous) redistribution of cations over crystal lattice sites has been observed. Then, the fcc lattice of the anion framework breaks down, the translational symmetry disappears, and topological chaos arises. The resulting cluster structural state is thermodynamically unstable, and heating of quenched ferrites causes stepwise energy liberation. As a result, the activity of ferrite powders in solid-state and catalytic reactions rises.

5.8kV SiC PiN Diode for Switching of High-Efficiency Inductive Pulsed Plasma Thruster Circuits

NASA Technical Reports Server (NTRS)

Toftul, Alexandra; Polzin, Kurt A.; Hudgins, Jerry L.

2014-01-01

Inductive Pulsed Plasma Thruster (IPPT) pulse circuits, such as those needed to operate the Pulsed Inductive Thruster (PIT), are required to quickly switch capacitor banks operating at a period of µs while conducting current at levels on the order of at least 10 kA. [1,2] For all iterations of the PIT to date, spark gaps have been used to discharge the capacitor bank through an inductive coil. Recent availability of fast, high-power solid state switching devices makes it possible to consider the use of semiconductor switches in modern IPPTs. In addition, novel pre-ionization schemes have led to a reduction in discharge energy per pulse for electric thrusters of this type, relaxing the switching requirements for these thrusters. [3,4] Solid state switches offer the advantage of greater controllability and reliability, as well as decreased drive circuit dimensions and mass relative to spark gap switches. The use of solid state devices such as Integrated Gate Bipolar Transistors (IGBTs), Gate Turn-off Thyristors (GTOs) and Silicon-Controlled Rectifiers (SCRs) often involves the use of power diodes. These semiconductor devices may be connected antiparallel to the switch for protection from reverse current, or used to reduce power loss in a circuit by clamping off current ringing. In each case, higher circuit efficiency may be achieved by using a diode that is able to transition, or 'switch,' from the forward conducting state ('on' state) to the reverse blocking state ('off' state) in the shortest amount of time, thereby minimizing current ringing and switching losses. Silicon Carbide (SiC) PiN diodes offer significant advantages to conventional fast-switching Silicon (Si) diodes for high power and fast switching applications. A wider band gap results in a breakdown voltage 10 times that of Si, so that a SiC device may have a thinner drift region for a given blocking voltage. [5] This leads to smaller, lighter devices for high voltage applications, as well as reduced forward conduction losses, faster reverse recovery time (faster turn-off), and lower-magnitude reverse recovery current. In addition, SiC devices have lower leakage current as compared to their Si counterparts, and a high thermal conductivity, potentially allowing the former to operate at higher temperatures with a smaller, lighter heatsink (or no heatsink at all).

Plasma power recycling at the divertor surface

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tang, Xian -Zhu; Guo, Zehua

With a divertor made of solid materials like carbon and tungsten, plasma ions are expected to be recycled at the divertor surface with a time-averaged particle recycling coefficient very close to unity in steady-state operation. This means that almost every plasma ion (hydrogen and helium) will be returned to the plasma, mostly as neutrals. The power flux deposited by the plasma on the divertor surface, on the other hand, can have varying recycling characteristics depending on the material choice of the divertor; the run-time atomic composition of the surface, which can be modified by material mix due to impurity migrationmore » in the chamber; and the surface morphology change over time. In general, a high-Z–material (such as tungsten) surface tends to reflect light ions and produce stronger power recycling, while a low-Z–material (such as carbon) surface tends to have a larger sticking coefficient for light ions and hence lower power recycling. Here, an explicit constraint on target plasma density and temperature is derived from the truncated bi-Maxwellian sheath model, in relation to the absorbed power load and power recycling coefficient at the divertor surface. Lastly, it is shown that because of the surface recombination energy flux, the attached plasma has a sharper response to power recycling in comparison to a detached plasma.« less

Plasma power recycling at the divertor surface

DOE PAGES

Tang, Xian -Zhu; Guo, Zehua

2016-12-03

With a divertor made of solid materials like carbon and tungsten, plasma ions are expected to be recycled at the divertor surface with a time-averaged particle recycling coefficient very close to unity in steady-state operation. This means that almost every plasma ion (hydrogen and helium) will be returned to the plasma, mostly as neutrals. The power flux deposited by the plasma on the divertor surface, on the other hand, can have varying recycling characteristics depending on the material choice of the divertor; the run-time atomic composition of the surface, which can be modified by material mix due to impurity migrationmore » in the chamber; and the surface morphology change over time. In general, a high-Z–material (such as tungsten) surface tends to reflect light ions and produce stronger power recycling, while a low-Z–material (such as carbon) surface tends to have a larger sticking coefficient for light ions and hence lower power recycling. Here, an explicit constraint on target plasma density and temperature is derived from the truncated bi-Maxwellian sheath model, in relation to the absorbed power load and power recycling coefficient at the divertor surface. Lastly, it is shown that because of the surface recombination energy flux, the attached plasma has a sharper response to power recycling in comparison to a detached plasma.« less

Targeted Therapy Directed by Genetic Testing in Treating Patients With Advanced Refractory Solid Tumors, Lymphomas, or Multiple Myeloma (The MATCH Screening Trial)

ClinicalTrials.gov

2018-06-25

Advanced Malignant Solid Neoplasm; Bladder Carcinoma; Breast Carcinoma; Cervical Carcinoma; Colon Carcinoma; Colorectal Carcinoma; Endometrial Carcinoma; Esophageal Carcinoma; Gastric Carcinoma; Glioma; Head and Neck Carcinoma; Kidney Carcinoma; Liver and Intrahepatic Bile Duct Carcinoma; Lung Carcinoma; Lymphoma; Malignant Uterine Neoplasm; Melanoma; Ovarian Carcinoma; Pancreatic Carcinoma; Plasma Cell Myeloma; Prostate Carcinoma; Rectal Carcinoma; Recurrent Bladder Carcinoma; Recurrent Breast Carcinoma; Recurrent Cervical Carcinoma; Recurrent Colon Carcinoma; Recurrent Colorectal Carcinoma; Recurrent Esophageal Carcinoma; Recurrent Gastric Carcinoma; Recurrent Glioma; Recurrent Head and Neck Carcinoma; Recurrent Liver Carcinoma; Recurrent Lung Carcinoma; Recurrent Lymphoma; Recurrent Malignant Solid Neoplasm; Recurrent Melanoma; Recurrent Ovarian Carcinoma; Recurrent Pancreatic Carcinoma; Recurrent Plasma Cell Myeloma; Recurrent Prostate Carcinoma; Recurrent Rectal Carcinoma; Recurrent Skin Carcinoma; Recurrent Thyroid Gland Carcinoma; Recurrent Uterine Corpus Carcinoma; Refractory Lymphoma; Refractory Malignant Solid Neoplasm; Refractory Plasma Cell Myeloma; Skin Carcinoma; Thyroid Gland Carcinoma; Uterine Corpus Cancer

Ab initio approach to the ion stopping power at the plasma-solid interface

NASA Astrophysics Data System (ADS)

Bonitz, Michael; Schlünzen, Niclas; Wulff, Lasse; Joost, Jan-Philip; Balzer, Karsten

2016-10-01

The energy loss of ions in solids is of key relevance for many applications of plasmas, ranging from plasma technology to fusion. Standard approaches are based on density functional theory or SRIM simulations, however, the applicability range and accuracy of these results are difficult to assess, in particular, for low energies. Here we present an independent approach that is based on ab initio nonequilibrium Green functions theory, e.g. that allows to incorporate electronic correlations effects of the solid. We present the first application of this method to low-temperature plasmas, concentrating on proton and alpha-particle stopping in a graphene layer. In addition to the stopping power we present time-dependent results for the local electron density, the spectral function and the photoemission spectrum that is directly accessible in optical, UV or x-ray diagnostics. http://www.itap.uni-kiel.de/theo-physik/bonitz/.

Determination of N-(trans-4-isopropylcyclohexylcarbonyl)-D-phenylalanine in human plasma by solid-phase extraction and column-switching high-performance liquid chromatography with ultraviolet detection.

PubMed

Ono, I; Matsuda, K; Kanno, S

1996-04-12

A column-switching high-performance liquid chromatography method with ultraviolet detection at 210 nm has been developed for the determination of N-(trans-4-isopropylcyclohexylcarbonyl)-D-phenylalanine (AY4166, I) in human plasma. Plasma samples were prepared by solid-phase extraction with Sep-Pak Light tC18, followed by HPLC. The calibration graph for I was linear in the range 0.1-20 micrograms/ml. The limit of quantitation of I, in plasma, was 0.05 microgram/ml. The recovery of spiked I (0.5 microgram/ml) to drug-free plasma was over 92% and the relative standard deviation of spiked I (0.5 microgram/ml) compared to drug-free plasma was 4.3% (n = 8).

Trace and surface analysis of ceramic layers of solid oxide fuel cells by mass spectrometry.

PubMed

Becker, J S; Breuer, U; Westheide, J; Saprykin, A I; Holzbrecher, H; Nickel, H; Dietze, H J

1996-06-01

For the trace analysis of impurities in thick ceramic layers of a solid oxide fuel cell (SOFC) sensitive solid-state mass spectrometric methods, such as laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) and radiofrequency glow discharge mass spectrometry (rf-GDMS) have been developed and used. In order to quantify the analytical results of LA-ICP-MS, the relative sensitivity coefficients of elements in a La(0.6)Sr(0.35)MnO(3) matrix have been determined using synthetic standards. Secondary ion mass spectrometry (SIMS) - as a surface analytical method - has been used to characterize the element distribution and diffusion profiles of matrix elements on the interface of a perovskite/Y-stabilized ZrO(2) layer. The application of different mass spectrometric methods for process control in the preparation of ceramic layers for the SOFC is described.

Solid State Division progress report for period ending September 30, 1993

DOE Office of Scientific and Technical Information (OSTI.GOV)

Green, P.H.; Hinton, L.W.

1994-08-01

This report covers research progress in the Solid State Division from April 1, 1992, to September 30, 1993. During this period, the division conducted a broad, interdisciplinary materials research program with emphasis on theoretical solid state physics, neutron scattering, synthesis and characterization of materials, ion beam and laser processing, and the structure of solids and surfaces. This research effort was enhanced by new capabilities in atomic-scale materials characterization, new emphasis on the synthesis and processing of materials, and increased partnering with industry and universities. The theoretical effort included a broad range of analytical studies, as well as a new emphasismore » on numerical simulation stimulated by advances in high-performance computing and by strong interest in related division experimental programs. Superconductivity research continued to advance on a broad front from fundamental mechanisms of high-temperature superconductivity to the development of new materials and processing techniques. The Neutron Scattering Program was characterized by a strong scientific user program and growing diversity represented by new initiatives in complex fluids and residual stress. The national emphasis on materials synthesis and processing was mirrored in division research programs in thin-film processing, surface modification, and crystal growth. Research on advanced processing techniques such as laser ablation, ion implantation, and plasma processing was complemented by strong programs in the characterization of materials and surfaces including ultrahigh resolution scanning transmission electron microscopy, atomic-resolution chemical analysis, synchrotron x-ray research, and scanning tunneling microscopy.« less

First Production of C60 Nanoparticle Plasma Jet for Study of Disruption Mitigation for ITER

NASA Astrophysics Data System (ADS)

Bogatu, I. N.; Thompson, J. R.; Galkin, S. A.; Kim, J. S.; Brockington, S.; Case, A.; Messer, S. J.; Witherspoon, F. D.

2012-10-01

Unique fast response and large mass-velocity delivery of nanoparticle plasma jets (NPPJs) provide a novel application for ITER disruption mitigation, runaway electrons diagnostics and deep fueling. NPPJs carry a much larger mass than usual gases. An electromagnetic plasma gun provides a very high injection velocity (many km/s). NPPJ has much higher ram pressure than any standard gas injection method and penetrates the tokamak confining magnetic field. Assimilation is enhanced due to the NP large surface-to-volume ratio. Radially expanding NPPJs help achieving toroidal uniformity of radiation power. FAR-TECH's NPPJ system was successfully tested: a coaxial plasma gun prototype (˜35 cm length, 96 kJ energy) using a solid state TiH2/C60 pulsed power cartridge injector produced a hyper-velocity (>4 km/s), high-density (>10^23 m-3), C60 plasma jet in ˜0.5 ms, with ˜1-2 ms overall response-delivery time. We present the TiH2/C60 cartridge injector output characterization (˜180 mg of sublimated C60 gas) and first production results of a high momentum C60 plasma jet (˜0.6 g.km/s).

Plasma-based polarizer and waveplate at large laser intensity

NASA Astrophysics Data System (ADS)

Lehmann, G.; Spatschek, K. H.

2018-06-01

A plasma photonic crystal consists of a plasma density grating which is created in underdense plasma by counterpropagating laser beams. When a high-power laser pulse impinges the crystal, it might be reflected or transmitted. So far only one type of pulse polarization, namely the so-called s wave (or TE mode) was investigated (when the electric field vector is perpendicular to the plane of incidence). Here, when investigating also so-called p waves (or TM modes, where the magnetic field vector is perpendicular to the plane of incidence), it is detected that the transmission and reflection properties of the plasma photonic crystal depend on polarization. A simple analytic model of the crystal allows one to make precise predictions. The first conclusion is that in some operational regime the crystal can act as a plasma polarizer for high-intensity laser pulses. Also, differences in phase velocities for grazing incidence between s and p polarization are found. Thus, secondly, the crystal can be utilized as a waveplate, e.g., transforming linearly polarized laser light into circular polarization. All these processes extend to laser intensities beyond the damage intensities of so far used solid state devices.

Mid-infrared lasers for energy frontier plasma accelerators

DOE PAGES

Pogorelsky, I. V.; Polyanskiy, M. N.; Kimura, W. D.

2016-09-12

Plasma wake field accelerators driven with solid-state near-IR lasers have been considered as an alternative to conventional rf accelerators for next-generation TeV-class lepton colliders. Here, we extend this study to the mid-IR spectral domain covered by CO 2 lasers. We conclude that the increase in the laser driver wavelength favors the regime of laser wake field acceleration with a low plasma density and high electric charge. This regime is the most beneficial for gamma colliders to be converted from lepton colliders via inverse Compton scattering. Selecting a laser wavelength to drive a Compton gamma source is essential for the designmore » of such a machine. In conclusion, the revealed benefits from spectral diversification of laser drivers for future colliders and off-spring applications validate ongoing efforts in advancing the ultrafast CO 2 laser technology.« less

X-Ray Radiation Measurements With Photodiodes In Plasmas Generated By 1017 W/Cm2 Intensity Krf Excimer Laser Pulses

NASA Astrophysics Data System (ADS)

Rácz, E.; Földes, I. B.; Ryć, L.

2006-01-01

Experiments were carried out using a prepulse-free hybrid KrF excimer-dye laser system (700fs pulse duration, 248nm wavelength, 15mJ pulse energy). The intensity of the p-polarized, focused laser beam was 1.5ṡ1017 W/cm2. Vacuum ultraviolet (VUV) and x-rays from solid state laser plasmas were generated in the laser-plasma interaction of subpicosecond laser pulses of nonrelativistic laser intensities. An x-ray sensitive FLM photodiode (ITE, Warsaw) was used to detect x-rays between 1-19 keV in front of the targets. The diode was filtered by a 4μm Al foil. The dependence of the x-ray flux on laser intensity and the angular distribution of x-rays for aluminum and copper targets in the half space of the front side of the targets were investigated.

Crystallization process of a three-dimensional complex plasma

NASA Astrophysics Data System (ADS)

Steinmüller, Benjamin; Dietz, Christopher; Kretschmer, Michael; Thoma, Markus H.

2018-05-01

Characteristic timescales and length scales for phase transitions of real materials are in ranges where a direct visualization is unfeasible. Therefore, model systems can be useful. Here, the crystallization process of a three-dimensional complex plasma under gravity conditions is considered where the system ranges up to a large extent into the bulk plasma. Time-resolved measurements exhibit the process down to a single-particle level. Primary clusters, consisting of particles in the solid state, grow vertically and, secondarily, horizontally. The box-counting method shows a fractal dimension of df≈2.72 for the clusters. This value gives a hint that the formation process is a combination of local epitaxial and diffusion-limited growth. The particle density and the interparticle distance to the nearest neighbor remain constant within the clusters during crystallization. All results are in good agreement with former observations of a single-particle layer.

Solid-state lighting for the International Space Station: Tests of visual performance and melatonin regulation

NASA Astrophysics Data System (ADS)

Brainard, George C.; Coyle, William; Ayers, Melissa; Kemp, John; Warfield, Benjamin; Maida, James; Bowen, Charles; Bernecker, Craig; Lockley, Steven W.; Hanifin, John P.

2013-11-01

The International Space Station (ISS) uses General Luminaire Assemblies (GLAs) that house fluorescent lamps for illuminating the astronauts' working and living environments. Solid-state light emitting diodes (LEDs) are attractive candidates for replacing the GLAs on the ISS. The advantages of LEDs over conventional fluorescent light sources include lower up-mass, power consumption and heat generation, as well as fewer toxic materials, greater resistance to damage and long lamp life. A prototype Solid-State Lighting Assembly (SSLA) was developed and successfully installed on the ISS. The broad aim of the ongoing work is to test light emitted by prototype SSLAs for supporting astronaut vision and assessing neuroendocrine, circadian, neurobehavioral and sleep effects. Three completed ground-based studies are presented here including experiments on visual performance, color discrimination, and acute plasma melatonin suppression in cohorts of healthy, human subjects under different SSLA light exposure conditions within a high-fidelity replica of the ISS Crew Quarters (CQ). All visual tests were done under indirect daylight at 201 lx, fluorescent room light at 531 lx and 4870 K SSLA light in the CQ at 1266 lx. Visual performance was assessed with numerical verification tests (NVT). NVT data show that there are no significant differences in score (F=0.73, p=0.48) or time (F=0.14, p=0.87) for subjects performing five contrast tests (10%-100%). Color discrimination was assessed with Farnsworth-Munsell 100 Hue tests (FM-100). The FM-100 data showed no significant differences (F=0.01, p=0.99) in color discrimination for indirect daylight, fluorescent room light and 4870 K SSLA light in the CQ. Plasma melatonin suppression data show that there are significant differences (F=29.61, p<0.0001) across the percent change scores of plasma melatonin for five corneal irradiances, ranging from 0 to 405 μW/cm2 of 4870 K SSLA light in the CQ (0-1270 lx). Risk factors for the health and safety of astronauts include disturbed circadian rhythms and altered sleep-wake patterns. These studies will help determine if SSLA lighting can be used both to support astronaut vision and serve as an in-flight countermeasure for circadian desynchrony, sleep disruption and cognitive performance deficits on the ISS.

Statistical Physics Experiments Using Dusty Plasmas

NASA Astrophysics Data System (ADS)

Goree, John

2016-10-01

Compared to other areas of physics research, Statistical Physics is heavily dominated by theory, with comparatively little experiment. One reason for the lack of experiments is the impracticality of tracking of individual atoms and molecules within a substance. Thus, there is a need for a different kind of experimental system, one where individual particles not only move stochastically as they collide with one another, but also are large enough to allow tracking. A dusty plasma can meet this need. A dusty plasma is a partially ionized gas containing small particles of solid matter. These micron-size particles gain thousands of electronic charges by collecting more electrons than ions. Their motions are dominated by Coulomb collisions with neighboring particles. In this so-called strongly coupled plasma, the dust particles self-organize in much the same way as atoms in a liquid or solid. Unlike atoms, however, these particles are large and slow, so that they can be tracked easily by video microscopy. Advantages of dusty plasma for experimental statistical physics research include particle tracking, lack of frictional contact with solid surfaces, and avoidance of overdamped motion. Moreover, the motion of a collection of dust particles can mimic an equilibrium system with a Maxwellian velocity distribution, even though the dust particles themselves are not truly in thermal equilibrium. Nonequilibrium statistical physics can be studied by applying gradients, for example by imposing a shear flow. In this talk I will review some of our recent experiments with shear flow. First, we performed the first experimental test to verify the Fluctuation Theorem for a shear flow, showing that brief violations of the Second Law of Thermodynamics occur with the predicted probabilities, for a small system. Second, we discovered a skewness of a shear-stress distribution in a shear flow. This skewness is a phenomenon that likely has wide applicability in nonequilibrium steady states. Third, we performed the first experimental test of a statistical physics theory (the Green-Kubo model) that is widely used by physical chemists to compute viscosity coefficients, and we found that it fails. Work supported by the U.S. Department of Energy, NSF, and NASA.

The Tea-Carbon Dioxide Laser as a Means of Generating Ultrasound in Solids

NASA Astrophysics Data System (ADS)

Taylor, Gregory Stuart

1990-01-01

Available from UMI in association with The British Library. Requires signed TDF. The aim of this thesis is to characterise the interaction between pulsed, high power, 10.6 mu m radiation and solids. The work is considered both in the general context of laser generation of ultrasound and specifically to gain a deeper understanding of the interaction between a laser supported plasma and a solid. The predominant experimental tools used are the homodyne Michelson interferometer and a range of electromagnetic acoustic transducers. To complement the ultrasonic data, various plasma inspection techniques, such as high speed, streak camera photography and reflection photometry, have been used to correlate the plasma properties with those of the ultrasonic transients. The work involving the characterisation of a laser supported plasma with a solid, which is based on previous experimental and theoretical analysis, gives an increased understanding of the plasma's ultrasonic generation mechanism. The ability to record the entire plasma-sample interaction, time history yields information of the internal dynamics of the plasma growth and shock wave generation. The interaction of the radiation with a solid is characterised in both the plasma breakdown and non-breakdown regimes by a wide ultrasonic source. The variation in source diameter enables the transition from a point to a near planar ultrasonic source to be studied. The resultant ultrasonic modifications are examined in terms of the wave structure and the directivity pattern. The wave structure is analysed in terms of existing wide source, bulk wave theories and extended to consider the effects on surface and Lamb waves. The directivity patterns of the longitudinal and shear waves are analysed in terms of top-hat and non -uniform source profiles, giving additional information into the radiation-solid interaction. The wide, one dimensional source analysis is continued to a two dimensional, extended ultrasonic source, generated on non-metals by the optical penetration of radiation within the target. The generation of ultrasound in both metals and non-metals, using the CO_2 laser, is shown to be an efficient process and may be employed almost totally non-destructively. Such a laser may therefore be used effectively on a greatly enhanced range of materials than those tested to-date via laser generation, resulting in the increased suitability of the laser technique within the field of Non Destructive Testing.

Comparative Plasma Exposure of Albendazole after Administration of Rapidly Disintegrating Tablets in Dogs

PubMed Central

Castro, Silvina G.; Dib, Alicia; Suarez, Gonzalo; Allemandi, Daniel; Lanusse, Carlos; Sanchez Bruni, Sergio; Palma, Santiago D.

2013-01-01

The main objectives of this study were (a) to evaluate the in vitro performance of the rapid disintegration tablets as a way to improve the solid dispersions and (b) to study the in vivo pharmacokinetics of the albendazole modified formulation in dogs. Rapid disintegration of tablets seems to be a key factor for efficiency of solid dispersions with regard to improvement of the albendazole bioavailability. The in vivo assays performed on dogs showed a marked increase in drug plasma exposure when albendazole was given in solid dispersions incorporated into rapid disintegration tablets compared with conventional solid dosage form. PMID:24063016

Hydrodynamic Instabilities in High-Energy-Density Settings

NASA Astrophysics Data System (ADS)

Smalyuk, Vladimir

2016-10-01

Our understanding of hydrodynamic instabilities, such as the Rayleigh-Taylor (RT), Richtmyer-Meshkov (RM), and Kelvin-Helmholtz (KH) instabilities, in high-energy-density (HED) settings over past two decades has progressed enormously. The range of conditions where hydrodynamic instabilities are experimentally observed now includes direct and indirect drive inertial confinement fusion (ICF) where surprises continue to emerge, linear and nonlinear regimes, classical interfaces vs. stabilized ablation fronts, tenuous ideal plasmas vs. high density Fermi degenerate plasmas, bulk fluid interpenetration vs. mixing down to the atomic level, in the presence of magnetic fields and/or intense radiation, and in solid state plastic flow at high pressures and strain rates. Regimes in ICF can involve extreme conditions of matter with temperatures up to kilovolts, densities of a thousand times solid densities, and time scales of nanoseconds. On the other hand, scaled conditions can be generated that map to exploding stars (supernovae) with length and time scales of millions of kilometers and hours to days or even years of instability evolution, planetary formation dynamics involving solid-state plastic flow which severely modifies the RT growth and continues to challenge reliable theoretical descriptions. This review will look broadly at progress in probing and understanding hydrodynamic instabilities in these very diverse HED settings, and then will examine a few cases in more depth to illustrate the detailed science involved. Experimental results on large-scale HED facilities such as the Omega, Nike, Gekko, and Shenguang lasers will be reviewed and the latest developments at the National Ignition Facility (NIF) and Z machine will be covered. Finally, current overarching questions and challenges will be summarized to motivate research directions for future. This work was performed under the auspices of the U.S. Department of Energy by LLNL under Contract DE-AC52-07NA27344.

Effects of anode geometry on forward wide-angle neon ion emissions in 3.5 kJ plasma focus device by novel mega-size panorama polycarbonate image detectors

NASA Astrophysics Data System (ADS)

Sohrabi, M.; Soltani, Z.; Sarlak, Z.

2018-03-01

Forward wide-angle neon ion emissions in a 3.5 kJ plasma focus device (PFD) were studied using 5 different anode top geometries; hollow-end cylinder, solid triangle, solid hemisphere, hollow-end cone and flat-end cone. Position-sensitive mega-size panorama polycarbonate ion image detectors (MS-PCID) developed by dual-cell circular mega-size electrochemical etching (MS-ECE) systems were applied for processesing wide-angle neon ion images on MS-PCIDs exposed on the PFD cylinder top base under a single pinch shot. The images can be simply observed, analyzed and relatively quantified in terms of ion emission angular distributions even by the unaided eyes. By analysis of the forward neon ion emission images, the ion emission yields, ion emission angular distributions, iso-fluence ion contours and solid angles of ion emissions in 4π PFD space were determined. The neon ion emission yields on the PFD cylinder top base are in an increasing order ~2.1×109, ~2.2 ×109, ~2.8×109, ~2.9×109, and ~3.5×109 neon ions/shot for the 5 stated anode top geometries respectively. The panorama neon ion images as diagnosed even by the unaided eyes demonstrate the lowest and highest ion yields from the hollow-end cylinder and flat-end cone anode tops respectively. Relative dynamic qualitative neon ion spectrometry was made by the unaided eyes demonstrating relative neon ion energy as they appear. The study also demonstrates the unique power of the MS-PCID/MS-ECE imaging system as an advanced state-of-the-art ion imaging method for wide-angle dynamic parametric studies in PFD space and other ion study applications.

CO2 laser drives extreme ultraviolet nano-lithography — second life of mature laser technology

NASA Astrophysics Data System (ADS)

Nowak, K. M.; Ohta, T.; Suganuma, T.; Fujimoto, J.; Mizoguchi, H.; Sumitani, A.; Endo, A.

2013-12-01

It was shown both theoretically and experimentally that nanosecond order laser pulses at 10.6 micron wavelength were superior for driving the Sn plasma extreme ultraviolet (EUV) source for nano-lithography for the reasons of higher conversion efficiency, lower production of debris and higher average power levels obtainable in CO2 media without serious problems of beam distortions and nonlinear effects occurring in competing solid-state lasers at high intensities. The renewed interest in such pulse format, wavelength, repetition rates in excess of 50 kHz and average power levels in excess of 18 kiloWatt has sparked new opportunities for a matured multi-kiloWatt CO2 laser technology. The power demand of EUV source could be only satisfied by a Master-Oscillator-Power-Amplifier system configuration, leading to a development of a new type of hybrid pulsed CO2 laser employing a whole spectrum of CO2 technology, such as fast flow systems and diffusion-cooled planar waveguide lasers, and relatively recent quantum cascade lasers. In this paper we review briefly the history of relevant pulsed CO2 laser technology and the requirements for multi-kiloWatt CO2 laser, intended for the laser-produced plasma EUV source, and present our recent advances, such as novel solid-state seeded master oscillator and efficient multi-pass amplifiers built on planar waveguide CO2 lasers.

Compact and multi-view solid state neutral particle analyzer arrays on National Spherical Torus Experiment-Upgrade

DOE PAGES

Liu, D.; Heidbrink, W. W.; Tritz, K.; ...

2016-07-29

A compact and multi-view solid state neutral particle analyzer (SSNPA) diagnostic based on silicon photodiode arrays has been successfully tested on the National Spherical Torus Experiment-Upgrade. The SSNPA diagnostic provides spatially, temporally, and pitch-angle resolved measurements of fast-ion distribution by detecting fast neutral flux resulting from the charge exchange (CX) reactions. The system consists of three 16-channel subsystems: t-SSNPA viewing the plasma mid-radius and neutral beam (NB) line #2 tangentially, r-SSNPA viewing the plasma core and NB line #1 radially, and p-SSNPA with no intersection with any NB lines. Due to the setup geometry, the active CX signals of t-SSNPAmore » and r-SSNPA are mainly sensitive to passing and trapped particles, respectively. Additionally, both t-SSNPA and r-SSNPA utilize three vertically stacked arrays with different filter thicknesses to obtain coarse energy information. The experimental data show that all channels are operational. The signal to noise ratio is typically larger than 10, and the main noise is x-ray induced signal. The active and passive CX signals are clearly observed on t-SSNPA and r-SSNPA during NB modulation. The SSNPA data also indicate significant losses of passing particles during sawteeth, while trapped particles are weakly affected. Fluctuations up to 120 kHz have been observed on SSNPA, and they are strongly correlated with magnetohydrodynamics instabilities.« less

Development of barrier coatings for cellulosic-based materials by cold plasma methods

NASA Astrophysics Data System (ADS)

Denes, Agnes Reka

Cellulose-based materials are ideal candidates for future industries that need to be based on environmentally safe technologies and renewable resources. Wood represents an important raw material and its application as construction material is well established. Cellophane is one of the most important cellulosic material and it is widely used as packaging material in the food industry. Outdoor exposure of wood causes a combination of physical and chemical degradation processes due to the combined effects of sunlight, moisture, fungi, and bacteria. Cold-plasma-induced surface modifications are an attractive way for tailoring the characteristics of lignocellulosic substrates to prevent weathering degradation. Plasma-polymerized hexamethyldisiloxane (PPHMDSO) was deposited onto wood surfaces to create water repellent characteristics. The presence of a crosslinked macromolecular structure was detected. The plasma coated samples exhibited very high water contact angle values indicating the existence of hydrophobic surfaces. Reflective and electromagnetic radiation-absorbent substances were incorporated with a high-molecular-weight polydimethylsiloxane polymer in liquid phase and deposited as thin layers on wood surfaces. The macromolecular films, containing the dispersed materials, were then converted into a three dimensional solid state network by exposure to a oxygen-plasma. It was demonstrated that both UV-absorbent and reflectant components incorporated into the plasma-generated PDMSO matrix protected the wood from weathering degradation. Reduced oxidation and less degradation was observed after simulated weathering. High water contact angle values indicated a strong hydrophobic character of the oxygen plasma-treated PDMSO-coated samples. Plasma-enhanced surface modifications and coatings were employed to create water-vapor barrier layers on cellophane substrate surfaces. HMDSO was selected as a plasma gas and oxygen was used to ablate amorphous regions. Oxygen plasma treated cellophane and oxygen plasma treated and PPHMDSO coated cellophane surfaces were comparatively analyzed and the corresponding surface wettability characteristics were evaluated. The plasma generated surface topographies controlled the morphology of the PPHMDSO layers. Higher temperature HMDSO plasma-state environments lead to insoluble, crosslinked layers. Continuous and pulsed Csb2Fsb6 plasmas were also used for surface modification and excellent surface fluorination was achieved under the pulsed plasma conditions.

Morphological Control of In x Ga 1–x P Nanocrystals Synthesized in a Nonthermal Plasma

DOE PAGES

Bronstein, Noah D.; Wheeler, Lance M.; Anderson, Nicholas C.; ...

2018-04-09

We explore the growth of InxGa1-xP nanocrystals (x = 1, InP; x = 0, GaP; and 1 > x > 0, alloys) in a nonthermal plasma. By tuning the reactor conditions, we gain control over the morphology of the final product, producing either 10 nm diameter hollow nanocrystals or smaller 3 nm solid nanocrystals. We observe the gas-phase chemistry in the plasma reactor using plasma emission spectroscopy to understand the growth mechanism of the hollow versus solid morphology. We also connect this plasma chemistry to the subsequent native surface chemistry of the nanocrystals, which is dominated by the presence ofmore » both dative- and lattice-bound phosphine species. The dative phosphines react readily with oleylamine in an L-type ligand exchange reaction, evolving phosphines and allowing the particles to be dispersed in nonpolar solvents. Subsequent treatment by HF causes the solid InP1.5 and In0.5Ga0.5P1.3 to become photoluminescent, whereas the hollow particles remain nonemissive.« less

Morphological Control of In xGa 1–xP Nanocrystals Synthesized in a Nonthermal Plasma

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bronstein, Noah D.; Wheeler, Lance M.; Anderson, Nicholas C.

Here, we explore the growth of In xGa 1–xP nanocrystals (x = 1, InP; x = 0, GaP; and 1 > x > 0, alloys) in a nonthermal plasma. By tuning the reactor conditions, we gain control over the morphology of the final product, producing either 10 nm diameter hollow nanocrystals or smaller 3 nm solid nanocrystals. We observe the gas-phase chemistry in the plasma reactor using plasma emission spectroscopy to understand the growth mechanism of the hollow versus solid morphology. We also connect this plasma chemistry to the subsequent native surface chemistry of the nanocrystals, which is dominated bymore » the presence of both dative- and lattice-bound phosphine species. The dative phosphines react readily with oleylamine in an L-type ligand exchange reaction, evolving phosphines and allowing the particles to be dispersed in nonpolar solvents. Subsequent treatment by HF causes the solid InP 1.5 and In 0.5Ga 0.5P 1.3 to become photoluminescent, whereas the hollow particles remain nonemissive.« less

Morphological Control of In xGa 1–xP Nanocrystals Synthesized in a Nonthermal Plasma

DOE PAGES

Bronstein, Noah D.; Wheeler, Lance M.; Anderson, Nicholas C.; ...

2018-04-09

Here, we explore the growth of In xGa 1–xP nanocrystals (x = 1, InP; x = 0, GaP; and 1 > x > 0, alloys) in a nonthermal plasma. By tuning the reactor conditions, we gain control over the morphology of the final product, producing either 10 nm diameter hollow nanocrystals or smaller 3 nm solid nanocrystals. We observe the gas-phase chemistry in the plasma reactor using plasma emission spectroscopy to understand the growth mechanism of the hollow versus solid morphology. We also connect this plasma chemistry to the subsequent native surface chemistry of the nanocrystals, which is dominated bymore » the presence of both dative- and lattice-bound phosphine species. The dative phosphines react readily with oleylamine in an L-type ligand exchange reaction, evolving phosphines and allowing the particles to be dispersed in nonpolar solvents. Subsequent treatment by HF causes the solid InP 1.5 and In 0.5Ga 0.5P 1.3 to become photoluminescent, whereas the hollow particles remain nonemissive.« less

Combustion flame-plasma hybrid reactor systems, and chemical reactant sources

DOEpatents

Kong, Peter C

2013-11-26

Combustion flame-plasma hybrid reactor systems, chemical reactant sources, and related methods are disclosed. In one embodiment, a combustion flame-plasma hybrid reactor system comprising a reaction chamber, a combustion torch positioned to direct a flame into the reaction chamber, and one or more reactant feed assemblies configured to electrically energize at least one electrically conductive solid reactant structure to form a plasma and feed each electrically conductive solid reactant structure into the plasma to form at least one product is disclosed. In an additional embodiment, a chemical reactant source for a combustion flame-plasma hybrid reactor comprising an elongated electrically conductive reactant structure consisting essentially of at least one chemical reactant is disclosed. In further embodiments, methods of forming a chemical reactant source and methods of chemically converting at least one reactant into at least one product are disclosed.

Enhancing Electrochemical Performance of Graphene Fiber-Based Supercapacitors by Plasma Treatment.

PubMed

Meng, Jie; Nie, Wenqi; Zhang, Kun; Xu, Fujun; Ding, Xin; Wang, Shiren; Qiu, Yiping

2018-04-25

Graphene fiber-based supercapacitors (GFSCs) hold high power density, fast charge-discharge rate, ultralong cycling life, exceptional mechanical/electrical properties, and safe operation conditions, making them very promising to power small wearable electronics. However, the electrochemical performance is still limited by the severe stacking of graphene sheets, hydrophobicity of graphene fibers, and complex preparation process. In this work, we develop a facile but robust strategy to easily enhance electrochemical properties of all-solid-state GFSCs by simple plasma treatment. We find that 1 min plasma treatment under an ambient condition results in 33.1% enhancement of areal specific capacitance (36.25 mF/cm 2 ) in comparison to the as-prepared GFSC. The energy density reaches 0.80 μW h/cm 2 in polyvinyl alcohol/H 2 SO 4 gel electrolyte and 18.12 μW h/cm 2 in poly(vinylidene difluoride)/ethyl-3-methylimidazolium tetrafluoroborate electrolyte, which are 22 times of that of as-prepared ones. The plasma-treated GFSCs also exhibit ultrahigh rate capability (69.13% for 40 s plasma-treated ones) and superior cycle stability (96.14% capacitance retention after 20 000 cycles for 1 min plasma-treated ones). This plasma strategy can be extended to mass-manufacture high-performance carbonaceous fiber-based supercapacitors, such as graphene and carbon nanotube-based ones.

One-dimensional hybrid model of plasma-solid interaction in argon plasma at higher pressures

NASA Astrophysics Data System (ADS)

Jelínek, P.; Hrach, R.

2007-04-01

One of problems important in the present plasma science is the surface treatment of materials at higher pressures, including the atmospheric pressure plasma. The theoretical analysis of processes in such plasmas is difficult, because the theories derived for collisionless or slightly collisional plasma lose their validity at medium and high pressures, therefore the methods of computational physics are being widely used. There are two basic ways, how to model the physical processes taking place during the interaction of plasma with immersed solids. The first technique is the particle approach, the second one is called the fluid modelling. Both these approaches have their limitations-small efficiency of particle modelling and limited accuracy of fluid models. In computer modelling is endeavoured to use advantages by combination of these two approaches, this combination is named hybrid modelling. In our work one-dimensional hybrid model of plasma-solid interaction has been developed for an electropositive plasma at higher pressures. We have used hybrid model for this problem only as the test for our next applications, e.g. pulsed discharge, RF discharge, etc. The hybrid model consists of a combined molecular dynamics-Monte Carlo model for fast electrons and fluid model for slow electrons and positive argon ions. The latter model also contains Poisson's equation, to obtain a self-consistent electric field distribution. The derived results include the spatial distributions of electric potential, concentrations and fluxes of individual charged species near the substrate for various pressures and for various probe voltage bias.

Di-p-xylylene polymer and method for making the same

DOEpatents

Jahn, Randy K.; Liepins, Raimond

1985-01-01

A method and apparatus for forming an improved poly-p-xylylene film. Solid di-para-xylylene dimer is sublimed in a sublimation furnace at approximately 100.degree. to 200.degree. C. and subsequently conducted to a pyrolysis furnace where it is pyrolyzed to the diradical p-xylylene monomer while in the vapor state at approximately 600 degrees C. The diradical monomer is then introduced into a deposition chamber for deposition onto a suitable substrate. The deposition chamber includes electrodes for producing a low pressure plasma through which the diradical monomer passes prior to deposition. The interaction of the diradical monomer with the low pressure plasma results in the formation of poly-p-xylylene film which is exceptionally hard and thermally stable.

Numerical study of transition to supersonic flows in the edge plasma

DOE Office of Scientific and Technical Information (OSTI.GOV)

Goswami, Rajiv, E-mail: rajiv@ipr.res.in; Artaud, Jean-François; Imbeaux, Frédéric

The plasma scrape-off layer (SOL) in a tokamak is characterized by ion flow down a long narrow flux tube terminating on a solid surface. The ion flow velocity along a magnetic field line can be equal to or greater than sonic at the entrance of a Debye sheath or upstream in the presheath. This paper presents a numerical study of the transition between subsonic and supersonics flows. A quasineutral one-dimensional (1D) fluid code has been used for modeling of plasma transport in the SOL along magnetic field lines, both in steady state and under transient conditions. The model uses coupledmore » equations for continuity, momentum, and energy balance with ionization, radiation, charge exchange, and recombination processes. The recycled neutrals are described in the diffusion approximation. Standard Bohm sheath criterion is used as boundary conditions at the material surface. Three conditions conducive for the generation of supersonic flows in SOL plasmas have been explored. It is found that in steady state high (attached) and low (detached) divertor temperatures cases, the role of particle, momentum, and energy loss is critical. For attached case, the appearance of shock waves in the divertor region if the incoming plasma flow is supersonic and its effect on impurity retention is presented. In the third case, plasma expansion along the magnetic field can yield time-dependent supersonic solutions in the quasineutral rarefaction wave. Such situations can arise in the parallel transport of intermittent structures such as blobs and edge localized mode filaments along field lines.« less

Laser ablation with applied magnetic field for electric propulsion

NASA Astrophysics Data System (ADS)

Batishcheva, Alla; Batishchev, Oleg; Cambier, Jean-Luc

2012-10-01

Using ultrafast lasers with tera-watt-level power allows efficient ablation and ionization of solid-density materials [1], creating dense and hot (˜100eV) plasma. We propose ablating small droplets in the magnetic nozzle configurations similar to mini-helicon plasma source [2]. Such approach may improve the momentum coupling compared to ablation of solid surfaces and facilitate plasma detachment. Results of 2D modeling of solid wire ablation in the applied magnetic field are presented and discussed. [4pt] [1] O. Batishchev et al, Ultrafast Laser Ablation for Space Propulsion, AIAA technical paper 2008-5294, -16p, 44th JPC, Hartford, 2008.[0pt] [2] O. Batishchev and J.L. Cambier, Experimental Study of the Mini-Helicon Thruster, Air Force Research Laboratory Report, AFRL-RZ-ED-TR-2009-0020, 2009.

N-MOSFETs Formed on Solid Phase Epitaxially Grown GeSn Film with Passivation by Oxygen Plasma Featuring High Mobility.

PubMed

Fang, Yung-Chin; Chen, Kuen-Yi; Hsieh, Ching-Heng; Su, Chang-Chia; Wu, Yung-Hsien

2015-12-09

Solid phase epitaxially grown GeSn was employed as the platform to assess the eligibility of direct O2 plasma treatment on GeSn surface for passivation of GeSn N-MOSFETs. It has been confirmed that O2 plasma treatment forms a GeSnO(x) film on the surface and the GeSnO(x) topped by in situ Al2O3 constitutes the gate stack of GeSn MOS devices. The capability of the surface passivation was evidenced by the low interface trap density (D(it)) of 1.62 × 10(11) cm(-2) eV(-1), which is primarily due to the formation of Ge-O and Sn-O bonds at the surface by high density/reactivity oxygen radicals that effectively suppress dangling bonds and decrease gap states. The good D(it) not only makes tiny frequency dispersion in the characterization of GeSn MOS capacitors, but results in GeSn N-MOSFETs with outstanding peak electron mobility as high as 518 cm(2)/(V s) which outperforms other devices reported in the literature due to reduced undesirable carrier scattering. In addition, the GeSn N-MOSFETs also exhibit promising characteristics in terms of acceptable subthreshold swing of 156 mV/dec and relatively large I(ON)/I(OFF) ratio more than 4 orders. Moreover, the robust reliability in terms small V(t) variation against high field stress attests the feasibility of using the O2 plasma-treated passivation to advanced GeSn technology.

Dense electron-positron plasmas and ultraintense γ rays from laser-irradiated solids.

PubMed

Ridgers, C P; Brady, C S; Duclous, R; Kirk, J G; Bennett, K; Arber, T D; Robinson, A P L; Bell, A R

2012-04-20

In simulations of a 10 PW laser striking a solid, we demonstrate the possibility of producing a pure electron-positron plasma by the same processes as those thought to operate in high-energy astrophysical environments. A maximum positron density of 10(26) m(-3) can be achieved, 7 orders of magnitude greater than achieved in previous experiments. Additionally, 35% of the laser energy is converted to a burst of γ rays of intensity 10(22) W cm(-2), potentially the most intense γ-ray source available in the laboratory. This absorption results in a strong feedback between both pair and γ-ray production and classical plasma physics in the new "QED-plasma" regime.

Status of the laser ion source at IMP

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sha, S.; Graduate University of Chinese Academy of Sciences, Beijing 100049; School of Nuclear science and technology, Lanzhou University, Lanzhou 73000

2012-02-15

A laser (Nd:YAG laser, 3 J, 1064 nm, 8-10 ns) ion source has been built and under development at IMP to provide pulsed high-charge-state heavy ion beams to a radio frequency quadrupole (RFQ) for upgrading the IMP accelerators with a new low-energy beam injector. The laser ion source currently operates in a direct plasma injection scheme to inject the high charge state ions produced from a solid target into the RFQ. The maximum power density on the target was about 8.4 x 10{sup 12} W/cm{sup 2}. The preliminary experimental results will be presented and discussed in this paper.

Signal Conditioning for Satellite Borne Energetic-Charged-Particle Experiments

NASA Technical Reports Server (NTRS)

Ludwig, George H.

1961-01-01

Many of the spacecraft launched thus far have carried detectors for investigating cosmic rays, solar protons, solar plasmas, and the geomagnetically trapped radiation. These detectors, which will find continued application in the future, include ion chambers; proportional, Geiger-Muller, scintillation, Cerenkov, and solid state detectors; ion collectors; and nuclear emulsions. The instrumentation required to condition the signals from these detectors prior to telemetering is steadily growing more complex in order to permit more meaningful measurements. This report describes a number of instrumentation elements typical of the present state of the art, and a present-generation three-detector system which illustrates the integration of such basic elements into a complex system.

Laser opacity in underdense preplasma of solid targets due to quantum electrodynamics effects

NASA Astrophysics Data System (ADS)

Wang, W.-M.; Gibbon, P.; Sheng, Z.-M.; Li, Y.-T.; Zhang, J.

2017-07-01

We investigate how next-generation laser pulses at 10 -200 PW interact with a solid target in the presence of a relativistically underdense preplasma produced by amplified spontaneous emission (ASE). Laser hole boring and relativistic transparency are strongly restrained due to the generation of electron-positron pairs and γ -ray photons via quantum electrodynamics (QED) processes. A pair plasma with a density above the initial preplasma density is formed, counteracting the electron-free channel produced by hole boring. This pair-dominated plasma can block laser transport and trigger an avalanchelike QED cascade, efficiently transferring the laser energy to the photons. This renders a 1 -μ m scale-length, underdense preplasma completely opaque to laser pulses at this power level. The QED-induced opacity therefore sets much higher contrast requirements for such a pulse in solid-target experiments than expected by classical plasma physics. Our simulations show, for example, that proton acceleration from the rear of a solid with a preplasma would be strongly impaired.

Lithium-based surfaces controlling fusion plasma behavior at the plasma-material interfacea)

NASA Astrophysics Data System (ADS)

Allain, Jean Paul; Taylor, Chase N.

2012-05-01

The plasma-material interface and its impact on the performance of magnetically confined thermonuclear fusion plasmas are considered to be one of the key scientific gaps in the realization of nuclear fusion power. At this interface, high particle and heat flux from the fusion plasma can limit the material's lifetime and reliability and therefore hinder operation of the fusion device. Lithium-based surfaces are now being used in major magnetic confinement fusion devices and have observed profound effects on plasma performance including enhanced confinement, suppression and control of edge localized modes (ELM), lower hydrogen recycling and impurity suppression. The critical spatial scale length of deuterium and helium particle interactions in lithium ranges between 5-100 nm depending on the incident particle energies at the edge and magnetic configuration. Lithium-based surfaces also range from liquid state to solid lithium coatings on a variety of substrates (e.g., graphite, stainless steel, refractory metal W/Mo/etc., or porous metal structures). Temperature-dependent effects from lithium-based surfaces as plasma facing components (PFC) include magnetohydrodynamic (MHD) instability issues related to liquid lithium, surface impurity, and deuterium retention issues, and anomalous physical sputtering increase at temperatures above lithium's melting point. The paper discusses the viability of lithium-based surfaces in future burning-plasma environments such as those found in ITER and DEMO-like fusion reactor devices.

Novel cryogenic sources for liquid droplet and solid filament beams

NASA Astrophysics Data System (ADS)

Grams, Michael P.

Two novel atomic and molecular beam sources have been created and tested consisting first of a superfluid helium liquid jet, and secondly a solid filament of argon. The superfluid helium apparatus is the second of its kind in the world and uses a modified liquid helium cryostat to inject a cylindrical stream of superfluid helium into vacuum through glass capillary nozzles with diameters on the order of one micron created on-site at Arizona State University. The superfluid beam is an entirely new way to study superfluid behavior, and has many new applications such as superfluid beam-surface scattering, beam-beam scattering, and boundary-free study of superfluidity. The solid beam of argon is another novel beam source created by flowing argon gas through a capillary 50 microns in diameter which is clamped by a small copper plate to a copper block kept at liquid nitrogen temperature. The gas subsequently cools and solidifies plugging the capillary. Upon heating, the solid plug melts and liquid argon exits the capillary and immediately freezes by evaporative cooling. The solid filaments may find application as wall-less cryogenic matrices, or targets for laser plasma sources of extreme UV and soft x-ray sources.

Relationship Between Particle and Plasma Properties and Coating Characteristics of Samaria-Doped Ceria Prepared by Atmospheric Plasma Spraying for Use in Solid Oxide Fuel Cells

NASA Astrophysics Data System (ADS)

Cuglietta, Mark; Kesler, Olivera

2012-06-01

Samaria-doped ceria (SDC) has become a promising material for the fabrication of high-performance, intermediate-temperature solid oxide fuel cells (SOFCs). In this study, the in-flight characteristics, such as particle velocity and surface temperature, of spray-dried SDC agglomerates were measured and correlated to the resulting microstructures of SDC coatings fabricated using atmospheric plasma spraying, a manufacturing technique with the capability of producing full cells in minutes. Plasmas containing argon, nitrogen and hydrogen led to particle surface temperatures higher than those in plasmas containing only argon and nitrogen. A threshold temperature for the successful deposition of SDC on porous stainless steel substrates was calculated to be 2570 °C. Coating porosity was found to be linked to average particle temperature, suggesting that plasma conditions leading to lower particle temperatures may be most suitable for fabricating porous SOFC electrode layers.

Comparison of cryogenic (hydrogen) and TESPEL (polystyrene) pellet particle deposition in a magnetically confined plasma

NASA Astrophysics Data System (ADS)

McCarthy, K. J.; Tamura, N.; Combs, S. K.; Panadero, N.; Ascabíbar, E.; Estrada, T.; García, R.; Hernández Sánchez, J.; López Fraguas, A.; Navarro, M.; Pastor, I.; Soleto, A.; TJ-II Team

2017-10-01

A cryogenic pellet injector (PI) and tracer encapsulated solid pellet (TESPEL) injector system has been operated in combination on the stellarator TJ-II. This unique arrangement has been created by piggy-backing a TESPEL injector onto the backend of a pipe-gun-type PI. The combined injector provides a powerful new tool for comparing ablation and penetration of polystyrene TESPEL pellets and solid hydrogen pellets, as well as for contrasting subsequent pellet particle deposition and plasma perturbation under analogous plasma conditions. For instance, a significantly larger increase in plasma line-averaged electron density, and electron content, is observed after a TESPEL pellet injection compared with an equivalent cryogenic pellet injection. Moreover, for these injections from the low-magnetic-field side of the plasma cross-section, TESPEL pellets deposit electrons deeper into the plasma core than cryogenic pellets. Finally, the physics behind these observations and possible implications for pellet injection studies are discussed.

Investigation of surface boundary conditions for continuum modeling of RF plasmas

NASA Astrophysics Data System (ADS)

Wilson, A.; Shotorban, B.

2018-05-01

This work was motivated by a lacking general consensus in the exact form of the boundary conditions (BCs) required on the solid surfaces for the continuum modeling of Radiofrequency (RF) plasmas. Various kinds of number and energy density BCs on solid surfaces were surveyed, and how they interacted with the electric potential BC to affect the plasma was examined in two fundamental RF plasma reactor configurations. A second-order local mean energy approximation with equations governing the electron and ion number densities and the electron energy density was used to model the plasmas. Zero densities and various combinations of drift, diffusion, and thermal fluxes were considered to set up BCs. It was shown that the choice of BC can have a significant impact on the sheath and bulk plasma. The thermal and diffusion fluxes to the surface were found to be important. A pure drift BC for dielectric walls failed to produce a sheath.

Ultrafast and nanoscale diodes

NASA Astrophysics Data System (ADS)

Zhang, Peng; Lau, Y. Y.

2016-10-01

Charge carrier transport across interfaces of dissimilar materials (including vacuum) is the essence of all electronic devices. Ultrafast charge transport across a nanometre length scale is of fundamental importance in the miniaturization of vacuum and plasma electronics. With the combination of recent advances in electronics, photonics and nanotechnology, these miniature devices may integrate with solid-state platforms, achieving superior performance. This paper reviews recent modelling efforts on quantum tunnelling, ultrafast electron emission and transport, and electrical contact resistance. Unsolved problems and challenges in these areas are addressed.

Solid State Research.

DTIC Science & Technology

1984-11-15

Coupling to Surface Plasma Waves 20 2.3 Theory of the Effect of Traps on the Spectral Charac- teristics of Diode Lasers 23 3 . MATERIALS RESEARCH 27...Page 1-1(a) Schematic Cross Section of InGaAs PSIN Structure. Gap Spac- ing (d) Is 3 , 5, 10, or 20 pm. 2 1-1(b) Curve Tracer I-V Characteristics of a...20-pim PSIN Device in Dark and Under Illumination 2 1-2 Pulse Response of a 3 -#Am PSIN Device, Under Forward and Reverse Bias. to a Comb-Generator

Rail damage in a solid-armature rail gun. Final report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Brassard, T.; Homan, C.G.

1987-12-01

Plasma-arc-drive rail guns operate by forming a high-temperature plasma behind the projectile using a thin metal fuze. These systems achieve the highest projectile velocities (about 12 km /sec), since the driving force includes a substantial plasma pressure as well as the electromagnetic or Lorentz force. Unfortunately, severe rail damage occurs primarily from the intense temperatures generated by the plasma arc and the wiping motion of the armature itself. The solid-armature gun replaces the plasma armature with a conducting metal armature. Since the plasma arcing is reduced or eliminated, the projectiles are accelerated mainly by the Lorentz force. Thus, solid armaturemore » rail guns operate at lower projectile velocities. The important tradeoff is that there is a substantial reduction in rail damage for metal armature projectiles. The elimination of the plasma force limits projectile velocities in the metal-armature rail guns. A more-subtle limit is the speed at which the commutation process can take place. Although the latter limit is still not well understood, experimental evidence indicates a commutation limit may occur near 6 to 7 km/sec. This velocity limit is still attractive for Army tactical missions for rail guns. The actual rail damage occurring with two types of metal armatures, wire brush contactors and monolithic metal contactors, and new developments in barrel technology, such as superconducting augmentation, are presented in this report.« less

Sintering of Lead-Free Piezoelectric Sodium Potassium Niobate Ceramics

PubMed Central

Malič, Barbara; Koruza, Jurij; Hreščak, Jitka; Bernard, Janez; Wang, Ke; Fisher, John G.; Benčan, Andreja

2015-01-01

The potassium sodium niobate, K0.5Na0.5NbO3, solid solution (KNN) is considered as one of the most promising, environment-friendly, lead-free candidates to replace highly efficient, lead-based piezoelectrics. Since the first reports of KNN, it has been recognized that obtaining phase-pure materials with a high density and a uniform, fine-grained microstructure is a major challenge. For this reason the present paper reviews the different methods for consolidating KNN ceramics. The difficulties involved in the solid-state synthesis of KNN powder, i.e., obtaining phase purity, the stoichiometry of the perovskite phase, and the chemical homogeneity, are discussed. The solid-state sintering of stoichiometric KNN is characterized by poor densification and an extremely narrow sintering-temperature range, which is close to the solidus temperature. A study of the initial sintering stage revealed that coarsening of the microstructure without densification contributes to a reduction of the driving force for sintering. The influences of the (K + Na)/Nb molar ratio, the presence of a liquid phase, chemical modifications (doping, complex solid solutions) and different atmospheres (i.e., defect chemistry) on the sintering are discussed. Special sintering techniques, such as pressure-assisted sintering and spark-plasma sintering, can be effective methods for enhancing the density of KNN ceramics. The sintering behavior of KNN is compared to that of a representative piezoelectric lead zirconate titanate (PZT). PMID:28793702

Dynamic electron-ion collisions and nuclear quantum effects in quantum simulation of warm dense matter.

PubMed

Kang, Dongdong; Dai, Jiayu

2018-02-21

The structural, thermodynamic and transport properties of warm dense matter (WDM) are crucial to the fields of astrophysics and planet science, as well as inertial confinement fusion. WDM refers to the states of matter in a regime of temperature and density between cold condensed matter and hot ideal plasmas, where the density is from near-solid up to ten times solid density, and the temperature between 0.1 and 100 eV. In the WDM regime, matter exhibits moderately or strongly coupled, partially degenerate properties. Therefore, the methods used to deal with condensed matter and isolated atoms need to be properly validated for WDM. It is therefore a big challenge to understand WDM within a unified theoretical description with reliable accuracy. Here, we review the progress in the theoretical study of WDM with state-of-the-art simulations, i.e. quantum Langevin molecular dynamics and first principles path integral molecular dynamics. The related applications for WDM are also included.

Dynamic electron-ion collisions and nuclear quantum effects in quantum simulation of warm dense matter

NASA Astrophysics Data System (ADS)

Kang, Dongdong; Dai, Jiayu

2018-02-01

The structural, thermodynamic and transport properties of warm dense matter (WDM) are crucial to the fields of astrophysics and planet science, as well as inertial confinement fusion. WDM refers to the states of matter in a regime of temperature and density between cold condensed matter and hot ideal plasmas, where the density is from near-solid up to ten times solid density, and the temperature between 0.1 and 100 eV. In the WDM regime, matter exhibits moderately or strongly coupled, partially degenerate properties. Therefore, the methods used to deal with condensed matter and isolated atoms need to be properly validated for WDM. It is therefore a big challenge to understand WDM within a unified theoretical description with reliable accuracy. Here, we review the progress in the theoretical study of WDM with state-of-the-art simulations, i.e. quantum Langevin molecular dynamics and first principles path integral molecular dynamics. The related applications for WDM are also included.

VUV/XUV measurements of impurity emission in plasmas with liquid lithium surfaces on LTX [VUV/XUV measurements of low recycling plasmas with liquid lithium surfaces on LTX

DOE PAGES

Tritz, Kevin; Bell, Ronald E.; Beiersdorfer, Peter; ...

2014-11-12

The VUV/XUV spectrum has been measured on the Lithium Tokamak eXperiment (LTX) using a transmission grating imaging spectrometer (TGIS) coupled to a direct-detection x-ray charge-coupled device camera. TGIS data show significant changes in the ratios between the lithium and oxygen impurity line emission during discharges with varying lithium wall conditions. Lithium coatings that have been passivated by lengthy exposure to significant levels of impurities contribute to a large O/Li ratio measured during LTX plasma discharges. Furthermore, previous results have indicated that a passivated lithium film on the plasma facing components will function as a stronger impurity source when in themore » form of a hot liquid layer compared to a solid lithium layer. However, recent TGIS measurements of plasma discharges in LTX with hot stainless steel boundary shells and a fresh liquid lithium coating show lower O/Li impurity line ratios when compared to discharges with a solid lithium film on cool shells. In conclusion, these new measurements help elucidate the somewhat contradictory results of the effects of solid and liquid lithium on plasma confinement observed in previous experiments.« less

Numerical study of the influence of dielectric tube on propagation of atmospheric pressure plasma jet based on coplanar dielectric barrier discharge

NASA Astrophysics Data System (ADS)

Haixin, HU; Feng, HE; Ping, ZHU; Jiting, OUYANG

2018-05-01

A 2D fluid model was employed to simulate the influence of dielectric on the propagation of atmospheric pressure helium plasma jet based on coplanar dielectric barrier discharge (DBD). The spatio-temporal distributions of electron density, ionization rate, electrical field, spatial charge and the spatial structure were obtained for different dielectric tubes that limit the helium flow. The results show that the change of the relative permittivity of the dielectric tube where the plasma jet travels inside has no influence on the formation of DBD itself, but has great impact on the jet propagation. The velocity of the plasma jet changes drastically when the jet passes from a tube of higher permittivity to one of lower permittivity, resulting in an increase in jet length, ionization rate and electric field, as well as a change in the distribution of space charges and discharge states. The radius of the dielectric tube has a great influence on the ring-shaped or solid bullet structure. These results can well explain the behavior of the plasma jet from the dielectric tube into the ambient air and the hollow bullet in experiments.

Fluorescence imaging as a diagnostic of M-band x-ray drive condition in hohlraum with fluorescent Si targets

NASA Astrophysics Data System (ADS)

Li, Qi; Hu, Zhimin; Yao, Li; Huang, Chengwu; Yuan, Zheng; Zhao, Yang; Xiong, Gang; Qing, Bo; Lv, Min; Zhu, Tuo; Deng, Bo; Li, Jin; Wei, Minxi; Zhan, Xiayu; Li, Jun; Yang, Yimeng; Su, Chunxiao; Yang, Guohong; Zhang, Jiyan; Li, Sanwei; Yang, Jiamin; Ding, Yongkun

2017-01-01

Fluorescence imaging of surrogate Si-doped CH targets has been used to provide a measurement for drive condition of high-energy x-ray (i.e. M-band x-ray) drive symmetry upon the capsule in hohlraum on Shenguang-II laser facility. A series of experiments dedicated to the study of photo-pumping and fluorescence effect in Si-plasma are presented. To investigate the feasibility of fluorescence imaging in Si-plasma, an silicon plasma in Si-foil target is pre-formed at ground state by the soft x-ray from a half-hohlraum, which is then photo-pumped by the K-shell lines from a spatially distinct laser-produced Si-plasma. The resonant Si photon pump is used to improve the fluorescence signal and cause visible image in the Si-foil. Preliminary fluorescence imaging of Si-ball target is performed in both Si-doped and pure Au hohlraum. The usual capsule at the center of the hohlraum is replaced with a solid Si-doped CH-ball (Si-ball). Since the fluorescence is proportional to the photon pump upon the Si-plasma, high-energy x-ray drive symmetry is equal to the fluorescence distribution of the Si-ball.

Shock-like pulse experiment in a strongly coupled dusty plasma

NASA Astrophysics Data System (ADS)

Kananovich, Anton; Goree, J.

2017-10-01

Compressional pulses are excited in a dusty plasma using a wire moved at a supersonic speed. The dusty plasma consists of a 2D monolayer of polymer microspheres electrically levitated in a low-temperature argon RF plasma. The microspheres gained a large negative charge so that they interacted with each other as a strongly coupled component, partly shielded by the electrons and ions. The wire, which had a negative potential that repelled microspheres, was moved at a constant speed, causing a compressional pulse to propagate. This pulse had shock-like properties because the wire was moved faster than the longitudinal sound speed in the microspheres. The experiment was repeated for the dusty plasma both in liquid and solid states, all of the controlled parameters except for the dust kinetic temperature being equal. The laser rastering method was used to change the kinetic temperature. Several experimental runs were done with different wire speeds for the both cases. An increase in the wire propagation speed increased the propagation speed of the compressional pulse. High pulse propagation speeds were obtained with Mach numbers up to 5. For high pulse propagation speeds crystal buckling was observed. Video microscopy was the main diagnostic. Supported by U.S. Dept. of Energy.

Super Configuration Accounting Equation of State for WDM and HED plasma

NASA Astrophysics Data System (ADS)

Lee, T. G.; Busquet, M.; Gilles, D.; Klapisch, M.

2017-10-01

Rad-Hydro numerical codes require Equation of State (EOS) and opacities. We describe a procedure to obtain an EOS compatible with our STA opacity model. We use our relativistic super-configuration code - STA-2.5 to compute the average 〈 Z 〉 and excitation-ionization internal energy U and chemical potential _. These and other data will serve as basic inputs into a Yukawa Monte-Carlo improved version of quotidian EOS, known as YMCQ. The screening in the Yukawa potential describing the ion-ion interaction is modified by the data from STA. This integrated procedure yields the excess internal energy due to the non-ideal behavior of the EOS concordant with our opacity model and allows us to have an EOS model applicable from solid matter to very tenuous plasmas as found in laser fusion, astrophysics, or tokamaks. We shall present its application to Carbon, Aluminum and Iron. This work is made possible by a financial support from DOE/NNSA.

Self-consistent modeling of CFETR baseline scenarios for steady-state operation

NASA Astrophysics Data System (ADS)

Chen, Jiale; Jian, Xiang; Chan, Vincent S.; Li, Zeyu; Deng, Zhao; Li, Guoqiang; Guo, Wenfeng; Shi, Nan; Chen, Xi; CFETR Physics Team

2017-07-01

Integrated modeling for core plasma is performed to increase confidence in the proposed baseline scenario in the 0D analysis for the China Fusion Engineering Test Reactor (CFETR). The steady-state scenarios are obtained through the consistent iterative calculation of equilibrium, transport, auxiliary heating and current drives (H&CD). Three combinations of H&CD schemes (NB + EC, NB + EC + LH, and EC + LH) are used to sustain the scenarios with q min > 2 and fusion power of ˜70-150 MW. The predicted power is within the target range for CFETR Phase I, although the confinement based on physics models is lower than that assumed in 0D analysis. Ideal MHD stability analysis shows that the scenarios are stable against n = 1-10 ideal modes, where n is the toroidal mode number. Optimization of RF current drive for the RF-only scenario is also presented. The simulation workflow for core plasma in this work provides a solid basis for a more extensive research and development effort for the physics design of CFETR.

The application of Cold Atmospheric Plasma (CAP) for the sterilisation of spacecraft materials

NASA Astrophysics Data System (ADS)

Rettberg, Petra; Barczyk, Simon; Morfill, Gregor; Thomas, Hubertus; Satoshi Shimizu, .; Shimizu, Tetsuji; Klaempfl, Tobias

2012-07-01

Plasma, oft called the fourth state of matter after solid, liquid and gas, is defined by its ionized state. Ionization can be induced by different means, such as a strong electromagnetic field applied with a microwave generator. The concentration and composition of reactive atoms and molecules produced in Cold Atmospheric Plasma (CAP) depends on the gases used, the gas flow, the power applied, the humidity level etc.. In medicine, low-temperature plasma is already used for the sterilization of surgical instruments, implants and packaging materials as plasma works at the atomic level and is able to reach all surfaces, even the interior of small hollow items like needles. Its ability to sterilise is due to the generation of biologically active bactericidal agents, such as free radicals and UV radiation. In the project PLASMA-DECON (DLR/BMWi support code 50JR1005) a prototype of a device for sterilising spacecraft material and components was built based on the surface micro-discharge (SMD) plasma technology. The produced plasma species are directed into a closed chamber which contains the parts that need to be sterilised. To test the inactivation efficiency of this new device bacterial spores were used as model organisms because in the COSPAR Planetary Protection Policy all bioburden constraints are defined with respect to the number of spores (and other heat-tolerant aerobic microorganisms). Spores from different Bacillus species and strains, i.e. wildtype strains from culture collections and isolates from spacecraft assembly cleanrooms, were dried on three different spacecraft relevant materials and exposed to CAP. The specificity, linearity, precision, and effective range of the device was investigated. From the results obtained it can be concluded that the application of CAP proved to be a suitable method for bioburden reduction / sterilisation in the frame of planetary protection measures and the design of a larger plasma device is planned in the future.

Specular reflectivity and hot-electron generation in high-contrast relativistic laser-plasma interactions

NASA Astrophysics Data System (ADS)

Kemp, Gregory Elijah

Ultra-intense laser (> 1018 W/cm2) interactions with matter are capable of producing relativistic electrons which have a variety of applications in state-of-the-art scientific and medical research conducted at universities and national laboratories across the world. Control of various aspects of these hot-electron distributions is highly desired to optimize a particular outcome. Hot-electron generation in low-contrast interactions, where significant amounts of under-dense pre-plasma are present, can be plagued by highly non-linear relativistic laser-plasma instabilities and quasi-static magnetic field generation, often resulting in less than desirable and predictable electron source characteristics. High-contrast interactions offer more controlled interactions but often at the cost of overall lower coupling and increased sensitivity to initial target conditions. An experiment studying the differences in hot-electron generation between high and low-contrast pulse interactions with solid density targets was performed on the Titan laser platform at the Jupiter Laser Facility at Lawrence Livermore National Laboratory in Livermore, CA. To date, these hot-electrons generated in the laboratory are not directly observable at the source of the interaction. Instead, indirect studies are performed using state-of-the-art simulations, constrained by the various experimental measurements. These measurements, more-often-than-not, rely on secondary processes generated by the transport of these electrons through the solid density materials which can susceptible to a variety instabilities and target material/geometry effects. Although often neglected in these types of studies, the specularly reflected light can provide invaluable insight as it is directly influenced by the interaction. In this thesis, I address the use of (personally obtained) experimental specular reflectivity measurements to indirectly study hot-electron generation in the context of high-contrast, relativistic laser-plasma interactions. Spatial, temporal and spectral properties of the incident and specular pulses, both near and far away from the interaction region where experimental measurements are obtained, are used to benchmark simulations designed to infer dominant hot-electron acceleration mechanisms and their corresponding energy/angular distributions. To handle this highly coupled interaction, I employed particle-in-cell modeling using a wide variety of algorithms (verified to be numerically stable and consistent with analytic expressions) and physical models (validated by experimental results) to reasonably model the interaction's sweeping range of plasma densities, temporal and spatial scales, electromagnetic wave propagation and its interaction with solid density matter. Due to the fluctuations in the experimental conditions and limited computational resources, only a limited number of full-scale simulations were performed under typical experimental conditions to infer the relevant physical phenomena in the interactions. I show the usefulness of the often overlooked specular reflectivity measurements in constraining both high and low-contrast simulations, as well as limitations of their experimental interpretations. Using these experimental measurements to reasonably constrain the simulation results, I discuss the sensitivity of relativistic electron generation in ultra-intense laser plasma interactions to initial target conditions and the dynamic evolution of the interaction region.

Fishbone activity in experimental advanced superconducting tokamak neutral beam injection plasma

DOE Office of Scientific and Technical Information (OSTI.GOV)

Xu, Liqing; Zhang, Jizong; Chen, Kaiyun, E-mail: Kychen@ipp.cas.cn, E-mail: lqhu@ipp.cas.cn

2015-12-15

Repetitive fishbones near the trapped ion procession frequency were observed for the first time in the neutral beam injection high confinement plasmas in Experimental Advanced Superconducting Tokamak (EAST) tokamak, and diagnosed using a solid-state neutral particle analyzer based on a compact silicon photodiode together with an upgraded high spatial-temporal-resolution multi-arrays soft X-ray (SX) system. This 1/1 typical internal kink mode propagates in the ion-diamagnetism direction with a rotation speed faster than the bulk plasma in the plasma frame. From the SX measurements, this mode frequency is typical of chirping down and the energetic particle effect related to the twisting modemore » structure. This ion fishbone was found able to trigger a multiple core sawtooth crashes with edge-2/1 sideband modes, as well as to lead to a transition from fishbone to long lived saturated kink mode to fishbone. Furthermore, using SX tomography, a correlation between mode amplitude and mode frequency was found. Finally, a phenomenological prey–predator model was found to reproduce the fishbone nonlinear process well.« less

A compact nanosecond pulse generator for DBD tube characterization.

PubMed

Rai, S K; Dhakar, A K; Pal, U N

2018-03-01

High voltage pulses of very short duration and fast rise time are required for generating uniform and diffuse plasma under various operating conditions. Dielectric Barrier Discharge (DBD) has been generated by high voltage pulses of short duration and fast rise time to produce diffuse plasma in the discharge gap. The high voltage pulse power generators have been chosen according to the requirement for the DBD applications. In this paper, a compact solid-state unipolar pulse generator has been constructed for characterization of DBD plasma. This pulsar is designed to provide repetitive pulses of 315 ns pulse width, pulse amplitude up to 5 kV, and frequency variation up to 10 kHz. The amplitude of the output pulse depends on the dc input voltage. The output frequency has been varied by changing the trigger pulse frequency. The pulsar is capable of generating pulses of positive or negative polarity by changing the polarity of pulse transformer's secondary. Uniform and stable homogeneous dielectric barrier discharge plasma has been produced successfully in a xenon DBD tube at 400-mbar pressure using the developed high voltage pulse generator.

A compact nanosecond pulse generator for DBD tube characterization

NASA Astrophysics Data System (ADS)

Rai, S. K.; Dhakar, A. K.; Pal, U. N.

2018-03-01

High voltage pulses of very short duration and fast rise time are required for generating uniform and diffuse plasma under various operating conditions. Dielectric Barrier Discharge (DBD) has been generated by high voltage pulses of short duration and fast rise time to produce diffuse plasma in the discharge gap. The high voltage pulse power generators have been chosen according to the requirement for the DBD applications. In this paper, a compact solid-state unipolar pulse generator has been constructed for characterization of DBD plasma. This pulsar is designed to provide repetitive pulses of 315 ns pulse width, pulse amplitude up to 5 kV, and frequency variation up to 10 kHz. The amplitude of the output pulse depends on the dc input voltage. The output frequency has been varied by changing the trigger pulse frequency. The pulsar is capable of generating pulses of positive or negative polarity by changing the polarity of pulse transformer's secondary. Uniform and stable homogeneous dielectric barrier discharge plasma has been produced successfully in a xenon DBD tube at 400-mbar pressure using the developed high voltage pulse generator.

Proton acceleration by multi-terawatt interaction with a near-critical density hydrogen jet

NASA Astrophysics Data System (ADS)

Goers, Andy; Feder, Linus; Hine, George; Salehi, Fatholah; Woodbury, Daniel; Su, J. J.; Papadopoulos, Dennis; Zigler, Arie; Milchberg, Howard

2016-10-01

We investigate the high intensity laser interaction with thin, near critical density plasmas as a means of efficient acceleration of MeV protons. A promising mechanism is magnetic vortex acceleration, where the ponderomotive force of a tightly focused laser pulse drives a relativistic electron current which generates a strong azimuthal magnetic field. The rapid expansion of this azimuthal magnetic field at the back side of the target can accelerate plasma ions to MeV scale energies. Compared to typical ion acceleration experiments utilizing a laser- thin solid foil interaction, magnetic vortex acceleration in near critical density plasma may be realized in a high density gas jet, making it attractive for applications requiring high repetition rates. We present preliminary experiments studying laser-plasma interaction and proton acceleration in a thin (< 200 μm) near-critical density hydrogen gas jet delivering electron densities 1020 -1021 cm-3 . This research was funded by the United States Department of Energy and the Defense Advanced Research Projects Agency (DARPA) under Contract Number W911-NF-15-C-0217, issued by the Army Research Office.

Sintering Behavior of Spark Plasma Sintered SiC with Si-SiC Composite Nanoparticles Prepared by Thermal DC Plasma Process

NASA Astrophysics Data System (ADS)

Yu, Yeon-Tae; Naik, Gautam Kumar; Lim, Young-Bin; Yoon, Jeong-Mo

2017-11-01

The Si-coated SiC (Si-SiC) composite nanoparticle was prepared by non-transferred arc thermal plasma processing of solid-state synthesized SiC powder and was used as a sintering additive for SiC ceramic formation. Sintered SiC pellet was prepared by spark plasma sintering (SPS) process, and the effect of nano-sized Si-SiC composite particles on the sintering behavior of micron-sized SiC powder was investigated. The mixing ratio of Si-SiC composite nanoparticle to micron-sized SiC was optimized to 10 wt%. Vicker's hardness and relative density was increased with increasing sintering temperature and holding time. The relative density and Vicker's hardness was further increased by reaction bonding using additional activated carbon to the mixture of micron-sized SiC and nano-sized Si-SiC. The maximum relative density (97.1%) and Vicker's hardness (31.4 GPa) were recorded at 1800 °C sintering temperature for 1 min holding time, when 0.2 wt% additional activated carbon was added to the mixture of SiC/Si-SiC.

Method of processing materials using an inductively coupled plasma

DOEpatents

Hull, Donald E.; Bieniewski, Thomas M.

1990-01-01

A method for making fine power using an inductively coupled plasma. The method provides a gas-free environment, since the plasma is formed without using a gas. The starting material used in the method is in solid form.

Cytotoxic macrophage-released tumour necrosis factor-alpha (TNF-α) as a killing mechanism for cancer cell death after cold plasma activation

NASA Astrophysics Data System (ADS)

Kaushik, Nagendra Kumar; Kaushik, Neha; Min, Booki; Choi, Ki Hong; Hong, Young June; Miller, Vandana; Fridman, Alexander; Choi, Eun Ha

2016-03-01

The present study aims at studying the anticancer role of cold plasma-activated immune cells. The direct anti-cancer activity of plasma-activated immune cells against human solid cancers has not been described so far. Hence, we assessed the effect of plasma-treated RAW264.7 macrophages on cancer cell growth after co-culture. In particular, flow cytometer analysis revealed that plasma did not induce any cell death in RAW264.7 macrophages. Interestingly, immunofluorescence and western blot analysis confirmed that TNF-α released from plasma-activated macrophages acts as a tumour cell death inducer. In support of these findings, activated macrophages down-regulated the cell growth in solid cancer cell lines and induced cell death in vitro. Together our findings suggest plasma-induced reactive species recruit cytotoxic macrophages to release TNF-α, which blocks cancer cell growth and can have the potential to contribute to reducing tumour growth in vivo in the near future.

Pulsed Plasma Lubrication Device and Method

NASA Technical Reports Server (NTRS)

Hofer, Richard R. (Inventor); Bickler, Donald B. (Inventor); D'Agostino, Saverio A. (Inventor)

2016-01-01

Disclosed herein is a lubrication device comprising a solid lubricant disposed between and in contact with a first electrode and a second electrode dimensioned and arranged such that application of an electric potential between the first electrode and the second electrode sufficient to produce an electric arc between the first electrode and the second electrode to produce a plasma in an ambient atmosphere at an ambient pressure which vaporizes at least a portion of the solid lubricant to produce a vapor stream comprising the solid lubricant. Methods to lubricate a surface utilizing the lubrication device in-situ are also disclosed.

Compact atmospheric pressure plasma self-resonant drive circuits

NASA Astrophysics Data System (ADS)

Law, V. J.; Anghel, S. D.

2012-02-01

This paper reports on compact solid-state self-resonant drive circuits that are specifically designed to drive an atmospheric pressure plasma jet and a parallel-plate dielectric barrier discharge of small volume (0.5 cm3). The atmospheric pressure plasma (APP) device can be operated with helium, argon or a mixture of both. Equivalent electrical models of the self-resonant drive circuits and discharge are developed and used to estimate the plasma impedance, plasma power density, current density or electron number density of three APP devices. These parameters and the kinetic gas temperature are dependent on the self-resonant frequency of the APP device. For a fixed switching frequency and APP device geometry, the plasma parameters are controlled by adjusting the dc voltage at the primary coil and the gas flow rate. The resonant frequency is controlled by the selection of the switching power transistor and means of step-up voltage transformation (ferrite core, flyback transformer, or Tesla coil). The flyback transformer operates in the tens of kHz, the ferrite core in the hundreds of kHz and Tesla coil in the MHz range. Embedded within this work is the principle of frequency pulling which is exemplified in the flyback transformer circuit that utilizes a pickup coil for feedback control of the switching frequency.

Specific food structures supress appetite through reduced gastric emptying rate

PubMed Central

Rafiee, Hameed; Malcolm, Paul; Salt, Louise; van Aken, George

2013-01-01

The aim of this study was to determine the extent to which gastric layering and retention of a meal could be used to reduce appetite using the same caloric load. Liquid (control) and semi-solid (active) meals were produced with the same protein, fat, carbohydrate, and mass. These were fed to 10 volunteers on separate days in a crossover study, and subjective appetite ratings, gastric contents, and plasma cholecystokinin (CCK) were assessed over a period of 3 h. The active meal showed food boluses in the stomach persisting for ∼45 min, slower emptying rates, and lower plasma CCK levels over the first hour. After the first hour, both gastric emptying rates and plasma CCK levels were similar for both systems and slightly increased compared with the unfed situation. Despite the lower plasma CCK levels for the active meal over the first hour, this meal reduced appetite more than the control meal over the 3 h of the study. For a moderately increased plasma CCK level in the fed state, appetite was correlated with the volume of gastric contents rather than gastric emptying rates or plasma CCK. This suggests that enhanced gastric retention was the key factor in decreasing appetite and was probably mediated by a combination of intestinal nutrient sensing and increased viscosity in the stomach. PMID:23578786

Design a 10 kJ IS Mather Type Plasma Focus for Solid Target Activation to Produce Short-Lived Radioisotopes 12C(d,n)13N

NASA Astrophysics Data System (ADS)

Sadat Kiai, S. M.; Adlparvar, S.; Sheibani, S.; Elahi, M.; Safarien, A.; Farhangi, S.; Zirak, A. R.; Alhooie, S.; Mortazavi, B. N.; Khalaj, M. M.; Khanchi, A. R.; Dabirzadeh, A. A.; Kashani, A.; Zahedi, F.

2010-10-01

A 10 kJ (15 kV, 88 μF) IS (Iranian Sun) Mather type plasma focus device has been studied to determine the activity of a compound exogenous carbon solid target through 12C(d,n)13N nuclear reaction. The produced 13N is a short-lived radioisotope with a half-life of 9.97 min and threshold energy of 0.28 MeV. The results indicate that energetic deuterons impinging on the solid target can produce yield of = 6.7 × 10-5 with an activity of A = 6.8 × 104 Bq for one plasma focus shut and A ν = 4 × 105 Bq for 6 shut per mint when the projectile maximum deuterons energy is E max = 3 MeV.

Optical spectroscopy of laser-produced plasmas for standoff isotopic analysis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Harilal, Sivanandan S.; Brumfield, Brian E.; LaHaye, Nicole L.

2018-04-20

This review article covers the present status of isotope detection through emission, absorption, and fluorescence spectroscopy of atoms and molecules in a laser-produced plasma formed from a solid sample. A description of the physics behind isotope shifts in atoms and molecules is presented, followed by the physics behind solid sampling of laser ablation plumes, optical methods for isotope measurements, the suitable physical conditions of laser-produced plasma plumes for isotopic analysis, and the current status. Finally, concluding remarks will be made on the existing gaps between previous works in the literature and suggestions for future work.

Optical spectroscopy of laser-produced plasmas for standoff isotopic analysis

DOE PAGES

Harilal, S. S.; Brumfield, B. E.; LaHaye, N. L.; ...

2018-04-20

This review article covers the present status of isotope detection through emission, absorption, and fluorescence spectroscopy of atoms and molecules in a laser-produced plasma formed from a solid sample. A description of the physics behind isotope shifts in atoms and molecules is presented, followed by the physics behind solid sampling of laser ablation plumes, optical methods for isotope measurements, the suitable physical conditions of laser-produced plasma plumes for isotopic analysis, and the current status. Lastly, concluding remarks will be made on the existing gaps between previous works in the literature and suggestions for future work.

Optical spectroscopy of laser-produced plasmas for standoff isotopic analysis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Harilal, S. S.; Brumfield, B. E.; LaHaye, N. L.

This review article covers the present status of isotope detection through emission, absorption, and fluorescence spectroscopy of atoms and molecules in a laser-produced plasma formed from a solid sample. A description of the physics behind isotope shifts in atoms and molecules is presented, followed by the physics behind solid sampling of laser ablation plumes, optical methods for isotope measurements, the suitable physical conditions of laser-produced plasma plumes for isotopic analysis, and the current status. Finally, concluding remarks will be made on the existing gaps between previous works in the literature and suggestions for future work.

Optical spectroscopy of laser-produced plasmas for standoff isotopic analysis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Harilal, S. S.; Brumfield, B. E.; LaHaye, N. L.

This review article covers the present status of isotope detection through emission, absorption, and fluorescence spectroscopy of atoms and molecules in a laser-produced plasma formed from a solid sample. A description of the physics behind isotope shifts in atoms and molecules is presented, followed by the physics behind solid sampling of laser ablation plumes, optical methods for isotope measurements, the suitable physical conditions of laser-produced plasma plumes for isotopic analysis, and the current status. Lastly, concluding remarks will be made on the existing gaps between previous works in the literature and suggestions for future work.

Optical spectroscopy of laser-produced plasmas for standoff isotopic analysis

DOE PAGES

Harilal, S. S.; Brumfield, B. E.; LaHaye, N. L.; ...

2018-06-01

This review article covers the present status of isotope detection through emission, absorption, and fluorescence spectroscopy of atoms and molecules in a laser-produced plasma formed from a solid sample. A description of the physics behind isotope shifts in atoms and molecules is presented, followed by the physics behind solid sampling of laser ablation plumes, optical methods for isotope measurements, the suitable physical conditions of laser-produced plasma plumes for isotopic analysis, and the current status. Finally, concluding remarks will be made on the existing gaps between previous works in the literature and suggestions for future work.

Two-dimensional studies of relativistic electron beam plasma instabilities in an inhomogeneous plasma

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shukla, Chandrasekhar; Das, Amita, E-mail: amita@ipr.res.in; Patel, Kartik

Relativistic electron beam propagation in plasma is fraught with several micro instabilities like two stream, filamentation, etc., in plasma. This results in severe limitation of the electron transport through a plasma medium. Recently, however, there has been an experimental demonstration of improved transport of Mega Ampere of electron currents (generated by the interaction of intense laser with solid target) in a carbon nanotube structured solid target [G. Chatterjee et al., Phys. Rev. Lett. 108, 235005 (2012)]. This then suggests that the inhomogeneous plasma (created by the ionization of carbon nanotube structured target) helps in containing the growth of the beammore » plasma instabilities. This manuscript addresses this issue with the help of a detailed analytical study and 2-D Particle-In-Cell simulations. The study conclusively demonstrates that the growth rate of the dominant instability in the 2-D geometry decreases when the plasma density is chosen to be inhomogeneous, provided the scale length 1/k{sub s} of the inhomogeneous plasma is less than the typical plasma skin depth (c/ω{sub 0}) scale. At such small scale lengths channelization of currents is also observed in simulation.« less

DEMONSTRATION BULLETIN: THE PLASMA CENTRIFUGAL FURNACE RETECH, INC.

EPA Science Inventory

The plasma centrifugal furnace is a thermal technology which uses the heat generated from a plasma torch to decontaminate metal and organic contaminated waste. This is accomplished by melting metal-bearing solids and, in the process, thermally destroying organic contaminants. The...

Two stage fluid bed-plasma gasification process for solid waste valorisation: Technical review and preliminary thermodynamic modelling of sulphur emissions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Morrin, Shane, E-mail: shane.morrin@ucl.ac.uk; Advanced Plasma Power, South Marston Business park, Swindon, SN3 4DE; Lettieri, Paola, E-mail: p.lettieri@ucl.ac.uk

2012-04-15

Highlights: Black-Right-Pointing-Pointer We investigate sulphur during MSW gasification within a fluid bed-plasma process. Black-Right-Pointing-Pointer We review the literature on the feed, sulphur and process principles therein. Black-Right-Pointing-Pointer The need for research in this area was identified. Black-Right-Pointing-Pointer We perform thermodynamic modelling of the fluid bed stage. Black-Right-Pointing-Pointer Initial findings indicate the prominence of solid phase sulphur. - Abstract: Gasification of solid waste for energy has significant potential given an abundant feed supply and strong policy drivers. Nonetheless, significant ambiguities in the knowledge base are apparent. Consequently this study investigates sulphur mechanisms within a novel two stage fluid bed-plasma gasification process.more » This paper includes a detailed review of gasification and plasma fundamentals in relation to the specific process, along with insight on MSW based feedstock properties and sulphur pollutant therein. As a first step to understanding sulphur partitioning and speciation within the process, thermodynamic modelling of the fluid bed stage has been performed. Preliminary findings, supported by plant experience, indicate the prominence of solid phase sulphur species (as opposed to H{sub 2}S) - Na and K based species in particular. Work is underway to further investigate and validate this.« less

Thin Film Deposition Using Energetic Ions

PubMed Central

Manova, Darina; Gerlach, Jürgen W.; Mändl, Stephan

2010-01-01

One important recent trend in deposition technology is the continuous expansion of available processes towards higher ion assistance with the subsequent beneficial effects to film properties. Nowadays, a multitude of processes, including laser ablation and deposition, vacuum arc deposition, ion assisted deposition, high power impulse magnetron sputtering and plasma immersion ion implantation, are available. However, there are obstacles to overcome in all technologies, including line-of-sight processes, particle contaminations and low growth rates, which lead to ongoing process refinements and development of new methods. Concerning the deposited thin films, control of energetic ion bombardment leads to improved adhesion, reduced substrate temperatures, control of intrinsic stress within the films as well as adjustment of surface texture, phase formation and nanotopography. This review illustrates recent trends for both areas; plasma process and solid state surface processes. PMID:28883323

Helicons, magnetoplasma edge, and faraday rotation in solid state plasmas at microwave frequencies.

PubMed

Furdyna, J K

1967-04-01

The effect of magnetic field on propagation of electromagnetic waves through free carrier plasmas in semiconductors is discussed. The Faraday configuration and the parameter ranges omega(c),omega(p) > omega and omega(c) > tau(-1) are specifically considered. Dispersion of helicon waves, propagation near the magnetoplasma edge (omega(p)(2) = omegaomega(c)), and the Faraday rotation are developed in terms of the one-electron Drude theory. Microwave transmission measurements at 35 Gc/s on n-type InSb are presented. Experiments near the magnetoplasma edge yield the value of the static dielectric constant of the InSb lattice K(l) = 19.3 +/- 0.8. Faraday rotation, observed beyond the edge, is found to be extremely large. Some practical possibilities for this effect are considered.

Structural and optical characterization of self-assembled Ge nanocrystal layers grown by plasma-enhanced chemical vapor deposition.

PubMed

Saeed, Saba; Buters, Frank; Dohnalova, Katerina; Wosinski, Lech; Gregorkiewicz, Tom

2014-10-10

We present a structural and optical study of solid-state dispersions of Ge nanocrystals prepared by plasma-enhanced chemical vapor deposition. Structural analysis shows the presence of nanocrystalline germanium inclusions embedded in an amorphous matrix of Si-rich SiO(2).Optical characterization reveals two prominent emission bands centered around 2.6 eV and 3.4 eV, and tunable by excitation energy. In addition, the lower energy band shows an excitation power-dependent blue shift of up to 0.3 eV. Decay dynamics of the observed emission contains fast (nanosecond) and slow (microseconds) components, indicating contributions of several relaxation channels. Based on these material characteristics, a possible microscopic origin of the individual emission bands is discussed.

Silica nanoparticles produced by DC arc plasma from a solid raw materials

NASA Astrophysics Data System (ADS)

Kosmachev, P. V.; Vlasov, V. A.; Skripnikova, N. K.

2017-05-01

Plasma synthesis of SiO2 nanoparticles in experimental atmospheric pressure plasma reactor on the basis of DC arc plasma generator was presented in this paper. Solid high-silica raw materials such as diatomite from Kamyshlovskoye deposit in Russia, quartzite from Chupinskoye deposit in Russia and milled window glass were used. The obtained nanoparticles were characterized based on their morphology, chemical composition and size distribution. Scanning electron microscopy, laser diffractometry, nitrogen absorption (Brunauer-Emmett-Teller method), X-ray photoelectron spectroscopy and energy-dispersive X-ray spectroscopy were used to characterize the synthesized products. The obtained silica nanoparticles are agglomerated, have spherical shape and primary diameters between 10-300 nm. All samples of synthesized nanopowders were compared with commercial nanopowders.

Characteristics of plasma plume in ultrafast laser ablation with a weakly ionized air channel

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hou, Huaming; Yang, Bo; Mao, Xianglei

We report the influence of femtosecond (fs) laser weakly ionized air channel on characteristics of plasma induced from fs-laser ablation of solid Zr metal target. A novel method to create high temperature, low electron density plasma with intense elemental emission and weak bremsstrahlung emission was demonstrated. Weakly ionized air channel was generated as a result of a non-linear phenomenon. Two-dimensional time-resolved optical-emission images of plasma plumes were taken for plume dynamics analysis. Dynamic physical properties of filament channels were simulated. In particular, we investigated the influence of weakly ionized air channel on the evolution of solid plasma plume. Plasma plumemore » splitting was observed whilst longer weakly ionized air channel formed above the ablation spot. The domination mechanism for splitting is attributed to the long-lived underdense channel created by fs-laser induced weakly ionization of air. The evolutions of atomic/molecular emission intensity, peak broadening, and plasma temperature were analyzed, and the results show that the part of plasma entering weakly ionized air channel features higher initial temperature, lower electron density and faster decay.« less

Characteristics of plasma plume in ultrafast laser ablation with a weakly ionized air channel

DOE PAGES

Hou, Huaming; Yang, Bo; Mao, Xianglei; ...

2018-05-10

We report the influence of femtosecond (fs) laser weakly ionized air channel on characteristics of plasma induced from fs-laser ablation of solid Zr metal target. A novel method to create high temperature, low electron density plasma with intense elemental emission and weak bremsstrahlung emission was demonstrated. Weakly ionized air channel was generated as a result of a non-linear phenomenon. Two-dimensional time-resolved optical-emission images of plasma plumes were taken for plume dynamics analysis. Dynamic physical properties of filament channels were simulated. In particular, we investigated the influence of weakly ionized air channel on the evolution of solid plasma plume. Plasma plumemore » splitting was observed whilst longer weakly ionized air channel formed above the ablation spot. The domination mechanism for splitting is attributed to the long-lived underdense channel created by fs-laser induced weakly ionization of air. The evolutions of atomic/molecular emission intensity, peak broadening, and plasma temperature were analyzed, and the results show that the part of plasma entering weakly ionized air channel features higher initial temperature, lower electron density and faster decay.« less

Innovative Plasma Disinfection Technique with the Reduced-pH Method and the Plasma-Treated Water (PTW) -Safety and Powerful Disinfection with Cryopreserved PTW-

NASA Astrophysics Data System (ADS)

Kitano, Katsuhisa; Ikawa, Satoshi; Nakashima, Yoichi; Tani, Atsushi; Yokoyama, Takashi; Ohshima, Tomoko

2015-09-01

Among the applications of the plasma disinfection to human body, plasma sterilization in liquid is crucial. We found that the plasma-treated water (PTW) has strong bactericidal activity under low pH condition and the half-lives of its activity depend on temperature. Lower temperature brings longer half-life and the bactericidal activity of PTW can be kept by cryopreservation. These physicochemical properties were in accordance with Arrhenius equation both in liquid and solid states. From the experimental results of ESR (Electron Spin Resonance) measurement of O2-in liquid against PTW with spin trapping method, half-lives of PTW were also in accordance with Arrhenius equation. It suggests that high concentration PTW as integrated value can be achieved by cooling of plasma apparatus. Pure PTW has disinfection power of 22 log reduction (B. subtilis). This corresponds to 65% H2O2, 14% hypochlorous acid and 0.33% peracetic acid, which are deadly poison for human. On the other hand, PTW is deactivated soon at body temperature. This indicates that toxicity to human body seems to be low. PTW, which is a sort of indirect plasma exposure, with pH and temperature controls could be applied for safety and powerful disinfection. MEXT (15H03583, 23340176, 25108505). NCCE (23-A-15).

High-Dose Chemotherapy, Total-Body Irradiation, and Autologous Stem Cell Transplantation or Bone Marrow Transplantation in Treating Patients With Hematologic Cancer or Solid Tumors

ClinicalTrials.gov

2013-05-07

Breast Cancer; Leukemia; Lymphoma; Multiple Myeloma and Plasma Cell Neoplasm; Testicular Germ Cell Tumor; Unspecified Adult Solid Tumor, Protocol Specific; Unspecified Childhood Solid Tumor, Protocol Specific

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Munson, C.P.; Benage, J.F. Jr.; Taylor, A.J.

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

Double pulse laser induced breakdown spectroscopy of a solid in water: Effect of hydrostatic pressure on laser induced plasma, cavitation bubble and emission spectra

NASA Astrophysics Data System (ADS)

López-Claros, M.; Dell'Aglio, M.; Gaudiuso, R.; Santagata, A.; De Giacomo, A.; Fortes, F. J.; Laserna, J. J.

2017-07-01

There is a growing interest in the development of sensors use in exploration of the deep ocean. Techniques for the chemical analysis of submerged solids are of special interest, as they show promise for subsea mining applications where a rapid sorting of materials found in the sea bottom would improve efficiency. Laser-Induced Breakdown Spectroscopy (LIBS) has demonstrated potential for this application thanks to its unique capability of providing the atomic composition of submerged solids. Here we present a study on the parameters that affect the spectral response of metallic targets in an oceanic pressure environment. Following laser excitation of the solid, the plasma persistence and the cavitation bubble size are considerably reduced as the hydrostatic pressure increases. These effects are of particular concern in dual pulse excitation as reported here, where a careful choice of the interpulse timing is required. Shadowgraphic images of the plasma demonstrate that cavitation bubbles are formed early after the plasma onset and that the effect of hydrostatic pressure is negligible during the early stage of plasma expansion. Contrarily to what is observed at atmospheric pressure, emission spectra observed at high pressures are characterized by self-absorbed atomic lines on continuum radiation resulting from strong radiative recombination in the electron-rich confined environment. This effect is much less evident with ionic lines due to the much higher energy of the levels involved and ionization energy of ions, as well as to the lower extent of absorption effects occurring in the inner part of the plasma, where ionized species are more abundant. As a result of the smaller shorter-lived cavitation bubble, the LIBS intensity enhancement resulting from dual pulse excitation is reduced when the applied pressure increases.

Influence of Ionization and Beam Quality on Interaction of TW-Peak CO2 Laser with Hydrogen Plasma

DOE Office of Scientific and Technical Information (OSTI.GOV)

Samulyak, Roman

3D numerical simulations of the interaction of a powerful CO2 laser with hydrogen jets demonstrating the role of ionization and laser beam quality are presented. Simulations are performed in support of the plasma wakefield accelerator experiments being conducted at the BNL Accelerator Test Facility (ATF). The CO2 laser at BNL ATF has several potential advantages for laser wakefield acceleration compared to widely used solid-state lasers. SPACE, a parallel relativistic Particle-in-Cell code, developed at SBU and BNL, has been used in these studies. A novelty of the code is its set of efficient atomic physics algorithms that compute ionization and recombinationmore » rates on the grid and transfer them to particles. The primary goal of the initial BNL experiments was to characterize the plasma density by measuring the sidebands in the spectrum of the probe laser. Simulations, that resolve hydrogen ionization and laser spectra, help explain several trends that were observed in the experiments.« less

Adjustable, High Voltage Pulse Generator with Isolated Output for Plasma Processing

NASA Astrophysics Data System (ADS)

Ziemba, Timothy; Miller, Kenneth E.; Prager, James; Slobodov, Ilia

2015-09-01

Eagle Harbor Technologies (EHT), Inc. has developed a high voltage pulse generator with isolated output for etch, sputtering, and ion implantation applications within the materials science and semiconductor processing communities. The output parameters are independently user adjustable: output voltage (0 - 2.5 kV), pulse repetition frequency (0 - 100 kHz), and duty cycle (0 - 100%). The pulser can drive loads down to 200 Ω. Higher voltage pulsers have also been tested. The isolated output allows the pulse generator to be connected to loads that need to be biased. These pulser generators take advantage modern silicon carbide (SiC) MOSFETs. These new solid-state switches decrease the switching and conduction losses while allowing for higher switching frequency capabilities. This pulse generator has applications for RF plasma heating; inductive and arc plasma sources; magnetron driving; and generation of arbitrary pulses at high voltage, high current, and high pulse repetition frequency. This work was supported in part by a DOE SBIR.

Fabrication of gas turbine water-cooled composite nozzle and bucket hardware employing plasma spray process

DOEpatents

Schilke, Peter W.; Muth, Myron C.; Schilling, William F.; Rairden, III, John R.

1983-01-01

In the method for fabrication of water-cooled composite nozzle and bucket hardware for high temperature gas turbines, a high thermal conductivity copper alloy is applied, employing a high velocity/low pressure (HV/LP) plasma arc spraying process, to an assembly comprising a structural framework of copper alloy or a nickel-based super alloy, or combination of the two, and overlying cooling tubes. The copper alloy is plamsa sprayed to a coating thickness sufficient to completely cover the cooling tubes, and to allow for machining back of the copper alloy to create a smooth surface having a thickness of from 0.010 inch (0.254 mm) to 0.150 inch (3.18 mm) or more. The layer of copper applied by the plasma spraying has no continuous porosity, and advantageously may readily be employed to sustain a pressure differential during hot isostatic pressing (HIP) bonding of the overall structure to enhance bonding by solid state diffusion between the component parts of the structure.

Photonic Weyl degeneracies in magnetized plasma

NASA Astrophysics Data System (ADS)

Gao, Wenlong; Yang, Biao; Lawrence, Mark; Fang, Fengzhou; Béri, Benjamin; Zhang, Shuang

2016-08-01

Weyl particles are elusive relativistic fermionic particles with vanishing mass. While not having been found as an elementary particle, they are found to emerge in solid-state materials where three-dimensional bands develop a topologically protected point-like crossing, a so-called Weyl point. Photonic Weyl points have been recently realised in three-dimensional photonic crystals with complex structures. Here we report the presence of a novel type of plasmonic Weyl points in a naturally existing medium--magnetized plasma, in which Weyl points arise as crossings between purely longitudinal plasma modes and transverse helical propagating modes. These photonic Weyl points are right at the critical transition between a Weyl point with the traditional closed finite equifrequency surfaces and the newly proposed `type II' Weyl points with open equifrequency surfaces. Striking observable features of plasmon Weyl points include a half k-plane chirality manifested in electromagnetic reflection. Our study introduces Weyl physics into homogeneous photonic media, which could pave way for realizing new topological photonic devices.

High-Speed, High-Power Active Control Coils for HBT-EP

NASA Astrophysics Data System (ADS)

Debono, Bryan

2010-11-01

We report the performance of a newly installed high-speed, high-power active control system for the application of non-symmetric magnetic fields and the study of rotating MHD and resistive wall modes in the HBTEP tokamak. The new control system consists of an array of 120 modular control coils and 40 solid-state, high-power amplifiers that can apply non-symmetric control fields that are more than 10 times larger than previous studies in HBT-EP and exceed 5% of the equilibrium poloidal field strength. Measurements of the current and field response of the control system are presented as a function of frequency and control coil geometry, and these demonstrate the effectiveness of the system to interact with both growing RWM instabilities and long-wavelength modes rotating with the plasma. We describe a research plan to study the interaction of both kink and tearing mode fluctuations with applied static and rotating magnetic perturbations while systematically changing the plasma rotation with a biased molybdenum electrode inserted into the edge plasma.

Plasma-wall interaction studies within the EUROfusion consortium: progress on plasma-facing components development and qualification

NASA Astrophysics Data System (ADS)

Brezinsek, S.; Coenen, J. W.; Schwarz-Selinger, T.; Schmid, K.; Kirschner, A.; Hakola, A.; Tabares, F. L.; van der Meiden, H. J.; Mayoral, M.-L.; Reinhart, M.; Tsitrone, E.; Ahlgren, T.; Aints, M.; Airila, M.; Almaviva, S.; Alves, E.; Angot, T.; Anita, V.; Arredondo Parra, R.; Aumayr, F.; Balden, M.; Bauer, J.; Ben Yaala, M.; Berger, B. M.; Bisson, R.; Björkas, C.; Bogdanovic Radovic, I.; Borodin, D.; Bucalossi, J.; Butikova, J.; Butoi, B.; Čadež, I.; Caniello, R.; Caneve, L.; Cartry, G.; Catarino, N.; Čekada, M.; Ciraolo, G.; Ciupinski, L.; Colao, F.; Corre, Y.; Costin, C.; Craciunescu, T.; Cremona, A.; De Angeli, M.; de Castro, A.; Dejarnac, R.; Dellasega, D.; Dinca, P.; Dittmar, T.; Dobrea, C.; Hansen, P.; Drenik, A.; Eich, T.; Elgeti, S.; Falie, D.; Fedorczak, N.; Ferro, Y.; Fornal, T.; Fortuna-Zalesna, E.; Gao, L.; Gasior, P.; Gherendi, M.; Ghezzi, F.; Gosar, Ž.; Greuner, H.; Grigore, E.; Grisolia, C.; Groth, M.; Gruca, M.; Grzonka, J.; Gunn, J. P.; Hassouni, K.; Heinola, K.; Höschen, T.; Huber, S.; Jacob, W.; Jepu, I.; Jiang, X.; Jogi, I.; Kaiser, A.; Karhunen, J.; Kelemen, M.; Köppen, M.; Koslowski, H. R.; Kreter, A.; Kubkowska, M.; Laan, M.; Laguardia, L.; Lahtinen, A.; Lasa, A.; Lazic, V.; Lemahieu, N.; Likonen, J.; Linke, J.; Litnovsky, A.; Linsmeier, Ch.; Loewenhoff, T.; Lungu, C.; Lungu, M.; Maddaluno, G.; Maier, H.; Makkonen, T.; Manhard, A.; Marandet, Y.; Markelj, S.; Marot, L.; Martin, C.; Martin-Rojo, A. B.; Martynova, Y.; Mateus, R.; Matveev, D.; Mayer, M.; Meisl, G.; Mellet, N.; Michau, A.; Miettunen, J.; Möller, S.; Morgan, T. W.; Mougenot, J.; Mozetič, M.; Nemanič, V.; Neu, R.; Nordlund, K.; Oberkofler, M.; Oyarzabal, E.; Panjan, M.; Pardanaud, C.; Paris, P.; Passoni, M.; Pegourie, B.; Pelicon, P.; Petersson, P.; Piip, K.; Pintsuk, G.; Pompilian, G. O.; Popa, G.; Porosnicu, C.; Primc, G.; Probst, M.; Räisänen, J.; Rasinski, M.; Ratynskaia, S.; Reiser, D.; Ricci, D.; Richou, M.; Riesch, J.; Riva, G.; Rosinski, M.; Roubin, P.; Rubel, M.; Ruset, C.; Safi, E.; Sergienko, G.; Siketic, Z.; Sima, A.; Spilker, B.; Stadlmayr, R.; Steudel, I.; Ström, P.; Tadic, T.; Tafalla, D.; Tale, I.; Terentyev, D.; Terra, A.; Tiron, V.; Tiseanu, I.; Tolias, P.; Tskhakaya, D.; Uccello, A.; Unterberg, B.; Uytdenhoven, I.; Vassallo, E.; Vavpetič, P.; Veis, P.; Velicu, I. L.; Vernimmen, J. W. M.; Voitkans, A.; von Toussaint, U.; Weckmann, A.; Wirtz, M.; Založnik, A.; Zaplotnik, R.; PFC contributors, WP

2017-11-01

The provision of a particle and power exhaust solution which is compatible with first-wall components and edge-plasma conditions is a key area of present-day fusion research and mandatory for a successful operation of ITER and DEMO. The work package plasma-facing components (WP PFC) within the European fusion programme complements with laboratory experiments, i.e. in linear plasma devices, electron and ion beam loading facilities, the studies performed in toroidally confined magnetic devices, such as JET, ASDEX Upgrade, WEST etc. The connection of both groups is done via common physics and engineering studies, including the qualification and specification of plasma-facing components, and by modelling codes that simulate edge-plasma conditions and the plasma-material interaction as well as the study of fundamental processes. WP PFC addresses these critical points in order to ensure reliable and efficient use of conventional, solid PFCs in ITER (Be and W) and DEMO (W and steel) with respect to heat-load capabilities (transient and steady-state heat and particle loads), lifetime estimates (erosion, material mixing and surface morphology), and safety aspects (fuel retention, fuel removal, material migration and dust formation) particularly for quasi-steady-state conditions. Alternative scenarios and concepts (liquid Sn or Li as PFCs) for DEMO are developed and tested in the event that the conventional solution turns out to not be functional. Here, we present an overview of the activities with an emphasis on a few key results: (i) the observed synergistic effects in particle and heat loading of ITER-grade W with the available set of exposition devices on material properties such as roughness, ductility and microstructure; (ii) the progress in understanding of fuel retention, diffusion and outgassing in different W-based materials, including the impact of damage and impurities like N; and (iii), the preferential sputtering of Fe in EUROFER steel providing an in situ W surface and a potential first-wall solution for DEMO.

Solid polymer electrolyte composite membrane comprising plasma etched porous support

DOEpatents

Liu, Han; LaConti, Anthony B.

2010-10-05

A solid polymer electrolyte composite membrane and method of manufacturing the same. According to one embodiment, the composite membrane comprises a rigid, non-electrically-conducting support, the support preferably being a sheet of polyimide having a thickness of about 7.5 to 15 microns. The support has a plurality of cylindrical pores extending perpendicularly between opposing top and bottom surfaces of the support. The pores, which preferably have a diameter of about 0.1 to 5 microns, are made by plasma etching and preferably are arranged in a defined pattern, for example, with fewer pores located in areas of high membrane stress and more pores located in areas of low membrane stress. The pores are filled with a first solid polymer electrolyte, such as a perfluorosulfonic acid (PFSA) polymer. A second solid polymer electrolyte, which may be the same as or different than the first solid polymer electrolyte, may be deposited over the top and/or bottom of the first solid polymer electrolyte.

Method of processing materials using an inductively coupled plasma

DOEpatents

Hull, Donald E.; Bieniewski, Thomas M.

1989-01-01

A method for coating surfaces or implanting ions in an object using an inductively coupled plasma. The method provides a gas-free environment, since the plasma is formed without using a gas. The coating material or implantation material is intitially in solid form.

Unified first wall - blanket structure for plasma device applications

DOEpatents

Gruen, D.M.

A plasma device is described for use in controlling nuclear reactions within the plasma including a first wall and blanket formed in a one-piece structure composed of a solid solution containing copper and lithium and melting above about 500/sup 0/C.

Comparison of cryogenic (hydrogen) and TESPEL (polystyrene) pellet particle deposition in a magnetically confined plasma

DOE PAGES

McCarthy, K. J.; Tamura, N.; Combs, S. K.; ...

2018-01-05

Here, a cryogenic pellet injector (PI) and tracer encapsulated solid pellet (TESPEL) injector system has been operated in combination on the stellarator TJ-II. This unique arrangement has been created by piggy-backing a TESPEL injector onto the backend of a pipe-gun–type PI. The combined injector provides a powerful new tool for comparing ablation and penetration of polystyrene TESPEL pellets and solid hydrogen pellets, as well as for contrasting subsequent pellet particle deposition and plasma perturbation under analogous plasma conditions. For instance, a significantly larger increase in plasma line-averaged electron density, and electron content, is observed after a TESPEL pellet injection comparedmore » with an equivalent cryogenic pellet injection. Moreover, for these injections from the low-magnetic-field side of the plasma cross-section, TESPEL pellets deposit electrons deeper into the plasma core than cryogenic pellets. Finally, the physics behind these observations and possible implications for pellet injection studies are discussed.« less

Comparison of cryogenic (hydrogen) and TESPEL (polystyrene) pellet particle deposition in a magnetically confined plasma

DOE Office of Scientific and Technical Information (OSTI.GOV)

McCarthy, K. J.; Tamura, N.; Combs, S. K.

Here, a cryogenic pellet injector (PI) and tracer encapsulated solid pellet (TESPEL) injector system has been operated in combination on the stellarator TJ-II. This unique arrangement has been created by piggy-backing a TESPEL injector onto the backend of a pipe-gun–type PI. The combined injector provides a powerful new tool for comparing ablation and penetration of polystyrene TESPEL pellets and solid hydrogen pellets, as well as for contrasting subsequent pellet particle deposition and plasma perturbation under analogous plasma conditions. For instance, a significantly larger increase in plasma line-averaged electron density, and electron content, is observed after a TESPEL pellet injection comparedmore » with an equivalent cryogenic pellet injection. Moreover, for these injections from the low-magnetic-field side of the plasma cross-section, TESPEL pellets deposit electrons deeper into the plasma core than cryogenic pellets. Finally, the physics behind these observations and possible implications for pellet injection studies are discussed.« less

Theory of warm ionized gases: equation of state and kinetic Schottky anomaly.

PubMed

Capolupo, A; Giampaolo, S M; Illuminati, F

2013-10-01

Based on accurate Lennard-Jones-type interaction potentials, we derive a closed set of state equations for the description of warm atomic gases in the presence of ionization processes. The specific heat is predicted to exhibit peaks in correspondence to single and multiple ionizations. Such kinetic analog in atomic gases of the Schottky anomaly in solids is enhanced at intermediate and low atomic densities. The case of adiabatic compression of noble gases is analyzed in detail and the implications on sonoluminescence are discussed. In particular, the predicted plasma electron density in a sonoluminescent bubble turns out to be in good agreement with the value measured in recent experiments.

Application of hot melt extrusion for improving bioavailability of artemisinin a thermolabile drug.

PubMed

Kulkarni, C; Kelly, A L; Gough, T; Jadhav, V; Singh, K K; Paradkar, A

2018-02-01

Hot melt extrusion has been used to produce a solid dispersion of the thermolabile drug artemisinin. Formulation and process conditions were optimized prior to evaluation of dissolution and biopharmaceutical performance. Soluplus ® , a low T g amphiphilic polymer especially designed for solid dispersions enabled melt extrusion at 110 °C although some drug-polymer incompatibility was observed. Addition of 5% citric acid as a pH modifier was found to suppress the degradation. The area under plasma concentration time curve (AUC 0-24h ) and peak plasma concentration (C max ) were four times higher for the modified solid dispersion compared to that of pure artemisinin.

Heterogeneity of hypoxia in solid tumours and mechanochemical reactions with oxygen nanobubbles.

PubMed

Orel, V B; Zabolotny, M A; Orel, V E

2017-05-01

Tumour hypoxia leads to radio and chemotherapy resistance among cancer patients. The aim of this paper is to formulate a hypothesis on the heterogeneity of hypoxia in solid tumours. Tumour vasculature is known to be significantly variable. The great structural and functional abnormalities of tumour microcirculation cause spatial and temporal heterogeneity in its perfusion. Tumours have constantly been under the influence of pulsatile blood perfusion with variable pressure that initiates inhomogeneous erythrocyte deformation and following impact on oxygen disorder release from red blood cells into plasma within the blood vessel. Furthermore, stochastically released oxygen in tumour vessel, plasma and interstitial fluid may lead to heterogeneity of hypoxia. Under the influence of increased heterogeneity of hemodynamic force, the oxygen molecules dissolved in blood plasma are inclined to form nanobubbles (NBs) in tumour vessels. Considering the fact that tumour interstitial fluid pressure is increased compared to normal tissues, we assume that oxygen NBs may burst under the impact of shear stress. During the course of mechanochemical reaction, when a nanobubble (NB) bursts, both reactive oxygen species and ions form in various charged states. In consequence of a chain reaction, free radical oxygen molecules bind to proteins and lipids, thus reducing oxygen molecules in a chaotic manner within the tumour. The proposed hypothesis should be used as a methodical approach based on the simultaneous ultrasound imaging diagnostic techniques and therapy, regarding the mechanochemical effect on NB conglomerates with drugs in the tumour. Copyright © 2017 Elsevier Ltd. All rights reserved.

Progress in Development of C60 Nanoparticle Plasma Jet for Diagnostic of Runaway Electron Beam-Plasma Interaction and Disruption Mitigation Study for ITER

NASA Astrophysics Data System (ADS)

Bogatu, I. N.; Thompson, J. R.; Galkin, S. A.; Kim, J. S.

2013-10-01

We produced a C60 nanoparticle plasma jet (NPPJ) with uniquely fast response-to-delivery time (~ 1 - 2 ms) and unprecedentedly high momentum (~ 0 . 6 g .km/s). The C60 NPPJ was obtained by using a solid state TiH2/C60 pulsed power cartridge producing ~180 mg of C60 molecular gas by sublimation and by electromagnetic acceleration of the C60 plasma in a coaxial gun (~35 cm length, 96 kJ energy) with the output of a high-density (>1023 m-3) hyper-velocity (>4 km/s) plasma jet. The ~ 75 mg C60/C plasma jet has the potential to rapidly and deeply deliver enough mass to significantly increase electron density (to ne ~ 2 . 4 ×1021 m-3, i.e. ~ 60 times larger than typical DIII-D pre-disruption value, ne 0 ~ 4 ×1019 m-3), and to modify the 'critical electric field' and the runaway electrons (REs) collisional drag during different phases of REs dynamics. The C60 NPPJ, as a novel injection technique, allows RE beam-plasma interaction diagnostic by quantitative spectroscopy of C ions visible/UV line intensity. The system is scalable to ~ 1 - 2 g C60/C plasma jet output and technology is adaptable to ITER acceptable materials (BN and Be) for disruption mitigation. Work supported by US DOE DE-FG02-08ER85196 grant.

Isochoric heating of low Z solid targets with sub 10 fs laser pulses

NASA Astrophysics Data System (ADS)

Osterholz, Jens

2004-11-01

The investigation of high density plasmas plays an important role for astrophysics, inertial confinement fusion and x-ray lasers. Therefore the generation of dense plasmas with ultra-intense laser pulses is a field of enormous topical interest. An upper limit of the maximum plasma density that can be achieved with this method, however, occurs due to the formation of a preplasma and the expansion of the plasma during the interaction [1,2]. Here we describe a novel approach that is based on a laser system that generates sub 10 fs pulses with a low prepulse energy. Isochoric heating is demonstrated with small Z solid targets. Time integrated XUV spectroscopy is used to investigate K-shell emission from the plasma. In the spectra, only the Ly α and He α lines are observed, whereas transitions from orbitals with principal quantum numbers n > 2 are not present. This series limit is explained by pressure ionisation in the dense plasma. The XUV spectra were simulated by two different models [3]. The first calculates the effect of pressure ionisation and the second calculates the line intensity ratios. Preliminary calculations suggest that the plasma density of the emitting region is close to solid density with an electron temperature of about 100eV. We conclude that our laser system is well suited for isochoric heating of solid targets and an efficient transfer of the laser energy to the dense region of the target is possible. In cooperation with: T. Fischer, F. Brandl, G. Pretzler and O. Willi, Heinrich-Heine-University Duesseldorf, Germany, S. J. Rose, University of Oxford, United Kingdom [1] D. Riley et al., PRL 69, 3739 (1992). [2] A. Saemann et al., PRL 82, 4843 (1999). [3] S. J. Rose, J Phys B: Atom Molec Opt Phys, 25, 1667 (1992), 31, 2129 (1998).

Flame propagation in two-dimensional solids: Particle-resolved studies with complex plasmas

NASA Astrophysics Data System (ADS)

Yurchenko, S. O.; Yakovlev, E. V.; Couëdel, L.; Kryuchkov, N. P.; Lipaev, A. M.; Naumkin, V. N.; Kislov, A. Yu.; Ovcharov, P. V.; Zaytsev, K. I.; Vorob'ev, E. V.; Morfill, G. E.; Ivlev, A. V.

2017-10-01

Using two-dimensional (2D) complex plasmas as an experimental model system, particle-resolved studies of flame propagation in classical 2D solids are carried out. Combining experiments, theory, and molecular dynamics simulations, we demonstrate that the mode-coupling instability operating in 2D complex plasmas reveals all essential features of combustion, such as an activated heat release, two-zone structure of the self-similar temperature profile ("flame front"), as well as thermal expansion of the medium and temperature saturation behind the front. The presented results are of relevance for various fields ranging from combustion and thermochemistry, to chemical physics and synthesis of materials.

Speciation of inorganic and organometallic compounds in solid biological samples by thermal vaporization and plasma emission spectrometry

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hanamura, S.; Smith, B.W.; Winefordner, J.D.

1983-11-01

By means of thermal vaporization, inorganic, organic, and metallorganic species are separated and elemental emission in a microwave plasma is detected as a function of vaporization temperature. Solid samples of 250 mg or more are used to avoid problems with sample heterogeneity. The precision of characteristic appearance temperatures is +/-2/sup 0/C. The single electrode atmosphere pressure microwave plasma system is extremely tolerant to the introduction of water, organic solvents, and air. The measurement system contained a repetition wavelength scan device to allow background correction. The plasma temperature was 5500 K. The system was used to measure C, H, N, O,more » and Hg in orchard leaves and in tuna fish. 9 figures, 5 tables.« less

Generation of warm dense matter using an argon based capillary discharge laser

NASA Astrophysics Data System (ADS)

Rossall, A. K.; Tallents, G. J.

2015-06-01

Argon based capillary discharge lasers operating in the extreme ultra violet (EUV) at 46.9 nm with output up to 0.5 mJ energy per pulse and repetition rates up to 10 Hz are capable of focused irradiances of 109-1012 W cm-2 and can be used to generate plasma in the warm dense matter regime by irradiating solid material. To model the interaction between such an EUV laser and solid material, the 2D radiative-hydrodynamic code POLLUX has been modified to include absorption via direct photo-ionisation, a super-configuration model to describe the ionization-dependent electronic configurations and a calculation of plasma refractive indices for ray tracing of the incident EUV laser radiation. A simulation study is presented, demonstrating how capillary discharge lasers of 1200 ps pulse duration can be used to generate warm dense matter at close to solid densities with temperatures of a few eV and energy densities up to 1 × 105 J cm-3. Plasmas produced by EUV laser irradiation are shown to be useful for examining the properties of warm dense matter as, for example, plasma emission is not masked by hotter, less dense plasma emission that occurs with visible/infra-red laser target irradiation.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Libby, S B; Weiss, M S

Edward Teller was one of the great physicists of the twentieth century. His career began just after the key ideas of the quantum revolution of the 1920's were completed, opening vast areas of physics and chemistry to detailed understanding. Thus, his early work in theoretical physics focused on applying the new quantum theory to the understanding of diverse phenomena. These topics included chemical physics, diamagnetism, and nuclear physics. Later, he made key contributions to statistical mechanics, surface physics, solid state, and plasma physics. In many cases, the ideas in these papers are still rich with important ramifications.

Impact of densification on microstructure and transport properties of CaFe5O7

NASA Astrophysics Data System (ADS)

Delacotte, C.; Hébert, S.; Hardy, V.; Bréard, Y.; Maki, R.; Mori, T.; Pelloquin, D.

2016-04-01

Monophasic CaFe5O7 ceramic has been synthesized by solid state route. Its microstructural features have been studied by diffraction techniques and electron microscopy images before and after Spark Plasma Sintering (SPS) annealings. This work is completed by measurements of electrical and thermal properties. Especially, attention is focused around the structural and electronic transition at 360 K for which specific heat measurements have revealed a sharp peak. Densification by SPS techniques led to a significant improvement of electrical conductivity above 360 K.

Determination of stoichiometry and concentration of trace elements in thin BaxSr1-xTiO3 perovskite layers.

PubMed

Becker, J S; Boulyga, S F

2001-07-01

This paper describes an analytical procedure for determining the stoichiometry of BaxSr1-xTiO3 perovskite layers using inductively coupled plasma mass spectrometry (ICP-MS). The analytical results of mass spectrometry measurements are compared to those of X-ray fluorescence analysis (XRF). The performance and the limits of solid-state mass spectrometry analytical methods for the surface analysis of thin BaxSr1-xTiO3 perovskite layers sputtered neutral mass spectrometry (SNMS)--are investigated and discussed.

Characterization, in Vivo and in Vitro Evaluation of Solid Dispersion of Curcumin Containing d-α-Tocopheryl Polyethylene Glycol 1000 Succinate and Mannitol.

PubMed

Song, Im-Sook; Cha, Jin-Sun; Choi, Min-Koo

2016-10-17

The aim of this study was to prepare a solid dispersion formulation of curcumin to enhance its solubility, dissolution rate, and oral bioavailability. The formulation was prepared with d-α-tocopheryl polyethylene glycol 1000 succinate (TPGS) and mannitol using solvent evaporation and freeze-drying methods, which yielded a solid dispersion composed of curcumin, TPGS, and mannitol at a ratio of 1:10:15 ( w / w / w ). The solubility and dissolution rate of the curcumin solid dispersion markedly improved compared with those of curcumin powder and a physical mixture of curcumin, TPGS, and mannitol. About 90% of the curcumin was released from the solid dispersion formulation within 10 min. After administering the formulation orally to rats, higher plasma concentrations of curcumin were observed, with increases in the maximum plasma concentration (C max ) and area under the plasma concentration-time curve (AUC) of 86- and 65-fold, respectively, compared with those of curcumin powder. The solid dispersion formulation effectively increased intestinal permeability and inhibited P-gp function. These effects increased the anti-proliferative effect of curcumin in MDA-MB-231 breast cancer cells. Moreover, 2 h incubation with curcumin powder, solid dispersion formulation, and its physical mixture resulted in differential cytotoxic effect of paclitaxel in P-gp overexpressed LLC-PK1-P-gp and MDA-MB-231 cells through the inhibition of P-gp-mediated paclitaxel efflux. In conclusion, compared with curcumin, a solid dispersion formulation of curcumin with TPGS and mannitol could be a promising option for enhancing the oral bioavailability and efficacy of curcumin through increased solubility, dissolution rate, cell permeability, and P-gp modulation.

Solid state recycling of aluminium alloys via a porthole die hot extrusion process: Scaling up to production

NASA Astrophysics Data System (ADS)

Paraskevas, Dimos; Kellens, Karel; Deng, Yelin; Dewulf, Wim; Kampen, Carlos; Duflou, Joost R.

2017-10-01

Whereas industrial symbiosis has led to increased energy and resource efficiency in process industries, this concept has not yet been applied in discrete product manufacturing. Metal scrap is first conventionally recycled, for which substantial energy and resource efficiency losses have been reported. Recent research has however proven the feasibility of `meltless' recycling of light metal scrap, yielding a first glimpse of potential industrial symbiosis. Various solid state recycling techniques (such as recycling via hot extrusion or Spark Plasma Sintering) have been proposed for scrap consolidation directly into bulk products or semis by physical disruption and dispersion of the oxide surface film by imposing significant plastic and shear strain. Solid State Recycling (SSR) methods can omit substantial material losses as they bypass the metallurgical recycling step. In this context the case of direct production of bulk aluminium profiles via hot extrusion at industrial scale is demonstrated within this paper. The extrusion tests were performed directly into the production line, highlighting the scaling up potentials and the industrial relevance of this research. A significant amount of machining chips were collected, chemically cleaned and cold compacted into chip based billets with ˜80% relative density. Afterwards the scrap consolidation was achieved by imposing significant plastic and shear deformation into the material during hot extrusion through a modified 2-porthole extrusion die-set. The production process sequence along with microstructural investigations and mechanical properties comparison of the cast based profile used as reference versus the chip based profile are presented.

Preliminary investigation on the use of low current pulsed power Z-pinch plasma devices for the study of early stage plasma instabilities

NASA Astrophysics Data System (ADS)

Kaselouris, E.; Dimitriou, V.; Fitilis, I.; Skoulakis, A.; Koundourakis, G.; Clark, E. L.; Chatzakis, J.; Bakarezos, Μ; Nikolos, I. K.; Papadogiannis, N. A.; Tatarakis, M.

2018-01-01

This article addresses key features for the implementation of low current pulsed power plasma devices for the study of matter dynamics from the solid to the plasma phase. The renewed interest in such low current plasma devices lies in the need to investigate methods for the mitigation of prompt seeding mechanisms for the generation of plasma instabilities. The low current when driven into thick wires (skin effect mode) allows for the simultaneous existence of all phases of matter from solid to plasma. Such studies are important for the concept of inertial confinement fusion where the mitigation of the instability seeding mechanisms arising from the very early moments within the target’s heating is of crucial importance. Similarly, in the magnetized liner inertial fusion concept it is an open question as to how much surface non-uniformity correlates with the magneto-Rayleigh-Taylor instability, which develops during the implosion. This study presents experimental and simulation results, which demonstrate that the use of low current pulsed power devices in conjunction with appropriate diagnostics can be important for studying seeding mechanisms for the imminent generation of plasma instabilities in future research.

WDM production with intense relativistic electrons

NASA Astrophysics Data System (ADS)

Coleman, Josh; Andrews, Heather; Klasky, Mark; Colgan, James; Burris-Mog, Trevor; Creveling, Dan; Miller, Craig; Welch, Dale; Berninger, Mike

2016-10-01

The production of warm dense matter (WDM) through collisional heating with intense relativistic electrons is underway. A 100-ns-long monochromatic bunch of electrons with energies of 19.1-19.8 MeV and currents of 0.2-1.7 kA is used to heat 100- μm-thick foils with Z <29. The principal objective of these experiments is to develop a controlled method of measuring the equation of state with particle beams and benchmark numerical models. Measurements indicate the formation of a warm dense plasma near the end of the pulse, which is on the order of the beam size. These plasmas expand 5 mm in the first microsecond and slow down to <0.5 mm/ μs over the next 10 μs. These plasmas also produce both emitted and absorbed spectra amongst a continuum for Ti, Fe, and Cu. Cu-I spectra is dominated by stark broadening, indicating a cool plasma with ne >1018 cm-3. At these densities our plasma is collisionally dominated making it possible to spectrally model the density and temperature in LTE. Preliminary density gradient measurements will also be presented indicating the spatial extent of the solid density cutoff. This work was supported by the National Nuclear Se- curity Administration of the U.S. Department of Energy under Contract No. DE-AC52-06NA25396.

Study of Plasma Liner Driven Magnetized Target Fusion Via Advanced Simulations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Samulyak, Roman V.; Brookhaven National Lab.; Parks, Paul

The feasibility of the plasma liner driven Magnetized Target Fusion (MTF) via terascale numerical simulations will be assessed. In the MTF concept, a plasma liner, formed by merging of a number (60 or more) of radial, highly supersonic plasma jets, implodes on the target in the form of two compact plasma toroids, and compresses it to conditions of the fusion ignition. By avoiding major difficulties associated with both the traditional laser driven inertial confinement fusion and solid liner driven MTF, the plasma liner driven MTF potentially provides a low-cost and fast R&D path towards the demonstration of practical fusion energy.more » High fidelity numerical simulations of full nonlinear models associated with the plasma liner MTF using state-of-art numerical algorithms and terascale computing are necessary in order to resolve uncertainties and provide guidance for future experiments. At Stony Brook University, we have developed unique computational capabilities that ideally suite the MTF problem. The FronTier code, developed in collaboration with BNL and LANL under DOE funding including SciDAC for the simulation of 3D multi-material hydro and MHD flows, has beenbenchmarked and used for fundamental and engineering problems in energy science applications. We have performed 3D simulations of converging supersonic plasma jets, their merger and the formation of the plasma liner, and a study of the corresponding oblique shock problem. We have studied the implosion of the plasma liner on the magnetized plasma target by resolving Rayleigh-Taylor instabilities in 2D and 3D and other relevant physics and estimate thermodynamic conditions of the target at the moment of maximum compression and the hydrodynamic efficiency of the method.« less

Schlieren Technique Applied to Magnetohydrodynamic Generator Plasma Torch

NASA Astrophysics Data System (ADS)

Chopra, Nirbhav; Pearcy, Jacob; Jaworski, Michael

2017-10-01

Magnetohydrodynamic (MHD) generators are a promising augmentation to current hydrocarbon based combustion schemes for creating electrical power. In recent years, interest in MHD generators has been revitalized due to advances in a number of technologies such as superconducting magnets, solid-state power electronics and materials science as well as changing economics associated with carbon capture, utilization, and sequestration. We use a multi-wavelength schlieren imaging system to evaluate electron density independently of gas density in a plasma torch under conditions relevant to MHD generators. The sensitivity and resolution of the optical system are evaluated alongside the development of an automated analysis and calibration program in Python. Preliminary analysis shows spatial resolutions less than 1mm and measures an electron density of ne = 1 ×1016 cm-3 in an atmospheric microwave torch. Work supported by DOE contract DE-AC02-09CH11466.

Etching Selectivity of Cr, Fe and Ni Masks on Si & SiO2 Wafers

NASA Astrophysics Data System (ADS)

Garcia, Jorge; Lowndes, Douglas H.

2000-10-01

During this Summer 2000 I joined the Semiconductors and Thin Films group led by Dr. Douglas H. Lowndes at Oak Ridge National Laboratory’s Solid State Division. Our objective was to evaluate the selectivity that Trifluoromethane (CHF3), and Sulfur Hexafluoride (SF6) plasmas have for Si, SiO2 wafers and the Ni, Cr, and Fe masks; being this etching selectivity the ratio of the etching rates of the plasmas for each of the materials. We made use of Silicon and Silicon Dioxide-coated wafers that have Fe, Cr or Ni masks. In the semiconductor field, metal layers are often used as masks to protect layers underneath during processing steps; when these wafers are taken to the dry etching process, both the wafer and the mask layers’ thickness are reduced.

Perovskite solar cells based on nanocolumnar plasma-deposited ZnO thin films.

PubMed

Ramos, F Javier; López-Santos, Maria C; Guillén, Elena; Nazeeruddin, Mohammad Khaja; Grätzel, Michael; Gonzalez-Elipe, Agustin R; Ahmad, Shahzada

2014-04-14

ZnO thin films having a nanocolumnar microstructure are grown by plasma-enhanced chemical vapor deposition at 423 K on pre-treated fluorine-doped tin oxide (FTO) substrates. The films consist of c-axis-oriented wurtzite ZnO nanocolumns with well-defined microstructure and crystallinity. By sensitizing CH3NH3PbI3 on these photoanodes a power conversion of 4.8% is obtained for solid-state solar cells. Poly(triarylamine) is found to be less effective when used as the hole-transport material, compared to 2,2',7,7'-tetrakis(N,N-di-p-methoxyphenylamine)-9,9'-spirobifluorene (spiro-OMeTAD), while the higher annealing temperature of the perovskite leads to a better infiltration in the nanocolumnar structure and an enhancement of the cell efficiency. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Structural Changes in the Vanadium Sample Surface Induced by Pulsed High-Temperature Deuterium Plasma and Deuterium Ion Fluxes

NASA Astrophysics Data System (ADS)

Borovitskaya, I. V.; Pimenov, V. N.; Gribkov, V. A.; Padukh, M.; Bondarenko, G. G.; Gaidar, A. I.; Paramonova, V. V.; Morozov, E. V.

2017-11-01

The structural changes in the vanadium sample surface are studied as functions of the conditions of irradiation by pulsed high-temperature deuterium plasma and deuterium ion fluxes in the Plasma Focus installation. It is found that processes of partial evaporation, melting, and crystallization of the surface layer of vanadium samples take place in the plasma flux power density range q = 108-1010 W/cm2 and the ion flux density range q = 1010-1012 W/cm2. The surface relief is wavelike. There are microcracks, gas-filled bubbles (blisters), and traces of fracture on the surface. The blisters are failed in the solid state. The character of blister fracture is similar to that observed during usual ion irradiation in accelerators. The samples irradiated at relatively low power density ( q = 107-108 W/cm2) demonstrate the ejection of microparticles (surface fragments) on the side facing plasma. This process is assumed to be due to the fact that the unloading wave formed in the sample-target volume reaches its irradiated surface. Under certain irradiation conditions (sample-anode distance, the number of plasma pulses), a block microstructure with block sizes of several tens of microns forms on the sample surfaces. This structure is likely to form via directional crack propagation upon cooling of a thin melted surface layer.

Sintering Behavior of Spark Plasma Sintered SiC with Si-SiC Composite Nanoparticles Prepared by Thermal DC Plasma Process.

PubMed

Yu, Yeon-Tae; Naik, Gautam Kumar; Lim, Young-Bin; Yoon, Jeong-Mo

2017-11-25

The Si-coated SiC (Si-SiC) composite nanoparticle was prepared by non-transferred arc thermal plasma processing of solid-state synthesized SiC powder and was used as a sintering additive for SiC ceramic formation. Sintered SiC pellet was prepared by spark plasma sintering (SPS) process, and the effect of nano-sized Si-SiC composite particles on the sintering behavior of micron-sized SiC powder was investigated. The mixing ratio of Si-SiC composite nanoparticle to micron-sized SiC was optimized to 10 wt%. Vicker's hardness and relative density was increased with increasing sintering temperature and holding time. The relative density and Vicker's hardness was further increased by reaction bonding using additional activated carbon to the mixture of micron-sized SiC and nano-sized Si-SiC. The maximum relative density (97.1%) and Vicker's hardness (31.4 GPa) were recorded at 1800 °C sintering temperature for 1 min holding time, when 0.2 wt% additional activated carbon was added to the mixture of SiC/Si-SiC.

Laser machining of explosives

DOEpatents

Perry, Michael D.; Stuart, Brent C.; Banks, Paul S.; Myers, Booth R.; Sefcik, Joseph A.

2000-01-01

The invention consists of a method for machining (cutting, drilling, sculpting) of explosives (e.g., TNT, TATB, PETN, RDX, etc.). By using pulses of a duration in the range of 5 femtoseconds to 50 picoseconds, extremely precise and rapid machining can be achieved with essentially no heat or shock affected zone. In this method, material is removed by a nonthermal mechanism. A combination of multiphoton and collisional ionization creates a critical density plasma in a time scale much shorter than electron kinetic energy is transferred to the lattice. The resulting plasma is far from thermal equilibrium. The material is in essence converted from its initial solid-state directly into a fully ionized plasma on a time scale too short for thermal equilibrium to be established with the lattice. As a result, there is negligible heat conduction beyond the region removed resulting in negligible thermal stress or shock to the material beyond a few microns from the laser machined surface. Hydrodynamic expansion of the plasma eliminates the need for any ancillary techniques to remove material and produces extremely high quality machined surfaces. There is no detonation or deflagration of the explosive in the process and the material which is removed is rendered inert.

Experimental Investigation of the Interaction of Electrothermal Plasmas with Solid Propellants

DTIC Science & Technology

2007-09-14

formation increases propellant burning rate (Koleczko, et al . 2001). The experiments described here were designed to create time and spatially resolved...Pesce-Rodriguez 2004, Koleczko, et al . 2001). Most tests involving plasma propellant interactions involve higher plasma energies than the 3.1 kJ of...product that scatters light. The large jump in pressurization seen in closed bomb plasma ignition tests (Lieb, et al . 2001) during the plasma discharge

Strong terahertz radiation from relativistic laser interaction with solid density plasmas

NASA Astrophysics Data System (ADS)

Li, Y. T.; Li, C.; Zhou, M. L.; Wang, W. M.; Du, F.; Ding, W. J.; Lin, X. X.; Liu, F.; Sheng, Z. M.; Peng, X. Y.; Chen, L. M.; Ma, J. L.; Lu, X.; Wang, Z. H.; Wei, Z. Y.; Zhang, J.

2012-06-01

We report a plasma-based strong THz source generated in intense laser-solid interactions at relativistic intensities >1018 W/cm2. Energies up to 50 μJ/sr per THz pulse is observed when the laser pulses are incident onto a copper foil at 67.5°. The temporal properties of the THz radiation are measured by a single shot, electro-optic sampling method with a chirped laser pulse. The THz radiation is attributed to the self-organized transient fast electron currents formed along the target surface. Such a source allows potential applications in THz nonlinear physics and provides a diagnostic of transient currents generated in intense laser-solid interactions.

Radiation from particles moving in small-scale magnetic fields created in solid-density laser-plasma laboratory experiments

DOE Office of Scientific and Technical Information (OSTI.GOV)

Keenan, Brett D., E-mail: bdkeenan@ku.edu; Medvedev, Mikhail V.

2015-11-15

Plasmas created by high-intensity lasers are often subject to the formation of kinetic-streaming instabilities, such as the Weibel instability, which lead to the spontaneous generation of high-amplitude, tangled magnetic fields. These fields typically exist on small spatial scales, i.e., “sub-Larmor scales.” Radiation from charged particles moving through small-scale electromagnetic (EM) turbulence has spectral characteristics distinct from both synchrotron and cyclotron radiation, and it carries valuable information on the statistical properties of the EM field structure and evolution. Consequently, this radiation from laser-produced plasmas may offer insight into the underlying electromagnetic turbulence. Here, we investigate the prospects for, and demonstrate themore » feasibility of, such direct radiative diagnostics for mildly relativistic, solid-density laser plasmas produced in lab experiments.« less

Studies for the Loss of Atomic and Molecular Species from Io

NASA Technical Reports Server (NTRS)

Smyth, William H.

1999-01-01

A summary discussion of research undertaken in this project is presented and is related to six published papers attached in the appendix. The discussion is divided into six sections describing a variety of studies for the loss of atomic and molecular species from Io. They include studies for: (1) atomic sodium, (2) SO2, (3) O and S, (4) spectacular high-spatial resolution ultraviolet image observations of O, S, and possibly H in Io's atmosphere and/or corona acquired by the Space Telescope Imaging Spectrometer (STIS) of the Hubble Space Telescope (HST), (5) spectacular high-spatial resolution visible Io eclipse image observations acquired by the Solid State Imager (SSI) of Galileo spacecraft, (6) ground-based observations acquired by the Solid State Imager (SSI) of Galileo spacecraft, and (7) ground-based observations of Io's neutral cloud in [OI] 6300 angstrom emission. New source rates at Io's exobase for SO2, O, and H are given and a variety of interesting implications for Io's atmosphere and for the Io plasma torus are discussed. Appendices that are comprised of articles published during the contract are also presented.

All optical electron injector using an intense ultrashort pulse laser and a solid wire target

NASA Astrophysics Data System (ADS)

Palchan, T.; Eisenmann, S.; Zigler, A.; Kaganovich, D.; Hubbard, R. F.; Fraenkel, M.; Fisher, D.; Henis, Z.

2006-05-01

Energetic electron bunches were generated by irradiating a solid tungsten wire 13 μm wide with 50 femtosecond pulses at an intensity of ˜3×1018 W/cm2. The electron yield, energy spectrum and angular distribution were measured. These energetic electron bunches are suitable for injection into a laser driven plasma accelerator. An all-optical electron injector based on this approach could simplify timing and alignment in future laser-plasma accelerator experiments.

Measurements of impurity concentrations and transport in the Lithium Tokamak Experiment

NASA Astrophysics Data System (ADS)

Boyle, Dennis Patrick

This thesis presents new measurements of core impurity concentrations and transport in plasmas with lithium coatings on all-metal plasma facing components (PFCs) in the Lithium Tokamak Experiment (LTX). LTX is a modest-sized spherical tokamak uniquely capable of operating with large area solid and/or liquid lithium coatings essentially surrounding the entire plasma (as opposed to just the divertor or limiter region in other devices). Lithium (Li) wall-coatings have improved plasma performance and confinement in several tokamaks with carbon (C) PFCs, including the National Spherical Torus Experiment (NSTX). In NSTX, contamination of the core plasma with Li impurities was very low (<0.1%) despite extensive divertor coatings. Low Li levels in NSTX were found to be largely due to neoclassical forces from the high level of C impurities. Studying impurity levels and transport with Li coatings on stainless steel surfaces in LTX is relevant to future devices (including future enhancements to NSTX-Upgrade) with all-metal PFCs. The new measurements in this thesis were enabled by a refurbished Thomson scattering system and improved impurity spectroscopy, primarily using a novel visible spectrometer monitoring several Li, C, and oxygen (O) emission lines. A simple model was used to account for impurities in unmeasured charge states, assuming constant density in the plasma core and constant concentration in the edge. In discharges with solid Li coatings, volume averaged impurity concentrations were low but non-negligible, with 2-4% Li, 0.6-2% C, 0.4-0.7% O, and Z eff<1.2. Transport was assessed using the TRANSP, NCLASS, and MIST codes. Collisions with the main H ions dominated the neoclassical impurity transport, unlike in NSTX, where collisions with C dominated. Furthermore, neoclassical transport coefficients calculated with NCLASS were similar across all impurity species and differed no more than a factor of two, in contrast to NSTX where they differed by an order of magnitude. However, time-independent simulations with MIST indicated that unlike NSTX, neoclassical theory did not fully capture the impurity transport and anomalous transport likely played a significant role in determining impurity profiles.

Measurements of impurity concentrations and transport in the Lithium Tokamak Experiment

DOE Office of Scientific and Technical Information (OSTI.GOV)

Boyle, Dennis Patrick

This thesis presents new measurements of core impurity concentrations and transport in plasmas with lithium coatings on all-metal plasma facing components (PFCs) in the Lithium Tokamak Experiment (LTX). LTX is a modest-sized spherical tokamak uniquely capable of operating with large area solid and/or liquid lithium coatings essentially surrounding the entire plasma (as opposed to just the divertor or limiter region in other devices). Lithium (Li) wall-coatings have improved plasma performance and confinement in several tokamaks with carbon (C) PFCs, including the National Spherical Torus Experiment (NSTX). In NSTX, contamination of the core plasma with Li impurities was very low (<0.1%)more » despite extensive divertor coatings. Low Li levels in NSTX were found to be largely due to neoclassical forces from the high level of C impurities. Studying impurity levels and transport with Li coatings on stainless steel surfaces in LTX is relevant to future devices (including future enhancements to NSTX-Upgrade) with all-metal PFCs. The new measurements in this thesis were enabled by a refurbished Thomson scattering system and improved impurity spectroscopy, primarily using a novel visible spectrometer monitoring several Li, C, and oxygen (O) emission lines. A simple model was used to account for impurities in unmeasured charge states, assuming constant density in the plasma core and constant concentration in the edge. In discharges with solid Li coatings, volume averaged impurity concentrations were low but non-negligible, with~2-4% Li, ~0.6-2% C, ~0.4-0.7% O, and Z_eff<1.2. Transport was assessed using the TRANSP, NCLASS, and MIST codes. Collisions with the main H ions dominated the neoclassical impurity transport, unlike in NSTX, where collisions with C dominated. Furthermore, neoclassical transport coefficients calculated with NCLASS were similar across all impurity species and differed no more than a factor of two, in contrast to NSTX where they differed by an order of magnitude. However, time-independent simulations with MIST indicated that unlike NSTX, neoclassical theory did not fully capture the impurity transport and anomalous transport likely played a significant role in determining impurity profiles.« less

Using penumbral imaging to measure micrometer size plasma hot spots in Gbar equation of state experiments on the National Ignition Facility.

PubMed

Bachmann, B; Kritcher, A L; Benedetti, L R; Falcone, R W; Glenn, S; Hawreliak, J; Izumi, N; Kraus, D; Landen, O L; Le Pape, S; Ma, T; Pérez, F; Swift, D; Döppner, T

2014-11-01

We have developed an experimental platform for absolute equation of state measurements up to Gbar pressures on the National Ignition Facility (NIF) within the Fundamental Science Program. We use a symmetry-tuned hohlraum drive to launch a spherical shock wave into a solid CH sphere. Streaked radiography is the primary diagnostic to measure the density change at the shock front as the pressure increases towards smaller radii. At shock stagnation in the center of the capsule, we observe a short and bright x-ray self emission from high density (∼50 g/cm(3)) plasma at ∼1 keV. Here, we present results obtained with penumbral imaging which has been carried out to characterize the size of the hot spot emission. This allows extending existing NIF diagnostic capabilities for spatial resolution (currently ∼10 μm) at higher sensitivity. At peak emission we find the hot spot radius to be as small as 5.8 +/- 1 μm, corresponding to a convergence ratio of 200.

Process for forming exoergic structures with the use of a plasma

DOEpatents

Kelly, M.D.

1987-05-29

A method of forming exoergic structures, as well as exoergic structures produced by the method, is provided. The method comprises the steps of passing a plasma-forming gas through a plasma spray gun, forming a plasma spray, introducing exoergic material into the plasma spray and directing the plasma spray toward a substrate, and allowing the exoergic material to become molten in the plasma spray and to thereafter impinge on the substrate to form a solid mass of exoergic material, the shape of which corresponds to the shape of the substrate.

Hydrodynamic Models for Multicomponent Plasmas with Collisional-Radiative Kinetics

DTIC Science & Technology

2014-12-01

16, 17]. The plasma, typically created by electric discharges , can deposit heat locally in the vicinity the flame, which quickly raises the gas...the corona layer of laser produced plasmas (LPP). Secondly, the self-consistent coupling of the plasma with the field gives rise to particle...excited species and reaction radicals; 7 n ncr solid transport layer (overdense) corona layer (underdense) temperature density shock wave ablation

Preparation and Evaluation of Solid Dispersion Tablets by a Simple and Manufacturable Wet Granulation Method Using Porous Calcium Silicate.

PubMed

Fujimoto, Yumi; Hirai, Nobuaki; Takatani-Nakase, Tomoka; Takahashi, Koichi

2016-01-01

The aim of this study was to prepare and evaluate solid dispersion tablets containing a poorly water-soluble drug using porous calcium silicate (PCS) by a wet granulation method. Nifedipine (NIF) was used as the model poorly water-soluble drug. Solid dispersion tablets were prepared with the wet granulation method using ethanol and water by a high-speed mixer granulator. The binder and disintegrant were selected from 7 and 4 candidates, respectively. The dissolution test was conducted using the JP 16 paddle method. The oral absorption of NIF was studied in fasted rats. Xylitol and crospovidone were selected as the binder and disintegrant, respectively. The dissolution rates of NIF from solid dispersion formulations were markedly enhanced compared with NIF powder and physical mixtures. Powder X-ray diffraction (PXRD) confirmed the reduced crystallinity of NIF in the solid dispersion formulations. Fourier transform infrared (FT-IR) showed the physical interaction between NIF and PCS in the solid dispersion formulations. NIF is present in an amorphous state in granules prepared by the wet granulation method using water. The area under the plasma concentration-time curve (AUC) and peak concentration (C(max)) values of NIF after dosing rats with the solid dispersion granules were significantly greater than those after dosing with NIF powder. The solid dispersion formulations of NIF prepared with PCS using the wet granulation method exhibited accelerated dissolution rates and superior oral bioavailability. This method is very simple, and may be applicable to the development of other poorly water-soluble drugs.

Disintegration of rocks based on magnetically isolated high voltage discharge

NASA Astrophysics Data System (ADS)

He, Mengbing; Jiang, Jinbo; Huang, Guoliang; Liu, Jun; Li, Chengzu

2013-02-01

Recently, a method utilizing pulsed power technology for disintegration of rocks arouses great interest of many researchers. In this paper, an improved method based on magnetic switch and the results shown that the uniform dielectrics like plastic can be broken down in water is presented, and the feasible mechanism explaining the breakdown of solid is proposed and proved experimentally. A high voltage pulse of 120 kV, rise time 0.2 μs was used to ignite the discharging channel in solids. When the plasma channel is formed in the solid, the resistance of the channel is quiet small; even if a relatively low voltage is applied on the channel on this occasion, it will produce high current to heat the plasma channel rapidly, and eventually disintegrate the solids. The feasibility of promising industrial application in the drilling and demolition of natural and artificial solid materials by the method we presented is verified by the experiment result in the paper.

Disintegration of rocks based on magnetically isolated high voltage discharge.

PubMed

He, Mengbing; Jiang, Jinbo; Huang, Guoliang; Liu, Jun; Li, Chengzu

2013-02-01

Recently, a method utilizing pulsed power technology for disintegration of rocks arouses great interest of many researchers. In this paper, an improved method based on magnetic switch and the results shown that the uniform dielectrics like plastic can be broken down in water is presented, and the feasible mechanism explaining the breakdown of solid is proposed and proved experimentally. A high voltage pulse of 120 kV, rise time 0.2 μs was used to ignite the discharging channel in solids. When the plasma channel is formed in the solid, the resistance of the channel is quiet small; even if a relatively low voltage is applied on the channel on this occasion, it will produce high current to heat the plasma channel rapidly, and eventually disintegrate the solids. The feasibility of promising industrial application in the drilling and demolition of natural and artificial solid materials by the method we presented is verified by the experiment result in the paper.

Air plasma spray processing and electrochemical characterization of Cu-SDC coatings for use in solid oxide fuel cell anodes

NASA Astrophysics Data System (ADS)

Benoved, Nir; Kesler, O.

Air plasma spraying has been used to produce porous composite anodes based on Ce 0.8Sm 0.2O 1.9 (SDC) and Cu for use in solid oxide fuel cells (SOFCs). Preliminarily, a range of plasma conditions has been examined for the production of composite coatings from pre-mixed SDC and CuO powders. Plasma gas compositions were varied to obtain a range of plasma temperatures. After reduction in H 2, coatings were characterized for composition and microstructure using EDX and SEM. As a result of these tests, symmetrical sintered electrolyte-supported anode-anode cells were fabricated by air plasma spraying of the anodes, followed by in situ reduction of the CuO to Cu. Full cells deposited on SS430 porous substrates were then produced in one integrated process. Fine CuO and SDC powders have been used to produce homogeneously mixed anode coatings with higher surface area microstructures, resulting in area-specific polarization resistances of 4.8 Ω cm 2 in impedance tests in hydrogen at 712 °C.

Extreme ultraviolet interferometry of warm dense matter in laser plasmas.

PubMed

Gartside, L M R; Tallents, G J; Rossall, A K; Wagenaars, E; Whittaker, D S; Kozlová, M; Nejdl, J; Sawicka, M; Polan, J; Kalal, M; Rus, B

2010-11-15

We demonstrate that interferometric probing with extreme ultraviolet (EUV) laser light enables determination of the degree of ionization of the "warm dense matter" produced between the critical and ablation surfaces of laser plasmas. Interferometry has been utilized to measure both transmission and phase information for an EUV laser beam at the photon energy of 58.5 eV, probing longitudinally through laser-irradiated plastic (parylene-N) targets (thickness 350 nm) irradiated by a 300 ps duration pulse of wavelength 438 nm and peak irradiance 10(12) W cm(-2). The transmission of the EUV probe beam provides a measure of the rate of target ablation, as ablated plasma becomes close to transparent when the photon energy is less than the ionization energy of the predominant ion species. We show that refractive indices η below the solid parylene N (η(solid) = 0.946) and expected plasma values are produced in the warm dense plasma created by laser irradiation due to bound-free absorption in C(+).

Solvent-modified solid-phase microextraction for the determination of diazepam in human plasma samples by capillary gas chromatography.

PubMed

Krogh, M; Grefslie, H; Rasmussen, K E

1997-02-21

This paper describes microextraction and gas chromatographic analysis of diazepam from human plasma. The method was based on immobilisation of 1.5 microliters of 1-octanol on a polyacrylate-coated fiber designed for solid-phase microextraction. The solvent-modified fibre was used to extract diazepam from the samples. The plasma sample was pre-treated to release diazepam from the protein binding. The fibre was inserted into the modified plasma sample, adjusted to pH 5.5 an internal standard was added and the mixture was carefully stirred for 4 min. The fibre with the immobilised solvent and the enriched analytes was injected into the capillary gas chromatograph. The solvent and the extracted analytes were evaporated at 300 degrees C in the split-splitless injection port of the gas chromatograph, separated on a methylsilicon capillary column and detected with a nitrogen-phosphorus detector. The method was shown to be reproducible with a detection limit of 0.10 nmol/ml in human plasma.

Microwave plasma generation of arsine from hydrogen and solid arsenic

NASA Astrophysics Data System (ADS)

Omstead, Thomas R.; Annapragada, Ananth V.; Jensen, Klavs F.

1990-12-01

The generation of arsine from the reactions of hydrogen and elemental arsenic in a microwave plasma reactor is described. The arsenic is evaporated from a solid source upstream and carried into the microwave plasma region by a mixture of hydrogen and argon. Stable reaction products, arsine and diarsine are observed by molecular beam sampled mass spectroscopy along with partially hydrogenated species (e.g., AsH and AsH2). The effect of composition and flow rate of the argon/hydrogen carrier gas mixture on the amount of arsine generated is investigated. The arsine production reaches a maximum for an argon-to-hydrogen ratio of unity indicating that metastable argon species act as energy transfer intermediates in the overall reaction. The generation of arsine and diarsine from easily handled solid arsenic by this technique makes it attractive as a possible arsenic source for the growth of compound semiconductors by low-pressure metalorganic chemical vapor deposition.

Increase in the Hydrophilicity and Lewis Acid-Base Properties of Solid Surfaces Achieved by Electric Gliding Discharge in Humid Air: Effects on Bacterial Adherence

NASA Astrophysics Data System (ADS)

Kamgang, J. O.; Naitali, M.; Herry, J.-M.; Bellon-Fontaine, M.-N.; Brisset, J.-L.; Briandet, R.

2009-04-01

This study addressed the effects of treatment with gliding discharge plasma on the surface properties of solid materials, as well as the consequences concerning adherence of a model bacterium. As evaluated by contact angles with selected liquids, plasma treatment caused an increase in surface hydrophilicity and in the Lewis acid-base components of the surface energy of all materials tested. These modifications were more marked for low density polyethylene and stainless steel than for polytetrafluoroethylene. After treatment, the hydrophilicity of the materials remained relatively stable for at least 20 days. Moreover, analysis of the topography of the materials by atomic force microscopy revealed that the roughness of both polymers was reduced by glidarc plasma treatment. As a result of all these modifications, solid substrates were activated towards micro-organisms and the adherence of S. epidermidis, a negatively charged Lewis-base and mildly hydrophilic strain selected as the model, was increased in almost all the cases tested.

Increased x-ray conversion efficiency from ultra high contrast, relativistic laser pulse irradiation of large aspect ratio, vertically aligned nanowires

NASA Astrophysics Data System (ADS)

Hollinger, R. C.; Bargsten, C.; Shlyaptsev, V. N.; Kaymak, V.; Pukhov, A.; Capeluto, M. G.; Wang, Y.; Wang, S.; Rockwood, A.; Curtis, A.; Rocca, J. J.

2016-10-01

Recent experiments at Colorado State University have shown that the effective trapping of clean, Joule-level fs laser pulses of relativistic intensity in arrays of high aspect ratio aligned nanowire creates multi-kev, near solid density, large scale (>4um deep) plasmas. The drastically decreased radiative life time and increased hydrodynamic cooling time from these plasmas increases the x-ray conversion efficiency. We measured a record conversion efficiency of 10% into hv>1KeV photons (2pi steradians), and of 0.3% for hv>6KeV. The experiments used Au and Ni nanowires of 55nm, 80nm and 100nm in diameter with 12% of solid density irradiated by high contrast (>1012) pulses of 60fs FWHM duration from a frequency doubled Ti:Sa laser at intensities of I =5x1019Wcm-2. We also present preliminary results on x-ray emission from Rhodium nanowires in the 19-22KeV range and demonstrate the potential of this picosecond X-ray source in flash radiography. This work was supported by the Fusion Energy Program, Office of Science of the U.S Department of Energy, and by the Defense Threat Reduction Agency Grant HDTRA-1-10-1-0079.

Ultrafast Kα x-ray Thomson scattering from shock compressed lithium hydride

DOE PAGES

Kritcher, A. L.; Neumayer, P.; Castor, J.; ...

2009-04-13

Spectrally and temporally resolved x-ray Thomson scattering using ultrafast Ti Kα x rays has provided experimental validation for modeling of the compression and heating of shocked matter. The coalescence of two shocks launched into a solid density LiH target by a shaped 6 ns heater beam was observed from rapid heating to temperatures of 2.2 eV, enabling tests of shock timing models. Here, the temperature evolution of the target at various times during shock progression was characterized from the intensity of the elastic scattering component. The observation of scattering from plasmons, electron plasma oscillations, at shock coalescence indicates a transitionmore » to a dense metallic plasma state in LiH. From the frequency shift of the measured plasmon feature the electron density was directly determined with high accuracy, providing a material compression of a factor of 3 times solid density. The quality of data achieved in these experiments demonstrates the capability for single shot dynamic characterization of dense shock compressed matter. Here, the conditions probed in this experiment are relevant for the study of the physics of planetary formation and to characterize inertial confinement fusion targets for experiments such as on the National Ignition Facility, Lawrence Livermore National Laboratory.« less

Nanostructure array plasmas generated by femtosecond pulses at highly relativistic intensities

NASA Astrophysics Data System (ADS)

Hollinger, R. C.; Wong, Y.; Wong, S.; Rockwood, A.; Glasby, J.; Shlyaptsev, V.; Rocca, J. J.; Capeluto, M. G.; Kaymak, V.; Pukhov, A.

2017-10-01

The irradiation of high aspect ratio ordered nanostructure arrays with ultra-high contrast femtosecond laser pulses of relativistic intensity provides a unique combination of nearly complete optical absorption and drastically enhanced light penetration into near-solid density targets. This allows the material to be volumetrically heated deep into the ultra-high energy density regime. In previous experiments we have shown that irradiation of Ni and Au nanostructures with femtosecond pulses focused to an intensity of 5x1018 Wcm-2 generate multi-KeV near solid density plasmas in which atoms are ionized to the Ni+26 and Au+52 charge states. Here we present the first results of the irradiation of nanostructure arrays with highly relativistic pulses of intensities up to 5x1021Wcm-2. Silver and Rhodium nanowire arrays were irradiated with frequency-doubled pulses of 30 fs duration from a petawatt-class Ti:Sa laser. Time integrated x-ray spectra show the presence of He-like and Li-like emission. Results of experiments conducted with a variety of different nanowires diameters with a range of interwire spacings will be presented and compared to the result of 3D particle-in-cell-simulations. This work was supported by the Fusion Energy Program, Office of Science of the U.S Department of Energy.

Design and experimental results of the 1-T Bitter Electromagnet Testing Apparatus (BETA)

NASA Astrophysics Data System (ADS)

Bates, E. M.; Birmingham, W. J.; Romero-Talamás, C. A.

2018-05-01

The Bitter Electromagnet Testing Apparatus (BETA) is a 1-Tesla (T) technical prototype of the 10 T Adjustable Long Pulsed High-Field Apparatus. BETA's final design specifications are highlighted in this paper which include electromagnetic, thermal, and stress analyses. We discuss here the design and fabrication of BETA's core, vessel, cooling, and electrical subsystems. The electrical system of BETA is composed of a scalable solid-state DC breaker circuit. Experimental results display the stable operation of BETA at 1 T. These results are compared to both analytical design and finite element calculations. Experimental results validate analytical magnet designing methods developed at the Dusty Plasma Laboratory. The theoretical steady state maxima and the limits of BETA's design are explored in this paper.

Design and experimental results of the 1-T Bitter Electromagnet Testing Apparatus (BETA).

PubMed

Bates, E M; Birmingham, W J; Romero-Talamás, C A

2018-05-01

The Bitter Electromagnet Testing Apparatus (BETA) is a 1-Tesla (T) technical prototype of the 10 T Adjustable Long Pulsed High-Field Apparatus. BETA's final design specifications are highlighted in this paper which include electromagnetic, thermal, and stress analyses. We discuss here the design and fabrication of BETA's core, vessel, cooling, and electrical subsystems. The electrical system of BETA is composed of a scalable solid-state DC breaker circuit. Experimental results display the stable operation of BETA at 1 T. These results are compared to both analytical design and finite element calculations. Experimental results validate analytical magnet designing methods developed at the Dusty Plasma Laboratory. The theoretical steady state maxima and the limits of BETA's design are explored in this paper.

Kinetic modeling of x-ray laser-driven solid Al plasmas via particle-in-cell simulation

NASA Astrophysics Data System (ADS)

Royle, R.; Sentoku, Y.; Mancini, R. C.; Paraschiv, I.; Johzaki, T.

2017-06-01

Solid-density plasmas driven by intense x-ray free-electron laser (XFEL) radiation are seeded by sources of nonthermal photoelectrons and Auger electrons that ionize and heat the target via collisions. Simulation codes that are commonly used to model such plasmas, such as collisional-radiative (CR) codes, typically assume a Maxwellian distribution and thus instantaneous thermalization of the source electrons. In this study, we present a detailed description and initial applications of a collisional particle-in-cell code, picls, that has been extended with a self-consistent radiation transport model and Monte Carlo models for photoionization and K L L Auger ionization, enabling the fully kinetic simulation of XFEL-driven plasmas. The code is used to simulate two experiments previously performed at the Linac Coherent Light Source investigating XFEL-driven solid-density Al plasmas. It is shown that picls-simulated pulse transmissions using the Ecker-Kröll continuum-lowering model agree much better with measurements than do simulations using the Stewart-Pyatt model. Good quantitative agreement is also found between the time-dependent picls results and those of analogous simulations by the CR code scfly, which was used in the analysis of the experiments to accurately reproduce the observed K α emissions and pulse transmissions. Finally, it is shown that the effects of the nonthermal electrons are negligible for the conditions of the particular experiments under investigation.

EFFECT OF SOLID MEDIUM DURING COOLED STORAGE ON STALLION SPERM PARAMETERS.

PubMed

Santos, F C; Corcini, C D; Costa, V G; Gheller, S M; Nogueira, C E; da Rosa Curcio, B; Varel, A S

2015-01-01

Solid storage medium prevents cellular sedimentation, reduces metabolic demand via limiting movement, and avoids the modification of an extender composition in the sedimentary microenvironment. It has been proven to prolong spermatozoa viability in mammalians. This experiment aims to evaluate the effect of cool storage in solid phase extender on stallion sperms. Semen was collected from 10 Crioulo stallions (n=30) and submitted to treatments: control group (semen extender) and groups with gelatin addition in different concentrations (semen extender + 1%, 2% and 3%). Seminal analyses included motility, mitochondrial functionality, plasma membrane integrity, DNA and acrosome at 0; 24; 48 and 72 hours during cooled storage at 5 degree C. Motility, mitochondrial functionality, plasma membrane and acrosome integrity declined during storage time, with no statistical difference between treatments. DNA integrity did not significantly change during storage period. Solid medium was not harmful and did not improved stallion sperm parameters during cooled storage.

Comparison of Standardized Cytomegalovirus (CMV) Viral Load Thresholds in Whole Blood and Plasma of Solid Organ and Hematopoietic Stem Cell Transplant Recipients with CMV Infection and Disease.

PubMed

Dioverti, M Veronica; Lahr, Brian D; Germer, Jeffrey J; Yao, Joseph D; Gartner, Michelle L; Razonable, Raymund R

2017-01-01

Quantification of cytomegalovirus (CMV) deoxyribonucleic acid (DNA) has important diagnostic, prognostic, and therapeutic implications in the management of transplant recipients. We aimed to assess a viral load in plasma and whole blood that distinguishes CMV disease from asymptomatic infection in a cohort of solid organ and hematopoietic stem cell transplantation. We prospectively measured and compared CMV viral load in paired plasma and whole blood samples collected from transplant recipients with CMV infection and disease. Cytomegalovirus viral loads were determined by a commercially available US Food and Drug Administration-approved quantitative assay (COBAS AmpliPrep/COBAS TaqMan CMV Test [CAP/CTM CMV]) calibrated to the first World Health Organization International Standard for CMV DNA quantification. Moderate agreement of CMV viral load was observed between plasma and whole blood, with 31% of samples having discordant findings, particularly among samples with low DNA levels. Among the subset of samples where both paired samples had quantifiable levels, we observed a systematic bias that reflected higher viral load in whole blood compared with plasma. Based on receiver operating curve analysis, an initial plasma CMV viral load threshold of 1700 IU/mL in solid organ transplant recipients (sensitivity 80%, specificity 74%) and 1350 IU/mL in allogeneic hematopoietic stem cell transplant recipients (sensitivity 87%, specificity 87%) distinguished CMV disease and asymptomatic infection. This study identifies standardized viral load thresholds that distinguish CMV disease from asymptomatic infection using CAP/CTM CMV assay. We propose these thresholds as potential triggers to be evaluated in prospective studies of preemptive therapy. Plasma was better than whole blood for measuring viral load using the CAP/CTM CMV assay.

Progress and prospect on failure mechanisms of solid-state lithium batteries

NASA Astrophysics Data System (ADS)

Ma, Jun; Chen, Bingbing; Wang, Longlong; Cui, Guanglei

2018-07-01

By replacing traditional liquid organic electrolyte with solid-state electrolyte, the solid-state lithium batteries powerfully come back to the energy storage field due to their eminent safety and energy density. In recent years, a variety of solid-state lithium batteries based on excellent solid-state electrolytes are developed. However, the performance degradation of solid-state lithium batteries during cycling and storing is still a serious challenge for practical application. Therefore, this review summarizes the research progress of solid-state lithium batteries from the perspectives of failure phenomena and failure mechanisms. Additionally, the development of methodologies on studying the failure mechanisms of solid-state lithium batteries is also reviewed. Moreover, some perspectives on the remaining questions for understanding the failure behaviors and achieving long cycle life, high safety and high energy density solid-state lithium batteries are presented. This review will help researchers to recognize the status of solid-state lithium batteries objectively and attract much more research interest in conquering the failure issues of solid-state lithium batteries.

Development of Terahertz Rayleigh Scattering Diagnostics for a Solid Rocket Exhaust Plume

DTIC Science & Technology

2010-10-28

experiment. Many of these experiments involve a diagnostic of a plasma which while different from strictly particles, still provides insight into the...investigate the properties of small plasma objects. Their study developed a method that could be used as a diagnostic for small scale plasmas such...as laser sparks, avalanche-streamer transitions, and resonance-enhanced multi- photon ionizations processes. They treated a plasma as a source of

Apparatus and methods for direct conversion of gaseous hydrocarbons to liquids

DOEpatents

Kong, Peter C.; Lessing, Paul A.

2006-04-25

A chemical reactor for direct conversion of hydrocarbons includes a dielectric barrier discharge plasma cell and a solid oxide electrochemical cell in fluid communication therewith. The discharge plasma cell comprises a pair of electrodes separated by a dielectric material and passageway therebetween. The electrochemical cell comprises a mixed-conducting solid oxide electrolyte membrane tube positioned between a porous cathode and a porous anode, and a gas inlet tube for feeding oxygen containing gas to the porous cathode. An inlet is provided for feeding hydrocarbons to the passageway of the discharge plasma cell, and an outlet is provided for discharging reaction products from the reactor. A packed bed catalyst may optionally be used in the reactor to increase efficiency of conversion. The reactor can be modified to allow use of a light source for directing ultraviolet light into the discharge plasma cell and the electrochemical cell.

Sn ion energy distributions of ns- and ps-laser produced plasmas

NASA Astrophysics Data System (ADS)

Bayerle, A.; Deuzeman, M. J.; van der Heijden, S.; Kurilovich, D.; de Faria Pinto, T.; Stodolna, A.; Witte, S.; Eikema, K. S. E.; Ubachs, W.; Hoekstra, R.; Versolato, O. O.

2018-04-01

Ion energy distributions arising from laser-produced plasmas of Sn are measured over a wide laser parameter space. Planar-solid and liquid-droplet targets are exposed to infrared laser pulses with energy densities between 1 J cm‑2 and 4 kJ cm‑2 and durations spanning 0.5 ps to 6 ns. The measured ion energy distributions are compared to two self-similar solutions of a hydrodynamic approach assuming isothermal expansion of the plasma plume into vacuum. For planar and droplet targets exposed to ps-long pulses, we find good agreement between the experimental results and the self-similar solution of a semi-infinite simple planar plasma configuration with an exponential density profile. The ion energy distributions resulting from solid Sn exposed to ns-pulses agrees with solutions of a limited-mass model that assumes a Gaussian-shaped initial density profile.

Method for direct conversion of gaseous hydrocarbons to liquids

DOEpatents

Kong, Peter C.; Lessing, Paul A.

2006-03-07

A chemical reactor for direct conversion of hydrocarbons includes a dielectric barrier discharge plasma cell and a solid oxide electrochemical cell in fluid communication therewith. The discharge plasma cell comprises a pair of electrodes separated by a dielectric material and passageway therebetween. The electrochemical cell comprises a mixed-conducting solid oxide electrolyte membrane tube positioned between a porous cathode and a porous anode, and a gas inlet tube for feeding oxygen containing gas to the porous cathode. An inlet is provided for feeding hydrocarbons to the passageway of the discharge plasma cell, and an outlet is provided for discharging reaction products from the reactor. A packed bed catalyst may optionally be used in the reactor to increase efficiency of conversion. The reactor can be modified to allow use of a light source for directing ultraviolet light into the discharge plasma cell and the electrochemical cell.

Solid oxide fuel cells fueled with reducible oxides

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chuang, Steven S.; Fan, Liang Shih

A direct-electrochemical-oxidation fuel cell for generating electrical energy includes a cathode provided with an electrochemical-reduction catalyst that promotes formation of oxygen ions from an oxygen-containing source at the cathode, a solid-state reduced metal, a solid-state anode provided with an electrochemical-oxidation catalyst that promotes direct electrochemical oxidation of the solid-state reduced metal in the presence of the oxygen ions to produce electrical energy, and an electrolyte disposed to transmit the oxygen ions from the cathode to the solid-state anode. A method of operating a solid oxide fuel cell includes providing a direct-electrochemical-oxidation fuel cell comprising a solid-state reduced metal, oxidizing themore » solid-state reduced metal in the presence of oxygen ions through direct-electrochemical-oxidation to obtain a solid-state reducible metal oxide, and reducing the solid-state reducible metal oxide to obtain the solid-state reduced metal.« less

Pedestal cleaning for high laser pulse contrast ratio with a 100 TW class laser system.

PubMed

Fourmaux, S; Payeur, S; Buffechoux, S; Lassonde, P; St-Pierre, C; Martin, F; Kieffer, J C

2011-04-25

Laser matter interaction at relativistic intensities using 100 TW class laser systems or higher is becoming more and more widespread. One of the critical issues of such laser systems is to let the laser pulse interact at high intensity with the solid target and avoid any pre-plasma. Thus, a high Laser Pulse Contrast Ratio (LPCR) parameter is of prime importance. We present the LPCR characterization of a high repetition 100 TW class laser system. We demonstrate that the generated Amplified Spontaneous Emission (ASE) degrades the overall LPCR performance. We propose a simple way to clean the pulse after the first amplification stage by introducing a solid state saturable absorber which results in a LPCR improvement to better than 10(10) with only a 30% energy loss at a 10 Hz repetition rate. We finally correlated this cleaning method with experimental results.

RX J1856.5-3754: A Strange Star with Solid Quark Surface?

NASA Technical Reports Server (NTRS)

Zhang, Xiaoling; Xu, Renxin; Zhang, Shuangnan

2003-01-01

The featureless spectra of isolated 'neutron stars' may indicate that they are actually bare strange stars but a definitive conclusion on the nature of the compact objects cannot be reached until accurate and theoretically calculated spectra of the bare quark surface are known. However due to the complex nonlinearity of quantum chromodynamics it is almost impossible to present a definitive and accurate calculation of the density-dominated quark-gluon plasma from the first principles. Nevertheless it was suggested that cold quark matter with extremely high baryon density could be in a solid state. Within the realms of this possibility we have fitted the 500ks Chandra LETG/HRC data for the brightest isolated neutron star RX 51856.5-3754 with a phenomenological spectral model and found that electric conductivity of quark matter on the stellar surface is about 1.5 x 10(exp 16)/s.

Mammalian monoamine-oxidizing enzymes, with special reference to benzylamine oxidase in human tissues.

PubMed

Lewinsohn, R

1984-01-01

A review is presented of the monoamine-oxidizing enzymes with special reference to the activity of benzylamine oxidase (BzAO) in human tissues. Methods of study of amine oxidases, properties (chiefly of BzAO) and some problems concerning substrate and inhibitor specificity and multiple forms of monoamine oxidase (MAO) are surveyed. The substrate specificity of human plasma BzAO is compared with that of amine-oxidizing enzymes in plasma or serum of other species. Correlations of plasma BzAO and platelet MAO activity with clinical findings are discussed. The distribution of amine oxidase activities in solid human tissues is reviewed, in particular BzAO in blood vessels and richly-vascularized tissues, as well as kinetic constants and altered patterns of activity of BzAO in human atherosclerosis. Activities of the amine oxidases in non-vascular smooth muscle, in cultured cells, and in various tissues related to human gestation, are discussed. The present knowledge of BzAO is discussed in terms of its possible clinical relevance to several human disease states, and the importance of the enzyme in the human body.

A compact, low cost Marx bank for generating capillary discharge plasmas.

PubMed

Dyson, A E; Thornton, C; Hooker, S M

2016-09-01

We describe in detail a low power Compact Marx Bank (CMB) circuit that can provide 20 kV, 500 A pulses of approximately 100-200 ns duration. One application is the generation of capillary discharge plasmas of density ≈10 18 cm -3 used in laser plasma accelerators. The CMB is triggered with a high speed solid state switch and gives a high voltage output pulse with a ns scale rise time into a 50 Ω load (coaxial cable) with <4 ns voltage jitter. Its small size (10 cm  ×  25 cm  ×  5 cm) means that it can be placed right next to the capillary discharge in the target chamber to avoid the need to impedance match. The electrical energy required per discharge is <1 J, and the CMB can be run at shot repetition rates of ≳1 Hz. This low power requirement means that the circuit can easily be powered by a small lead acid battery and, therefore, can be floated relative to laboratory earth. The CMB is readily scalable and pulses >45 kV are demonstrated in air discharges.

A compact, low cost Marx bank for generating capillary discharge plasmas

NASA Astrophysics Data System (ADS)

Dyson, A. E.; Thornton, C.; Hooker, S. M.

2016-09-01

We describe in detail a low power Compact Marx Bank (CMB) circuit that can provide 20 kV, 500 A pulses of approximately 100-200 ns duration. One application is the generation of capillary discharge plasmas of density ≈1018 cm-3 used in laser plasma accelerators. The CMB is triggered with a high speed solid state switch and gives a high voltage output pulse with a ns scale rise time into a 50 Ω load (coaxial cable) with <4 ns voltage jitter. Its small size (10 cm × 25 cm × 5 cm) means that it can be placed right next to the capillary discharge in the target chamber to avoid the need to impedance match. The electrical energy required per discharge is <1 J, and the CMB can be run at shot repetition rates of ≳1 Hz. This low power requirement means that the circuit can easily be powered by a small lead acid battery and, therefore, can be floated relative to laboratory earth. The CMB is readily scalable and pulses >45 kV are demonstrated in air discharges.

Two component X-ray emission from RS CVn binaries

NASA Technical Reports Server (NTRS)

Swank, J. H.; White, N. E.; Holt, S. S.; Becker, R. H.

1980-01-01

A summary of results from the solid state spectrometer on the Einstein Observatory for 7 RS CVn binaries is presented. The spectra of all require two emission components, evidenced by line emission characteristic of plasma at 4 to 8 x 10 to the 6th power and bremsstrahlung characteristic of 20 to 100 x 10 to the 6th power K. The data are interpreted in terms of magnetic coronal loops similar to those seen on the Sun, although with different characteristic parameters. The emission regions could be defined by separate magnetic structures. For pressure less than approximately 10 dynes/sq cm the low temperature plasma would be confined within the stellar radii, while the high temperature plasma would, for the synchronous close binaries, fill the binary orbits. However, for loop pressures exceeding 100 dynes/sq cm, the high temperature components would also be confined to within the stellar radii, in loops covering only small fractions of the stellar surfaces. While the radio properties and the occurrence of X-ray flares suggest the larger emission regions, the observations of time variations leave the ambiguity unresolved.

Compton scattering measurements from dense plasmas

DOE PAGES

Glenzer, S. H.; Neumayer, P.; Doppner, T.; ...

2008-06-12

Here, Compton scattering techniques have been developed for accurate measurements of densities and temperatures in dense plasmas. One future challenge is the application of this technique to characterize compressed matter on the National Ignition Facility where hydrogen and beryllium will approach extremely dense states of matter of up to 1000 g/cc. In this regime, the density, compressibility, and capsule fuel adiabat may be directly measured from the Compton scattered spectrum of a high-energy x-ray line source. Specifically, the scattered spectra directly reflect the electron velocity distribution. In non-degenerate plasmas, the width provides an accurate measure of the electron temperatures, whilemore » in partially Fermi degenerate systems that occur in laser-compressed matter it provides the Fermi energy and hence the electron density. Both of these regimes have been accessed in experiments at the Omega laser by employing isochorically heated solid-density beryllium and moderately compressed beryllium foil targets. In the latter experiment, compressions by a factor of 3 at pressures of 40 Mbar have been measured in excellent agreement with radiation hydrodynamic modeling.« less

Development of modular scalable pulsed power systems for high power magnetized plasma experiments

NASA Astrophysics Data System (ADS)

Bean, I. A.; Weber, T. E.; Adams, C. S.; Henderson, B. R.; Klim, A. J.

2017-10-01

New pulsed power switches and trigger drivers are being developed in order to explore higher energy regimes in the Magnetic Shock Experiment (MSX) at Los Alamos National Laboratory. To achieve the required plasma velocities, high-power (approx. 100 kV, 100s of kA), high charge transfer (approx. 1 C), low-jitter (few ns) gas switches are needed. A study has been conducted on the effects of various electrode geometries and materials, dielectric media, and triggering strategies; resulting in the design of a low-inductance annular field-distortion switch, optimized for use with dry air at 90 psig, and triggered by a low-jitter, rapid rise-time solid-state Linear Transformer Driver. The switch geometry and electrical characteristics are designed to be compatible with Syllac style capacitors, and are intended to be deployed in modular configurations. The scalable nature of this approach will enable the rapid design and implementation of a wide variety of high-power magnetized plasma experiments. This work is supported by the U.S. Department of Energy, National Nuclear Security Administration. Approved for unlimited release, LA-UR-17-2578.

Modeling the Dynamics of Micro- and Macroparticles in a Combined Gas-Discharge Installation

NASA Astrophysics Data System (ADS)

Astashinskii, V. V.; Bogach, M. I.; Burachevskii, A. V.

2016-05-01

We present a model of the dynamics of micro- and macroparticles in a combined gas-discharge installation that accounts for the processes of metal explosion (heating of a metal in its solid state, melting, heating of the liquid metal, intense evaporation, ionization in metal vapor), a magnetohydrodynamic description of plasma acceleration (on the basis of the mass, momentum, and energy conservation laws neglecting the plasma viscosity and thermal conductivity), and a description of the processes of energy transfer from a high-velocity stream to accelerated particles. It has been established that the process of melting terminates in 1.3 ns after the start of the discharge and that the evaporation terminates in 480 ns. The stage of cooling starts in 21 μs. The average density of the plasma upon completion of the evaporation process can be estimated to be 1.7·10-5 g/cm3, with the pressure being of the order of 1.5·104 Pa and the total time of discharge, of about 250 μs.

Method and apparatus for producing oxygenates from hydrocarbons

DOEpatents

Kong, Peter C.; Lessing, Paul A.

1995-01-01

A chemical reactor for oxygenating hydrocarbons includes: a) a dielectric barrier discharge plasma cell, the plasma cell comprising a pair of electrodes having a dielectric material and void therebetween, the plasma cell comprising a hydrocarbon gas inlet feeding to the void; b) a solid oxide electrochemical cell, the electrochemical cell comprising a solid oxide electrolyte positioned between a porous cathode and a porous anode, an oxygen containing gas inlet stream feeding to the porous cathode side of the electrochemical cell; c) a first gas passageway feeding from the void to the anode side of the electrochemical cell; and d) a gas outlet feeding from the anode side of the electrochemical cell to expel reaction products from the chemical reactor. A method of oxygenating hydrocarbons is also disclosed.

Quantitative determination of a chemically modified hammerhead ribozyme in blood plasma using 96-well solid-phase extraction coupled with high-performance liquid chromatography or capillary gel electrophoresis.

PubMed

Bellon, L; Maloney, L; Zinnen, S P; Sandberg, J A; Johnson, K E

2000-08-01

Versatile bioanalytical assays to detect chemically stabilized hammerhead ribozyme and putative ribozyme metabolites from plasma are described. The extraction protocols presented are based on serial solid-phase extractions performed on a 96-well plate format and are compatible with either IEX-HPLC or CGE back-end analysis. A validation of both assays confirmed that both the HPLC and the CGE methods possess the required linearity, accuracy, and precision to accurately measure concentrations of hammerhead ribozyme extracted from plasma. These methods should be of general use to detect and quantitate ribozymes from other biological fluids such as serum and urine. Copyright 2000 Academic Press.

Odd harmonics-enhanced supercontinuum in bulk solid-state dielectric medium.

PubMed

Garejev, N; Jukna, V; Tamošauskas, G; Veličkė, M; Šuminas, R; Couairon, A; Dubietis, A

2016-07-25

We report on generation of ultrabroadband, more than 4 octave spanning supercontinuum in thin CaF₂ crystal, as pumped by intense mid-infrared laser pulses with central wavelength of 2.4 μm. The supercontinuum spectrum covers wavelength range from the ultraviolet to the mid-infrared and its short wavelength side is strongly enhanced by cascaded generation of third, fifth and seventh harmonics. Our results capture the transition from Kerr-dominated to plasma-dominated filamentation regime and uncover that in the latter the spectral superbroadening originates from dramatic plasma-induced compression of the driving pulse, which in turn induces broadening of the harmonics spectra due to cross-phase modulation effects. The experimental measurements are backed up by the numerical simulations based on a nonparaxial unidirectional propagation equation for the electric field of the pulse, which accounts for the cubic nonlinearity-induced effects, and which reproduce the experimental data in great detail.

A novel reconfigurable electromagnetically induced transparency based on S-PINs

NASA Astrophysics Data System (ADS)

Xue, Feng; Liu, Shao-Bin; Zhang, Hai-Feng; Wen, Yong-Diao; Kong, Xiang-Kun; Li, Hai-Ming

2018-02-01

In this paper, a tunable electromagnetically induced transparency (EIT) based on S-PINs is theoretically analyzed. Unit cell of the structure consists of a cutwire (CW), split ring resonator (SRR), and solid state plasma (SS plasma) patches which are composed of S-PIN array. The destructive interference between the CW and SRR results in a narrowband transparency window accompanied with strong phase dispersion. The proposed design can obtain a tunable EIT with different frequencies range from 12.8 GHz to 16.5 GHz in a simple method by switching these S-PINs on or off selectively. The related parameters of the S-PIN such as the size, carrier concentration, and volt-ampere characteristics have been studied theoretically. The interaction and coupling between two resonators are investigated in detail by the analysis of the current distribution and E-field strength as well. The research results provide an effective way to realize reconfigurable compact slow-light devices.

Influence of chemistry on wetting dynamics of nanotextured hydrophobic surfaces.

PubMed

Di Mundo, Rosa; Palumbo, Fabio; d'Agostino, Riccardo

2010-04-06

In this work, the role of a chemical parameter, such as the degree of fluorination, on the wetting behavior of nanotextured hydrophobic surfaces is investigated. Texture and chemistry tuning of the surfaces has been accomplished with single batch radiofrequency low-pressure plasma processes. Polystyrene substrates have been textured by CF(4) plasma etching and subsequently covered by thin films with a tunable F-to-C ratio, obtained in discharges fed with C(4)F(8)-C(2)H(4). Measurements of wetting dynamics reveal a regime transition from adhesive-hydrophobic to slippery-superhydrophobic, i.e., from wet to non wet states, as the F-to-C rises at constant topography. Such achievements are strengthened by calculation of the solid fraction of surface water contact area applying Cassie-Baxter advancing and receding equations to water contact angle data of textured and flat reference surfaces.

Friction surfaced Stellite6 coatings

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rao, K. Prasad; Damodaram, R.; Rafi, H. Khalid, E-mail: khalidrafi@gmail.com

2012-08-15

Solid state Stellite6 coatings were deposited on steel substrate by friction surfacing and compared with Stellite6 cast rod and coatings deposited by gas tungsten arc and plasma transferred arc welding processes. Friction surfaced coatings exhibited finer and uniformly distributed carbides and were characterized by the absence of solidification structure and compositional homogeneity compared to cast rod, gas tungsten arc and plasma transferred coatings. Friction surfaced coating showed relatively higher hardness. X-ray diffraction of samples showed only face centered cubic Co peaks while cold worked coating showed hexagonally close packed Co also. - Highlights: Black-Right-Pointing-Pointer Stellite6 used as coating material formore » friction surfacing. Black-Right-Pointing-Pointer Friction surfaced (FS) coatings compared with casting, GTA and PTA processes. Black-Right-Pointing-Pointer Finer and uniformly distributed carbides in friction surfaced coatings. Black-Right-Pointing-Pointer Absence of melting results compositional homogeneity in FS Stellite6 coatings.« less

Simulating plasma production from hypervelocity impacts

NASA Astrophysics Data System (ADS)

Fletcher, Alex; Close, Sigrid; Mathias, Donovan

2015-09-01

Hypervelocity particles, such as meteoroids and space debris, routinely impact spacecraft and are energetic enough to vaporize and ionize themselves and as well as a portion of the target material. The resulting plasma rapidly expands into the surrounding vacuum. While plasma measurements from hypervelocity impacts have been made using ground-based technologies such as light gas guns and Van de Graaff dust accelerators, some of the basic plasma properties vary significantly between experiments. There have been both ground-based and in-situ measurements of radio frequency (RF) emission from hypervelocity impacts, but the physical mechanism responsible and the possible connection to the impact-produced plasma are not well understood. Under certain conditions, the impact-produced plasma can have deleterious effects on spacecraft electronics by providing a new current path, triggering an electrostatic discharge, causing electromagnetic interference, or generating an electromagnetic pulse. Multi-physics simulations of plasma production from hypervelocity impacts are presented. These simulations incorporate elasticity and plasticity of the solid target, phase change and plasma formation, and non-ideal plasma physics due to the high density and low temperature of the plasma. A smoothed particle hydrodynamics method is used to perform a continuum dynamics simulation with these additional physics. By examining a series of hypervelocity impacts, basic properties of the impact produced plasma plume (density, temperature, expansion speed, charge state) are determined for impactor speeds between 10 and 72 km/s. For a large range of higher impact speeds (30-72 km/s), we find the temperature is unvarying at 2.5 eV. We also find that the plasma plume is weakly ionized for impact speeds less than 14 km/s and fully ionized for impact speeds greater than 20 km/s, independent of impactor mass. This is the same velocity threshold for the detection of RF emission in recent Van de Graaff experiments, suggesting that the RF is correlated to the formation of fully ionized plasma.

Simulating plasma production from hypervelocity impacts

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fletcher, Alex, E-mail: alexcf@stanford.edu; Close, Sigrid; Mathias, Donovan

2015-09-15

Hypervelocity particles, such as meteoroids and space debris, routinely impact spacecraft and are energetic enough to vaporize and ionize themselves and as well as a portion of the target material. The resulting plasma rapidly expands into the surrounding vacuum. While plasma measurements from hypervelocity impacts have been made using ground-based technologies such as light gas guns and Van de Graaff dust accelerators, some of the basic plasma properties vary significantly between experiments. There have been both ground-based and in-situ measurements of radio frequency (RF) emission from hypervelocity impacts, but the physical mechanism responsible and the possible connection to the impact-producedmore » plasma are not well understood. Under certain conditions, the impact-produced plasma can have deleterious effects on spacecraft electronics by providing a new current path, triggering an electrostatic discharge, causing electromagnetic interference, or generating an electromagnetic pulse. Multi-physics simulations of plasma production from hypervelocity impacts are presented. These simulations incorporate elasticity and plasticity of the solid target, phase change and plasma formation, and non-ideal plasma physics due to the high density and low temperature of the plasma. A smoothed particle hydrodynamics method is used to perform a continuum dynamics simulation with these additional physics. By examining a series of hypervelocity impacts, basic properties of the impact produced plasma plume (density, temperature, expansion speed, charge state) are determined for impactor speeds between 10 and 72 km/s. For a large range of higher impact speeds (30–72 km/s), we find the temperature is unvarying at 2.5 eV. We also find that the plasma plume is weakly ionized for impact speeds less than 14 km/s and fully ionized for impact speeds greater than 20 km/s, independent of impactor mass. This is the same velocity threshold for the detection of RF emission in recent Van de Graaff experiments, suggesting that the RF is correlated to the formation of fully ionized plasma.« less

Process for forming exoergic structures with the use of a plasma

DOEpatents

Kelly, Michael D.

1989-02-21

A method of forming exoergic structures, as well as exoergic structures produced by the method, is provided. The method comprises the steps of passing a plasma-forming gas through a plasma spray gun, forming a plasma spray, introducing exoergic material into the plasma spray and directing the plasma spray toward a substrate, and allowing the exoergic material to become molten, without chemically reacting in the plasma spray and to thereafter impinge on the substrate to form a solid mass of exoergic material, the shape of which corresponds to the shape of the substrate.

Collecting and Storing Blood Samples From Patients With Cancer

ClinicalTrials.gov

2011-12-08

Brain and Central Nervous System Tumors; Chronic Myeloproliferative Disorders; Leukemia; Lymphoma; Lymphoproliferative Disorder; Multiple Myeloma and Plasma Cell Neoplasm; Myelodysplastic Syndromes; Myelodysplastic/Myeloproliferative Neoplasms; Nonmalignant Neoplasm; Unspecified Adult Solid Tumor, Protocol Specific; Unspecified Childhood Solid Tumor, Protocol Specific

Responses of Solid Tumor Cells in DMEM to Reactive Oxygen Species Generated by Non-Thermal Plasma and Chemically Induced ROS Systems

PubMed Central

Kaushik, Neha; Uddin, Nizam; Sim, Geon Bo; Hong, Young June; Baik, Ku Youn; Kim, Chung Hyeok; Lee, Su Jae; Kaushik, Nagendra Kumar; Choi, Eun Ha

2015-01-01

In this study, we assessed the role of different reactive oxygen species (ROS) generated by soft jet plasma and chemical-induced ROS systems with regard to cell death in T98G, A549, HEK293 and MRC5 cell lines. For a comparison with plasma, we generated superoxide anion (O2−), hydroxyl radical (HO·), and hydrogen peroxide (H2O2) with chemicals inside an in vitro cell culture. Our data revealed that plasma decreased the viability and intracellular ATP values of cells and increased the apoptotic population via a caspase activation mechanism. Plasma altered the mitochondrial membrane potential and eventually up-regulated the mRNA expression levels of BAX, BAK1 and H2AX gene but simultaneously down-regulated the levels of Bcl-2 in solid tumor cells. Moreover, a western blot analysis confirmed that plasma also altered phosphorylated ERK1/2/MAPK protein levels. At the same time, using ROS scavengers with plasma, we observed that scavengers of HO· (mannitol) and H2O2 (catalase and sodium pyruvate) attenuated the activity of plasma on cells to a large extent. In contrast, radicals generated by specific chemical systems enhanced cell death drastically in cancer as well as normal cell lines in a dose-dependent fashion but not specific with regard to the cell type as compared to plasma. PMID:25715710

Responses of Solid Tumor Cells in DMEM to Reactive Oxygen Species Generated by Non-Thermal Plasma and Chemically Induced ROS Systems

NASA Astrophysics Data System (ADS)

Kaushik, Neha; Uddin, Nizam; Sim, Geon Bo; Hong, Young June; Baik, Ku Youn; Kim, Chung Hyeok; Lee, Su Jae; Kaushik, Nagendra Kumar; Choi, Eun Ha

2015-02-01

In this study, we assessed the role of different reactive oxygen species (ROS) generated by soft jet plasma and chemical-induced ROS systems with regard to cell death in T98G, A549, HEK293 and MRC5 cell lines. For a comparison with plasma, we generated superoxide anion (O2-), hydroxyl radical (HO.), and hydrogen peroxide (H2O2) with chemicals inside an in vitro cell culture. Our data revealed that plasma decreased the viability and intracellular ATP values of cells and increased the apoptotic population via a caspase activation mechanism. Plasma altered the mitochondrial membrane potential and eventually up-regulated the mRNA expression levels of BAX, BAK1 and H2AX gene but simultaneously down-regulated the levels of Bcl-2 in solid tumor cells. Moreover, a western blot analysis confirmed that plasma also altered phosphorylated ERK1/2/MAPK protein levels. At the same time, using ROS scavengers with plasma, we observed that scavengers of HO. (mannitol) and H2O2 (catalase and sodium pyruvate) attenuated the activity of plasma on cells to a large extent. In contrast, radicals generated by specific chemical systems enhanced cell death drastically in cancer as well as normal cell lines in a dose-dependent fashion but not specific with regard to the cell type as compared to plasma.

Development of very compact soft X-ray lasers

NASA Astrophysics Data System (ADS)

Korobkin, Dmitriy Vladlenovich

1999-10-01

A powerful subpicosecond laser system, based on solid state (Ti:Al 2O3) front end and gas excimer (KrF*) amplifiers, has been developed. It is capable of producing 40-50 mJ pulses at 248 nm (285 fs pulse duration) with 2 Hz repetition rate. That radiation can be focused to intensities greater than 1017 W/cm2 and cause the optical field ionization of lithium. The system was used in experiments on gain generation in hydrogen-like Li III. Lasing action in hydrogen-like Li III 2-1 transition to ground state (13.5 nm) has been demonstrated for the first time. Gain G = 11 cm-1 in 5-mm long plasma column, created in LiF microcapillary, was measured. The observed gain-length product was GL = 5.5. In another set of experiments an inversion population between levels n = 3 and n = 2 in hydrogen-like BV was created using a low-energy compact laser system at 1 Hz repetition rate. Gain G = 17 cm-1 at 26.2 nm was measured in 3 mm long B2O3 microcapillary, which corresponds to GL = 5.1. The entire experimental setup can be fit on a single medium size optical table. Also propagation of laser radiation through plasma, created in microcapillaries has been investigated at various experimental conditions. Real-time plasma probing with low intensity HeNe laser beam has been performed.

ZrB 2-HfB 2 solid solutions as electrode materials for hydrogen reaction in acidic and basic solutions

DOE PAGES

Sitler, Steven J.; Raja, Krishnan S.; Charit, Indrajit

2016-11-09

Spark plasma sintered transition metal diborides such as HfB 2, ZrB 2 and their solid solutions were investigated as electrode materials for electrochemical hydrogen evolutions reactions (HER) in 1 M H 2SO 4 and 1 M NaOH electrolytes. HfB 2 and ZrB 2 formed complete solid solutions when mixed in 1:1, 1:4, and 4:1 ratios and they were stable in both electrolytes. The HER kinetics of the diborides were slower in the basic solution than in the acidic solutions. The Tafel slopes in 1 M H 2SO 4 were in the range of 0.15 - 0.18 V/decade except for puremore » HfB 2 which showed a Tafel slope of 0.38 V/decade. In 1 M NaOH the Tafel slopes were in the range of 0.12 - 0.27 V/decade. The composition of Hf xZr 1-xB 2 solid solutions with x = 0.2 - 0.8, influenced the exchange current densities, overpotentials and Tafel slopes of the HER. As a result, the EIS data were fitted with a porous film equivalent circuit model in order to better understand the HER behavior. In addition, modeling calculations, using density functional theory approach, were carried out to estimate the density of states and band structure of the boride solid solutions.« less

LPP-EUV light source for HVM lithography

NASA Astrophysics Data System (ADS)

Saito, T.; Ueno, Y.; Yabu, T.; Kurosawa, A.; Nagai, S.; Yanagida, T.; Hori, T.; Kawasuji, Y.; Abe, T.; Kodama, T.; Nakarai, H.; Yamazaki, T.; Mizoguchi, H.

2017-01-01

We have been developing a laser produced plasma extremely ultra violet (LPP-EUV) light source for a high volume manufacturing (HVM) semiconductor lithography. It has several unique technologies such as the high power short pulse carbon dioxide (CO2) laser, the short wavelength solid-state pre-pulse laser and the debris mitigation technology with the magnetic field. This paper presents the key technologies for a high power LPP-EUV light source. We also show the latest performance data which is 188W EUV power at intermediate focus (IF) point with 3.7% conversion efficiency (CE) at 100 kHz.

Electrodynamics in cylindrical symmetry in the magnetic plasma state

NASA Astrophysics Data System (ADS)

López-Bara, F. I.; López-Aguilar, F.

2018-05-01

Excited states in magnetic structures of the so-called spin-ices and in some artificial magnetic materials present a behaviour as being a magnetic neutral plasma. In this state the electromagnetic waves in confined systems (waveguides) filled with materials with magnetic charges are able to transmit information and energy. In the natural spin-ices, the difficulty is the very low temperature for which these magnetic entities appear, whose phenomenology under the electromagnetic interaction is that of solids containing magnetic charges. However, similar behaviour may be present in other compounds at higher temperatures, even at room temperature and they are named artificial spin-ice compounds. This analysis is addressed to obtain theoretical results about magnetic responses and frequency-dependent magnetricity. The key physical magnitudes are the plasmon frequency () which is related to the cut-off frequency in a wave guide and the effective inertial masses () of these magnetic charges. All properties of the electromagnetic propagation in these compounds with effective magnetic monopoles depend on and m. This is carried out including the dissipative forces among magnetic charges which give new characteristic features to the electromagnetic propagation. The main goal of this work is the analysis of these electromagnetic properties in order to find possible circuital applications of these materials to be utilized by devices.

Plasma sprayed ceria-containing interlayer

DOEpatents

Schmidt, Douglas S.; Folser, George R.

2006-01-10

A plasma sprayed ceria-containing interlayer is provided. The interlayer has particular application in connection with a solid oxide fuel cell used within a power generation system. The fuel cell advantageously comprises an air electrode, a plasma sprayed interlayer disposed on at least a portion of the air electrode, a plasma sprayed electrolyte disposed on at least a portion of the interlayer, and a fuel electrode applied on at least a portion of the electrolyte.

Plasma–wall interaction studies within the EUROfusion consortium: progress on plasma-facing components development and qualification

DOE PAGES

Brezinsek, S.; Coenen, J. W.; Schwarz-Selinger, T.; ...

2017-06-14

The provision of a particle and power exhaust solution which is compatible with first-wall components and edge-plasma conditions is a key area of present-day fusion research and mandatory for a successful operation of ITER and DEMO. The work package plasma-facing components (WP PFC) within the European fusion programme complements with laboratory experiments, i.e. in linear plasma devices, electron and ion beam loading facilities, the studies performed in toroidally confined magnetic devices, such as JET, ASDEX Upgrade, WEST etc. The connection of both groups is done via common physics and engineering studies, including the qualification and specification of plasma-facing components, andmore » by modelling codes that simulate edge-plasma conditions and the plasma–material interaction as well as the study of fundamental processes. WP PFC addresses these critical points in order to ensure reliable and efficient use of conventional, solid PFCs in ITER (Be and W) and DEMO (W and steel) with respect to heat-load capabilities (transient and steady-state heat and particle loads), lifetime estimates (erosion, material mixing and surface morphology), and safety aspects (fuel retention, fuel removal, material migration and dust formation) particularly for quasi-steady-state conditions. Alternative scenarios and concepts (liquid Sn or Li as PFCs) for DEMO are developed and tested in the event that the conventional solution turns out to not be functional. Here, we present an overview of the activities with an emphasis on a few key results: (i) the observed synergistic effects in particle and heat loading of ITER-grade W with the available set of exposition devices on material properties such as roughness, ductility and microstructure; (ii) the progress in understanding of fuel retention, diffusion and outgassing in different W-based materials, including the impact of damage and impurities like N; and (iii), the preferential sputtering of Fe in EUROFER steel providing an in situ W surface and a potential first-wall solution for DEMO.« less

Plasma–wall interaction studies within the EUROfusion consortium: progress on plasma-facing components development and qualification

DOE Office of Scientific and Technical Information (OSTI.GOV)

Brezinsek, S.; Coenen, J. W.; Schwarz-Selinger, T.

The provision of a particle and power exhaust solution which is compatible with first-wall components and edge-plasma conditions is a key area of present-day fusion research and mandatory for a successful operation of ITER and DEMO. The work package plasma-facing components (WP PFC) within the European fusion programme complements with laboratory experiments, i.e. in linear plasma devices, electron and ion beam loading facilities, the studies performed in toroidally confined magnetic devices, such as JET, ASDEX Upgrade, WEST etc. The connection of both groups is done via common physics and engineering studies, including the qualification and specification of plasma-facing components, andmore » by modelling codes that simulate edge-plasma conditions and the plasma–material interaction as well as the study of fundamental processes. WP PFC addresses these critical points in order to ensure reliable and efficient use of conventional, solid PFCs in ITER (Be and W) and DEMO (W and steel) with respect to heat-load capabilities (transient and steady-state heat and particle loads), lifetime estimates (erosion, material mixing and surface morphology), and safety aspects (fuel retention, fuel removal, material migration and dust formation) particularly for quasi-steady-state conditions. Alternative scenarios and concepts (liquid Sn or Li as PFCs) for DEMO are developed and tested in the event that the conventional solution turns out to not be functional. Here, we present an overview of the activities with an emphasis on a few key results: (i) the observed synergistic effects in particle and heat loading of ITER-grade W with the available set of exposition devices on material properties such as roughness, ductility and microstructure; (ii) the progress in understanding of fuel retention, diffusion and outgassing in different W-based materials, including the impact of damage and impurities like N; and (iii), the preferential sputtering of Fe in EUROFER steel providing an in situ W surface and a potential first-wall solution for DEMO.« less

Diagnostics of Particles emitted from a Laser generated Plasma: Experimental Data and Simulations

NASA Astrophysics Data System (ADS)

Costa, Giuseppe; Torrisi, Lorenzo

2018-01-01

The charge particle emission form laser-generated plasma was studied experimentally and theoretically using the COMSOL simulation code. The particle acceleration was investigated using two lasers at two different regimes. A Nd:YAG laser, with 3 ns pulse duration and 1010 W/cm2 intensity, when focused on solid target produces a non-equilibrium plasma with average temperature of about 30-50 eV. An Iodine laser with 300 ps pulse duration and 1016 W/cm2 intensity produces plasmas with average temperatures of the order of tens keV. In both cases charge separation occurs and ions and electrons are accelerated at energies of the order of 200 eV and 1 MeV per charge state in the two cases, respectively. The simulation program permits to plot the charge particle trajectories from plasma source in vacuum indicating how they can be deflected by magnetic and electrical fields. The simulation code can be employed to realize suitable permanent magnets and solenoids to deflect ions toward a secondary target or detectors, to focalize ions and electrons, to realize electron traps able to provide significant ion acceleration and to realize efficient spectrometers. In particular it was applied to the study two Thomson parabola spectrometers able to detect ions at low and at high laser intensities. The comparisons between measurements and simulation is presented and discussed.

Nonlinear increase of X-ray intensities from thin foils irradiated with a 200 TW femtosecond laser

PubMed Central

Faenov, A. Ya.; Colgan, J.; Hansen, S. B.; Zhidkov, A.; Pikuz, T. A.; Nishiuchi, M.; Pikuz, S. A.; Skobelev, I. Yu.; Abdallah, J.; Sakaki, H.; Sagisaka, A.; Pirozhkov, A. S.; Ogura, K.; Fukuda, Y.; Kanasaki, M.; Hasegawa, N.; Nishikino, M.; Kando, M.; Watanabe, Y.; Kawachi, T.; Masuda, S.; Hosokai, T.; Kodama, R.; Kondo, K.

2015-01-01

We report, for the first time, that the energy of femtosecond optical laser pulses, E, with relativistic intensities I > 1021  W/cm2 is efficiently converted to X-ray radiation, which is emitted by “hot” electron component in collision-less processes and heats the solid density plasma periphery. As shown by direct high-resolution spectroscopic measurements X-ray radiation from plasma periphery exhibits unusual non-linear growth ~E4–5 of its power. The non-linear power growth occurs far earlier than the known regime when the radiation reaction dominates particle motion (RDR). Nevertheless, the radiation is shown to dominate the kinetics of the plasma periphery, changing in this regime (now labeled RDKR) the physical picture of the laser plasma interaction. Although in the experiments reported here we demonstrated by observation of KK hollow ions that X-ray intensities in the keV range exceeds ~1017  W/cm2, there is no theoretical limit of the radiation power. Therefore, such powerful X-ray sources can produce and probe exotic material states with high densities and multiple inner-shell electron excitations even for higher Z elements. Femtosecond laser-produced plasmas may thus provide unique ultra-bright X-ray sources, for future studies of matter in extreme conditions, material science studies, and radiography of biological systems. PMID:26330230

Nonlinear increase of X-ray intensities from thin foils irradiated with a 200 TW femtosecond laser

DOE PAGES

Faenov, A. Ya.; Colgan, J.; Hansen, S. B.; ...

2015-09-02

We report, for the first time, that the energy of femtosecond optical laser pulses, E, with relativistic intensities I > 10 21 W/cm 2 is efficiently converted to X-ray radiation, which is emitted by “hot” electron component in collision-less processes and heats the solid density plasma periphery. As shown by direct high-resolution spectroscopic measurements X-ray radiation from plasma periphery exhibits unusual non-linear growth ~E 4–5 of its power. The non-linear power growth occurs far earlier than the known regime when the radiation reaction dominates particle motion (RDR). Nevertheless, the radiation is shown to dominate the kinetics of the plasma periphery,more » changing in this regime (now labeled RDKR) the physical picture of the laser plasma interaction. Although in the experiments reported here we demonstrated by observation of KK hollow ions that X-ray intensities in the keV range exceeds ~10 17 W/cm 2, there is no theoretical limit of the radiation power. Therefore, such powerful X-ray sources can produce and probe exotic material states with high densities and multiple inner-shell electron excitations even for higher Z elements. As a result, femtosecond laser-produced plasmas may thus provide unique ultra-bright X-ray sources, for future studies of matter in extreme conditions, material science studies, and radiography of biological systems.« less

Combining plasma gasification and solid oxide cell technologies in advanced power plants for waste to energy and electric energy storage applications.

PubMed

Perna, Alessandra; Minutillo, Mariagiovanna; Lubrano Lavadera, Antonio; Jannelli, Elio

2018-03-01

The waste to energy (WtE) facilities and the renewable energy storage systems have a strategic role in the promotion of the "eco-innovation", an emerging priority in the European Union. This paper aims to propose advanced plant configurations in which waste to energy plants and electric energy storage systems from intermittent renewable sources are combined for obtaining more efficient and clean energy solutions in accordance with the "eco-innovation" approach. The advanced plant configurations consist of an electric energy storage (EES) section based on a solid oxide electrolyzer (SOEC), a waste gasification section based on the plasma technology and a power generation section based on a solid oxide fuel cell (SOFC). The plant configurations differ for the utilization of electrolytic hydrogen and oxygen in the plasma gasification section and in the power generation section. In the first plant configuration IAPGFC (Integrated Air Plasma Gasification Fuel Cell), the renewable oxygen enriches the air stream, that is used as plasma gas in the gasification section, and the renewable hydrogen is used to enrich the anodic stream of the SOFC in the power generation section. In the second plant configuration IHPGFC (Integrated Hydrogen Plasma Gasification Fuel Cell) the renewable hydrogen is used as plasma gas in the plasma gasification section, and the renewable oxygen is used to enrich the cathodic stream of the SOFC in the power generation section. The analysis has been carried out by using numerical models for predicting and comparing the systems performances in terms of electric efficiency and capability in realizing the waste to energy and the electric energy storage of renewable sources. Results have highlighted that the electric efficiency is very high for all configurations (35-45%) and, thanks to the combination with the waste to energy technology, the storage efficiencies are very attractive (in the range 72-92%). Copyright © 2017 Elsevier Ltd. All rights reserved.

Studies of the influence of nonequilibrium plasma thermal exposure on the characteristics of the capillary-porous polymer material

NASA Astrophysics Data System (ADS)

Makhotkina, L. Yu; Khristoliubova, V. I.

2017-01-01

Capillary-porous materials, which include natural macromolecular tanning material, are exposed to a number of factors during the treatment by a nonequilibrium plasma. Plasma particles exchange the charge and energy with the atoms of the material during the interaction of the plasma with the surface. The results of treatment are desorption of atoms and molecules from the body surface, sputtering and evaporation of material’s particles, changes of the structure and phase state. In real terms during the modification of solids by nonequilibrium low-temperature plasma thermal effect influences the process. The energy supplied from the discharge during the process with low pressure, which is converted into heat, is significantly less than during the atmospheric pressure, but the thermal stability of high-molecular compounds used in the manufacture of materials and products of the tanning industry, is very limited and depends on the duration of the effect of temperature. Even short heating of hydrophilic polymers (proteins) (100-180 °C) causes a change in their properties. It decreases the collagen ability to absorb water vapor, to swell in water, acids, alkalis, and thus decreases their durability. Prolonged heating leads to a deterioration of the physical and mechanical properties. Higher heating temperatures it leads to the polymer degradation. The natural leather temperature during plasma exposure does not rise to a temperature of collagen degradation and does not result in changes of physical phase of the dermis. However, the thermal plasma exposure must be considered, since the high temperatures influence on physical and mechanical properties.

Time-resolved characteristics of deuteron-beam generated by plasma focus discharge.

PubMed

Lim, Lian-Kuang; Yap, Seong-Ling; Bradley, D A

2018-01-01

The plasma focus device discussed herein is a Z-pinch pulsed-plasma arrangement. In this, the plasma is heated and compressed into a cylindrical column, producing a typical density of > 1025 particles/m3 and a temperature of (1-3) × 107 oC. The plasma focus has been widely investigated as a radiation source, including as ion-beams, electron-beams and as a source of x-ray and neutron production, providing considerable scope for use in a variety of technological situations. Thus said, the nature of the radiation emission depends on the dynamics of the plasma pinch. In this study of the characteristics of deuteron-beam emission, in terms of energy, fluence and angular distribution were analyzed. The 2.7 kJ plasma focus discharge has been made to operate at a pressure of less than 1 mbar rather than at its more conventional operating pressure of a few mbar. Faraday cup were used to determine deuteron-beam energy and deuteron-beam fluence per shot while CR-39 solid-state nuclear track detectors were employed in studying the angular distribution of deuteron emission. Beam energy and deuteron-beam fluence per shot have been found to be pressure dependent. The largest value of average deuteron energy measured for present conditions was found to be (52 ± 7) keV, while the deuteron-beam fluence per shot was of the order of 1015 ions/m2 when operated at a pressure of 0.2 mbar. The deuteron-beam emission is in the forward direction and is observed to be highly anisotropic.

Time-resolved characteristics of deuteron-beam generated by plasma focus discharge

PubMed Central

Bradley, D. A.

2018-01-01

The plasma focus device discussed herein is a Z-pinch pulsed-plasma arrangement. In this, the plasma is heated and compressed into a cylindrical column, producing a typical density of > 1025 particles/m3 and a temperature of (1–3) × 107 oC. The plasma focus has been widely investigated as a radiation source, including as ion-beams, electron-beams and as a source of x-ray and neutron production, providing considerable scope for use in a variety of technological situations. Thus said, the nature of the radiation emission depends on the dynamics of the plasma pinch. In this study of the characteristics of deuteron-beam emission, in terms of energy, fluence and angular distribution were analyzed. The 2.7 kJ plasma focus discharge has been made to operate at a pressure of less than 1 mbar rather than at its more conventional operating pressure of a few mbar. Faraday cup were used to determine deuteron-beam energy and deuteron-beam fluence per shot while CR-39 solid-state nuclear track detectors were employed in studying the angular distribution of deuteron emission. Beam energy and deuteron-beam fluence per shot have been found to be pressure dependent. The largest value of average deuteron energy measured for present conditions was found to be (52 ± 7) keV, while the deuteron-beam fluence per shot was of the order of 1015 ions/m2 when operated at a pressure of 0.2 mbar. The deuteron-beam emission is in the forward direction and is observed to be highly anisotropic. PMID:29309425

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sitler, Steven J.; Raja, Krishnan S.; Charit, Indrajit

Spark plasma sintered transition metal diborides such as HfB 2, ZrB 2 and their solid solutions were investigated as electrode materials for electrochemical hydrogen evolutions reactions (HER) in 1 M H 2SO 4 and 1 M NaOH electrolytes. HfB 2 and ZrB 2 formed complete solid solutions when mixed in 1:1, 1:4, and 4:1 ratios and they were stable in both electrolytes. The HER kinetics of the diborides were slower in the basic solution than in the acidic solutions. The Tafel slopes in 1 M H 2SO 4 were in the range of 0.15 - 0.18 V/decade except for puremore » HfB 2 which showed a Tafel slope of 0.38 V/decade. In 1 M NaOH the Tafel slopes were in the range of 0.12 - 0.27 V/decade. The composition of Hf xZr 1-xB 2 solid solutions with x = 0.2 - 0.8, influenced the exchange current densities, overpotentials and Tafel slopes of the HER. As a result, the EIS data were fitted with a porous film equivalent circuit model in order to better understand the HER behavior. In addition, modeling calculations, using density functional theory approach, were carried out to estimate the density of states and band structure of the boride solid solutions.« less

Volumetric Heating of Ultra-High Energy Density Relativistic Plasmas by Ultrafast Laser Irradiation of Aligned Nanowire Arrays

NASA Astrophysics Data System (ADS)

Bargsten, Clayton; Hollinger, Reed; Shlyaptsev, Vyacheslav; Pukhov, Alexander; Keiss, David; Townsend, Amanda; Wang, Yong; Wang, Shoujun; Prieto, Amy; Rocca, Jorge

2014-10-01

We have demonstrated the volumetric heating of near-solid density plasmas to keV temperatures by ultra-high contrast femtosecond laser irradiation of arrays of vertically aligned nanowires with an average density up to 30% solid density. X-ray spectra show that irradiation of Ni and Au nanowire arrays with laser pulses of relativistic intensities ionizes plasma volumes several micrometers in depth to the He-like and Co-like (Au 52 +) stages respectively. The penetration depth of the heat into the nanowire array was measured monitoring He-like Co lines from irradiated arrays in which the nanowires are composed of a Co segment buried under a selected length of Ni. The measurement shows the ionization reaches He-like Co for depth of up to 5 μm within the target. This volumetric plasma heating approach creates a new laboratory plasma regime in which extreme plasma parameters can be accessed with table-top lasers. Scaling to higher laser intensities promises to create plasmas with temperatures and pressures approaching those in the center of the sun. Work supported by the U.S Department of Energy, Fusion Energy Sciences and the Defense Threat Reduction Agency grant HDTRA-1-10-1-0079. A.P was supported by of DFG-funded project TR18.

Performance summary on a high power dense plasma focus x-ray lithography point source producing 70 nm line features in AlGaAs microcircuits

NASA Astrophysics Data System (ADS)

Petr, Rodney; Bykanov, Alexander; Freshman, Jay; Reilly, Dennis; Mangano, Joseph; Roche, Maureen; Dickenson, Jason; Burte, Mitchell; Heaton, John

2004-08-01

A high average power dense plasma focus (DPF), x-ray point source has been used to produce ˜70 nm line features in AlGaAs-based monolithic millimeter-wave integrated circuits (MMICs). The DPF source has produced up to 12 J per pulse of x-ray energy into 4π steradians at ˜1 keV effective wavelength in ˜2 Torr neon at pulse repetition rates up to 60 Hz, with an effective x-ray yield efficiency of ˜0.8%. Plasma temperature and electron concentration are estimated from the x-ray spectrum to be ˜170 eV and ˜5.1019 cm-3, respectively. The x-ray point source utilizes solid-state pulse power technology to extend the operating lifetime of electrodes and insulators in the DPF discharge. By eliminating current reversals in the DPF head, an anode electrode has demonstrated a lifetime of more than 5 million shots. The x-ray point source has also been operated continuously for 8 h run times at 27 Hz average pulse recurrent frequency. Measurements of shock waves produced by the plasma discharge indicate that overpressure pulses must be attenuated before a collimator can be integrated with the DPF point source.

Opportunities offered by the interaction of plasma and droplets to elaborate nanostructured oxide materials

NASA Astrophysics Data System (ADS)

Nikravech, Mehrdad; Rahmani, Abdelkader

2016-09-01

The association of plasma and spray will permit to process materials where organometallic precursors are not available or economically non-reliable. The injection of aerosols in low pressure plasma results in the rapid evaporation of solvent and the rapid transformation of small amounts of precursors contained in each droplet leading to form nanoscale oxide particles. We developed two configurations of this technique: one is Spray Plasma that permits to deposit this layers on flat substrates; the second one is Fluidized Spray Plasma that permits to deposit thin layers on the surface of solid beads. The aim of this presentation is to describe the principles of this new technique together with several applications. The influence of experimental parameters to deposit various mixed metal oxides will be demonstrated: thin dense layers of nanostructured ZnO for photovoltaic applications, porous layers of LaxSr1-x MnO3 as the cathode for fuel cells, ZnO-Cu, NiO layers on solid pellets in fluidized bed for catalysis applications. Aknowledgement to Programme interdisciplinaire SPC Énergies de Demain.

Atomic rate coefficients in a degenerate plasma

NASA Astrophysics Data System (ADS)

Aslanyan, Valentin; Tallents, Greg

2015-11-01

The electrons in a dense, degenerate plasma follow Fermi-Dirac statistics, which deviate significantly in this regime from the usual Maxwell-Boltzmann approach used by many models. We present methods to calculate the atomic rate coefficients for the Fermi-Dirac distribution and present a comparison of the ionization fraction of carbon calculated using both models. We have found that for densities close to solid, although the discrepancy is small for LTE conditions, there is a large divergence from the ionization fraction by using classical rate coefficients in the presence of strong photoionizing radiation. We have found that using these modified rates and the degenerate heat capacity may affect the time evolution of a plasma subject to extreme ultraviolet and x-ray radiation such as produced in free electron laser irradiation of solid targets.

Method and apparatus for producing oxygenates from hydrocarbons

DOEpatents

Kong, P.C.; Lessing, P.A.

1995-06-27

A chemical reactor for oxygenating hydrocarbons includes: (a) a dielectric barrier discharge plasma cell, the plasma cell comprising a pair of electrodes having a dielectric material and void therebetween, the plasma cell comprising a hydrocarbon gas inlet feeding to the void; (b) a solid oxide electrochemical cell, the electrochemical cell comprising a solid oxide electrolyte positioned between a porous cathode and a porous anode, an oxygen containing gas inlet stream feeding to the porous cathode side of the electrochemical cell; (c) a first gas passageway feeding from the void to the anode side of the electrochemical cell; and (d) a gas outlet feeding from the anode side of the electrochemical cell to expel reaction products from the chemical reactor. A method of oxygenating hydrocarbons is also disclosed. 4 figs.

Prevention of Infection in Patients With Hematologic Cancer and Persistent Fever Caused by a Low White Blood Cell Count

ClinicalTrials.gov

2012-09-20

Bone Marrow Suppression; Fever, Sweats, and Hot Flashes; Infection; Leukemia; Lymphoma; Multiple Myeloma and Plasma Cell Neoplasm; Myelodysplastic Syndromes; Unspecified Adult Solid Tumor, Protocol Specific; Unspecified Childhood Solid Tumor, Protocol Specific

Ondansetron in Treating Patients With Advanced Cancer and Chronic Nausea and Vomiting Not Caused by Cancer Treatment

ClinicalTrials.gov

2016-07-01

Chronic Myeloproliferative Disorders; Leukemia; Lymphoma; Multiple Myeloma and Plasma Cell Neoplasm; Myelodysplastic Syndromes; Nausea and Vomiting; Precancerous Condition; Small Intestine Cancer; Unspecified Adult Solid Tumor, Protocol Specific; Unspecified Childhood Solid Tumor, Protocol Specific

Methane Post-Processing for Oxygen Loop Closure

NASA Technical Reports Server (NTRS)

Greenwood, Zachary W.; Abney, Morgan B.; Miller, Lee

2016-01-01

State-of-the-art United States Atmospheric Revitalization carbon dioxide (CO2) reduction is based on the Sabatier reaction process, which recovers approximately 50% of the oxygen (O2) from crew metabolic CO2. Oxygen recovery from carbon dioxide is constrained by the limited availability of reactant hydrogen. Post-processing of methane to recover hydrogen with the Umpqua Research Company Plasma Pyrolysis Assembly (PPA) has the potential to further close the Atmospheric Revitalization oxygen loop. The PPA decomposes methane into hydrogen and hydrocarbons, predominantly acetylene, and a small amount of solid carbon. The hydrogen must then be purified before it can be recycled for additional oxygen recovery. Long duration testing and evaluation of a four crew-member sized PPA and a discussion of hydrogen recycling system architectures are presented.

Coordinated garbage collection for raid array of solid state disks

DOEpatents

Dillow, David A; Ki, Youngjae; Oral, Hakki S; Shipman, Galen M; Wang, Feiyi

2014-04-29

An optimized redundant array of solid state devices may include an array of one or more optimized solid-state devices and a controller coupled to the solid-state devices for managing the solid-state devices. The controller may be configured to globally coordinate the garbage collection activities of each of said optimized solid-state devices, for instance, to minimize the degraded performance time and increase the optimal performance time of the entire array of devices.

The Effects of Temperature and Oxidation on Deuterium Retention in Solid and Liquid Lithium Films on Molybdenum Plasma-Facing Components

NASA Astrophysics Data System (ADS)

Capece, Angela

2014-10-01

Liquid metal plasma-facing components (PFCs) enable in-situ renewal of the surface, thereby offering a solution to neutron damage, erosion, and thermal fatigue experienced by solid PFCs. Lithium in particular has a high chemical affinity for hydrogen, which has resulted in reduced recycling and enhanced plasma performance on many fusion devices including TFTR, T11-M, FTU, CDX-U, LTX, TJ-II, and NSTX. A key component to the improvement in plasma performance is deuterium retention in Li; however, this process is not well understood in the complex tokamak environment. Recent surface science experiments conducted at the Princeton Plasma Physics Laboratory have used electron spectroscopy and temperature programmed desorption to understand the mechanisms for D retention in Li coatings on Mo substrates. The experiments were designed to give monolayer-control of Li films and were conducted in ultrahigh vacuum under controlled environments. An electron cyclotron resonance plasma source was used to deliver a beam of deuterium ions to the surface over a range of ion energies. Our work shows that D is retained as LiD in metallic Li films. However, when oxygen is present in the film, either by diffusion from the subsurface at high temperature or as a contaminant during the deposition process, Li oxides are formed that retain D as LiOD. Experiments indicate that LiD is more thermally stable than LiOD, which decomposes to liberate D2 gas and D2O at temperatures 100 K lower than the LiD decomposition temperature. Other experiments show how D retention varies with substrate temperature to provide insight into the differences between solid and liquid lithium films. This work was supported by DOE Contract No. DE AC02-09CH11466.

Simultaneous determination of atorvastatin and valsartan in human plasma by solid-based disperser liquid-liquid microextraction followed by high-performance liquid chromatography-diode array detection.

PubMed

Farajzadeh, Mir Ali; Khorram, Parisa; Pazhohan, Azar

2016-04-01

A simple, sensitive, and efficient method has been developed for simultaneous estimation of valsartan and atorvastatin in human plasma by combination of solid-based dispersive liquid-liquid microextraction and high performance liquid chromatography-diode array detection. In the proposed method, 1,2-dibromoethane (extraction solvent) is added on a sugar cube (as a solid disperser) and it is introduced into plasma sample containing the analytes. After manual shaking and centrifugation, the resultant sedimented phase is subjected to back extraction into a small volume of sodium hydrogen carbonate solution using air-assisted liquid-liquid microextraction. Then the cloudy solution is centrifuged and the obtained aqueous phase is transferred into a microtube and analyzed by the separation system. Under the optimal conditions, extraction recoveries are obtained in the range of 81-90%. Calibration curves plotted in drug-free plasma sample are linear in the ranges of 5-5000μgL(-1) for valsartan and 10-5000μgL(-1) for atorvastatin with the coefficients of determination higher than 0.997. Limits of detection and quantification of the studied analytes in plasma sample are 0.30-2.6 and 1.0-8.2μgL(-1), respectively. Intra-day (n=6) and inter-days (n=4) precisions of the method are satisfactory with relative standard deviations less than 7.4% (at three levels of 10, 500, and 2000μgL(-1), each analyte). These data suggest that the method can be successfully applied to determine trace amounts of valsartan and atorvastatin in human plasma samples. Copyright © 2016 Elsevier B.V. All rights reserved.

A combined segmented anode gas ionization chamber and time-of-flight detector for heavy ion elastic recoil detection analysis

NASA Astrophysics Data System (ADS)

Ström, Petter; Petersson, Per; Rubel, Marek; Possnert, Göran

2016-10-01

A dedicated detector system for heavy ion elastic recoil detection analysis at the Tandem Laboratory of Uppsala University is presented. Benefits of combining a time-of-flight measurement with a segmented anode gas ionization chamber are demonstrated. The capability of ion species identification is improved with the present system, compared to that obtained when using a single solid state silicon detector for the full ion energy signal. The system enables separation of light elements, up to Neon, based on atomic number while signals from heavy elements such as molybdenum and tungsten are separated based on mass, to a sample depth on the order of 1 μm. The performance of the system is discussed and a selection of material analysis applications is given. Plasma-facing materials from fusion experiments, in particular metal mirrors, are used as a main example for the discussion. Marker experiments using nitrogen-15 or oxygen-18 are specific cases for which the described improved species separation and sensitivity are required. Resilience to radiation damage and significantly improved energy resolution for heavy elements at low energies are additional benefits of the gas ionization chamber over a solid state detector based system.

Aircraft Propeller Hub Repair

DOE Office of Scientific and Technical Information (OSTI.GOV)

Muth, Thomas R.; Peter, William H.

The team performed a literature review, conducted residual stress measurements, performed failure analysis, and demonstrated a solid state additive manufacturing repair technique on samples removed from a scrapped propeller hub. The team evaluated multiple options for hub repair that included existing metal buildup technologies that the Federal Aviation Administration (FAA) has already embraced, such as cold spray, high velocity oxy-fuel deposition (HVOF), and plasma spray. In addition the team helped Piedmont Propulsion Systems, LLC (PPS) evaluate three potential solutions that could be deployed at different stages in the life cycle of aluminum alloy hubs, in addition to the conventional spraymore » coating method for repair. For new hubs, a machining practice to prevent fretting with the steel drive shaft was recommended. For hubs that were refurbished with some material remaining above the minimal material condition (MMC), a silver interface applied by an electromagnetic pulse additive manufacturing method was recommended. For hubs that were at or below the MMC, a solid state additive manufacturing technique using ultrasonic welding (UW) of thin layers of 7075 aluminum to the hub interface was recommended. A cladding demonstration using the UW technique achieved mechanical bonding of the layers showing promise as a viable repair method.« less

Accessing ultrahigh-pressure, quasi-isentropic states of mattera)

NASA Astrophysics Data System (ADS)

Lorenz, K. T.; Edwards, M. J.; Glendinning, S. G.; Jankowski, A. F.; McNaney, J.; Pollaine, S. M.; Remington, B. A.

2005-05-01

A new approach to the study of material strength of metals at extreme pressures has been developed on the Omega laser, using a ramped plasma piston drive. The laser drives a shock through a solid plastic reservoir that unloads at the rear free surface, expands across a vacuum gap, and stagnates on the metal sample under study. This produces a gently increasing ram pressure, compressing the sample nearly isentropically. The peak pressure on the sample, inferred from interferometric measurements of velocity, can be varied by adjusting the laser energy and pulse length, gap size, and reservoir density, and obeys a simple scaling relation [J. Edwards et al., Phys. Rev. Lett. 92, 075002 (2004)]. In an important application, using in-flight x-ray radiography, the material strength of solid-state samples at high pressure can be inferred by measuring the reductions in the growth rates (stabilization) of Rayleigh-Taylor unstable interfaces. This paper reports the first attempt to use this new laser-driven, quasi-isentropic technique for determining material strength in high-pressure solids. Modulated foils of Al-6061-T6 were accelerated and compressed to peak pressures of ˜200kbar. Modulation growth was recorded at a series of times after peak acceleration and well into the release phase. Fits to the growth data, using a Steinberg-Guinan constitutive strength model, give yield strengths 38% greater than those given by the nominal parameters for Al-6061-T6. Calculations indicate that the dynamic enhancement to the yield strength at ˜200kbar is a factor of ˜3.6× over the ambient yield strength of 2.9kbar. Experimental designs based on this drive developed for the National Ignition Facility laser [W. Hogan, E. Moses, B. Warner, M. Sorem, and J. Soures, Nuclear Fusion 41, 567 (2001)] predict that solid-state samples can be quasi-isentropically driven to pressures an order of magnitude higher than on Omega, accessing new regimes of dense, high-pressure matter.

Radial density distribution of a warm dense plasma formed by underwater electrical explosion of a copper wire

NASA Astrophysics Data System (ADS)

Nitishinskiy, M.; Yanuka, D.; Virozub, A.; Krasik, Ya. E.

2017-12-01

Time- and space-resolved evolution of the density (down to 0.07 of solid state density) of a copper wire during its microsecond timescale electrical explosion in water was obtained by X-ray backlighting. In the present research, a flash X-ray source of 20 ns pulse-width and >60 keV photon energy was used. The conductivity of copper was evaluated for a temperature of 10 kK and found to be in good agreement with the data obtained in earlier experiments [DeSilva and Katsouros, Phys. Rev. E 57, 5945 (1998) and Sheftman and Krasik, Phys. Plasmas 18, 092704 (2011)] where only electrical and optical diagnostics were applied. Magneto-hydrodynamic simulation shows a good agreement between the simulated and experimental waveforms of the current and voltage and measured the radial expansion of the exploding wire. Also, the radial density distribution obtained by an inverse Abel transform analysis agrees with the results of these simulations. Thus, the validity of the equations of state for copper and the conductivity model used in the simulations was confirmed for the parameters of the exploding wire realized in the present research.

Science Objectives of the FOXSI Small Explorer Mission Concept

NASA Astrophysics Data System (ADS)

Shih, Albert Y.; Christe, Steven; Alaoui, Meriem; Allred, Joel C.; Antiochos, Spiro K.; Battaglia, Marina; Buitrago-Casas, Juan Camilo; Caspi, Amir; Dennis, Brian R.; Drake, James; Fleishman, Gregory D.; Gary, Dale E.; Glesener, Lindsay; Grefenstette, Brian; Hannah, Iain; Holman, Gordon D.; Hudson, Hugh S.; Inglis, Andrew R.; Ireland, Jack; Ishikawa, Shin-Nosuke; Jeffrey, Natasha; Klimchuk, James A.; Kontar, Eduard; Krucker, Sam; Longcope, Dana; Musset, Sophie; Nita, Gelu M.; Ramsey, Brian; Ryan, Daniel; Saint-Hilaire, Pascal; Schwartz, Richard A.; Vilmer, Nicole; White, Stephen M.; Wilson-Hodge, Colleen

2016-05-01

Impulsive particle acceleration and plasma heating at the Sun, from the largest solar eruptive events to the smallest flares, are related to fundamental processes throughout the Universe. While there have been significant advances in our understanding of impulsive energy release since the advent of RHESSI observations, there is a clear need for new X-ray observations that can capture the full range of emission in flares (e.g., faint coronal sources near bright chromospheric sources), follow the intricate evolution of energy release and changes in morphology, and search for the signatures of impulsive energy release in even the quiescent Sun. The FOXSI Small Explorer (SMEX) mission concept combines state-of-the-art grazing-incidence focusing optics with pixelated solid-state detectors to provide direct imaging of hard X-rays for the first time on a solar observatory. We present the science objectives of FOXSI and how its capabilities will address and resolve open questions regarding impulsive energy release at the Sun. These questions include: What are the time scales of the processes that accelerate electrons? How do flare-accelerated electrons escape into the heliosphere? What is the energy input of accelerated electrons into the chromosphere, and how is super-heated coronal plasma produced?

Enhancing Understanding of Magnetized High Energy Density Plasmas from Solid Liner Implosions Using Fluid Modeling with Kinetic Closures

NASA Astrophysics Data System (ADS)

Masti, Robert; Srinivasan, Bhuvana; King, Jacob; Stoltz, Peter; Hansen, David; Held, Eric

2017-10-01

Recent results from experiments and simulations of magnetically driven pulsed power liners have explored the role of early-time electrothermal instability in the evolution of the MRT (magneto-Rayleigh-Taylor) instability. Understanding the development of these instabilities can lead to potential stabilization mechanisms; thereby providing a significant role in the success of fusion concepts such as MagLIF (Magnetized Liner Inertial Fusion). For MagLIF the MRT instability is the most detrimental instability toward achieving fusion energy production. Experiments of high-energy density plasmas from wire-array implosions have shown the requirement for more advanced physics modeling than that of ideal magnetohydrodynamics. The overall focus of this project is on using a multi-fluid extended-MHD model with kinetic closures for thermal conductivity, resistivity, and viscosity. The extended-MHD model has been updated to include the SESAME equation-of-state tables and numerical benchmarks with this implementation will be presented. Simulations of MRT growth and evolution for MagLIF-relevant parameters will be presented using this extended-MHD model with the SESAME equation-of-state tables. This work is supported by the Department of Energy Office of Science under Grant Number DE-SC0016515.

A review of lithium and non-lithium based solid state batteries

NASA Astrophysics Data System (ADS)

Kim, Joo Gon; Son, Byungrak; Mukherjee, Santanu; Schuppert, Nicholas; Bates, Alex; Kwon, Osung; Choi, Moon Jong; Chung, Hyun Yeol; Park, Sam

2015-05-01

Conventional lithium-ion liquid-electrolyte batteries are widely used in portable electronic equipment such as laptop computers, cell phones, and electric vehicles; however, they have several drawbacks, including expensive sealing agents and inherent hazards of fire and leakages. All solid state batteries utilize solid state electrolytes to overcome the safety issues of liquid electrolytes. Drawbacks for all-solid state lithium-ion batteries include high resistance at ambient temperatures and design intricacies. This paper is a comprehensive review of all aspects of solid state batteries: their design, the materials used, and a detailed literature review of various important advances made in research. The paper exhaustively studies lithium based solid state batteries, as they are the most prevalent, but also considers non-lithium based systems. Non-lithium based solid state batteries are attaining widespread commercial applications, as are also lithium based polymeric solid state electrolytes. Tabular representations and schematic diagrams are provided to underscore the unique characteristics of solid state batteries and their capacity to occupy a niche in the alternative energy sector.

Microstructure of the multiple-filamentation zone formed by femtosecond laser radiation in a solid dielectric

DOE Office of Scientific and Technical Information (OSTI.GOV)

Geints, Yu E; Zemlyanov, A A; Kabanov, A M

The regularities of multiple filamentation of gigawatt femtosecond laser pulses in a solid dielectric (optical glass) have been considered. The fine spatial structure of the plasma region that is formed under glass photoionisation and accompanies the formation of light filaments is analysed experimentally and by means of numerical simulation. The dependence of the number, position, and extension of individual 'generations' of plasma channels on the laser pulse energy has been investigated for the first time. It is found that the distribution of the number of plasma channels over the length of a dielectric sample has a maximum, the position ofmore » which correlates well with the position of the nonlinear focus of the light beam as a whole; at the same time, the average channel length decreases with increasing pulse power, whereas the number of successive channel 'generations', on the contrary, increases. (interaction of laser radiation with matter. laser plasma)« less

Atmospheric Plasma Spraying Low-Temperature Cathode Materials for Solid Oxide Fuel Cells

NASA Astrophysics Data System (ADS)

Harris, J.; Kesler, O.

2010-01-01

Atmospheric plasma spraying (APS) is attractive for manufacturing solid oxide fuel cells (SOFCs) because it allows functional layers to be built rapidly with controlled microstructures. The technique allows SOFCs that operate at low temperatures (500-700 °C) to be fabricated by spraying directly onto robust and inexpensive metallic supports. However, standard cathode materials used in commercial SOFCs exhibit high polarization resistances at low operating temperatures. Therefore, alternative cathode materials with high performance at low temperatures are essential to facilitate the use of metallic supports. Coatings of lanthanum strontium cobalt ferrite (LSCF) were fabricated on steel substrates using axial-injection APS. The thickness and microstructure of the coating layers were evaluated, and x-ray diffraction analysis was performed on the coatings to detect material decomposition and the formation of undesired phases in the plasma. These results determined the envelope of plasma spray parameters in which coatings of LSCF can be manufactured, and the range of conditions in which composite cathode coatings could potentially be manufactured.

A Novel Hybrid Axial-Radial Atmospheric Plasma Spraying Technique for the Fabrication of Solid Oxide Fuel Cell Anodes Containing Cu, Co, Ni, and Samaria-Doped Ceria

NASA Astrophysics Data System (ADS)

Cuglietta, Mark; Kuhn, Joel; Kesler, Olivera

2013-06-01

Composite coatings containing Cu, Co, Ni, and samaria-doped ceria (SDC) have been fabricated using a novel hybrid atmospheric plasma spraying technique, in which a multi-component aqueous suspension of CuO, Co3O4, and NiO was injected axially simultaneously with SDC injected radially in a dry powder form. Coatings were characterized for their microstructure, permeability, porosity, and composition over a range of plasma spray conditions. Deposition efficiency of the metal oxides and SDC was also estimated. Depending on the conditions, coatings displayed either layering or high levels of mixing between the SDC and metal phases. The deposition efficiencies of both feedstock types were strongly dependent on the nozzle diameter. Plasma-sprayed metal-supported solid oxide fuel cells utilizing anodes fabricated with this technique demonstrated power densities at 0.7 V as high as 366 and 113 mW/cm2 in humidified hydrogen and methane, respectively, at 800 °C.

3D Modeling of Transport Phenomena and the Injection of the Solution Droplets in the Solution Precursor Plasma Spraying

NASA Astrophysics Data System (ADS)

Shan, Yanguang; Coyle, Thomas W.; Mostaghimi, Javad

2007-12-01

Solution precursor plasma spraying has been used to produce finely structured ceramic coatings with nano- and sub-micrometric features. This process involves the injection of a solution spray of ceramic salts into a DC plasma jet under atmospheric condition. During the process, the solvent vaporizes as the droplet travel downstream. Solid particles are finally formed due to the precipitation of the solute, and the particle are heated up and accelerated to the substrate to generate the coating. This article describes a 3D model to simulate the transport phenomena and the trajectory and heating of the solution spray in the process. The jet-spray two-way interactions are considered. A simplified model is employed to simulate the evolution process and the formation of the solid particle from the solution droplet in the plasma jet. The temperature and velocity fields of the jet are obtained and validated. The particle size, velocity, temperature, and position distribution on the substrate are predicted.

Characteristics of hydroxyapatite coated titanium porous coatings on Ti-6Al-4V substrates by plasma sprayed method.

PubMed

Yang, C Y; Chen, C R; Chang, E; Lee, T M

2007-08-01

A porous metal coating applied to solid substrate implants has been shown, in vivo, to anchor implants by bone ingrowth. Calcium phosphate ceramics, in particular hydroxyapatite [Ca(10)(PO(4))(6)(OH)(2), HA], are bioactive ceramics, which are known to be biocompatible and osteoconductive, and these ceramics deposited on to porous-coated devices may enhance bone ingrowth and implant fixation. In this study, bi-feedstock of the titanium powder and composite (Na(2)CO(3)/HA) powder were simultaneously deposited on a Ti-6Al-4V substrate by a plasma sprayed method. At high temperature of plasma torch, the solid state of Na(2)CO(3) would decompose to release CO(2) gas and then eject the molten Ti powder to induce the interconnected pores in the coatings. After cleaning and soaking in deionized water, the residual Na(2)CO(3) in the coating would dissolve to form the open pores, and the HA would exist at the surface of pores in the inner coatings. By varying the particle size of the composite powder, the porosity of porous coating could be varied from 25.0 to 34.0%, and the average pore size of the porous coating could be varied to range between 158.5 and 202.0 microm. Using a standard adhesive test (ASTM C-633), the bonding strength of the coating is between 27.3 and 38.2 MPa. By SEM, the HA was observed at the surface of inner pore in the porous coating. These results suggest that the method exhibits the potential to manufacture the bioactive ceramics on to porous-coated specimen to achieve bone ingrowth fixation for biomedical applications.

Self-healing atmospheric plasma sprayed Mn1.0Co1.9Fe0.1O4 protective interconnector coatings for solid oxide fuel cells

NASA Astrophysics Data System (ADS)

Grünwald, Nikolas; Sebold, Doris; Sohn, Yoo Jung; Menzler, Norbert Heribert; Vaßen, Robert

2017-09-01

Dense coatings on metallic interconnectors are necessary to suppress chromium poisoning of SOFC cathodes. Atmospherically plasma sprayed (APS) Mn1.0Co1.9Fe0.1O4 (MCF) protective layers demonstrated reduced chromium related degradation in laboratory and stack tests. Previous analyses revealed strong microstructural changes comparing the coating's as-sprayed and operated condition. This work concentrates on the layer-densification and crack-healing observed by annealing APS-MCF in air, which simulates the cathode operation conditions. The effect is described by a volume expansion induced by a phase transformation. Reducing conditions during the spray process lead to a deposition of the MCF in a metastable rock salt configuration. Annealing in air activates diffusion processes for a phase transformation to the low temperature stable spinel phase (T < 1050 °C). This transformation is connected to an oxygen incorporation which occurs at regions facing high oxygen partial pressures, as there are the sample surface, cracks and pore surfaces. Calculations reveal a volume expansion induced by the oxygen uptake which seals the cracks and densifies the coating. The process decelerates when the cracks are closed, as the gas route is blocked and further oxidation continues over solid state diffusion. The self-healing abilities of metastable APS coatings could be interesting for other applications.

Method of processing materials using an inductively coupled plasma

DOEpatents

Hull, D.E.; Bieniewski, T.M.

1987-04-13

A method of processing materials. The invention enables ultrafine, ultrapure powders to be formed from solid ingots in a gas free environment. A plasma is formed directly from an ingot which insures purity. The vaporized material is expanded through a nozzle and the resultant powder settles on a cold surface. An inductively coupled plasma may also be used to process waste chemicals. Noxious chemicals are directed through a series of plasma tubes, breaking molecular bonds and resulting in relatively harmless atomic constituents. 3 figs.

Performance evaluation of laser induced breakdown spectroscopy in the measurement of liquid and solid samples

NASA Astrophysics Data System (ADS)

Bilge, Gonca; Sezer, Banu; Boyaci, Ismail Hakki; Eseller, Kemal Efe; Berberoglu, Halil

2018-07-01

Liquid analysis by using LIBS is a complicated process due to difficulties encountered during the collection of light and formation of plasma in liquid. To avoid these, some applications are performed such as aerosol formation and transforming liquid into solid state. However, performance of LIBS in liquid samples still remains a challenging issue. In this study, performance evaluation of LIBS and parameter optimizations in liquid and solid phase samples were performed. For this purpose, milk was chosen as model sample; milk powder was used as solid sample, and milk was used as liquid sample in the experiments. Different experimental setups have been constructed for each sampling technique, and optimizations were performed to determine suitable parameters such as delay time, laser energy, repetition rate and speed of rotary table for solid sampling technique, and flow rate of carrier gas for liquid sampling technique. Target element was determined as Ca, which is a critically important element in milk for determining its nutritional value and Ca addition. In optimum parameters, limit of detection (LOD), limit of quantification (LOQ) and relative standard deviation (RSD) values were calculated as 0.11%, 0.36% and 8.29% respectively for milk powders samples; while LOD, LOQ and RSD values were calculated as 0.24%, 0.81%, and 10.93% respectively for milk samples. It can be said that LIBS is an applicable method in both liquid and solid samples with suitable systems and parameters. However, liquid analysis requires much more developed systems for more accurate results.

Investigation of the effect of a power feed vacuum gap in solid liner experiments at 1 MA

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bott-Suzuki, S. C., E-mail: sbottsuzuki@ucsd.edu, E-mail: sbottsuzuki@p3ucsd.com; Cordaro, S. W.; Caballero Bendixsen, L. S.

We present an experimental study of plasma initiation of a solid metal liner at the 1 MA level. In contrast to previous work, we introduce a vacuum gap at one of the liner connections to the power feed to investigate how this affects plasma initiation and to infer how this may affect the symmetry of the liner in compression experiments. We observed that the vacuum gap causes non-uniform plasma initiation both azimuthally and axially in liners, diagnosed by gated optical imaging. Using magnetic field probes external to the liner, we also determined that the optical emission is strongly linked to themore » current distribution in the liner. The apparent persistent of azimuthal non-uniformities may have implications for fusion-scale liner experiments.« less

Validated high-performance liquid chromatographic method utilizing solid-phase extraction for the simultaneous determination of naringenin and hesperetin in human plasma.

PubMed

Kanaze, Feras Imad; Kokkalou, Eugene; Georgarakis, Manolis; Niopas, Ioannis

2004-03-05

Naringenin and hesperetin, the aglycones of the flavanone glucosides naringin and hesperidin occur naturally in citrus fruits. They exert a variety of pharmacological effects such as antioxidant, blood lipid-lowering, anticarcinogenic and inhibit selected cytochrome P-450 enzymes resulting in drug interactions. A specific, sensitive, precise, and accurate solid-phase extraction high-performance liquid chromatographic (HPLC) assay for the simultaneous determination of naringenin and hesperetin in human plasma was developed and validated. After addition of 7-ethoxycoumarin as internal standard, plasma samples were incubated with beta-glucuronidase/sulphatase, and the analytes were isolated from plasma by solid-phase extraction using C(18) cartridges and separated on a C(8) reversed phase column with methanol/water/acetic acid (40:58:2, v/v/v) as the eluent at 45 degrees C. The method was linear in the 10-300 ng/ml concentration range for both naringenin and hesperetin (r>0.999). Recovery for naringenin, hesperetin and internal standard was greater than 76.7%. Intra- and inter-day precision for naringenin ranged from 1.4 to 4.2% and from 1.9 to 5.2%, respectively, and for hesperetin ranged from 1.3 to 4.1% and from 1.7 to 5.1%, respectively. Accuracy was better than 91.5 and 91.3% for naringenin and hesperetin, respectively.

Sensitive determination of three aconitum alkaloids and their metabolites in human plasma by matrix solid-phase dispersion with vortex-assisted dispersive liquid-liquid microextraction and HPLC with diode array detection.

PubMed

Wang, Xiaozhong; Li, Xuwen; Li, Lanjie; Li, Min; Liu, Ying; Wu, Qian; Li, Peng; Jin, Yongri

2016-05-01

A simple and sensitive method for determination of three aconitum alkaloids and their metabolites in human plasma was developed using matrix solid-phase dispersion combined with vortex-assisted dispersive liquid-liquid microextraction and high-performance liquid chromatography with diode array detection. The plasma sample was directly purified by matrix solid-phase dispersion and the eluate obtained was concentrated and further clarified by vortex-assisted dispersive liquid-liquid microextraction. Some important parameters affecting the extraction efficiency, such as type and amount of dispersing sorbent, type and volume of elution solvent, type and volume of extraction solvent, salt concentration as well as sample solution pH, were investigated in detail. Under optimal conditions, the proposed method has good repeatability and reproducibility with intraday and interday relative standard deviations lower than 5.44 and 5.75%, respectively. The recoveries of the aconitum alkaloids ranged from 73.81 to 101.82%, and the detection limits were achieved within the range of 1.6-2.1 ng/mL. The proposed method offered the advantages of good applicability, sensitivity, simplicity, and feasibility, which makes it suitable for the determination of trace amounts of aconitum alkaloids in human plasma samples. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Advanced density profile reflectometry; the state-of-the-art and measurement prospects for ITER

NASA Astrophysics Data System (ADS)

Doyle, E. J.

2006-10-01

Dramatic progress in millimeter-wave technology has allowed the realization of a key goal for ITER diagnostics, the routine measurement of the plasma density profile from millimeter-wave radar (reflectometry) measurements. In reflectometry, the measured round-trip group delay of a probe beam reflected from a plasma cutoff is used to infer the density distribution in the plasma. Reflectometer systems implemented by UCLA on a number of devices employ frequency-modulated continuous-wave (FM-CW), ultrawide-bandwidth, high-resolution radar systems. One such system on DIII-D has routinely demonstrated measurements of the density profile over a range of electron density of 0-6.4x10^19,m-3, with ˜25 μs time and ˜4 mm radial resolution, meeting key ITER requirements. This progress in performance was made possible by multiple advances in the areas of millimeter-wave technology, novel measurement techniques, and improved understanding, including: (i) fast sweep, solid-state, wide bandwidth sources and power amplifiers, (ii) dual polarization measurements to expand the density range, (iii) adaptive radar-based data analysis with parallel processing on a Unix cluster, (iv) high memory depth data acquisition, and (v) advances in full wave code modeling. The benefits of advanced system performance will be illustrated using measurements from a wide range of phenomena, including ELM and fast-ion driven mode dynamics, L-H transition studies and plasma-wall interaction. The measurement capabilities demonstrated by these systems provide a design basis for the development of the main ITER profile reflectometer system. This talk will explore the extent to which these reflectometer system designs, results and experience can be translated to ITER, and will identify what new studies and experimental tests are essential.

Plasma Immersion Ion Implantation with Solid Targets for Space and Aerospace Applications

DOE Office of Scientific and Technical Information (OSTI.GOV)

Oliveira, R. M.; Goncalves, J. A. N.; Ueda, M.

2009-01-05

This paper describes successful results obtained by a new type of plasma source, named as Vaporization of Solid Targets (VAST), for treatment of materials for space and aerospace applications, by means of plasma immersion ion implantation and deposition (PIII and D). Here, the solid element is vaporized in a high pressure glow discharge, being further ionized and implanted/deposited in a low pressure cycle, with the aid of an extra electrode. First experiments in VAST were run using lithium as the solid target. Samples of silicon and aluminum alloy (2024) were immersed into highly ionized lithium plasma, whose density was measuredmore » by a double Langmuir probe. Measurements performed with scanning electron microscopy (SEM) showed clear modification of the cross-sectioned treated silicon samples. X-ray photoelectron spectroscopy (XPS) analysis revealed that lithium was implanted/deposited into/onto the surface of the silicon. Implantation depth profiles may vary according to the condition of operation of VAST. One direct application of this treatment concerns the protection against radiation damage for silicon solar cells. For the case of the aluminum alloy, X-ray diffraction analysis indicated the appearance of prominent new peaks. Surface modification of A12024 by lithium implantation/deposition can lower the coefficient of friction and improve the resistance to fatigue of this alloy. Recently, cadmium was vaporized and ionized in VAST. The main benefit of this element is associated with the improvement of corrosion resistance of metallic substrates. Besides lithium and cadmium, VAST allows to performing PIII and D with other species, leading to the modification of the near-surface of materials for distinct purposes, including applications in the space and aerospace areas.« less

A simple graphene-based pipette tip solid-phase extraction of malondialdehyde from human plasma and its determination by spectrofluorometry.

PubMed

Kaykhaii, Massoud; Yahyavi, Hossain; Hashemi, Mohammad; Khoshroo, Mohammad Reza

2016-07-01

Determination of malondialdehyde (MDA) in human blood plasma is important because of its role as a biomarker of lipid peroxidation in biological and medical sciences. In this work, a miniaturized graphene-based pipette tip solid-phase extraction technique was developed for very efficient extraction of MDA as its dithiobarbituric acid (TBA) adduct from human plasma. Two milligrams of graphene as sorbent were placed into a pipette tip and MDA-TBA compound was extracted and preconcentrated by it, after 4 repeated aspirating/dispensing cycles, then the column was eluted with 80 μL of dimethyl sulfoxide by 4 repeated aspirating/dispensing cycles and elusion was measured spectrofluorimetrically. Various effective parameters such as type and volume of eluent solvent, temperature, sample volume, number of cycles of extraction and desorption, derivatization reaction time, and pH of the sample solution were investigated and optimized. Under optimum conditions, a linear calibration curve was obtained in the range of 0.5-90 μg L(-1) (r (2) = 0.991) with a detection limit of 0.3 μg L(-1). The relative standard deviations for 8 replicate measurements of 10 and 40 μg L(-1) of MDA were found to be 4.51 and 3.78 % respectively. The developed protocol was successfully applied to the determination of MDA in a human blood plasma sample. Graphical Abstract A simple graphene-based pipette tip solid-phase extraction of malondialdehyde from human plasma and its determination by spectrofluorometry.

Modeling dynamic plasmas driven by ultraintense nano-focused x-ray laser pulses in solid iron targets

NASA Astrophysics Data System (ADS)

Royle, Ryan; Sentoku, Yasuhiko; Mancini, Roberto

2017-10-01

The hard x-ray free electron laser has proven to be a valuable tool for high energy density (HED) physics as it is able to produce well-characterized samples of HED matter at exactly solid density and homogeneous temperatures. However, if the x-ray pulses are focused to sub-micron spot sizes, where peak intensities can exceed 1020 W/cm2, the plasmas driven by sources of non-thermal photoelectrons and Auger electrons can be highly dynamic and so cannot be modeled by atomic kinetics or fluid codes. We apply the 2D/3D particle-in-cell code, PICLS-which has been extended with numerous physics models to enable the simulation of XFEL-driven plasmas-to the modeling of such dynamic plasmas driven by nano-focused XFEL pulses in solid iron targets. In the case of the smallest focal spot investigated of just 100 nm in diameter, keV plasmas induce strong radial E-fields that accelerate keV ions radially as well as sheath fields that accelerate surface ions to hundreds of keV. The heated spot, which is initially larger than the laser spot due to the kinetic nature of the fast Auger electrons, expands as ion and electron waves propagate radially, leaving a low density region along the laser axis. This research was supported by the US DOE-OFES under Grant No. DE-SC0008827, the DOE-NNSA under Grant No. DE-NA0002075, and the JSPS KAKENHI under Grant No. JP15K21767.

Anticorrelated Emission of High Harmonics and Fast Electron Beams From Plasma Mirrors.

PubMed

Bocoum, Maïmouna; Thévenet, Maxence; Böhle, Frederik; Beaurepaire, Benoît; Vernier, Aline; Jullien, Aurélie; Faure, Jérôme; Lopez-Martens, Rodrigo

2016-05-06

We report for the first time on the anticorrelated emission of high-order harmonics and energetic electron beams from a solid-density plasma with a sharp vacuum interface-plasma mirror-driven by an intense ultrashort laser pulse. We highlight the key role played by the nanoscale structure of the plasma surface during the interaction by measuring the spatial and spectral properties of harmonics and electron beams emitted by a plasma mirror. We show that the nanoscale behavior of the plasma mirror can be controlled by tuning the scale length of the electron density gradient, which is measured in situ using spatial-domain interferometry.

Fractal structure of low-temperature plasma of arc discharge as a consequence of the interaction of current sheets

NASA Astrophysics Data System (ADS)

Smolanov, N. A.

2016-01-01

The structure of the particles deposited from the plasma arc discharge were studied. The flow of plasma spreading from the cathode spot to the walls of the vacuum chamber. Electric and magnetic fields to influence the plasma flow. The fractal nature of the particles from the plasma identified by small-angle X-ray scattering. Possible cause of their formation is due to the instability of the growth front and nonequilibrium conditions for their production - a high speed transition of the vapor-liquid-solid or vapor - crystal. The hypothesis of a plasma arc containing dust particles current sheets was proposed.

Ceramic Electrolyte Membrane Technology: Enabling Revolutionary Electrochemical Energy Storage

DTIC Science & Technology

2015-10-05

ion batteries . Solid-state Li- ion batteries could significantly improve safety and eliminate the need for complex...advancing ceramic electrolyte technology for use in solid-state Li- ion batteries . Solid-state Li- ion batteries could significantly improve safety and...technology for use in solid-state Li- ion batteries and high specific energy Li-S and Li- air batteries . Solid-state Li- ion batteries could

Solid-state pulse modulator using Marx generator for a medical linac electron-gun

NASA Astrophysics Data System (ADS)

Lim, Heuijin; Hyeok Jeong, Dong; Lee, Manwoo; Lee, Mujin; Yi, Jungyu; Yang, Kwangmo; Ro, Sung Chae

2016-04-01

A medical linac is used for the cancer treatment and consists of an accelerating column, waveguide components, a magnetron, an electron-gun, a pulse modulator, and an irradiation system. The pulse modulator based on hydrogen thyratron-switched pulse-forming network is commonly used in linac. As the improvement of the high power semiconductors in switching speed, voltage rating, and current rating, an insulated gate bipolar transistor has become the more popular device used for pulsed power systems. We propose a solid-state pulse modulator to generator high voltage by multi-stacked storage-switch stages based on the Marx generator. The advantage of our modulator comes from the use of two semiconductors to control charging and discharging of the storage capacitor at each stage and it allows to generate the pulse with various amplitudes, widths, and shapes. In addition, a gate driver for two semiconductors is designed to reduce the control channels and to protect the circuits. It is developed for providing the pulsed power to a medical linac electron-gun that requires 25 kV and 1 A as the first application. In order to improve the power efficiency and achieve the compactness modulator, a capacitor charging power supply, a Marx pulse generator, and an electron-gun heater isolated transformer are constructed and integrated. This technology is also being developed to extend the high power pulsed system with > 1 MW and also other applications such as a plasma immersed ion implantation and a micro pulse electrostatic precipitator which especially require variable pulse shape and high repetition rate > 1 kHz. The paper describes the design features and the construction of this solid-state pulse modulator. Also shown are the performance results into the linac electron-gun.

Monolithic translucent BaMgAl 10O 17:Eu 2+ phosphors for laser-driven solid state lighting

DOE PAGES

Cozzan, Clayton; Brady, Michael J.; O’Dea, Nicholas; ...

2016-10-11

With high power light emitting diodes and laser diodes being explored for white light generation and visible light communication, thermally robust encapsulation schemes for color-converting inorganic phosphors are essential. In the current work, the canonical blue-emitting phosphor, high purity Eu-doped BaMgAl 10O 17, has been prepared using microwave-assisted heating (25 min) and densified into translucent ceramic phosphor monoliths using spark plasma sintering (30 min). Lastly, the resulting translucent ceramic monoliths convert UV laser light to blue light with the same efficiency as the starting powder and provide superior thermal management in comparison with silicone encapsulation.

Utilization of selected laser-ablation-based diagnostic methods for study of elemental distribution in various solid samples

NASA Astrophysics Data System (ADS)

Kaiser, J.; Novotný, K.; Hrdlička, A.; Malina, R.; Novotný, J.; Prochazka, D.; Petrilak, M.; Krajcarová, L.; Vítková, G.; Kučerová, P.

2010-12-01

Here we report on the recent developments and upgrades of our Laser-Induced Breakdown Spectroscopy setups and their different modification for high-resolution mapping. Mapping capabilities of Laser-Induced Breakdown Spectroscopy (LIBS) and Laser Ablation Inductively Coupled Plasma Mass Spectrometry are compared. The applied improvements as an autofocus algorithm, together with the realization of double-pulse LIBS or combination of LIBS by Laser-Induced Fluorescence Spectroscopy (LIFS) with technique are detailed. The signal enhancement obtained by double-pulse approach is demonstrated. The state of the art on development of portable remote LIBS apparatus is also presented.

Metal-like self-organization of periodic nanostructures on silicon and silicon carbide under femtosecond laser pulses

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gemini, Laura; Department of Physics, Graduate School of Science, Kyoto University, 606-85802 Kyoto; FNSPE, Czech Technical University in Prague, 11519 Prague

Periodic structures were generated on Si and SiC surfaces by irradiation with femtosecond laser pulses. Self-organized structures with spatial periodicity of approximately 600 nm appear on silicon and silicon carbide in the laser fluence range just above the ablation threshold and upon irradiation with a large number of pulses. As in the case of metals, the dependence of the spatial periodicity on laser fluence can be explained by the parametric decay of laser light into surface plasma waves. The results show that the proposed model might be universally applicable to any solid state material.

Energy and lighting

NASA Astrophysics Data System (ADS)

Berman, Samuel

1985-11-01

Advances in research for new types of lighting with increased efficacies (lumens/watt) are discussed in the following areas: (1) high-frequency, solid-state ballasts, (2) isotopic enhancement of mercury isotopes, (3) magnetic augmentation, (4) electrodeless, ultra-high frequency, (5) tuned phosphors, (6) two-photon phosphors, (7) heat mirrors, and (8) advanced control circuits to take advantage of daylight and occupancy. As of 1985, improvements in efficacy have been accomplished on an economic basis to save energy for (1) high frequency ballasts (25%), (2) isotopic enhancement (5%), and (8) advanced control circuits (up to 50%). Most of these advances depend on a deeper understanding of the weakly ionized plasma as a radiating and diffusing medium.

ELI-Beamlines: development of next generation short-pulse laser systems

NASA Astrophysics Data System (ADS)

Rus, B.; Bakule, P.; Kramer, D.; Naylon, J.; Thoma, J.; Green, J. T.; Antipenkov, R.; Fibrich, M.; Novák, J.; Batysta, F.; Mazanec, T.; Drouin, M. A.; Kasl, K.; Baše, R.; Peceli, D.; Koubíková, L.; Trojek, P.; Boge, R.; Lagron, J. C.; Vyhlídka, Å.; Weiss, J.; Cupal, J.,; Hřebíček, J.; Hříbek, P.; Durák, M.; Polan, J.; Košelja, M.; Korn, G.; Horáček, M.; Horáček, J.; Himmel, B.; Havlíček, T.; Honsa, A.; Korouš, P.; Laub, M.; Haefner, C.; Bayramian, A.; Spinka, T.; Marshall, C.; Johnson, G.; Telford, S.; Horner, J.; Deri, B.; Metzger, T.; Schultze, M.; Mason, P.; Ertel, K.; Lintern, A.; Greenhalgh, J.; Edwards, C.; Hernandez-Gomez, C.; Collier, J.; Ditmire, T.,; Gaul, E.; Martinez, M.; Frederickson, C.; Hammond, D.; Malato, C.; White, W.; Houžvička, J.

2015-05-01

Overview of the laser systems being built for ELI-Beamlines is presented. The facility will make available high-brightness multi-TW ultrashort laser pulses at kHz repetition rate, PW 10 Hz repetition rate pulses, and kilojoule nanosecond pulses for generation of 10 PW peak power. The lasers will extensively employ the emerging technology of diode-pumped solid-state lasers (DPSSL) to pump OPCPA and Ti:sapphire broadband amplifiers. These systems will provide the user community with cutting-edge laser resources for programmatic research in generation and applications of high-intensity X-ray sources, in particle acceleration, and in dense-plasma and high-field physics.

Optical Properties in Nonequilibrium Phase Transitions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ao, T.; Lee, E.; Tam, H.

An open question about the dynamical behavior of materials is how phase transition occurs in highly nonequilibrium systems. One important class of study is the excitation of a solid by an ultrafast, intense laser. The preferential heating of electrons by the laser field gives rise to initial states dominated by hot electrons in a cold lattice. Using a femtosecond laser pump-probe approach, we have followed the temporal evolution of the optical properties of such a system. The results show interesting correlation to nonthermal melting and lattice disordering processes. They also reveal a liquid-plasma transition when the lattice energy density reachesmore » a critical value.« less

Optical Properties in Non-equilibrium Phase Transitions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ao, T; Ping, Y; Widmann, K

An open question about the dynamical behavior of materials is how phase transition occurs in highly non-equilibrium systems. One important class of study is the excitation of a solid by an ultrafast, intense laser. The preferential heating of electrons by the laser field gives rise to initial states dominated by hot electrons in a cold lattice. Using a femtosecond laser pump-probe approach, we have followed the temporal evolution of the optical properties of such a system. The results show interesting correlation to non-thermal melting and lattice disordering processes. They also reveal a liquid-plasma transition when the lattice energy density reachesmore » a critical value.« less

Profiling of tryptophan-related plasma indoles in patients with carcinoid tumors by automated, on-line, solid-phase extraction and HPLC with fluorescence detection.

PubMed

Kema, I P; Meijer, W G; Meiborg, G; Ooms, B; Willemse, P H; de Vries, E G

2001-10-01

Profiling of the plasma indoles tryptophan, 5-hydroxytryptophan (5-HTP), serotonin, and 5-hydroxyindoleacetic acid (5-HIAA) is useful in the diagnosis and follow-up of patients with carcinoid tumors. We describe an automated method for the profiling of these indoles in protein-containing matrices as well as the plasma indole concentrations in healthy controls and patients with carcinoid tumors. Plasma, cerebrospinal fluid, and tissue homogenates were prepurified by automated on-line solid-phase extraction (SPE) in Hysphere Resin SH SPE cartridges containing strong hydrophobic polystyrene resin. Analytes were eluted from the SPE cartridge by column switching. Subsequent separation and detection were performed by reversed-phase HPLC combined with fluorometric detection in a total cycle time of 20 min. We obtained samples from 14 healthy controls and 17 patients with metastasized midgut carcinoid tumors for plasma indole analysis. In the patient group, urinary excretion of 5-HIAA and serotonin was compared with concentrations of plasma indoles. Within- and between-series CVs for indoles in platelet-rich plasma were 0.6-6.2% and 3.7-12%, respectively. Results for platelet-rich plasma serotonin compared favorably with those obtained by single-component analysis. Plasma 5-HIAA, but not 5-HTP was detectable in 8 of 17 patients with carcinoid tumors. In the patient group, platelet-rich plasma total tryptophan correlated negatively with platelet-rich plasma serotonin (P = 0.021; r = -0.56), urinary 5-HIAA (P = 0.003; r = -0.68), and urinary serotonin (P <0.0001; r = -0.80). The present chromatographic approach reduces analytical variation and time needed for analysis and gives more detailed information about metabolic deviations in indole metabolism than do manual, single-component analyses.

Plasma column and nano-powder generation from solid titanium by localized microwaves in air

DOE Office of Scientific and Technical Information (OSTI.GOV)

Popescu, Simona; Jerby, Eli, E-mail: jerby@eng.tau.ac.il; Meir, Yehuda

2015-07-14

This paper studies the effect of a plasma column ejected from solid titanium by localized microwaves in an ambient air atmosphere. Nanoparticles of titanium dioxide (titania) are found to be directly synthesized in this plasma column maintained by the microwave energy in the cavity. The process is initiated by a hotspot induced by localized microwaves, which melts the titanium substrate locally. The molten hotspot emits ionized titanium vapors continuously into the stable plasma column, which may last for more than a minute duration. The characterization of the dusty plasma obtained is performed in-situ by small-angle X-ray scattering (SAXS), optical spectroscopy,more » and microwave reflection analyses. The deposited titania nanoparticles are structurally and morphologically analyzed by ex-situ optical and scanning-electron microscope observations, and also by X-ray diffraction. Using the Boltzmann plot method combined with the SAXS results, the electron temperature and density in the dusty plasma are estimated as ∼0.4 eV and ∼10{sup 19 }m{sup −3}, respectively. The analysis of the plasma product reveals nanoparticles of titania in crystalline phases of anatase, brookite, and rutile. These are spatially arranged in various spherical, cubic, lamellar, and network forms. Several applications are considered for this process of titania nano-powder production.« less

Method for producing metallic microparticles

DOEpatents

Phillips, Jonathan; Perry, William L.; Kroenke, William J.

2004-06-29

Method for producing metallic particles. The method converts metallic nanoparticles into larger, spherical metallic particles. An aerosol of solid metallic nanoparticles and a non-oxidizing plasma having a portion sufficiently hot to melt the nanoparticles are generated. The aerosol is directed into the plasma where the metallic nanoparticles melt, collide, join, and spheroidize. The molten spherical metallic particles are directed away from the plasma and enter the afterglow where they cool and solidify.

Electromagnetic and geometric characterization of accelerated ion beams by laser ablation

NASA Astrophysics Data System (ADS)

Nassisi, V.; Velardi, L.; Side, D. Delle

2013-05-01

Laser ion sources offer the possibility to get ion beam useful to improve particle accelerators. Pulsed lasers at intensities of the order of 108 W/cm2 and of ns pulse duration, interacting with solid matter in vacuum, produce plasma of high temperature and density. The charge state distribution of the plasma generates high electric fields which accelerate ions along the normal to the target surface. The energy of emitted ions has a Maxwell-Boltzmann distribution which depends on the ion charge state. To increase the ion energy, a post-acceleration system can be employed by means of high voltage power supplies of about 100 kV. The post acceleration system results to be a good method to obtain high ion currents by a not expensive system and the final ion beams find interesting applications in the field of the ion implantation, scientific applications and industrial use. In this work we compare the electromagnetic and geometric properties, like emittance, of the beams delivered by pure Cu, Y and Ag targets. The characterization of the plasma was performed by a Faraday cup for the electromagnetic characteristics, whereas a pepper pot system was used for the geometric ones. At 60 kV accelerating voltage the three examined ion bunches get a current peak of 5.5, 7.3 and 15 mA, with a normalized beam emittance of 0.22, 0.12 and 0.09 π mm mrad for the targets of Cu, Y, and Ag, respectively.

Near Earth Inner-Source and Interstellar Pickup Ions Observed with the Hot Plasma Composition Analyzer of the Magnetospheric Multiscale Mission Mms-Hpca

NASA Astrophysics Data System (ADS)

Gomez, R. G.; Fuselier, S. A.; Mukherjee, J.; Gonzalez, C. A.

2017-12-01

Pickup ions found near the earth are generally picked up in the rest frame of the solar wind, and propagate radially outward from their point of origin. While propagating, they simultaneously gyrate about the magnetic field. Pickup ions come in two general populations; interstellar and inner source ions. Interstellar ions originate in the interstellar medium, enter the solar system in a neutral charge state, are gravitationally focused on the side of the sun opposite their arrival direction and, are ionized when they travel near the sun. Inner-source ions originate at a location within the solar system and between the sun and the observation point. Both pickup ion populations share similarities in composition and charge states, so measuring of their dynamics, using their velocity distribution functions, f(v)'s, is absolutely essential to distinguishing them, and to determining their spatial and temporal origins. Presented here will be the results of studies conducted with the four Hot Plasma Composition Analyzers of the Magnetospheric Multiscale Mission (MMS-HPCA). These instruments measure the full sky (4π steradians) distribution functions of near earth plasmas at a 10 second cadence in an energy-to-charge range 0.001-40 keV/e. The instruments are also capable of parsing this combined energy-solid angle phase space with 22.5° resolution polar angle, and 11.25° in azimuthal angle, allowing for clear measurement of the pitch angle scattering of the ions.

III International Conference on Laser and Plasma Researches and Technologies

NASA Astrophysics Data System (ADS)

2017-12-01

A.P. Kuznetsov and S.V. Genisaretskaya III Conference on Plasma and Laser Research and Technologies took place on January 24th until January 27th, 2017 at the National Research Nuclear University "MEPhI" (NRNU MEPhI). The Conference was organized by the Institute for Laser and Plasma Technologies and was supported by the Competitiveness Program of NRNU MEPhI. The conference program consisted of nine sections: • Laser physics and its application • Plasma physics and its application • Laser, plasma and radiation technologies in industry • Physics of extreme light fields • Controlled thermonuclear fusion • Modern problems of theoretical physics • Challenges in physics of solid state, functional materials and nanosystems • Particle accelerators and radiation technologies • Modern trends of quantum metrology. The conference is based on scientific fields as follows: • Laser, plasma and radiation technologies in industry, energetic, medicine; • Photonics, quantum metrology, optical information processing; • New functional materials, metamaterials, “smart” alloys and quantum systems; • Ultrahigh optical fields, high-power lasers, Mega Science facilities; • High-temperature plasma physics, environmentally-friendly energetic based on controlled thermonuclear fusion; • Spectroscopic synchrotron, neutron, laser research methods, quantum mechanical calculation and computer modelling of condensed media and nanostructures. More than 250 specialists took part in the Conference. They represented leading Russian scientific research centers and universities (National Research Centre "Kurchatov Institute", A.M. Prokhorov General Physics Institute, P.N. Lebedev Physical Institute, Troitsk Institute for Innovation and Fusion Research, Joint Institute for Nuclear Research, Moscow Institute of Physics and Tecnology and others) and leading scientific centers and universities from Germany, France, USA, Canada, Japan. We would like to thank heartily all of the speakers, participants, organizing and program committee members for their contribution to the conference.

Helicon modes in uniform plasmas. I. Low m modes

NASA Astrophysics Data System (ADS)

Urrutia, J. M.; Stenzel, R. L.

2015-09-01

Helicons are whistler modes with azimuthal wave numbers. They arise in bounded gaseous and solid state plasmas, but the present work shows that very similar modes also exist in unbounded uniform plasmas. The antenna properties determine the mode structure. A simple antenna is a magnetic loop with dipole moment aligned either along or across the ambient background magnetic field B0. For such configurations, the wave magnetic field has been measured in space and time in a large and uniform laboratory plasma. The observed wave topology for a dipole along B0 is similar to that of an m = 0 helicon mode. It consists of a sequence of alternating whistler vortices. For a dipole across B0, an m = 1 mode is excited which can be considered as a transverse vortex which rotates around B0. In m = 0 modes, the field lines are confined to each half-wavelength vortex while for m = 1 modes they pass through the entire wave train. A subset of m = 1 field lines forms two nested helices which rotate in space and time like corkscrews. Depending on the type of the antenna, both m = + 1 and m = -1 modes can be excited. Helicons in unbounded plasmas also propagate transverse to B0. The transverse and parallel wave numbers are about equal and form oblique phase fronts as in whistler Gendrin modes. By superimposing small amplitude fields of several loop antennas, various antenna combinations have been created. These include rotating field antennas, helical antennas, and directional antennas. The radiation efficiency is quantified by the radiation resistance. Since helicons exist in unbounded laboratory plasmas, they can also arise in space plasmas.

X-Ray Spectroscopies of Warm Dense Matter

NASA Astrophysics Data System (ADS)

Hoidn, Oliver

This dissertation provides a perspective on the role of x-ray spectroscopy and diffraction diagnostics in experimental studies of warm dense matter (WDM). The primary focus of the work I discuss is the development of techniques to measure the structure and state variables of laboratory-generated WDM with a view towards both phenomenlogy and placing contraints on theoretical models. I present techniques adapted to two experimental venues for WDM studies: large-scale laser plasma facilities and x-ray free electron lasers. My focus is on the latter, in the context of which I have studied a dose enhancement technique that exploits nonlocal heat transport in nanostructured targets and considered several aspects of optimizing x-ray diffraction measurements. This work came into play in beam runs at the Linac Coherent Light Source (LCLS) in which my group performed x-ray diffraction studies of several materials heated to eV-scale temperatures. The results from these experiments include confirmation of the persistence of long-range crystalline order upon heating of metal oxides to tens of eV temperarures on the 40 fs timescale. One material, MgO, additionally manifested a surprising anomalous early onset in delocalization of valence charge density, contradicting predictions of all models based on either ground state electronic structure or (high-energy density) plasma physics. This particular result outlines a future path for studies of ordered insulators heated to temperatures on the order of the band gap. Such experiments will offer strong tests of electronic strucure theory, implementing a scientific approach that sees measurement of real-space charge density via x-ray diffraction (XRD) as a particularly effectve means to constrain density functional theory (DFT)-based modeling of the solid state/plasma transitional regime.

Fast, deep record length, time-resolved visible spectroscopy of plasmas using fiber grids

NASA Astrophysics Data System (ADS)

Brockington, Samuel; Case, Andrew; Cruz, Edward; Witherspoon, F. Douglas; Horton, Robert; Klauser, Ruth; Hwang, D. Q.

2016-10-01

HyperV Technologies is developing a fiber-coupled, deep-record-length, low-light camera head for performing high time resolution spectroscopy on visible emission from plasma events. New solid-state Silicon Photo-Multiplier (SiPM) chips are capable of single photon event detection and high speed data acquisition. By coupling the output of a spectrometer to an imaging fiber bundle connected to a bank of amplified SiPMs, time-resolved spectroscopic imagers of 100 to 1,000 pixels can be constructed. Target pixel performance is 10 Megaframes/sec with record lengths of up to 256,000 frames yielding 25.6 milliseconds of record at10 Megasamples/sec resolution. Pixel resolutions of 8 to 12 bits are pos- sible. Pixel pitch can be refined by using grids of 100 μm to 1000 μm diameter fibers. A prototype 32-pixel spectroscopic imager employing this technique was constructed and successfully tested at the University of California at Davis Compact Toroid Injection Experiment (CTIX) as a full demonstration of the concept. Experimental results will be dis-cussed, along with future plans for the Phase 2 project, and potential applications to plasma experiments . Work supported by USDOE SBIR Grant DE-SC0013801.

Environmental Benign Process for Production of Molybdenum Metal from Sulphide Based Minerals

NASA Astrophysics Data System (ADS)

Rajput, Priyanka; Janakiram, Vangada; Jayasankar, Kalidoss; Angadi, Shivakumar; Bhoi, Bhagyadhar; Mukherjee, Partha Sarathi

2017-10-01

Molybdenum is a strategic and high temperature refractory metal which is not found in nature in free state, it is predominantly found in earth's crust in the form of MoO3/MoS2. The main disadvantage of the industrial treatment of Mo concentrate is that the process contains many stages and requires very high temperature. Almost in every step many gaseous, liquid, solid chemical substances are formed which require further treatment. To overcome the above drawback, a new alternative one step novel process is developed for the treatment of sulphide and trioxide molybdenum concentrates. This paper presents the results of the investigations on molybdenite dissociation (MoS2) using microwave assisted plasma unit as well as transferred arc thermal plasma torch. It is a single step process for the preparation of pure molybdenum metal from MoS2 by hydrogen reduction in thermal plasma. Process variable such as H2 gas, Ar gas, input current, voltage and time have been examined to prepare molybdenum metal. Molybdenum recovery of the order of 95% was achieved. The XRD results confirm the phases of molybdenum metal and the chemical analysis of the end product indicate the formation of metallic molybdenum (Mo 98%).

A pulse-compression-ring circuit for high-efficiency electric propulsion.

PubMed

Owens, Thomas L

2008-03-01

A highly efficient, highly reliable pulsed-power system has been developed for use in high power, repetitively pulsed inductive plasma thrusters. The pulsed inductive thruster ejects plasma propellant at a high velocity using a Lorentz force developed through inductive coupling to the plasma. Having greatly increased propellant-utilization efficiency compared to chemical rockets, this type of electric propulsion system may one day propel spacecraft on long-duration deep-space missions. High system reliability and electrical efficiency are extremely important for these extended missions. In the prototype pulsed-power system described here, exceptional reliability is achieved using a pulse-compression circuit driven by both active solid-state switching and passive magnetic switching. High efficiency is achieved using a novel ring architecture that recovers unused energy in a pulse-compression system with minimal circuit loss after each impulse. As an added benefit, voltage reversal is eliminated in the ring topology, resulting in long lifetimes for energy-storage capacitors. System tests were performed using an adjustable inductive load at a voltage level of 3.3 kV, a peak current of 20 kA, and a current switching rate of 15 kA/micros.

The Arabidopsis COBRA Protein Facilitates Cellulose Crystallization at the Plasma Membrane*

PubMed Central

Sorek, Nadav; Sorek, Hagit; Kijac, Aleksandra; Szemenyei, Heidi J.; Bauer, Stefan; Hématy, Kian; Wemmer, David E.; Somerville, Chris R.

2014-01-01

Mutations in the Arabidopsis COBRA gene lead to defects in cellulose synthesis but the function of COBRA is unknown. Here we present evidence that COBRA localizes to discrete particles in the plasma membrane and is sensitive to inhibitors of cellulose synthesis, suggesting that COBRA and the cellulose synthase complex reside in close proximity on the plasma membrane. Live-cell imaging of cellulose synthesis indicated that, once initiated, cellulose synthesis appeared to proceed normally in the cobra mutant. Using isothermal calorimetry, COBRA was found to bind individual β1–4-linked glucan chains with a KD of 3.2 μm. Competition assays suggests that COBRA binds individual β1–4-linked glucan chains with higher affinity than crystalline cellulose. Solid-state nuclear magnetic resonance studies of the cell wall of the cobra mutant also indicated that, in addition to decreases in cellulose amount, the properties of the cellulose fibrils and other cell wall polymers differed from wild type by being less crystalline and having an increased number of reducing ends. We interpret the available evidence as suggesting that COBRA facilitates cellulose crystallization from the emerging β1–4-glucan chains by acting as a “polysaccharide chaperone.” PMID:25331944

Measurement of Velocity Induced by a Propagating Arc Magnetohydrodynamic Plasma Actuator

NASA Astrophysics Data System (ADS)

Choi, Young Joon; Gray, Miles; Sirohi, Jayant; Raja, Laxminarayan

2016-09-01

Plasma actuators can substantially improve the maneuverability and efficiency of aerial vehicles. These solid state devices have low mass, small volume, and high bandwidth that make them excellent alternatives to conventional mechanical actuators. In particular, a Rail Plasma Actuator (RailPAc) has the potential to delay flow separation on an aerodynamic surface by generating a large body force. A RailPAc consists of parallel rails and an electrical arc that propagates along the rails with a self-induced Lorentz force. The motion of the arc transfers momentum to the surrounding neutral air. A study was conducted to understand how the motion and shape of a propagating arc couples with the fluid momentum. In particular, we used Particle Imaging Velocimetry (PIV) and seedless PIV based on Background Oriented Schlieren (BOS) technique to measure the induced velocity of a propagating arc in one atmosphere. Results obtained provide insight into how the flow field responds to the passage of a RailPAc electrical arc. A complete description of the RailPAc actuation mechanism can be obtained if the fluid momentum measurements from PIV and seedless PIV are compared to the transit characteristics of an arc. US ARL Grant W911NF1410226.

Progress in neutron-, X-ray- and VIS spectroscopic diagnostics of large-scale plasma focus experiments at ICDMP

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schmidt, Hellmut

Substantial progress has been made in various diagnostics for investigating results of experiments during the last years performed with the PF1000 device at IPPLM, Warsaw, Poland. In addition to standard diagnostics of the electrical characteristics of up to 1 MJ discharges in a Mather type plasma focus geometry, such as high speed photography, X-ray, fast electron beam and time-integrated neutron measurements, there have been made among others at least three quite successful efforts recently: 1) Setting up of a neutron time-of-flight line with up to five scintillation detectors including optical fibre based data collection equipment, 2) Use of a Mechellemore » spectrometer with CCD registration and possibility to take time-resolved spectra with resolutions down to 100 ns and 3) Setting up and using pinhole cameras equipped with solid state nuclear track detectors for the detection of fusion generated protons. Correlations of emission events as well as plasma and electrical current dynamics are investigated. Neutron emission characteristics and fusion products production mechanisms are discussed considering a generalized beam target model, called Gyrating Particle Model.« less

Packaging of solid state devices

DOEpatents

Glidden, Steven C.; Sanders, Howard D.

2006-01-03

A package for one or more solid state devices in a single module that allows for operation at high voltage, high current, or both high voltage and high current. Low thermal resistance between the solid state devices and an exterior of the package and matched coefficient of thermal expansion between the solid state devices and the materials used in packaging enables high power operation. The solid state devices are soldered between two layers of ceramic with metal traces that interconnect the devices and external contacts. This approach provides a simple method for assembling and encapsulating high power solid state devices.

Coating of plasma polymerized film

NASA Technical Reports Server (NTRS)

Morita, S.; Ishibashi, S.

1980-01-01

Plasma polymerized thin film coating and the use of other coatings is suggested for passivation film, thin film used for conducting light, and solid body lubrication film of dielectrics of ultra insulators for electrical conduction, electron accessories, etc. The special features of flow discharge development and the polymerized film growth mechanism are discussed.

Fast heating of ultrahigh-density plasma as a step towards laser fusion ignition.

PubMed

Kodama, R; Norreys, P A; Mima, K; Dangor, A E; Evans, R G; Fujita, H; Kitagawa, Y; Krushelnick, K; Miyakoshi, T; Miyanaga, N; Norimatsu, T; Rose, S J; Shozaki, T; Shigemori, K; Sunahara, A; Tampo, M; Tanaka, K A; Toyama, Y; Yamanaka, T; Zepf, M

2001-08-23

Modern high-power lasers can generate extreme states of matter that are relevant to astrophysics, equation-of-state studies and fusion energy research. Laser-driven implosions of spherical polymer shells have, for example, achieved an increase in density of 1,000 times relative to the solid state. These densities are large enough to enable controlled fusion, but to achieve energy gain a small volume of compressed fuel (known as the 'spark') must be heated to temperatures of about 108 K (corresponding to thermal energies in excess of 10 keV). In the conventional approach to controlled fusion, the spark is both produced and heated by accurately timed shock waves, but this process requires both precise implosion symmetry and a very large drive energy. In principle, these requirements can be significantly relaxed by performing the compression and fast heating separately; however, this 'fast ignitor' approach also suffers drawbacks, such as propagation losses and deflection of the ultra-intense laser pulse by the plasma surrounding the compressed fuel. Here we employ a new compression geometry that eliminates these problems; we combine production of compressed matter in a laser-driven implosion with picosecond-fast heating by a laser pulse timed to coincide with the peak compression. Our approach therefore permits efficient compression and heating to be carried out simultaneously, providing a route to efficient fusion energy production.

Modeling the Transport Phenomena in the Solution Precursor Plasma Spraying

NASA Astrophysics Data System (ADS)

Shan, Yanguang

2008-10-01

Solution precursor plasma spraying has been used to produce finely structured ceramic coatings with nano- and sub-micrometric features. This process involves the injection of a solution spray of ceramic salts into a DC plasma jet under atmospheric condition. During the process, the solvent vaporizes as the droplet travel downstream. Solid particles are finally formed due to the precipitation of the solute, and the particle are heated up and accelerated to the substrate to generate the coating. This work describes a 3D model to simulate the transport phenomena and the trajectory and heating of the solution spray in the process. The jet-spray two-way interactions are considered. A simplified model is employed to simulate the evolution process and the formation of the solid particle from the solution droplet in the plasma jet. O'Rourke's droplet collision model is used to take into account of the influence of droplet collision. The influence of droplet breakup is also considered by implementing TAB droplet breakup models into the plasma jet model. The temperature and velocity fields of the jet are obtained and validated. The particle size, velocity, temperature and position distribution on the substrate are predicted.

Properties of nanostructured undoped ZrO{sub 2} thin film electrolytes by plasma enhanced atomic layer deposition for thin film solid oxide fuel cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cho, Gu Young; Noh, Seungtak; Lee, Yoon Ho

2016-01-15

Nanostructured ZrO{sub 2} thin films were prepared by thermal atomic layer deposition (ALD) and by plasma-enhanced atomic layer deposition (PEALD). The effects of the deposition conditions of temperature, reactant, plasma power, and duration upon the physical and chemical properties of ZrO{sub 2} films were investigated. The ZrO{sub 2} films by PEALD were polycrystalline and had low contamination, rough surfaces, and relatively large grains. Increasing the plasma power and duration led to a clear polycrystalline structure with relatively large grains due to the additional energy imparted by the plasma. After characterization, the films were incorporated as electrolytes in thin film solidmore » oxide fuel cells, and the performance was measured at 500 °C. Despite similar structure and cathode morphology of the cells studied, the thin film solid oxide fuel cell with the ZrO{sub 2} thin film electrolyte by the thermal ALD at 250 °C exhibited the highest power density (38 mW/cm{sup 2}) because of the lowest average grain size at cathode/electrolyte interface.« less

Hydrogen leak detection using laser-induced breakdown spectroscopy.

PubMed

Ball, A J; Hohreiter, V; Hahn, D W

2005-03-01

Laser-induced breakdown spectroscopy (LIBS) is investigated as a technique for real-time monitoring of hydrogen gas. Two methodologies were examined: The use of a 100 mJ laser pulse to create a laser-induced breakdown directly in a sample gas stream, and the use of a 55 mJ laser pulse to create a laser-induced plasma on a solid substrate surface, with the expanding plasma sampling the gas stream. Various metals were analyzed as candidate substrate surfaces, including aluminum, copper, molybdenum, stainless steel, titanium, and tungsten. Stainless steel was selected, and a detailed analysis of hydrogen detection in binary mixtures of nitrogen and hydrogen at atmospheric pressure was performed. Both the gaseous plasma and the plasma initiated on the stainless steel surface generated comparable hydrogen emission signals, using the 656.28 Halpha emission line, and exhibited excellent signal linearity. The limit of detection is about 20 ppm (mass) as determined for both methodologies, with the solid-initiated plasma yielding a slightly better value. Overall, LIBS is concluded to be a viable candidate for hydrogen sensing, offering a combination of high sensitivity with a technique that is well suited to implementation in field environments.

Altered Antioxidant System Stimulates Dielectric Barrier Discharge Plasma-Induced Cell Death for Solid Tumor Cell Treatment

PubMed Central

Park, Daehoon; Choi, Eun H.

2014-01-01

This study reports the experimental findings and plasma delivery approach developed at the Plasma Bioscience Research Center, Korea for the assessment of antitumor activity of dielectric barrier discharge (DBD) for cancer treatment. Detailed investigation of biological effects occurring after atmospheric pressure non-thermal (APNT) plasma application during in vitro experiments revealed the role of reactive oxygen species (ROS) in modulation of the antioxidant defense system, cellular metabolic activity, and apoptosis induction in cancer cells. To understand basic cellular mechanisms, we investigated the effects of APNT DBD plasma on antioxidant defense against oxidative stress in various malignant cells as well as normal cells. T98G glioblastoma, SNU80 thyroid carcinoma, KB oral carcinoma and a non-malignant HEK293 embryonic human cell lines were treated with APNT DBD plasma and cellular effects due to reactive oxygen species were observed. Plasma significantly decreased the metabolic viability and clonogenicity of T98G, SNU80, KB and HEK293 cell lines. Enhanced ROS in the cells led to death via alteration of total antioxidant activity, and NADP+/NADPH and GSH/GSSG ratios 24 hours (h) post plasma treatment. This effect was confirmed by annexin V-FITC and propidium iodide staining. These consequences suggested that the failure of antioxidant defense machinery, with compromised redox status, might have led to sensitization of the malignant cells. These findings suggest a promising approach for solid tumor therapy by delivering a lethal dose of APNT plasma to tumor cells while sparing normal healthy tissues. PMID:25068311

Multirail electromagnetic launcher powered from a pulsed magnetohydrodynamic generator

NASA Astrophysics Data System (ADS)

Afonin, A. G.; Butov, V. G.; Panchenko, V. P.; Sinyaev, S. V.; Solonenko, V. A.; Shvetsov, G. A.; Yakushev, A. A.

2015-09-01

The operation of an electromagnetic multirail launcher of solids powered from a pulsed magnetohydrodynamic (MHD) generator is studied. The plasma flow in the channel of the pulsed MHD generator and the possibility of launching solids in a rapid-fire mode of launcher operation are considered. It is shown that this mode of launcher operation can be implemented by matching the plasma flow dynamics in the channel of the pulsed MHD generator and the launching conditions. It is also shown that powerful pulsed MHD generators can be used as a source of electrical energy for rapid-fire electromagnetic rail launchers operating in a burst mode.

Kinetic Modeling of Ultraintense X-ray Laser-Matter Interactions

NASA Astrophysics Data System (ADS)

Royle, Ryan; Sentoku, Yasuhiko; Mancini, Roberto

2016-10-01

Hard x-ray free-electron lasers (XFELs) have had a profound impact on the physical, chemical, and biological sciences. They can produce millijoule x-ray laser pulses just tens of femtoseconds in duration with more than 1012 photons each, making them the brightest laboratory x-ray sources ever produced by several orders of magnitude. An XFEL pulse can be intensified to 1020 W/cm2 when focused to submicron spot sizes, making it possible to isochorically heat solid matter well beyond 100 eV. These characteristics enable XFELs to create and probe well-characterized warm and hot dense plasmas of relevance to HED science, planetary science, laboratory astrophysics, relativistic laser plasmas, and fusion research. Several newly developed atomic physics models including photoionization, Auger ionization, and continuum-lowering have been implemented in a particle-in-cell code, PICLS, which self-consistently solves the x-ray transport, to enable the simulation of the non-LTE plasmas created by ultraintense x-ray laser interactions with solid density matter. The code is validated against the results of several recent experiments and is used to simulate the maximum-intensity x-ray heating of solid iron targets. This work was supported by DOE/OFES under Contract No. DE-SC0008827.

Effect of Microstructure on the Radioluminescence and Transparency of Ce-Doped Strontium Hafnate Ceramics

PubMed Central

van Loef, Edgar V.; Wang, Yimin; Miller, Stuart R.; Brecher, Charles; Rhodes, William H.; Baldoni, Gary; Topping, Stephen; Lingertat, Helmut; Sarin, Vinod K.; Shah, Kanai S.

2011-01-01

In this paper we report on the fabrication and characterization of SrHfO3:Ce ceramics. Powders were prepared by solid-state synthesis using metal oxides and carbonates. X-ray diffraction measurements showed that phase-pure SrHfO3 is formed at 1200°C. Inductively coupled plasma spectroscopy confirmed the purity and composition of each batch. SrHfO3 exhibits several phase changes in the solid, but this does not appear to be detrimental to the ceramics. Microprobe experiments showed uniform elemental grain composition, whereas aluminum added as charge compensation for trivalent cerium congregated at grain boundaries and triple points. Radioluminescence spectra revealed that the light yield decreases when the concentration of excess Sr increases. The decrease in the light yield may be related to the change of Ce3+ into Ce4+ ions. For stoichiometric SrHfO3:Ce, the light yield is about four times that of bismuth germanate (BGO), the conventional benchmark, indicating great potential for many scintillator applications. PMID:21339835

Solid state recorders for airborne reconnaissance

NASA Astrophysics Data System (ADS)

Klang, Mark R.

2003-08-01

Solid state recorders have become the recorder of choice for meeting airborne ruggedized requirements for reconnaissance and flight test. The cost of solid state recorders have decreased over the past few years that they are now less expense than the traditional high speed tape recorders. CALCULEX, Inc manufactures solid state recorders called MONSSTR (Modular Non-volatile Solid State Recorder). MONSSTR is being used on many different platforms such as F/A-22, Global Hawk, F-14, F-15, F-16, U-2, RF-4, and Tornado. This paper will discuss the advantages of using solid state recorders to meet the airborne reconnaissance requirement and the ability to record instrumentation data. The CALCULEX recorder has the ability to record sensor data and flight test data in the same chassis. This is an important feature because it eliminates additional boxes on the aircraft. The major advantages to using a solid state recorder include; reliability, small size, light weight, and power. Solid state recorders also have a larger storage capacity and higher bandwidth capability than other recording devices.

The solid-state terahertz spectrum of MDMA (Ecstasy) - A unique test for molecular modeling assignments

NASA Astrophysics Data System (ADS)

Allis, Damian G.; Hakey, Patrick M.; Korter, Timothy M.

2008-10-01

The terahertz (THz, far-infrared) spectrum of 3,4-methylene-dioxymethamphetamine hydrochloride (Ecstasy) is simulated using solid-state density functional theory. While a previously reported isolated-molecule calculation is noteworthy for the precision of its solid-state THz reproduction, the solid-state calculation predicts that the isolated-molecule modes account for only half of the spectral features in the THz region, with the remaining structure arising from lattice vibrations that cannot be predicted without solid-state molecular modeling. The molecular origins of the internal mode contributions to the solid-state THz spectrum, as well as the proper consideration of the protonation state of the molecule, are also considered.

Shock-wave proton acceleration from a hydrogen gas jet

NASA Astrophysics Data System (ADS)

Cook, Nathan; Pogorelsky, Igor; Polyanskiy, Mikhail; Babzien, Marcus; Tresca, Olivier; Maharjan, Chakra; Shkolnikov, Peter; Yakimenko, Vitaly

2013-04-01

Typical laser acceleration experiments probe the interaction of intense linearly-polarized solid state laser pulses with dense metal targets. This interaction generates strong electric fields via Transverse Normal Sheath Acceleration and can accelerate protons to high peak energies but with a large thermal spectrum. Recently, the advancement of high pressure amplified CO2 laser technology has allowed for the creation of intense (10^16 Wcm^2) pulses at λ˜10 μm. These pulses may interact with reproducible, high rep. rate gas jet targets and still produce plasmas of critical density (nc˜10^19 cm-3), leading to the transference of laser energy via radiation pressure. This acceleration mode has the advantage of producing narrow energy spectra while scaling well with pulse intensity. We observe the interaction of an intense CO2 laser pulse with an overdense hydrogen gas jet. Using two pulse optical probing in conjunction with interferometry, we are able to obtain density profiles of the plasma. Proton energy spectra are obtained using a magnetic spectrometer and scintillating screen.

Sub-THz Imaging Using Non-Resonant HEMT Detectors.

PubMed

Delgado-Notario, Juan A; Velazquez-Perez, Jesus E; Meziani, Yahya M; Fobelets, Kristel

2018-02-10

Plasma waves in gated 2-D systems can be used to efficiently detect THz electromagnetic radiation. Solid-state plasma wave-based sensors can be used as detectors in THz imaging systems. An experimental study of the sub-THz response of II-gate strained-Si Schottky-gated MODFETs (Modulation-doped Field-Effect Transistor) was performed. The response of the strained-Si MODFET has been characterized at two frequencies: 150 and 300 GHz: The DC drain-to-source voltage transducing the THz radiation (photovoltaic mode) of 250-nm gate length transistors exhibited a non-resonant response that agrees with theoretical models and physics-based simulations of the electrical response of the transistor. When imposing a weak source-to-drain current of 5 μA, a substantial increase of the photoresponse was found. This increase is translated into an enhancement of the responsivity by one order of magnitude as compared to the photovoltaic mode, while the NEP (Noise Equivalent Power) is reduced in the subthreshold region. Strained-Si MODFETs demonstrated an excellent performance as detectors in THz imaging.

Dual-comb spectroscopy of laser-induced plasmas

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bergevin, Jenna; Wu, Tsung-Han; Yeak, Jeremy

Dual-comb spectroscopy has become a powerful spectroscopic technique in applications that rely on its broad spectral coverage combined with high frequency resolution capabilities. Experiments to date have primarily focused on detection and analysis of multiple gas species under semi-static conditions, with applications ranging from environmental monitoring of greenhouse gases to high resolution molecular spectroscopy. Here, we utilize dual-comb spectroscopy to demonstrate broadband, high-resolution, and time-resolved measurements in a laser induced plasma for the first time. As a first demonstration, we simultaneously detect trace amounts of Rb and K in solid samples with a single laser ablation shot, with transitions separatedmore » by over 6 THz (13 nm) and spectral resolution sufficient to resolve isotopic and ground state hyperfine splittings of the Rb D2 line. This new spectroscopic approach offers the broad spectral coverage found in the powerful techniques of laser-induced breakdown spectroscopy (LIBS) while providing the high-resolution and accuracy of cw laser-based spectroscopies.« less

ASCA observations of SS Cygni during an anomalous outburst

NASA Technical Reports Server (NTRS)

Nousek, John A.; Baluta, Christopher J.; Corbet, Robin H. D.; Mukai, Koji; Osborne, Julian P.; Ishida, Manabu

1994-01-01

SS Cygni was observed by the ASCA satellite on 1993 May 27, the first cataclysmic variable studied by ASCA. The observations were conducted while the system was in an outburst of the 'anomalous' variety. The SIS spectrum cannot be explained by two-temperature Raymond-Smith coronal plasma models as invoked in previous studies with lower spectral resolution. Significantly better agreement is found for models with plasma emission at kT = 0.8, 3.5 keV and thermal bremsstrahlung at kT = 18 keV. The gas imaging spectrometer (GIS) data are consistent with the solid state imaging spectrometer (SIS) data, showing evidence for Fe line emission but showing no evidence of pulsation over times ranging from seconds to minutes. These observations seem at variance with standard theory in two regards: we simultaneously see hard X-rays and optically thin soft X-rays while the system is in outburst, and we see a nonsmooth emission measure distribution. We speculate on possible scenarios which might resolve these differences.

On the implementation of a chain nuclear reaction of thermonuclear fusion on the basis of the p+11B process

NASA Astrophysics Data System (ADS)

Belyaev, V. S.; Krainov, V. P.; Zagreev, B. V.; Matafonov, A. P.

2015-07-01

Various theoretical and experimental schemes for implementing a thermonuclear reactor on the basis of the p+11B reaction are considered. They include beam collisions, fusion in degenerate plasmas, ignition upon plasma acceleration by ponderomotive forces, and the irradiation of a solid-state target from 11B with a proton beam under conditions of a Coulomb explosion of hydrogen microdrops. The possibility of employing ultra-short high-intensity laser pulses to initiate the p+11B reaction under conditions far from thermodynamic equilibrium is discussed. This and some other weakly radioactive thermonuclear reactions are promising owing to their ecological cleanness—there are virtually no neutrons among fusion products. Nuclear reactions that follow the p+11B reaction may generate high-energy protons, sustaining a chain reaction, and this is an advantage of the p+11B option. The approach used also makes it possible to study nuclear reactions under conditions close to those in the early Universe or in the interior of stars.

Design and Testing of a Small Inductive Pulsed Plasma Thruster

NASA Technical Reports Server (NTRS)

Martin, Adam K.; Dominguez, Alexandra; Eskridge, Richard H.; Polzin, Kurt A.; Riley, Daniel P.; Perdue, Kevin A.

2015-01-01

The design and testing of a small inductive pulsed plasma thruster (IPPT) is described. The device was built as a test-bed for the pulsed gas-valves and solid-state switches required for a thruster of this kind, and was designed to be modular to facilitate modification. The thruster in its present configuration consists of a multi-turn, spiral-wound acceleration coil (270 millimeters outer diameter, 100 millimeters inner diameter) driven by a 10 microfarad capacitor and switched with a high-voltage thyristor, a propellant delivery system including a fast pulsed gas-valve, and a glow-discharge pre-ionizer circuit. The acceleration coil circuit may be operated at voltages up to 4 kilovolts (the thyristor limit is 4.5 kilovolts) and the thruster operated at cyclic-rates up to 30 Herz. Initial testing of the thruster, both bench-top and in-vacuum, has been performed. Cyclic operation of the complete device was demonstrated (at 2 Herz), and a number of valuable insights pertaining to the design of these devices have been gained.

Transport Properties of La- doped SrTiO3 Ceramics Prepared Using Spark Plasma Sintering

NASA Astrophysics Data System (ADS)

Mehdizadeh Dehkordi, Arash; Bhattacharya, Sriparna; Tritt, Terry M.; Alshareef, Husam N.

2012-02-01

In this work, thermoelectric transport properties of La-doped SrTiO3 ceramics prepared using conventional solid state reaction and spark plasma sintering have been investigated. Room temperature power factor of single crystal strontium titanate (SrTiO3), comparable to that of Bi2Te3, has brought new attention to this perovskite-type transition metal-oxide as a potential n-type thermoelectric for high temperature applications. Electronic properties of this model complex oxide, SrTiO3 (ABO3), can be tuned in a wide range through different doping mechanisms. In addition to A site (La-doped) or B site (Nb-doped) substitutional doping, introducing oxygen vacancies plays an important role in electrical and thermal properties of these structures. Having multiple doping mechanisms makes the transport properties of these perovskites more dependent on preparation parameters. The effect of these synthesis parameters and consolidation conditions on the transport properties of these materials has been studied.

Strongly coupled colloidal plasmas

NASA Astrophysics Data System (ADS)

Thomas, Hubertus M.; Morfill, Gregor E.; Konopka, Uwe; Rothermel, Hermann; Zuzic, Milenko

1998-11-01

The research of strongly coupled effects in colloidal plasmas started a few years ago with the discovery of the Coulomb crystallization of micron-sized particles in a plasma. The particles are charged negatively to a few thousands of electron charges due to the flux of electrons and ions from the plasma and then react via their Coulomb-potentials. The Coulomb coupling parameter Γ - which is the ratio of the Coulomb energy between two neighboring particles to their thermal energy - could be much larger than the critical value of 172 (calculated for an one-component-plasma). That means that Coulomb-crystallization can be achieved easily. Such systems, which reach equilibrium very rapidly and can be easily tuned between their ordered and disordered states, are ideally suited for investigating the processes underlying the solid-to-liquid phase transition. Furthermore, the strongly coupled collidal plasma can be excited externally and the response can be studied in great detail dynamically. Gravity plays an important role for the production and stability of plasma crystals. In laboratory plasmas gravity has to be balanced out by the electrostatic field in the sheath of the electrodes of the experimental apparatus. Thus, in the vertical direction only monolayer crystals or crystals with a few lattice layers can be formed. This restricts the analysis to processes in 2-dimensional or ``2 1/2-dimensional'' crystals (e.g. the physics of monolayers, nano-crystals or grain boundaries). Under zero gravity larger (volume) systems are possible and the field of plasma crystal research can be extended to include the physics of 3-dimensional systems. We performed the worldwide first experiments under zero-g conditions on parabolic flights and two sounding rockets. During these experiments the behaviour of dust particles in a rf-discharge under zero-g conditions was investigated. Very interesting experiments were performed, which are possible only under low gravity conditions.

Hollow structure formation of intense ion beams with sharp edge in background plasmas

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hu, Zhang-Hu; Wang, You-Nian, E-mail: ynwang@dlut.edu.cn

The transport of intense ion beams with sharp radial beam edge in plasmas has been studied with two-dimensional electromagnetic particle simulations. The initial solid beam evolves into a hollow beam due to the nonlinear sharp transverse force peak in the regions of beam edge. The magnitude and nonlinearity of this peak are enhanced as the ion beam travels further into the plasma, due to the self-consistent interactions between the beam ions and the plasma electrons. This structure formation is shown to be independent on the beam radius.

Implications of electronic short circuiting in plasma sprayed solid oxide fuel cells on electrode performance evaluation by electrochemical impedance spectroscopy

NASA Astrophysics Data System (ADS)

White, B. D.; Kesler, O.

Electronic short circuiting of the electrolyte in a solid oxide fuel cell (SOFC) arising from flaws in the plasma spray fabrication process has been found to have a significant effect on the perceived performance of the electrodes, as evaluated by electrochemical impedance spectroscopy (EIS). The presence of a short circuit has been found to lead to the underestimation of the electrode polarization resistance (R p) and hence an overestimation of electrode performance. The effect is particularly noticeable when electrolyte resistance is relatively high, for example during low to intermediate temperature operation, leading to an obvious deviation from the expected Arrhenius-type temperature dependence of R p. A method is developed for determining the real electrode performance from measurements of various cell properties, and strategies for eliminating the occurrence of short circuiting in plasma sprayed cells are identified.

Mini-cavity plasma core reactors for dual-mode space nuclear power/propulsion systems. M.S. Thesis

NASA Technical Reports Server (NTRS)

Chow, S.

1976-01-01

A mini-cavity plasma core reactor is investigated for potential use in a dual-mode space power and propulsion system. In the propulsive mode, hydrogen propellant is injected radially inward through the reactor solid regions and into the cavity. The propellant is heated by both solid driver fuel elements surrounding the cavity and uranium plasma before it is exhausted out the nozzle. The propellant only removes a fraction of the driver power, the remainder is transferred by a coolant fluid to a power conversion system, which incorporates a radiator for heat rejection. Neutronic feasibility of dual mode operation and smaller reactor sizes than those previously investigated are shown to be possible. A heat transfer analysis of one such reactor shows that the dual-mode concept is applicable when power generation mode thermal power levels are within the same order of magnitude as direct thrust mode thermal power levels.

Role of carbon nanotube dispersion in fracture toughening of plasma sprayed aluminum oxide-carbon nanotube nanocomposite coating

NASA Astrophysics Data System (ADS)

Balani, Kantesh

Aluminum oxide (Al2O3, or alumina) is a conventional ceramic known for applications such as wear resistant coatings, thermal liners, heaters, crucibles, dielectric systems, etc. However applications of Al 2O3 are limited owing to its inherent brittleness. Due to its excellent mechanical properties and bending strength, carbon nanotubes (CNT) is an ideal reinforcement for Al2O3 matrix to improve its fracture toughness. The role of CNT dispersion in the fracture toughening of the plasma sprayed Al2O3-CNT nanocomposite coating is discussed in the current work. Pretreatment of powder feedstock is required for dispersing CNTs in the matrix. Four coatings namely spray dried Al2O 3 (A-SD), Al2O3 blended with 4wt.% CNT (A4C-B), composite spray dried Al2O3-4wt.% CNT (A4C-SD) and composite spray dried A1203-8wt.% CNT (A8C-SD), are synthesized by plasma spraying. Owing to extreme temperatures and velocities involved in the plasma spraying of ceramics, retention of CNTs in the resulting coatings necessitates optimizing plasma processing parameters using an inflight particle diagnostic sensor. A bimodal microstructure was obtained in the matrix that consists of fully melted and resolidified structure and solid state sintered structure. CNTs are retained both in the fully melted region and solid-state sintered regions of processed coatings. Fracture toughness of A-SD, A4C-B, A4C-SD and A8C-SD coatings was 3.22, 3.86, 4.60 and 5.04 MPa m1/2 respectively. This affirms the improvement of fracture toughness from 20% (in A4C-B coating) to 43% (in A4C-SD coating) when compared to the A-SD coating because of the CNT dispersion. Fracture toughness improvement from 43% (in A4C-SD) to 57% (in A8C-SD) coating is evinced because of the CNT content. Reinforcement by CNTs is described by its bridging, anchoring, hook formation, impact alignment, fusion with splat, and mesh formation. The Al2O3/CNT interface is critical in assisting the stress transfer and utilizing excellent mechanical properties of CNTs. Mathematical and computational modeling using ab-initio principle is applied to understand the wetting behavior at the Al2O 3/CNT interface. Contrasting storage modulus was obtained by nanoindentation (˜210, 250, 250-350 and 325-420 GPa in A-SD, A4C-B, A4C-SD, and A8C-SD coatings respectively) depicting the toughening associated with CNT content and dispersion.

600 eV falcon-linac thomson x-ray source

DOE Office of Scientific and Technical Information (OSTI.GOV)

Crane, J K; LeSage, G P; Ditmire, T

2000-12-15

The advent of 3rd generation light sources such as the Advanced Light Source (ALS) at LBL, and the Advanced Photon Source at Argonne, have produced a revolution in x-ray probing of dense matter during the past decade. These machines use electron-synchrotrons in conjunction with undulator stages to produce 100 psec x-ray pulses with photon energies of several kiloelectronvolts (keV). The applications for x-ray probing of matter are numerous and diverse with experiments in medicine and biology, semiconductors and materials science, and plasma and solid state physics. In spite of the success of the 3rd generation light sources there is strongmore » motivation to push the capabilities of x-ray probing into new realms, requiring shorter pulses, higher brightness and harder x-rays. A 4th generation light source, the Linac Coherent Light Source (LCLS), is being considered at the Stanford Linear Accelerator [1]. The LCLS will produce multi-kilovolt x-rays of subpicosecond duration that are 10 orders of magnitude brighter than today's 3rd generation light sources.[1] Although the LCLS will provide unprecedented capability for performing time-resolved x-ray probing of ultrafast phenomena at solid densities, this machine will not be completed for many years. In the meantime there is a serious need for an ultrashort-pulse, high-brightness, hard x-ray source that is capable of probing deep into high-Z solid materials to measure dynamic effects that occur on picosecond time scales. Such an instrument would be ideal for probing the effects of shock propagation in solids using Bragg and Laue diffraction. These techniques can be used to look at phase transitions, melting and recrystallization, and the propagation of defects and dislocations well below the surface in solid materials. [2] These types of dynamic phenomena undermine the mechanical properties of metals and are of general interest in solid state physics, materials science, metallurgy, and have specific relevance to stockpile stewardship. Another x-ray diagnostic technique, extended x-ray absorption fine structure (EXAFS) spectroscopy, can be used to measure small-scale structural changes to understand the underlying atomic physics associated with the formation of defects. [2]« less

Nuclear Reactions Studies in Laser-Plasmas at the forthcoming ELI-NP facilities

NASA Astrophysics Data System (ADS)

Lanzalone, G.; Muoio, A.; Altana, C.; Frassetto, M.; Malferrari, L.; Mascali, D.; Odorici, F.; Tudisco, S.; Gizzi, L. A.; Labate, L.; Puglia, S. M. R.; Trifirò, A.

2018-05-01

This work aim to prepare a program of studies on nuclear physics and astrophysics, which will be conducted at the new ELI-NP Laser facility, which actually is under construction in Bucharest, Romania. For the arguments treated, such activity has required also a multidisciplinary approach and knowledge in the fields of nuclear physics, astrophysics, laser and plasma physics join with also some competences on solid state physics related to the radiation detection. A part of this work has concerned to the experimental test, which have been performed in several laboratories and in order to study and increase the level of knowledge on the different parts of the project. In particular have been performed studies on the laser matter interaction at the ILIL laboratory of Pisa Italy and at the LENS laboratory in Catania, where (by using different experimental set-ups) has been investigated some key points concerning the production of the plasma stream. Test has been performed on several target configurations in terms of: composition, structure and size. All the work has been devoted to optimize the conditions of target in order to have the best performance on the production yields and on energies distribution of the inner plasma ions. A parallel activity has been performed in order to study the two main detectors, which will constitute the full detections system, which will be installed at the ELI-NP facility.

Solid state lighting devices and methods with rotary cooling structures

DOE Office of Scientific and Technical Information (OSTI.GOV)

Koplow, Jeffrey P.

Solid state lighting devices and methods for heat dissipation with rotary cooling structures are described. An example solid state lighting device includes a solid state light source, a rotating heat transfer structure in thermal contact with the solid state light source, and a mounting assembly having a stationary portion. The mounting assembly may be rotatably coupled to the heat transfer structure such that at least a portion of the mounting assembly remains stationary while the heat transfer structure is rotating. Examples of methods for dissipating heat from electrical devices, such as solid state lighting sources are also described. Heat dissipationmore » methods may include providing electrical power to a solid state light source mounted to and in thermal contact with a heat transfer structure, and rotating the heat transfer structure through a surrounding medium.« less

Plasma, The Fourth State of Matter

ERIC Educational Resources Information Center

Zandy, Hassan F.

1970-01-01

Discusses plasma as a source of energy through nuclear fission processes, as well as the difficulties encountered in such a process. States that 99 percent of the matter in the universe is plasma, and only 1 percent is the common three states of matter. Describes the fundamental properties of plasma, plasma "pinch, and plasma oscillations. (RR)

Reduction of the ionization energy for 1s-electrons in dense aluminum plasmas

NASA Astrophysics Data System (ADS)

Lin, C.; Reinholz, H.; Röpke, G.

2017-02-01

The properties of a bound multi-electron system immersed in a plasma environment are strongly modified by the surrounding plasma. In particular, the modification of the ionization energy is described by the electronic self-energy within the framework of the quantum statistical theory. We present the energy shift of the eigenstates and the lowering of the continuum edge of free electrons in a plasma. The reduction of the ionization potential is determined by their difference. This ionization potential depression for the 1s-levels in dense aluminum plasmas is calculated. Comparisons with other theories and the experimental data are shown for aluminum plasma at solid density 2.7 g/cm3.

Arbitrary electron acoustic waves in degenerate dense plasmas

NASA Astrophysics Data System (ADS)

Rahman, Ata-ur; Mushtaq, A.; Qamar, A.; Neelam, S.

2017-05-01

A theoretical investigation is carried out of the nonlinear dynamics of electron-acoustic waves in a collisionless and unmagnetized plasma whose constituents are non-degenerate cold electrons, ultra-relativistic degenerate electrons, and stationary ions. A dispersion relation is derived for linear EAWs. An energy integral equation involving the Sagdeev potential is derived, and basic properties of the large amplitude solitary structures are investigated in such a degenerate dense plasma. It is shown that only negative large amplitude EA solitary waves can exist in such a plasma system. The present analysis may be important to understand the collective interactions in degenerate dense plasmas, occurring in dense astrophysical environments as well as in laser-solid density plasma interaction experiments.

Thermosensitive In Situ Gel Based on Solid Dispersion for Rectal Delivery of Ibuprofen.

PubMed

Liu, Yangdan; Wang, Xin; Liu, Youping; Di, Xin

2018-01-01

The objective of this study was to develop a thermosensitive in situ gel based on solid dispersions (SDs) for rectal delivery of ibuprofen (IBU). Thermosensitive (poloxamer 407) and mucoadhesive (hydroxypropylmethyl cellulose E5 and sodium alginate) polymers were used to prepare the in situ gel and the sol-gel transition temperature (T sol-gel ) and gel strength were optimized. The in vitro release performance and in vivo pharmacokinetic properties of the in situ gel after their rectal administration to rabbits were investigated. Compared with the solid suppository, the cumulative release of the IBU SDs loaded in situ gel was significantly increased. The in vivo pharmacokinetics indicated that in situ gel had a higher peak plasma concentration (C max ) and area under the curve (AUC (0-∞) ) in plasma than the solid suppositories. Histopathology results showed that the IBU in situ gel given at a dose of 15 mg/kg did not produce any irritation. In conclusion, this study suggested that the in situ gel could be an effective rectal formulation for IBU.

Split Flow Online Solid-Phase Extraction Coupled with Inductively Coupled Plasma Mass Spectrometry System for One-Shot Data Acquisition of Quantification and Recovery Efficiency.

PubMed

Furukawa, Makoto; Takagai, Yoshitaka

2016-10-04

Online solid-phase extraction (SPE) coupled with inductively coupled plasma mass spectrometry (ICPMS) is a useful tool in automatic sequential analysis. However, it cannot simultaneously quantify the analytical targets and their recovery percentages (R%) in one-shot samples. We propose a system that simultaneously acquires both data in a single sample injection. The main flowline of the online solid-phase extraction is divided into main and split flows. The split flow line (i.e., bypass line), which circumvents the SPE column, was placed on the main flow line. Under program-controlled switching of the automatic valve, the ICPMS sequentially measures the targets in a sample before and after column preconcentration and determines the target concentrations and the R% on the SPE column. This paper describes the system development and two demonstrations to exhibit the analytical significance, i.e., the ultratrace amounts of radioactive strontium ( 90 Sr) using commercial Sr-trap resin and multielement adsorbability on the SPE column. This system is applicable to other flow analyses and detectors in online solid phase extraction.

The impact of food viscosity on eating rate, subjective appetite, glycemic response and gastric emptying rate.

PubMed

Zhu, Yong; Hsu, Walter H; Hollis, James H

2013-01-01

Understanding the impact of rheological properties of food on postprandial appetite and glycemic response helps to design novel functional products. It has been shown that solid foods have a stronger satiating effect than their liquid equivalent. However, whether a subtle change in viscosity of a semi-solid food would have a similar effect on appetite is unknown. Fifteen healthy males participated in the randomized cross-over study. Each participant consumed a 1690 kJ portion of a standard viscosity (SV) and a high viscosity (HV) semi-solid meal with 1000 mg acetaminophen in two separate sessions. At regular intervals during the three hours following the meal, subjective appetite ratings were measured and blood samples collected. The plasma samples were assayed for insulin, glucose-dependent insulinotropic peptide (GIP), glucose and acetaminophen. After three hours, the participants were provided with an ad libitum pasta meal. Compared with the SV meal, HV was consumed at a slower eating rate (P = 0.020), with postprandial hunger and desire to eat being lower (P = 0.019 and P<0.001 respectively) while fullness was higher (P<0.001). In addition, consuming the HV resulted in lower plasma concentration of GIP (P<0.001), higher plasma concentration of glucose (P<0.001) and delayed gastric emptying as revealed by the acetaminophen absorption test (P<0.001). However, there was no effect of food viscosity on insulin or food intake at the subsequent meal. In conclusion, increasing the viscosity of a semi-solid food modulates glycemic response and suppresses postprandial satiety, although the effect may be short-lived. A slower eating rate and a delayed gastric emptying rate can partly explain for the stronger satiating properties of high viscous semi-solid foods.

Characteristics of a non-volatile liquid propellant in liquid-fed ablative pulsed plasma thrusters

NASA Astrophysics Data System (ADS)

Ling, William Yeong Liang; Schönherr, Tony; Koizumi, Hiroyuki

2017-02-01

In the past several decades, the use of electric propulsion in spacecraft has experienced tremendous growth. With the increasing adoption of small satellites in the kilogram range, suitable propulsion systems will be necessary in the near future. Pulsed plasma thrusters (PPTs) were the first form of electric propulsion to be deployed in orbit, and are highly suitable for small satellites due to their inherent simplicity. However, their lifetime is limited by disadvantages such as carbon deposition leading to thruster failure, and complicated feeding systems required due to the conventional use of solid propellants (usually polytetrafluoroethylene (PTFE)). A promising alternative to solid propellants has recently emerged in the form of non-volatile liquids that are stable in vacuum. This study presents a broad comparison of the non-volatile liquid perfluoropolyether (PFPE) and solid PTFE as propellants on a PPT with a common design base. We show that liquid PFPE can be successfully used as a propellant, and exhibits similar plasma discharge properties to conventional solid PTFE, but with a mass bit that is an order of magnitude higher for an identical ablation area. We also demonstrate that the liquid PFPE propellant has exceptional resistance to carbon deposition, completely negating one of the major causes of thruster failure, while solid PTFE exhibited considerable carbon build-up. Energy dispersive X-ray spectroscopy was used to examine the elemental compositions of the surface deposition on the electrodes and the ablation area of the propellant (or PFPE encapsulator). The results show that based on its physical characteristics and behavior, non-volatile liquid PFPE is an extremely promising propellant for use in PPTs, with an extensive scope available for future research and development.

The Impact of Food Viscosity on Eating Rate, Subjective Appetite, Glycemic Response and Gastric Emptying Rate

PubMed Central

Zhu, Yong; Hsu, Walter H.; Hollis, James H.

2013-01-01

Understanding the impact of rheological properties of food on postprandial appetite and glycemic response helps to design novel functional products. It has been shown that solid foods have a stronger satiating effect than their liquid equivalent. However, whether a subtle change in viscosity of a semi-solid food would have a similar effect on appetite is unknown. Fifteen healthy males participated in the randomized cross-over study. Each participant consumed a 1690 kJ portion of a standard viscosity (SV) and a high viscosity (HV) semi-solid meal with 1000 mg acetaminophen in two separate sessions. At regular intervals during the three hours following the meal, subjective appetite ratings were measured and blood samples collected. The plasma samples were assayed for insulin, glucose-dependent insulinotropic peptide (GIP), glucose and acetaminophen. After three hours, the participants were provided with an ad libitum pasta meal. Compared with the SV meal, HV was consumed at a slower eating rate (P = 0.020), with postprandial hunger and desire to eat being lower (P = 0.019 and P<0.001 respectively) while fullness was higher (P<0.001). In addition, consuming the HV resulted in lower plasma concentration of GIP (P<0.001), higher plasma concentration of glucose (P<0.001) and delayed gastric emptying as revealed by the acetaminophen absorption test (P<0.001). However, there was no effect of food viscosity on insulin or food intake at the subsequent meal. In conclusion, increasing the viscosity of a semi-solid food modulates glycemic response and suppresses postprandial satiety, although the effect may be short-lived. A slower eating rate and a delayed gastric emptying rate can partly explain for the stronger satiating properties of high viscous semi-solid foods. PMID:23818981

Destruction of inorganic municipal solid waste incinerator fly ash in a DC arc plasma furnace.

PubMed

Zhao, Peng; Ni, Guohua; Jiang, Yiman; Chen, Longwei; Chen, Mingzhou; Meng, Yuedong

2010-09-15

Due to the toxicity of dioxins, furans and heavy metals, there is a growing environmental concern on municipal solid waste incinerator (MSWI) fly ash in China. The purpose of this study is directed towards the volume-reduction of fly ash without any additive by thermal plasma and recycling of vitrified slag. This process uses extremely high-temperature in an oxygen-starved environment to completely decompose complex waste into very simple molecules. For developing the proper plasma processes to treat MSWI fly ash, a new crucible-type plasma furnace was built. The melting process metamorphosed fly ash to granulated slag that was less than 1/3 of the volume of the fly ash, and about 64% of the weight of the fly ash. The safety of the vitrified slag was tested. The properties of the slag were affected by the differences in the cooling methods. Water-cooled and composite-cooled slag showed more excellent resistance against the leaching of heavy metals and can be utilized as building material without toxicity problems. Copyright 2010 Elsevier B.V. All rights reserved.

Solid phase extraction--non-aqueous capillary electrophoresis for determination of metformin, phenformin and glyburide in human plasma.

PubMed

Lai, Edward P C; Feng, Sherry Y

2006-10-20

Solid phase extraction (SPE) was coupled at line to capillary electrophoresis (CE) for the determination of three basic and neutral diabetic drugs (metformin, phenformin and glyburide) in human plasma. The SPE procedure employed a C(18) cartridge to remove most of the water and proteins from the plasma sample. Analyte detectability was increased due to trace enrichment during the SPE process. Elution of metformin, phenformin and glyburide was achieved with methanol+3% acetic acid. CE analysis was performed using a non-aqueous buffer, acetonitrile+5mM ammonium acetate+5% acetic acid, which afforded rapid separation of metformin from phenformin within 3 min. Glyburide, with a migration time longer than 6 min, did not cause any interference. The present SPE-CE method, with an electrokinetic injection time of 6s and UV detection at 240 nm, was useful for monitoring down to 1 microg/mL of metformin and phenformin in human plasma. When the electrokinetic injection time was increased to 36s, the detection limits were improved to 12 ng/mL for metformin and 6 ng/mL for phenformin.

Real-time interferometric diagnostics of rubidium plasma

NASA Astrophysics Data System (ADS)

Djotyan, G. P.; Bakos, J. S.; Kedves, M. Á.; Ráczkevi, B.; Dzsotjan, D.; Varga-Umbrich, K.; Sörlei, Zs.; Szigeti, J.; Ignácz, P.; Lévai, P.; Czitrovszky, A.; Nagy, A.; Dombi, P.; Rácz, P.

2018-03-01

A method of interferometric real-time diagnostics is developed and applied to rubidium plasma created by strong laser pulses in the femtosecond duration range at different initial rubidium vapor densities using a Michelson-type interferometer. A cosine fit with an exponentially decaying relative phase is applied to the obtained time-dependent interferometry signals to measure the density-length product of the created plasma and its recombination time constant. The presented technique may be applicable for real-time measurements of rubidium plasma dynamics in the AWAKE experiment at CERN, as well as for real-time diagnostics of plasmas created in different gaseous media and on surfaces of solid targets.

Low Temperature Plasma Science: Not Only the Fourth State of Matter but All of Them. Report of the Department of Energy Office of Fusion Energy Sciences Workshop on Low Temperature Plasmas, March 25-57, 2008

DOE Office of Scientific and Technical Information (OSTI.GOV)

None

2008-09-01

Low temperature plasma science (LTPS) is a field on the verge of an intellectual revolution. Partially ionized plasmas (often referred to as gas discharges) are used for an enormous range of practical applications, from light sources and lasers to surgery and making computer chips, among many others. The commercial and technical value of low temperature plasmas (LTPs) is well established. Modern society would simply be less advanced in the absence of LTPs. Much of this benefit has resulted from empirical development. As the technology becomes more complex and addresses new fields, such as energy and biotechnology, empiricism rapidly becomes inadequatemore » to advance the state of the art. The focus of this report is that which is less well understood about LTPs - namely, that LTPS is a field rich in intellectually exciting scientific challenges and that addressing these challenges will result in even greater societal benefit by placing the development of plasma technologies on a solid science foundation. LTPs are unique environments in many ways. Their nonequilibrium and chemically active behavior deviate strongly from fully ionized plasmas, such as those found in magnetically confined fusion or high energy density plasmas. LTPs are strongly affected by the presence of neutral species-chemistry adds enormous complexity to the plasma environment. A weakly to partially ionized gas is often characterized by strong nonequilibrium in the velocity and energy distributions of its neutral and charged constituents. In nonequilibrium LTP, electrons are generally hot (many to tens of electron volts), whereas ions and neutrals are cool to warm (room temperature to a few tenths of an electron volt). Ions and neutrals in thermal LTP can approach or exceed an electron volt in temperature. At the same time, ions may be accelerated across thin sheath boundary layers to impact surfaces, with impact energies ranging up to thousands of electron volts. These moderately energetic electrons can efficiently create reactive radical fragments and vibrationally and electronically excited species from collisions with neutral molecules. These chemically active species can produce unique structures in the gas phase and on surfaces, structures that cannot be produced in other ways, at least not in an economically meaningful way. Photons generated by electron impact excited species in the plasma can interact more or less strongly with other species in the plasma or with the plasma boundaries, or they can escape from the plasma. The presence of boundaries around the plasma creates strong gradients where plasma properties change dramatically. It is in these boundary regions where externally generated electromagnetic radiation interacts most strongly with the plasma, often producing unique responses. And it is at bounding surfaces where complex plasma-surface interactions occur. The intellectual challenges associated with LTPS center on several themes, and these are discussed in the chapters that follow this overview. These themes are plasma-surface interactions; kinetic, nonlinear properties of LTP; plasmas in multiphase media; scaling laws for LTP; and crosscutting themes: diagnostics, modeling, and fundamental data.« less

Layered composites made from bimetallic strips produced by plasma spraying of TiAl on niobium

NASA Astrophysics Data System (ADS)

Burmistrov, V. I.; Antonova, A. V.; Povarova, K. B.; Bannykh, I. O.

2007-12-01

The production and structure of a multilayer TiAl/Nb composite material made from bimetallic TiAl/Nb strips fabricated by plasma spraying of TiAl granules onto niobium plates are studied. Here, 3-mm-and 2-mm-thick plates of a layered composite material (LCM) are produced by hot isostatic pressing of a stack of 35 bimetallic plates followed by hot rolling (the total degree of reduction is 78.6 and 85.7%, respectively). The LCM consists of discontinuous TiAl layers separated by niobium layers, and the adhesion between the layers is good. Diffusional intermediate layers form at the TiAl/Nb interfaces in the 3-mm-thick LCM and consist of the following two solid solutions: an α2-Ti3Al-based solid solution contains up to 28 at % Nb, and a niobiumbased solid solution contains up to 27 at % Ti and 32 at % Al. The diffusional intermediate layers in the 2-mmthick LCM plates consist of an α2-Ti3Al-based solid solution with up to 16.0 at % Nb; a τ-Ti3Al2Nb-or Ti4Al3Nb-based solid solution with 51.5 at % Ti, 32 at % Al, and 16.5 at % Nb; and a niobium-based solid solution with up to 22 at % Ti and 30.5 at % Al. When a bimetallic TiAl/Nb strip is fabricated by plasma spraying of granules of the Ti-48 at % Al alloy, this alloy is depleted of aluminum to 42 45 at %, and the fraction of the α2-Ti3Al phase in the sprayed layer increases. When the LCM is produced by hot isostatic pressing followed by hot rolling, the layer of plain niobium (Nb1) dissolves up to 5 at % Ti and 7 at % Al.

Architecture and method for a burst buffer using flash technology

DOEpatents

Tzelnic, Percy; Faibish, Sorin; Gupta, Uday K.; Bent, John; Grider, Gary Alan; Chen, Hsing-bung

2016-03-15

A parallel supercomputing cluster includes compute nodes interconnected in a mesh of data links for executing an MPI job, and solid-state storage nodes each linked to a respective group of the compute nodes for receiving checkpoint data from the respective compute nodes, and magnetic disk storage linked to each of the solid-state storage nodes for asynchronous migration of the checkpoint data from the solid-state storage nodes to the magnetic disk storage. Each solid-state storage node presents a file system interface to the MPI job, and multiple MPI processes of the MPI job write the checkpoint data to a shared file in the solid-state storage in a strided fashion, and the solid-state storage node asynchronously migrates the checkpoint data from the shared file in the solid-state storage to the magnetic disk storage and writes the checkpoint data to the magnetic disk storage in a sequential fashion.

Development of a Simple and Rapid Method to Measure the Free Fraction of Tacrolimus in Plasma Using Ultrafiltration and LC-MS/MS.

PubMed

Stienstra, Nicolaas A; Sikma, Maaike A; van Dapperen, Anouk L; de Lange, Dylan W; van Maarseveen, Erik M

2016-12-01

Tacrolimus is an immunosuppressant mainly used in the prophylaxis of solid organ transplant rejection. Therapeutic drug monitoring of tacrolimus is essential for avoiding toxicity related to overexposure and transplant rejection from underexposure. Previous studies suggest that unbound tacrolimus concentrations in the plasma may serve as a better predictor of tacrolimus-associated nephrotoxicity and neurotoxicity compared to tacrolimus concentration in whole blood. Monitoring the plasma concentrations of unbound tacrolimus might be of interest in preventing tacrolimus-related toxicity. Therefore, the aim was to develop a method for the measurement of total and unbound tacrolimus concentrations in plasma. The sample preparation for the determination of the plasma concentrations of unbound tacrolimus consisted of an easy-to-use ultrafiltration method followed by solid-phase extraction. To determine the total concentration of tacrolimus in plasma, a simple method based on protein precipitation was developed. The extracts were injected into a Thermo Scientific HyPurity C18 column using gradient elution. The analytes were detected by liquid chromatography-tandem mass spectrometry with positive ionization. The method was validated over a linear range of 1.00-200 ng/L for unbound tacrolimus concentrations in plasma and 100-3200 ng/L for total plasma concentrations. The lower limit of quantification was 1.00 ng/L in ultrafiltrate and 100 ng/L in plasma. The inaccuracy and imprecision for the determination of unbound tacrolimus concentrations in ultrafiltrate and plasma showed a maximum coefficients of variation (CV) of 11.7% and a maximum bias of 3.8%. A rapid and easy method based on ultrafiltration and liquid chromatography-tandem mass spectrometry was established to measure the total and unbound tacrolimus concentrations in plasma. This method can facilitate further investigations on the relationship between plasma concentrations of unbound tacrolimus and clinical outcomes in transplant recipients.

Electrical Conductivity of Dense Al, Ti, Fe, Ni, Cu, Mo, Ta, and W Plasmas

DTIC Science & Technology

2011-06-01

for all but tantalum and titanium shows a minimum at approximately 0.01 times solid density, followed by an increase as the density decreases further...internal energy and specific volume. Conductivity is observed to fall as the plasma expands for fixed internal energy, and for all but tantalum and...plasmas formed from elemental metal wires heated rapidly in a water bath by the electric current from discharge of a charged capacitor . Electrical

X-ray Emission Characteristics of Ultra-High Energy Density Relativistic Plasmas Created by Ultrafast Laser Irradiation of Nanowire Arrays

NASA Astrophysics Data System (ADS)

Hollinger, R. C.; Bargsten, C.; Shlyaptsev, V. N.; Pukhov, A.; Purvis, M. A.; Townsend, A.; Keiss, D.; Wang, Y.; Wang, S.; Prieto, A.; Rocca, J. J.

2014-10-01

Irradiation of ordered nanowire arrays with high contrast femtosecond laser pulses of relativistic intensity creates volumetrically heated near solid density plasmas characterized by multi-KeV temperatures and extreme degrees of ionization. The large hydrodynamic-to-radiative lifetime ratio of these plasmas results in very efficient X-ray generation. Au nanowire array plasmas irradiated at I 5×1018 Wcm-2 are measured to convert ~ 5 percent of the laser energy into h ν > 0.9 KeV X-rays, and >1 × 10-4 into h ν > 9 KeV photons, creating bright picosecond X-ray sources. The angular distribution of the higher energy photons is measured to change from isotropic into annular as the intensity increases, while softer X-ray emission (h ν >1 KeV) remains isotropic and nearly unchanged. Model simulations suggest the unexpected annular distribution of the hard X-rays might result from bremsstrahlung of fast electrons confined in a high aspect ratio near solid density plasma in which the electron-ion collision mean free-path is of the order of the plasma thickness. Work supported by the U.S Department of Energy, Fusion Energy Sciences and the Defense Threat Reduction Agency Grant HDTRA-1-10-1-0079. A.P was supported by of DFG-funded project TR18.

Integration of acoustic radiation force and optical imaging for blood plasma clot stiffness measurement.

PubMed

Wang, Caroline W; Perez, Matthew J; Helmke, Brian P; Viola, Francesco; Lawrence, Michael B

2015-01-01

Despite the life-preserving function blood clotting serves in the body, inadequate or excessive blood clot stiffness has been associated with life-threatening diseases such as stroke, hemorrhage, and heart attack. The relationship between blood clot stiffness and vascular diseases underscores the importance of quantifying the magnitude and kinetics of blood's transformation from a fluid to a viscoelastic solid. To measure blood plasma clot stiffness, we have developed a method that uses ultrasound acoustic radiation force (ARF) to induce micron-scaled displacements (1-500 μm) on microbeads suspended in blood plasma. The displacements were detected by optical microscopy and took place within a micro-liter sized clot region formed within a larger volume (2 mL sample) to minimize container surface effects. Modulation of the ultrasound generated acoustic radiation force allowed stiffness measurements to be made in blood plasma from before its gel point to the stage where it was a fully developed viscoelastic solid. A 0.5 wt % agarose hydrogel was 9.8-fold stiffer than the plasma (platelet-rich) clot at 1 h post-kaolin stimulus. The acoustic radiation force microbead method was sensitive to the presence of platelets and strength of coagulation stimulus. Platelet depletion reduced clot stiffness 6.9 fold relative to platelet rich plasma. The sensitivity of acoustic radiation force based stiffness assessment may allow for studying platelet regulation of both incipient and mature clot mechanical properties.

The THS Experiment: Simulating Titans Atmospheric Chemistry at Low Temperature (200K)

NASA Technical Reports Server (NTRS)

Sciamma-O'Brien, Ella; Upton, Kathleen; Beauchamp, Jack L.; Salama, Farid; Contreras, Cesar Sanchez; Bejaoui, Salma; Foing, Bernard; Pascale, Ehrenfreund

2015-01-01

In Titan's atmosphere, composed mainly of N2 (95-98%) and CH4 (2-5%), a complex chemistry occurs at low temperature, and leads to the production of heavy organic molecules and subsequently solid aerosols. Here, we used the Titan Haze Simulation (THS) experiment, an experimental setup developed at the NASA Ames COSmIC simulation facility to study Titan's atmospheric chemistry at low temperature. In the THS, the chemistry is simulated by plasma in the stream of a supersonic expansion. With this unique design, the gas is cooled to Titan-like temperature ( approximately 150K) before inducing the chemistry by plasma, and remains at low temperature in the plasma discharge (approximately 200K). Different N2-CH4-based gas mixtures can be injected in the plasma, with or without the addition of heavier precursors present as trace elements on Titan, in order to monitor the evolution of the chemical growth. Both the gas- and solid phase products resulting from the plasma-induced chemistry can be monitored and analyzed using a combination of complementary in situ and ex situ diagnostics. A recent mass spectrometry[1] study of the gas phase has demonstrated that the THS is a unique tool to probe the first and intermediate steps of Titan's atmospheric chemistry at Titan-like temperature. In particular, the mass spectra obtained in a N2-CH4-C2H2-C6H6 mixture are relevant for comparison to Cassini's CAPS-IBS instrument. The results of a complementary study of the solid phase are consistent with the chemical growth evolution observed in the gas phase. Grains and aggregates form in the gas phase and can be jet deposited on various substrates for ex situ analysis. Scanning Electron Microscopy images show that more complex mixtures produce larger aggregates. A mass spectrometry analysis of the solid phase has detected the presence of aminoacetonitrile, a precursor of glycine, in the THS aerosols. X-ray Absorption Near Edge Structure (XANES) measurements also show the presence of imine and nitrile functional groups, showing evidence of nitrogen chemistry. These complementary studies show the high potential of THS to better understand Titan's chemistry and the origin of aerosol formation.

High coupling efficiency of foam spherical hohlraum driven by 2ω laser light

NASA Astrophysics Data System (ADS)

Chen, Yao-Hua; Lan, Ke; Zheng, Wanguo; Campbell, E. M.

2018-02-01

The majority of solid state laser facilities built for laser fusion research irradiate targets with third harmonic light (0.35 μm) up-converted from the fundamental Nd wavelength at 1.05 μm. The motivation for this choice of wavelength is improved laser-plasma coupling. Significant disadvantages to this choice of wavelength are the reduced damage threshold of optical components and the efficiency of energy conversion to third harmonic light. Both these issues are significantly improved if second harmonic (0.53 μm) radiation is used, but theory and experiments have shown lower optical to x-ray energy conversion efficiency and increased levels of laser-plasma instabilities, resulting in reduced laser-target coupling. In this letter, we propose to use a 0.53 μm laser for the laser ignition facilities and use a low density foam wall to increase the coupling efficiency from the laser to the capsule and present two-dimensional radiation-hydrodynamic simulations of 0.53 μm laser light irradiating an octahedral-spherical hohlraum with a low density foam wall. The simulations show that the reduced optical depth of the foam wall leads to an increased laser-light conversion into thermal x-rays and about 10% higher radiation flux on the capsule than that achieved with 0.35 μm light irradiating a solid density wall commonly used in laser indirect drive fusion research. The details of the simulations and their implications and suggestions for wavelength scaling coupled with innovative hohlraum designs will be discussed.

The quantum pinch effect in semiconducting quantum wires: A bird’s-eye view

NASA Astrophysics Data System (ADS)

Kushwaha, Manvir S.

2016-01-01

Those who measure success with culmination do not seem to be aware that life is a journey not a destination. This spirit is best reflected in the unceasing failures in efforts for solving the problem of controlled thermonuclear fusion for even the simplest pinches for over decades; and the nature keeps us challenging with examples. However, these efforts have permitted researchers the obtention of a dense plasma with a lifetime that, albeit short, is sufficient to study the physics of the pinch effect, to create methods of plasma diagnostics, and to develop a modern theory of plasma processes. Most importantly, they have impregnated the solid state plasmas, particularly the electron-hole plasmas in semiconductors, which do not suffer from the issues related with the confinement and which have demonstrated their potential not only for the fundamental physics but also for the device physics. Here, we report on a two-component, cylindrical, quasi-one-dimensional quantum plasma subjected to a radial confining harmonic potential and an applied magnetic field in the symmetric gauge. It is demonstrated that such a system, as can be realized in semiconducting quantum wires, offers an excellent medium for observing the quantum pinch effect at low temperatures. An exact analytical solution of the problem allows us to make significant observations: Surprisingly, in contrast to the classical pinch effect, the particle density as well as the current density display a determinable maximum before attaining a minimum at the surface of the quantum wire. The effect will persist as long as the equilibrium pair density is sustained. Therefore, the technological promise that emerges is the route to the precise electronic devices that will control the particle beams at the nanoscale.

Trapped nonneutral plasmas, liquids, and crystals (the thermal equilibrium states)

NASA Astrophysics Data System (ADS)

Dubin, Daniel H.; O'neil, T. M.

1999-01-01

Plasmas consisting exclusively of particles with a single sign of charge (e.g., pure electron plasmas and pure ion plasmas) can be confined by static electric and magnetic fields (in a Penning trap) and also be in a state of global thermal equilibrium. This important property distinguishes these totally unneutralized plasmas from neutral and quasineutral plasmas. This paper reviews the conditions for, and the structure of, the thermal equilibrium states. Both theory and experiment are discussed, but the emphasis is decidedly on theory. It is a huge advantage to be able to use thermal equilibrium statistical mechanics to describe the plasma state. Such a description is easily obtained and complete, including for example the details of the plasma shape and microscopic order. Pure electron and pure ion plasmas are routinely confined for hours and even days, and thermal equilibrium states are observed. These plasmas can be cooled to the cryogenic temperature range, where liquid and crystal-like states are realized. The authors discuss the structure of the correlated states separately for three plasma sizes: large plasmas, in which the free energy is dominated by the bulk plasma; mesoscale plasmas, in which the free energy is strongly influenced by the surface; and Coulomb clusters, in which the number of particles is so small that the canonical ensemble is not a good approximation for the microcanonical ensemble. All three cases have been studied through numerical simulations, analytic theory, and experiment. In addition to describing the structure of the thermal equilibrium states, the authors develop a thermodynamic theory of the trapped plasma system. Thermodynamic inequalities and Maxwell relations provide useful bounds on and general relationships between partial derivatives of the various thermodynamic variables.

Task 2: Flight prototype system design report, pulsed plasma solid propellant microthruster for the Synchronous Meteorological Satellite

NASA Technical Reports Server (NTRS)

Guman, W. J. (Editor)

1972-01-01

Design details are presented of the solid propellant pulsed plasma microthruster which was analyzed during the Task 1 effort. The design details presented show that the inherent functional simplicity underlying the flight proven LES-6 design can be maintained in the SMS systems design even with minimum weight constraints imposed. A 1293 hour uninterrupted vacuum test with the engineering thermal model, simulating an 18.8 to 33 g environment of the propellant, its feed system and electrode assembly, revealed that program thruster performance requirements could be met. This latter g environment is a more severe environment than will be ever encountered in the SMS spacecraft.

Experimental Investigation of the Properties of an Acoustic Wave Induced by Laser Ablation of a Solid Target in Water-Confined Plasma Propulsion

NASA Astrophysics Data System (ADS)

Zheng, Zhiyuan; Gao, Hua; Gao, Lu; Xing, Jie

2014-11-01

Acoustic waves generated in nanosecond pulsed-laser ablation of a solid target in both air and water-confined environments were measured experimentally. It was found that the amplitude of the acoustic wave tended to decrease with an increase in water thickness. The waves were analyzed by means of fast Fourier transform. It was shown that there are several frequency components in the acoustic waves with the dominant frequency shifting from high frequency to low frequency as the thickness of the water layer increases. Furthermore, strong acoustic pressure led to enhancement of the coupling of the laser energy to the target in laser plasma propulsion.

Visualization of expanding warm dense gold and diamond heated rapidly by laser-generated ion beams

DOE PAGES

Bang, W.; Albright, B. J.; Bradley, P. A.; ...

2015-09-22

With the development of several novel heating sources, scientists can now heat a small sample isochorically above 10,000 K. Although matter at such an extreme state, known as warm dense matter, is commonly found in astrophysics (e.g., in planetary cores) as well as in high energy density physics experiments, its properties are not well understood and are difficult to predict theoretically. This is because the approximations made to describe condensed matter or high-temperature plasmas are invalid in this intermediate regime. A sufficiently large warm dense matter sample that is uniformly heated would be ideal for these studies, but has beenmore » unavailable to date. We have used a beam of quasi-monoenergetic aluminum ions to heat gold and diamond foils uniformly and isochorically. For the first time, we visualized directly the expanding warm dense gold and diamond with an optical streak camera. Furthermore, we present a new technique to determine the initial temperature of these heated samples from the measured expansion speeds of gold and diamond into vacuum. We anticipate the uniformly heated solid density target will allow for direct quantitative measurements of equation-of-state, conductivity, opacity, and stopping power of warm dense matter, benefiting plasma physics, astrophysics, and nuclear physics.« less

Visualization of expanding warm dense gold and diamond heated rapidly by laser-generated ion beams.

PubMed

Bang, W; Albright, B J; Bradley, P A; Gautier, D C; Palaniyappan, S; Vold, E L; Santiago Cordoba, M A; Hamilton, C E; Fernández, J C

2015-09-22

With the development of several novel heating sources, scientists can now heat a small sample isochorically above 10,000 K. Although matter at such an extreme state, known as warm dense matter, is commonly found in astrophysics (e.g., in planetary cores) as well as in high energy density physics experiments, its properties are not well understood and are difficult to predict theoretically. This is because the approximations made to describe condensed matter or high-temperature plasmas are invalid in this intermediate regime. A sufficiently large warm dense matter sample that is uniformly heated would be ideal for these studies, but has been unavailable to date. Here we have used a beam of quasi-monoenergetic aluminum ions to heat gold and diamond foils uniformly and isochorically. For the first time, we visualized directly the expanding warm dense gold and diamond with an optical streak camera. Furthermore, we present a new technique to determine the initial temperature of these heated samples from the measured expansion speeds of gold and diamond into vacuum. We anticipate the uniformly heated solid density target will allow for direct quantitative measurements of equation-of-state, conductivity, opacity, and stopping power of warm dense matter, benefiting plasma physics, astrophysics, and nuclear physics.

Visualization of expanding warm dense gold and diamond heated rapidly by laser-generated ion beams

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bang, W.; Albright, B. J.; Bradley, P. A.

With the development of several novel heating sources, scientists can now heat a small sample isochorically above 10,000 K. Although matter at such an extreme state, known as warm dense matter, is commonly found in astrophysics (e.g., in planetary cores) as well as in high energy density physics experiments, its properties are not well understood and are difficult to predict theoretically. This is because the approximations made to describe condensed matter or high-temperature plasmas are invalid in this intermediate regime. A sufficiently large warm dense matter sample that is uniformly heated would be ideal for these studies, but has beenmore » unavailable to date. We have used a beam of quasi-monoenergetic aluminum ions to heat gold and diamond foils uniformly and isochorically. For the first time, we visualized directly the expanding warm dense gold and diamond with an optical streak camera. Furthermore, we present a new technique to determine the initial temperature of these heated samples from the measured expansion speeds of gold and diamond into vacuum. We anticipate the uniformly heated solid density target will allow for direct quantitative measurements of equation-of-state, conductivity, opacity, and stopping power of warm dense matter, benefiting plasma physics, astrophysics, and nuclear physics.« less

Visualization of expanding warm dense gold and diamond heated rapidly by laser-generated ion beams

NASA Astrophysics Data System (ADS)

Bang, W.; Albright, B. J.; Bradley, P. A.; Gautier, D. C.; Palaniyappan, S.; Vold, E. L.; Cordoba, M. A. Santiago; Hamilton, C. E.; Fernández, J. C.

2015-09-01

With the development of several novel heating sources, scientists can now heat a small sample isochorically above 10,000 K. Although matter at such an extreme state, known as warm dense matter, is commonly found in astrophysics (e.g., in planetary cores) as well as in high energy density physics experiments, its properties are not well understood and are difficult to predict theoretically. This is because the approximations made to describe condensed matter or high-temperature plasmas are invalid in this intermediate regime. A sufficiently large warm dense matter sample that is uniformly heated would be ideal for these studies, but has been unavailable to date. Here we have used a beam of quasi-monoenergetic aluminum ions to heat gold and diamond foils uniformly and isochorically. For the first time, we visualized directly the expanding warm dense gold and diamond with an optical streak camera. Furthermore, we present a new technique to determine the initial temperature of these heated samples from the measured expansion speeds of gold and diamond into vacuum. We anticipate the uniformly heated solid density target will allow for direct quantitative measurements of equation-of-state, conductivity, opacity, and stopping power of warm dense matter, benefiting plasma physics, astrophysics, and nuclear physics.

Review—Practical Challenges Hindering the Development of Solid State Li Ion Batteries

DOE PAGES

Kerman, Kian; Luntz, Alan; Viswanathan, Venkatasubramanian; ...

2017-06-09

Solid state electrolyte systems boasting Li+ conductivity of >10 mS cm -1 at room temperature have opened the potential for developing a solid state battery with power and energy densities that are competitive with conventional liquid electrolyte systems. The primary focus of this review is twofold. First, differences in Li penetration resistance in solid state systems are discussed, and kinetic limitations of the solid state interface are highlighted. Second, technological challenges associated with processing such systems in relevant form factors are elucidated, and architectures needed for cell level devices in the context of product development are reviewed. Specific research vectorsmore » that provide high value to advancing solid state batteries are outlined and discussed.« less

Solid state division progress report, period ending February 29, 1980

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1980-09-01

Research is reported concerning theoretical solid state physics; surface and near-surface properties of solids; defects in solids; transport properties of solids; neutron scattering; crystal growth and characterization; and isotope research materials.

Gaseous fuel nuclear reactor research

NASA Technical Reports Server (NTRS)

Schwenk, F. C.; Thom, K.

1975-01-01

Gaseous-fuel nuclear reactors are described; their distinguishing feature is the use of fissile fuels in a gaseous or plasma state, thereby breaking the barrier of temperature imposed by solid-fuel elements. This property creates a reactor heat source that may be able to heat the propellant of a rocket engine to 10,000 or 20,000 K. At this temperature level, gas-core reactors would provide the breakthrough in propulsion needed to open the entire solar system to manned and unmanned spacecraft. The possibility of fuel recycling makes possible efficiencies of up to 65% and nuclear safety at reduced cost, as well as high-thrust propulsion capabilities with specific impulse up to 5000 sec.

Universal linear and nonlinear electrodynamics of a Dirac fluid

NASA Astrophysics Data System (ADS)

Sun, Zhiyuan; Basov, Dmitry N.; Fogler, Michael M.

2018-03-01

A general relation is derived between the linear and second-order nonlinear ac conductivities of an electron system in the hydrodynamic regime of frequencies below the interparticle scattering rate. The magnitude and tensorial structure of the hydrodynamic nonlinear conductivity are shown to differ from their counterparts in the more familiar kinetic regime of higher frequencies. Due to universality of the hydrodynamic equations, the obtained formulas are valid for systems with an arbitrary Dirac-like dispersion, ranging from solid-state electron gases to free-space plasmas, either massive or massless, at any temperature, chemical potential, or space dimension. Predictions for photon drag and second-harmonic generation in graphene are presented as one application of this theory.

Steady state compact toroidal plasma production

DOEpatents

Turner, William C.

1986-01-01

Apparatus and method for maintaining steady state compact toroidal plasmas. A compact toroidal plasma is formed by a magnetized coaxial plasma gun and held in close proximity to the gun electrodes by applied magnetic fields or magnetic fields produced by image currents in conducting walls. Voltage supply means maintains a constant potential across the electrodes producing an increasing magnetic helicity which drives the plasma away from a minimum energy state. The plasma globally relaxes to a new minimum energy state, conserving helicity according to Taylor's relaxation hypothesis, and injecting net helicity into the core of the compact toroidal plasma. Controlling the voltage so as to inject net helicity at a predetermined rate based on dissipative processes maintains or increases the compact toroidal plasma in a time averaged steady state mode.

Solid matrix transformation and tracer addition using molten ammonium bifluoride salt as a sample preparation method for laser ablation inductively coupled plasma mass spectrometry.

PubMed

Grate, Jay W; Gonzalez, Jhanis J; O'Hara, Matthew J; Kellogg, Cynthia M; Morrison, Samuel S; Koppenaal, David W; Chan, George C-Y; Mao, Xianglei; Zorba, Vassilia; Russo, Richard E

2017-09-08

Solid sampling and analysis methods, such as laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS), are challenged by matrix effects and calibration difficulties. Matrix-matched standards for external calibration are seldom available and it is difficult to distribute spikes evenly into a solid matrix as internal standards. While isotopic ratios of the same element can be measured to high precision, matrix-dependent effects in the sampling and analysis process frustrate accurate quantification and elemental ratio determinations. Here we introduce a potentially general solid matrix transformation approach entailing chemical reactions in molten ammonium bifluoride (ABF) salt that enables the introduction of spikes as tracers or internal standards. Proof of principle experiments show that the decomposition of uranium ore in sealed PFA fluoropolymer vials at 230 °C yields, after cooling, new solids suitable for direct solid sampling by LA. When spikes are included in the molten salt reaction, subsequent LA-ICP-MS sampling at several spots indicate that the spikes are evenly distributed, and that U-235 tracer dramatically improves reproducibility in U-238 analysis. Precisions improved from 17% relative standard deviation for U-238 signals to 0.1% for the ratio of sample U-238 to spiked U-235, a factor of over two orders of magnitude. These results introduce the concept of solid matrix transformation (SMT) using ABF, and provide proof of principle for a new method of incorporating internal standards into a solid for LA-ICP-MS. This new approach, SMT-LA-ICP-MS, provides opportunities to improve calibration and quantification in solids based analysis. Looking forward, tracer addition to transformed solids opens up LA-based methods to analytical methodologies such as standard addition, isotope dilution, preparation of matrix-matched solid standards, external calibration, and monitoring instrument drift against external calibration standards.

Environmental and economic vision of plasma treatment of waste in Makkah

NASA Astrophysics Data System (ADS)

Galaly, Ahmed Rida; van Oost, Guido

2017-10-01

An environmental and economic assessment of the development of a plasma-chemical reactor equipped with plasma torches for the environmentally friendly treatment of waste streams by plasma is outlined with a view to the chemical and energetic valorization of the sustainability in the Kingdom of Saudi Arabia (KSA). This is especially applicable in the pilgrimage season in the city of Makkah, which is a major challenge since the amount of waste was estimated at about 750 thousand tons through Arabic Year 1435H (2015), and is growing at a rate of 3%-5% annually. According to statistics, the value of waste in Saudi Arabia ranges between 8 and 9 billion EUR. The Plasma-Treatment Project (PTP) encompasses the direct plasma treatment of all types of waste (from source and landfill), as well as an environmental vision and economic evaluation of the use of the gas produced for fuel and electricity production in KSA, especially in the pilgrimage season in the holy city Makkah. The electrical power required for the plasma-treatment process is estimated at 5000 kW (2000 kW used for the operation of the system and 3000 kW sold), taking into account the fact that: (1) the processing capacity of solid waste is 100 tons per day (2) and the sale of electricity amounts to 23.8 MW at 0.18 EUR per kWh. (3) The profit from the sale of electricity per year is estimated at 3.27 million EUR and the estimated profit of solid-waste treatment amounts to 6 million EUR per year and (4) the gross profit per ton of solid waste totals 8 million EUR per year. The present article introduces the first stage of the PTP, in Makkah in the pilgrimage season, which consists of five stages: (1) study and treatment of waste streams, (2) slaughterhouse waste treatment, (3) treatment of refuse-derived fuel, (4) treatment of car tires and (5) treatment of slag (the fifth stage associated with each stage from the four previous stages).

Hydrophilic interaction liquid chromatography-solid phase extraction directly combined with protein precipitation for the determination of triptorelin in plasma.

PubMed

Wang, Jixia; Kong, Song; Yan, Jingyu; Jin, Gaowa; Guo, Zhimou; Shen, Aijin; Xu, Junyan; Zhang, Xiuli; Zou, Lijuan; Liang, Xinmiao

2014-06-01

Peptide drugs play a critical role in therapeutic treatment. However, as the complexity of plasma, determination of peptide drugs using liquid chromatography-tandem mass spectrometry (LC-MS/MS) is a daunting task. To solve this problem, hydrophilic interaction liquid chromatography-solid phase extraction (HILIC-SPE) directly combined with protein precipitation (PPT) was developed for the selective extraction of triptorelin from plasma. The extracts were analyzed by reversed-phase liquid chromatography (RPLC). Proteins, phospholipids and highly polar interferences could be removed from plasma by the efficient combination of PPT, HILIC-SPE and RPLC-MS/MS. This method was evaluated by matrix effect, recovery and process efficiency at different concentration levels (50, 500 and 5,000 ng/mL) of triptorelin. Furthermore, the performance of HILIC-SPE was compared with that of reversed-phase C18 SPE and hydrophilic lipophilic balance (Oasis HLB) SPE. Among them, HILIC-SPE provided the minimum matrix effect (ranging from 96.02% to 103.41%), the maximum recovery (ranging from 80.68% to 90.54%) and the satisfactory process efficiency (ranging from 82.83% to 92.95%). The validated method was successfully applied to determine triptorelin in rat plasma. Copyright © 2014 Elsevier B.V. All rights reserved.

Direct injection of liquids into low pressure plasmas

NASA Astrophysics Data System (ADS)

Goeckner, Matthew; Ogawa, Daisuke; Timmons, Richard; Overzet, Lawrence; Sanchez, Sam

2006-10-01

Being forced to use only gaseous precursors in plasma processing reactors is a significant and irrational limitation. Only a small minority of the molecules that could prove useful can be put into the vapor phase. On the other hand, a much greater fraction can be put into solution. We have found that by using a simple fuel injector directly coupled to a heated reactor, one can inject a variety of liquids directly into the plasma environment. A temperature controlled capillary tube can be used to accomplish the same thing. The liquids can also have a variety of solids dispersed in them: metals, dielectrics, aromatics, proteins, viruses, etc. While we have not had time yet to do detailed studies on a very wide range of liquids and dispersed solids, we do have the proof of principle. We have made films from injecting 1] ethanol, 2] hexane 3] iron nanoparticles dispersed in hexane and 4] ferrocene dissolved in benzene into capacitively coupled plasmas at approximately 50 mTorr. The details of the reactor and the films produced to date will be explained in the poster. Briefly: we use capacitively coupled plasma sources. Typical pressures are well below 1 Torr and powers below 10 Watts. The hexane films have growth rates around 10 nm/min.

On the improvement of signal repeatability in laser-induced air plasmas

NASA Astrophysics Data System (ADS)

Zhang, Shuai; Sheta, Sahar; Hou, Zong-Yu; Wang, Zhe

2018-04-01

The relatively low repeatability of laser-induced breakdown spectroscopy (LIBS) severely hinders its wide commercialization. In the present work, we investigate the optimization of LIBS system for repeatability improvement for both signal generation (plasma evolution) and signal collection. Timeintegrated spectra and images were obtained under different laser energies and focal lengths to investigate the optimum configuration for stable plasmas and repeatable signals. Using our experimental setup, the optimum conditions were found to be a laser energy of 250 mJ and a focus length of 100 mm. A stable and homogeneous plasma with the largest hot core area in the optimum condition yielded the most stable LIBS signal. Time-resolved images showed that the rebounding processes through the air plasma evolution caused the relative standard deviation (RSD) to increase with laser energies of > 250 mJ. In addition, the emission collection was improved by using a concave spherical mirror. The line intensities doubled as their RSDs decreased by approximately 25%. When the signal generation and collection were optimized simultaneously, the pulse-to-pulse RSDs were reduced to approximately 3% for O(I), N(I), and H(I) lines, which are better than the RSDs reported for solid samples and showed great potential for LIBS quantitative analysis by gasifying the solid or liquid samples.

The COSmIC/THS experiment: gas and solid phase studies of Titan aerosol simulants produced at cold temperature

NASA Astrophysics Data System (ADS)

Sciamma-OBrien, E. M.; Upton, K.; Beauchamp, J. L.; Salama, F.

2013-12-01

In Titan's atmosphere, a complex chemistry between N2 and CH4 occurs at temperatures lower than 200K and leads to the production of heavy molecules and subsequently solid aerosols that form the haze surrounding Titan. The Titan Haze Simulation (THS) experiment has been developed at the NASA Ames COSmIC facility to study Titan's atmospheric chemistry at low temperature, and in particular to study the chemical pathways that link the simple molecules resulting from the first steps of the N2-CH4 chemistry to benzene, and to PAHs and nitrogen-containing PAHs (PANHs), potential precursors to Titan's solid aerosols. In the COSmIC/THS, the chemistry is simulated by plasma in the stream of a supersonic expansion. With this unique design, the gas is jet-cooled to Titan-like temperature (~150K) before inducing the chemistry by plasma, and remains at low temperature in the plasma discharge (~200K measured by optical emission spectroscopy). Different N2-CH4-based gas mixtures can be injected in the plasma, with or without the addition of trace elements present on Titan. Both the gas phase and solid phase products resulting from the plasma-induced chemistry can be monitored and analyzed using a combination of complementary in situ and ex situ diagnostics: Cavity Ring Down Spectroscopy and Time-Of-Flight Mass Spectrometry (TOF-MS) for the gas phase; Direct Analysis in Real Time Mass Spectrometry (DART-MS), Gas Chromatography-Mass Spectrometry (GC-MS), Scanning Electron Microscopy (SEM), Raman spectroscopy, Nuclear Magnetic Resonance (NMR) and Infrared (IR) spectroscopy for the solid phase. Previous TOF-MS mass spectrometry analyses of the gas phase have demonstrated that the COSmIC/THS experiment can be used to study the first and intermediate steps as well as specific chemical pathways of Titan's atmospheric chemistry. The more complex chemistry, observed in the gas phase when adding trace elements to the initial N2-CH4 mixture, has been confirmed by an extensive study of the solid phase products: SEM images show that grains produced in N2-CH4-C6H6 mixtures (1-5 μm) are much larger than those produced in N2-CH4 mixtures (0.1-0.5 μm), and the NMR results support a growth evolution of the chemistry when adding acetylene to the N2-CH4 mixture, resulting in the production of more complex (possibly double/triple or nitrogen-hydrogen) hydrogen bonds than with a simple N2-CH4 mixture. Here we present the complementary results of the gas- and solid-phase analyses as well an additional set of data from Raman spectroscopy, IR spectroscopy, and GC-MS. A new study is in progress to detect the negative ions present in the plasma expansion and the preliminary results of this study will be presented as well. These complementary studies show the high potential of COSmIC/THS to better understand Titan's chemistry and the origin of aerosol formation. Acknowledgments This research is supported by the NASA SMD Planetary Atmospheres Program. The authors acknowledge the technical support of R. Walker and E. Quigley (NASA ARC).

Propagation distance-resolved characteristics of filament-induced copper plasma

DOE PAGES

Ghebregziabher, Isaac; Hartig, Kyle C.; Jovanovic, Igor

2016-03-02

Copper plasma generated at different filament-copper interaction points was characterized by spectroscopic, acoustic, and imaging measurements. The longitudinal variation of the filament intensity was qualitatively determined by acoustic measurements in air. The maximum plasma temperature was measured at the location of peak filament intensity, corresponding to the maximum mean electron energy during plasma formation. The highest copper plasma density was measured past the location of the maximum electron density in the filament, where spectral broadening of the filament leads to enhanced ionization. Acoustic measurements in air and on solid target were correlated to reconstructed plasma properties. Lastly, optimal line emissionmore » is measured near the geometric focus of the lens used to produce the filament.« less

Electron density measurement in gas discharge plasmas by optical and acoustic methods

NASA Astrophysics Data System (ADS)

Biagioni, A.; Anania, M. P.; Bellaveglia, M.; Chiadroni, E.; Cianchi, A.; Di Giovenale, D.; Di Pirro, G.; Ferrario, M.; Filippi, F.; Mostacci, A.; Pompili, R.; Shpakov, V.; Vaccarezza, C.; Villa, F.; Zigler, A.

2016-08-01

Plasma density represents a very important parameter for both laser wakefield and plasma wakefield acceleration, which use a gas-filled capillary plasma source. Several techniques can be used to measure the plasma density within a capillary discharge, which are mainly based on optical diagnostic methods, as for example the well-known spectroscopic method using the Stark broadening effect. In this work, we introduce a preliminary study on an alternative way to detect the plasma density, based on the shock waves produced by gas discharge in a capillary. Firstly, the measurements of the acoustic spectral content relative to the laser-induced plasmas by a solid target allowed us to understand the main properties of the acoustic waves produced during this kind of plasma generation; afterwards, we have extended such acoustic technique to the capillary plasma source in order to calibrate it by comparison with the stark broadening method.

A unique control system simulator for the evaluation of pulsed plasma thrusters

NASA Technical Reports Server (NTRS)

Dahlgren, J. B.

1973-01-01

Because of the low thrust characteristics of solid-propellant pulsed plasma thrusters and their operational requirement to operate in a vacuum environment, unique and sensitive test techniques are required. A technique evolved for testing and evaluating pulsed plasma thrusters in an open- or closed-loop system mode employs a unique air bearing platform as a single-axis simulator on which the thruster is mounted. The simulator described was developed to evaluate pulsed plasma thrusters in the low micropound range; however, the simulator can be extended to cover the operational range of currently developed millipound thrusters.

Administration of exogenous acylated ghrelin or rikkunshito, an endogenous ghrelin enhancer, improves the decrease in postprandial gastric motility in an acute restraint stress mouse model

PubMed Central

Nahata, M; Saegusa, Y; Sadakane, C; Yamada, C; Nakagawa, K; Okubo, N; Ohnishi, S; Hattori, T; Sakamoto, N; Takeda, H

2014-01-01

Background Physical or psychological stress causes functional disorders in the upper gastrointestinal tract. This study aims to elucidate the ameliorating effect of exogenous acylated ghrelin or rikkunshito, a Kampo medicine which acts as a ghrelin enhancer, on gastric dysfunction during acute restraint stress in mice. Methods Fasted and postprandial motor function of the gastric antrum was wirelessly measured using a strain gauge force transducer and solid gastric emptying was detected in mice exposed to restraint stress. Plasma corticosterone and ghrelin levels were also measured. To clarify the role of ghrelin on gastrointestinal dysfunction in mice exposed to stress, exogenous acylated ghrelin or rikkunshito was administered, then the mice were subjected to restraint stress. Key Results Mice exposed to restraint stress for 60 min exhibited delayed gastric emptying and increased plasma corticosterone levels. Gastric motility was decreased in mice exposed to restraint stress in both fasting and postprandial states. Restraint stress did not cause any change in plasma acylated ghrelin levels, but it significantly increased the plasma des-acyl ghrelin levels. Administration of acylated ghrelin or rikkunshito improved the restraint stress-induced delayed gastric emptying and decreased antral motility. Ameliorating effects of rikkunshito on stress-induced gastric dysfunction were abolished by simultaneous administration of a ghrelin receptor antagonist. Conclusions & Inferences Plasma acylated/des-acyl ghrelin imbalance was observed in acute restraint stress. Supplementation of exogenous acylated ghrelin or enhancement of endogenous ghrelin signaling may be useful in the treatment of decreased gastric function caused by stress. PMID:24684160

Nanoscale control of energy and matter in plasma-surface interactions: towards energy-efficient nanotech

NASA Astrophysics Data System (ADS)

Ostrikov, Kostya

2010-11-01

This presentation focuses on the plasma issues related to the solution of the grand challenge of directing energy and matter at nanoscales. This ability is critical for the renewable energy and energy-efficient technologies for sustainable future development. It will be discussed how to use environmentally and human health benign non-equilibrium plasma-solid systems and control the elementary processes of plasma-surface interactions to direct the fluxes of energy and matter at multiple temporal and spatial scales. In turn, this makes it possible to achieve the deterministic synthesis of self- organised arrays of metastable nanostructures in the size range beyond the reach of the present-day nanofabrication. Such structures have tantalising prospects to enhance performance of nanomaterials in virtually any area of human activity yet remain almost inaccessible because the Nature's energy minimisation rules allow only a small number of stable equilibrium states. By using precisely controlled and kinetically fast nanoscale transfer of energy and matter under non-equilibrium conditions and harnessing numerous plasma- specific controls of species creation, delivery to the surface, nucleation and large-scale self-organisation of nuclei and nanostructures, the arrays of metastable nanostructures can be created, arranged, stabilised, and further processed to meet the specific requirements of the envisaged applications. These approaches will eventually lead to faster, unprecedentedly- clean, human-health-friendly, and energy-efficient nanoscale synthesis and processing technologies for the next-generation renewable energy and light sources, biomedical devices, information and communication systems, as well as advanced functional materials for applications ranging from basic food, water, health and clean environment needs to national security and space missions.

Laser Driven Compression Equations of State and Hugoniot Pressure Measurements in Thick Solid Metallic Targets at ˜0.17-13 TW/cm2

NASA Astrophysics Data System (ADS)

Remo, John L.

2010-10-01

An electro-optic laser probe was developed to obtain parameters for high energy density equations of state (EoS), Hugoniot pressures (PH), and strain rates for high energy density laser irradiation intensity, I, experiments at ˜170 GW/cm2 (λ = 1064 nm) to ˜13 TW/cm2 (λ = 527 nm) on Al, Cu, Ti, Fe, Ni metal targets in a vacuum. At I ˜7 TW/cm2 front surface plasma pressures and temperatures reached 100's GPa and over two million K. Rear surface PH ranged from 7-120 GPa at average shock wave transit velocities 4.2-8.5 km/s, depending on target thickness and I. A surface plasma compression ˜100's GPa generated an impulsive radial expanding shock wave causing compression, rarefactions, and surface elastic and plastic deformations depending on I. A laser/fiber optic system measured rear surface shock wave emergence and particle velocity with ˜3 GHz resolution by monitoring light deflection from diamond polished rear surfaces of malleable metallic targets, analogous to an atomic force microscope. Target thickness, ˜0.5-2.9 mm, prevented front surface laser irradiation penetration, due to low radiation skin depth, from altering rear surface reflectivity (refractive index). At ˜10 TW electromagnetic plasma pulse noise generated from the target chamber overwhelmed detector signals. Pulse frequency analysis using Moebius loop antennae probed transient noise characteristics. Average shock (compression) and particle (rear surface displacement) velocity measurements determined rear surface PH and GPa) EoS that are compared with gas guns.

Solid-state modeling of the terahertz spectrum of the high explosive HMX.

PubMed

Allis, Damian G; Prokhorova, Darya A; Korter, Timothy M

2006-02-09

The experimental solid-state terahertz (THz) spectrum (3-120 cm(-1)) of the beta-crystal form of the high explosive octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX) has been analyzed using solid-state density functional theory calculations. Various density functionals (both generalized gradient approximation and local density approximation) are compared in terms of their abilities to reproduce the experimentally observed solid-state structure and low-frequency vibrational motions. Good-to-excellent agreement between solid-state theory and experiment can be achieved in the THz region where isolated-molecule calculations fail to reproduce the observed spectral features, demonstrating a clear limitation of using isolated-molecule calculations for the assignment of THz frequency motions in molecular solids. The deficiency of isolated-molecule calculations is traced to modification of the molecular structure in the solid state through crystal packing effects and the formation of weak C-H...O hydrogen bonds.

Optofluidic devices with integrated solid-state nanopores

PubMed Central

Hawkins, Aaron R.; Schmidt, Holger

2016-01-01

This review (with 90 refs.) covers the state of the art in optofluidic devices with integrated solid-state nanopores for use in detection and sensing. Following an introduction into principles of optofluidics and solid-state nanopore technology, we discuss features of solid-state nanopore based assays using optofluidics. This includes the incorporation of solid-state nanopores into optofluidic platforms based on liquid-core anti-resonant reflecting optical waveguides (ARROWs), methods for their fabrication, aspects of single particle detection and particle manipulation. We then describe the new functionalities provided by solid-state nanopores integrated into optofluidic chips, in particular acting as smart gates for correlated electro-optical detection and discrimination of nanoparticles. This enables the identification of viruses and λ-DNA, particle trajectory simulations, enhancing sensitivity by tuning the shape of nanopores. The review concludes with a summary and an outlook. PMID:27046940

Publications of LASL research, 1972--1976

DOE Office of Scientific and Technical Information (OSTI.GOV)

Petersen, L.

1977-04-01

This bibliography is a compilation of unclassified work done at the Los Alamos Scientific Laboratory and published during the years 1972 to 1976. Publications too late for inclusion in earlier compilations are also listed. Declassification of previously classified reports is considered to constitute publication. The bibliography includes LASL reports, journal articles, books, conference papers, papers published in congressional hearings, theses, patents, etc. The following subject areas are included: aerospace studies; analytical technology; astrophysics; atomic and molecular physics, equation of state, opacity; biology and medicine; chemical dynamics and kinetics; chemistry; cryogenics; crystallography; CTR and plasma physics; earth science and engineering; energymore » (nonnuclear); engineering and equipment; EPR, ESR, NMR studies; explosives and detonations; fission physics; health and safety; hydrodynamics and radiation transport; instruments; lasers; mathematics and computers; medium-energy physics; metallurgy and ceramics technology; neutronics and criticality studies; nuclear physics; nuclear safeguards; physics; reactor technology; solid state science; and miscellaneous (including Project Rover). (RWR)« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gundlach-Graham, Alexander W.; Dennis, Elise; Ray, Steven J.

An inductively coupled plasma distance-of-flight mass spectrometer (ICP-DOFMS) has been coupled with laser-ablation (LA) sample introduction for the elemental analysis of solids. ICP-DOFMS is well suited for the analysis of laser-generated aerosols because it offers both high-speed mass analysis and simultaneous multi-elemental detection. Here, we evaluate the analytical performance of the LA-ICP-DOFMS instrument, equipped with a microchannel plate-based imaging detector, for the measurement of steady-state LA signals, as well as transient signals produced from single LA events. Steady-state detection limits are 1 mg g1, and absolute single-pulse LA detection limits are 200 fg for uranium; the system is shown capablemore » of performing time-resolved single-pulse LA analysis. By leveraging the benefits of simultaneous multi-elemental detection, we also attain a good shot-to-shot reproducibility of 6% relative standard deviation (RSD) and isotope-ratio precision of 0.3% RSD with a 10 s integration time.« less

Theoretical predictions for the phase stability of dense binary mixtures

NASA Astrophysics Data System (ADS)

Macfarlane, J. J.

1983-08-01

A new approach is developed for evaluating the mixing properties of binary solutions at high pressure. This involves solving Poisson's equation throughout three-dimensional cubic lattices, consistent with Thomas-Fermi-Dirac (TFD) theory. Zero temperature calculations are carried out for a variety of compositions and crystal structures in 3 pressure groups relevant to Jovian planetary interiors. Pseudopotentials based on the two-component-plasma model (with a uniform electron background) are fitted to the solid-state results, and are then used in liquid-state calculations using hard-sphere perturbation theory. TFD results if H-He solutions find critical temperatures (above which all compositions are soluble) to be approx. 0.500, and 1500 K at pressures of 10, 100, and 1000 Mbar, respectively. These temperatures are much lower than those obtained using free electron perturbation theory, where Tcrit approx. 10,000 K at 10 Mbar.

Effects of K-Doping on Thermoelectric Properties of Bi1- x K x CuOTe

NASA Astrophysics Data System (ADS)

An, Tae-Ho; Lim, Young Soo; Seo, Won-Seon; Park, Cheol-Hee; Yoo, Mi Duk; Park, Chan; Lee, Chang Hoon; Shim, Ji Hoon

2017-05-01

The effects of K-doping on the thermoelectric properties of Bi1- x K x CuOTe ( x = 0 to 0.08) have been investigated. The compounds were synthesized by a one-step solid-state reaction method and consolidated by a spark plasma sintering process. As the amount of K-doping was increased, the electrical and thermal conductivities increased while the Seebeck coefficient decreased due to increasing hole concentration. A ZT value of 0.69 was obtained for the compound K0.01Bi0.99CuOTe at 700 K, to the best of our knowledge the highest value reported for this material system. The origin of this enhanced ZT is discussed in terms of the density of states effective mass estimated by a single parabolic band model and electronic structures calculated based on density functional theory.

Recent advances in vacuum sciences and applications

NASA Astrophysics Data System (ADS)

Mozetič, M.; Ostrikov, K.; Ruzic, D. N.; Curreli, D.; Cvelbar, U.; Vesel, A.; Primc, G.; Leisch, M.; Jousten, K.; Malyshev, O. B.; Hendricks, J. H.; Kövér, L.; Tagliaferro, A.; Conde, O.; Silvestre, A. J.; Giapintzakis, J.; Buljan, M.; Radić, N.; Dražić, G.; Bernstorff, S.; Biederman, H.; Kylián, O.; Hanuš, J.; Miloševič, S.; Galtayries, A.; Dietrich, P.; Unger, W.; Lehocky, M.; Sedlarik, V.; Stana-Kleinschek, K.; Drmota-Petrič, A.; Pireaux, J. J.; Rogers, J. W.; Anderle, M.

2014-04-01

Recent advances in vacuum sciences and applications are reviewed. Novel optical interferometer cavity devices enable pressure measurements with ppm accuracy. The innovative dynamic vacuum standard allows for pressure measurements with temporal resolution of 2 ms. Vacuum issues in the construction of huge ultra-high vacuum devices worldwide are reviewed. Recent advances in surface science and thin films include new phenomena observed in electron transport near solid surfaces as well as novel results on the properties of carbon nanomaterials. Precise techniques for surface and thin-film characterization have been applied in the conservation technology of cultural heritage objects and recent advances in the characterization of biointerfaces are presented. The combination of various vacuum and atmospheric-pressure techniques enables an insight into the complex phenomena of protein and other biomolecule conformations on solid surfaces. Studying these phenomena at solid-liquid interfaces is regarded as the main issue in the development of alternative techniques for drug delivery, tissue engineering and thus the development of innovative techniques for curing cancer and cardiovascular diseases. A review on recent advances in plasma medicine is presented as well as novel hypotheses on cell apoptosis upon treatment with gaseous plasma. Finally, recent advances in plasma nanoscience are illustrated with several examples and a roadmap for future activities is presented.

Study on Formation of Plasma Nanobubbles in Water

NASA Astrophysics Data System (ADS)

Sato, Takehiko; Nakatani, Tatsuyuki; Miyahara, Takashi; Ochiai, Shiroh; Oizumi, Masanobu; Fujita, Hidemasa; Miyazaki, Takamichi

2015-12-01

Nanobubbles of less than 400 nm in diameter were formed by plasma in pure water. Pre-breakdown plasma termed streamer discharges, generated gas channels shaped like fine dendritic coral leading to the formation of small bubbles. Nanobubbles were visualized by an optical microscope and measured by dynamic laser scattering. However, it is necessary to verify that these nanobubbles are gas bubbles, not solid, because contamination such as platinum particles and organic compounds from electrode and residue in ultrapure water were also observed.

The creation of radiation dominated plasmas using laboratory extreme ultra-violet lasers

NASA Astrophysics Data System (ADS)

Tallents, G. J.; Wilson, S.; West, A.; Aslanyan, V.; Lolley, J.; Rossall, A. K.

2017-06-01

Ionization in experiments where solid targets are irradiated by high irradiance extreme ultra-violet (EUV) lasers is examined. Free electron degeneracy effects on ionization in the presence of a high EUV flux of radiation is shown to be important. Overlap of the physics of such plasmas with plasma material under compression in indirect inertial fusion is explored. The design of the focusing optics needed to achieve high irradiance (up to 1014 Wcm-2) using an EUV capillary laser is presented.

First principles study on electrochemical and chemical stability of solid electrolyte–electrode interfaces in all-solid-state Li-ion batteries

DOE PAGES

Zhu, Yizhou; He, Xingfeng; Mo, Yifei

2015-12-11

All-solid-state Li-ion batteries based on ceramic solid electrolyte materials are a promising next-generation energy storage technology with high energy density and enhanced cycle life. The poor interfacial conductance is one of the key limitations in enabling all-solid-state Li-ion batteries. However, the origin of this poor conductance has not been understood, and there is limited knowledge about the solid electrolyte–electrode interfaces in all-solid-state Li-ion batteries. In this paper, we performed first principles calculations to evaluate the thermodynamics of the interfaces between solid electrolyte and electrode materials and to identify the chemical and electrochemical stabilities of these interfaces. Our computation results revealmore » that many solid electrolyte–electrode interfaces have limited chemical and electrochemical stability, and that the formation of interphase layers is thermodynamically favorable at these interfaces. These formed interphase layers with different properties significantly affect the electrochemical performance of all-solid-state Li-ion batteries. The mechanisms of applying interfacial coating layers to stabilize the interface and to reduce interfacial resistance are illustrated by our computation. This study demonstrates a computational scheme to evaluate the chemical and electrochemical stability of heterogeneous solid interfaces. Finally, the enhanced understanding of the interfacial phenomena provides the strategies of interface engineering to improve performances of all-solid-state Li-ion batteries.« less

Plasma reactor waste management systems

NASA Technical Reports Server (NTRS)

Ness, Robert O., Jr.; Rindt, John R.; Ness, Sumitra R.

1992-01-01

The University of North Dakota is developing a plasma reactor system for use in closed-loop processing that includes biological, materials, manufacturing, and waste processing. Direct-current, high-frequency, or microwave discharges will be used to produce plasmas for the treatment of materials. The plasma reactors offer several advantages over other systems, including low operating temperatures, low operating pressures, mechanical simplicity, and relatively safe operation. Human fecal material, sunflowers, oats, soybeans, and plastic were oxidized in a batch plasma reactor. Over 98 percent of the organic material was converted to gaseous products. The solids were then analyzed and a large amount of water and acid-soluble materials were detected. These materials could possibly be used as nutrients for biological systems.

An extrapolation scheme for solid-state NMR chemical shift calculations

NASA Astrophysics Data System (ADS)

Nakajima, Takahito

2017-06-01

Conventional quantum chemical and solid-state physical approaches include several problems to accurately calculate solid-state nuclear magnetic resonance (NMR) properties. We propose a reliable computational scheme for solid-state NMR chemical shifts using an extrapolation scheme that retains the advantages of these approaches but reduces their disadvantages. Our scheme can satisfactorily yield solid-state NMR magnetic shielding constants. The estimated values have only a small dependence on the low-level density functional theory calculation with the extrapolation scheme. Thus, our approach is efficient because the rough calculation can be performed in the extrapolation scheme.

Modeling and Simulation of a 5.8kV SiC PiN Diode for Inductive Pulsed Plasma Thruster Applications

NASA Technical Reports Server (NTRS)

Toftul, Alexandra; Hudgins, Jerry L.; Polzin, Kurt A.; Martin, Adam K.

2014-01-01

Current ringing in an Inductive Pulsed Plasma Thruster (IPPT) can lead to reduced energy efficiency, excess heating, and wear on circuit components such as capacitors and solid state devices. Clamping off the current using a fast turn-off power diode is an effective way to reduce current ringing and increase energy efficiency. A diode with a shorter reverse recovery time will allow the least amount of current to ring back through the circuit, as well as minimize switching losses. The reverse recovery response of a new 5.8 kilovolt SiC PiN diode from Cree, Inc. in the IPPT plasma drive circuit is investigated using a physicsbased Simulink model, and compared with that of a 5SDF 02D6004 5.5 kilovolt fast-switching Si diode from ABB. Parameter extraction was carried out for each diode using both datasheet specifications and experimental waveforms, in order to most accurately adapt the model to the specific device. Further experimental data will be discussed using a flat-plate IPPT developed at NASA Marshall Space Flight Center and used to verify the simulation results. A final quantitative measure of circuit efficiency will be described for both the Si and SiC diode configuration.

Solid-state rechargeable magnesium battery

DOEpatents

Shao, Yuyan; Liu, Jun; Liu, Tianbiao; Li, Guosheng

2016-09-06

Embodiments of a solid-state electrolyte comprising magnesium borohydride, polyethylene oxide, and optionally a Group IIA or transition metal oxide are disclosed. The solid-state electrolyte may be a thin film comprising a dispersion of magnesium borohydride and magnesium oxide nanoparticles in polyethylene oxide. Rechargeable magnesium batteries including the disclosed solid-state electrolyte may have a coulombic efficiency .gtoreq.95% and exhibit cycling stability for at least 50 cycles.

Solid State Research, 1980:1.

DTIC Science & Technology

1980-02-15

ESD-TR-79-325 H 1 Solid State Research 1980 Prepared under Electronic Systems Division Contract FI%28-80-C-0002 by Lincoln Laboratory MASSkCHIISETTS...it is no longer needed. MASSACHUSETTS IN*STITUTE OF TECHNOLOGY LINCOLN LABORATORY V SOLID STATE RESEARCH QUARTERLY TECHNICAL SUMMARY REPORT I NOVEMBER...January 1990. The topics covered a-e Solid State Device Research , Quantum Electronics, Materials Rese.rch, Microelec- tronics, and Analog Device

Integrated Interface Strategy toward Room Temperature Solid-State Lithium Batteries.

PubMed

Ju, Jiangwei; Wang, Yantao; Chen, Bingbing; Ma, Jun; Dong, Shanmu; Chai, Jingchao; Qu, Hongtao; Cui, Longfei; Wu, Xiuxiu; Cui, Guanglei

2018-04-25

Solid-state lithium batteries have drawn wide attention to address the safety issues of power batteries. However, the development of solid-state lithium batteries is substantially limited by the poor electrochemical performances originating from the rigid interface between solid electrodes and solid-state electrolytes. In this work, a composite of poly(vinyl carbonate) and Li 10 SnP 2 S 12 solid-state electrolyte is fabricated successfully via in situ polymerization to improve the rigid interface issues. The composite electrolyte presents a considerable room temperature conductivity of 0.2 mS cm -1 , an electrochemical window exceeding 4.5 V, and a Li + transport number of 0.6. It is demonstrated that solid-state lithium metal battery of LiFe 0.2 Mn 0.8 PO 4 (LFMP)/composite electrolyte/Li can deliver a high capacity of 130 mA h g -1 with considerable capacity retention of 88% and Coulombic efficiency of exceeding 99% after 140 cycles at the rate of 0.5 C at room temperature. The superior electrochemical performance can be ascribed to the good compatibility of the composite electrolyte with Li metal and the integrated compatible interface between solid electrodes and the composite electrolyte engineered by in situ polymerization, which leads to a significant interfacial impedance decrease from 1292 to 213 Ω cm 2 in solid-state Li-Li symmetrical cells. This work provides vital reference for improving the interface compatibility for room temperature solid-state lithium batteries.

Modified Reference SPS with Solid State Transmitting Antenna

NASA Technical Reports Server (NTRS)

Woodcock, G. R.; Sperber, B. R.

1980-01-01

The development of solid state microwave power amplifiers for a solar power satellite transmitting antenna is discussed. State-of-the-art power-added efficiency, gain, and single device power of various microwave solid state devices are compared. The GaAs field effect transistors and the Si-bipolar transistors appear potentially feasible for solar power satellite use. The integration of solid state devices into antenna array elements is examined and issues concerning antenna integration and consequent satellite configurations are examined.