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Note: This page contains sample records for the topic "density plasma science" from the National Library of EnergyBeta (NLEBeta).
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they are not comprehensive nor are they the most current set.
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1

2810 IEEE TRANSACTIONS ON PLASMA SCIENCE, VOL. 39, NO. 11, NOVEMBER 2011 The Effect of Critical Plasma Densities of  

E-Print Network [OSTI]

-produced plasma (LPP) for various applications should consider details of spatial and temporal input power de in hydro- dynamic evolution of the produced plasma sources. Index Terms--CO2 laser, critical density and optimization of radiation sources for the next generation of nanolithography, i.e., the extreme ultravi- olet

Harilal, S. S.

2

844 IEEE TRANSACTIONS ON PLASMA SCIENCE, VOL. 34, NO. 3, JUNE 2006 Energy Balance and Plasma Potential in Low-Density  

E-Print Network [OSTI]

844 IEEE TRANSACTIONS ON PLASMA SCIENCE, VOL. 34, NO. 3, JUNE 2006 Energy Balance and Plasma, and Zoltan Sternovsky Abstract--Electron energy balance is shown to play an impor- tant role in determining that satisfy the energy balance equation. The ion loss rate af- fects the electron loss rate through the quasi

Kaganovich, Igor

3

Michigan Institute Plasma Science  

E-Print Network [OSTI]

Michigan Institute Plasma Science and Engineering Seminar Neutral Atom Imaging of the Terrestrial re- search includes ion heating in the solar corona, electric double layers, magne- tosphere neutral

Shyy, Wei

4

Boundary Plasma Issues in Burning Plasma Science  

E-Print Network [OSTI]

of operation ) ···· we know a lot more now than during the BPX design! #12;(1) Wide Dispersal of Power plasma/neutral densities · criterion for high recycling and cold divertor, Tt ~ 5 eV (a prerequisite high energy threshold) · interaction at walls of tenuous plasma: 1. how does plasma reach wall? (rapid

Pitcher, C. S.

5

Boundary Plasma Issues in Burning Plasma Science  

E-Print Network [OSTI]

of operation ) · we know a lot more now than during the BPX design! #12;(1) Wide Dispersal of Power plasma/neutral densities · criterion for high recycling and cold divertor, Tt ~ 5 eV (a prerequisite) · interaction at walls of tenuous plasma: 1.how does plasma reach wall? (rapid transport?) 2.can dominate core

6

Betatron radiation from density tailored plasmas  

E-Print Network [OSTI]

Betatron radiation from density tailored plasmas K. Tathe resulting betatron radiation spectrum can therefore bepro?le, the betatron radiation emitted by theses electrons

Ta Phuoc, Kim

2010-01-01T23:59:59.000Z

7

The temperature dependence of equilibrium plasma density  

E-Print Network [OSTI]

Temperature dependence of an electron-nuclear plasma equilibrium density is considered basing on known approaches, which are given in (1)(2). It is shown that at a very high temperature, which is characteristic for a star interior, the equilibrium plasma density is almost constant and equals approximately to $10^{25}$ particles per $cm^3$. At a relatively low temperature, which is characteristic for star surface, the equilibrium plasma density is in several orders lower and depends on temperature as $T^{3/2}$.

B. V. Vasiliev

2002-03-17T23:59:59.000Z

8

High Energy Density Laboratory Plasmas Program | National Nuclear...  

National Nuclear Security Administration (NNSA)

Photo Gallery Jobs Apply for Our Jobs Our Jobs Working at NNSA Blog Home High Energy Density Laboratory Plasmas Program High Energy Density Laboratory Plasmas Program...

9

Measuring the plasma density of a ferroelectric plasma source in an expanding plasma  

E-Print Network [OSTI]

Measuring the plasma density of a ferroelectric plasma source in an expanding plasma A. Dunaevsky and N. J. Fisch Princeton Plasma Physics Laboratory, Princeton University, P.O. Box 451, Princeton, New temperature at the surface of a ferroelectric plasma source were deduced from floating probe measurements

10

Plasma Physics PART Al: INTRODUCTION TO PLASMA SCIENCE  

E-Print Network [OSTI]

PART A7: PLASMA DIAGNOSTICS X. Introduction 75 XI. Remote diagnostics 75 1. Optical spectroscopy 2 and rotational excitation IV. Heavy particle collisions 142 V. Gas phase kinetics 143 PART B5: PLASMA DIAGNOSTICSPlasma Physics PART Al: INTRODUCTION TO PLASMA SCIENCE I. What is a plasma? 1 II. Plasma

Chen, Francis F.

11

N.P. Basse1 Plasma Science and Fusion Center  

E-Print Network [OSTI]

) The energy spectrum E(k) is related to P(k) through E(k) = Ad × P(k), where Ad is the surface area 33rd IEEE International Conference on Plasma Science, Traverse City, Michigan, USA (2006) A study of multiscale density fluctuations Work supported by US DoE Office of Fusion Energy Sciences #12;Introduction

Basse, Nils Plesner

12

Exploration of Plasma Jets Approach to High Energy Density Physics  

SciTech Connect (OSTI)

High-energy-density laboratory plasma (HEDLP) physics is an emerging, important area of research in plasma physics, nuclear physics, astrophysics, and particle acceleration. While the HEDLP regime occurs at extreme conditions which are often found naturally in space but not on the earth, it may be accessible by colliding high intensity plasmas such as high-energy-density plasma jets, plasmoids or compact toroids from plasma guns. The physics of plasma jets is investigated in the context of high energy density laboratory plasma research. This report summarizes results of theoretical and computational investigation of a plasma jet undergoing adiabatic compression and adiabatic expansion. A root-mean-squared (rms) envelope theory of plasma jets is developed. Comparison between theory and experiment is made. Good agreement between theory and experiment is found.

Chen, Chiping [Massachusetts Institute of Technology

2013-08-26T23:59:59.000Z

13

Wavefront-sensor-based electron density measurements for laser-plasma accelerators  

E-Print Network [OSTI]

Principles of Plasma Diagnostics, 2nd ed. (CambridgeSchematic of the plasma density diagnostics. When using theshot-to-shot plasma-density diagnostics. PACS numbers:

Plateau, Guillaume

2010-01-01T23:59:59.000Z

14

Boundary Plasma Issues in Burning Plasma Science  

E-Print Network [OSTI]

during the BPX design! #12;(1) Wide Dispersal of Power/(cont) ···· high recycling or detached regimes for high recycling and cold divertor, Tt ~ 5 eV (a prerequisite for detachment), L = connection length, nu high energy threshold) · interaction at walls of tenuous plasma: 1. how does plasma reach wall? (rapid

Pitcher, C. S.

15

ISRAELI PLASMA SCIENCE AND TECHNOLOGY ASSOCIATION  

E-Print Network [OSTI]

AND APPLICATIONS H.I.T. ­ Holon Institute of Technology February 4th, 2013 BOOK OF ABSTRACTS http://plasma-gate.weizmann.ac.il/ipsta2013/ #12;15th Israeli Conference on Plasma Science and Applications, HIT, Holon, February 4th , 2013 2 Science and Applications, HIT, Holon, February 4th , 2013 3 PREFACE We are delighted to host the 15th

16

Relativistic plasma nanophotonics for ultrahigh energy density physics  

E-Print Network [OSTI]

Relativistic plasma nanophotonics for ultrahigh energy density physics Michael A. Purvis1 volumetrically heat dense matter into a new ultrahot plasma regime. Electron densities nearly 100 times greater) and gigabar press- ures only exceeded in the central hot spot of highly compressed thermonuclear fusion

Rocca, Jorge J.

17

Proposed method for high-speed plasma density measurement in proton-driven plasma wakefield acceleration  

SciTech Connect (OSTI)

Recently a proton-bunch-driven plasma wakefield acceleration experiment using the CERN-SPS beam was proposed. Different types of plasma cells are under study, especially laser ionization, plasma discharge, and helicon sources. One of the key parameters is the spatial uniformity of the plasma density profile along the cell that has to be within < 1% of the nominal density (6 Multiplication-Sign 10{sup 14} cm{sup -3}). Here a setup based on a photomixing concept is proposed to measure the plasma cut-off frequency and determine the plasma density.

Tarkeshian, R.; Reimann, O.; Muggli, P. [Max-Planck-Institut fuer Physik, 80805 Munich (Germany)

2012-12-21T23:59:59.000Z

18

Operational plasma density and laser parameters for future colliders based on laser-plasma accelerators  

SciTech Connect (OSTI)

The operational plasma density and laser parameters for future colliders based on laser-plasma accelerators are discussed. Beamstrahlung limits the charge per bunch at low plasma densities. Reduced laser intensity is examined to improve accelerator efficiency in the beamstrahlung-limited regime.

Schroeder, C. B.; Esarey, E.; Leemans, W. P. [Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States)

2012-12-21T23:59:59.000Z

19

CENTER FOR PULSED POWER DRIVEN HIGH ENERGY DENSITY PLASMA STUDIES  

SciTech Connect (OSTI)

This annual report summarizes the activities of the Cornell Center for Pulsed-Power-Driven High-Energy-Density Plasma Studies, for the 12-month period October 1, 2005-September 30, 2006. This period corresponds to the first year of the two-year extension (awarded in October, 2005) to the original 3-year NNSA/DOE Cooperative Agreement with Cornell, DE-FC03-02NA00057. As such, the period covered in this report also corresponds to the fourth year of the (now) 5-year term of the Cooperative Agreement. The participants, in addition to Cornell University, include Imperial College, London (IC), the University of Nevada, Reno (UNR), the University of Rochester (UR), the Weizmann Institute of Science (WSI), and the P.N. Lebedev Physical Institute (LPI), Moscow. A listing of all faculty, technical staff and students, both graduate and undergraduate, who participated in Center research activities during the year in question is given in Appendix A.

Professor Bruce R. Kusse; Professor David A. Hammer

2007-04-18T23:59:59.000Z

20

Local thermodynamic equilibrium in rapidly heated high energy density plasmas  

SciTech Connect (OSTI)

Emission spectra and the dynamics of high energy density plasmas created by optical and Free Electron Lasers (FELs) depend on the populations of atomic levels. Calculations of plasma emission and ionization may be simplified by assuming Local Thermodynamic Equilibrium (LTE), where populations are given by the Saha-Boltzmann equation. LTE can be achieved at high densities when collisional processes are much more significant than radiative processes, but may not be valid if plasma conditions change rapidly. A collisional-radiative model has been used to calculate the times taken by carbon and iron plasmas to reach LTE at varying densities and heating rates. The effect of different energy deposition methods, as well as Ionization Potential Depression are explored. This work shows regimes in rapidly changing plasmas, such as those created by optical lasers and FELs, where the use of LTE is justified, because timescales for plasma changes are significantly longer than the times needed to achieve an LTE ionization balance.

Aslanyan, V.; Tallents, G. J. [York Plasma Institute, Department of Physics, University of York, Heslington, York YO10 5DD (United Kingdom)

2014-06-15T23:59:59.000Z

Note: This page contains sample records for the topic "density plasma science" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


21

Ducted kinetic Alfven waves in plasma with steep density gradients  

SciTech Connect (OSTI)

Given their high plasma density (n {approx} 10{sup 13} cm{sup -3}), it is theoretically possible to excite Alfven waves in a conventional, moderate length (L {approx} 2 m) helicon plasma source. However, helicon plasmas are decidedly inhomogeneous, having a steep radial density gradient, and typically have a significant background neutral pressure. The inhomogeneity introduces regions of kinetic and inertial Alfven wave propagation. Ion-neutral and electron-neutral collisions alter the Alfven wave dispersion characteristics. Here, we present the measurements of propagating kinetic Alfven waves in helium helicon plasma. The measured wave dispersion is well fit with a kinetic model that includes the effects of ion-neutral damping and that assumes the high density plasma core defines the radial extent of the wave propagation region. The measured wave amplitude versus plasma radius is consistent with the pile up of wave magnetic energy at the boundary between the kinetic and inertial regime regions.

Houshmandyar, Saeid [Solar Observatory Department, Prairie View A and M University, Prairie View, Texas 77446 (United States); Department of Physics, West Virginia University, Morgantown, West Virginia 26506-6315 (United States); Scime, Earl E. [Department of Physics, West Virginia University, Morgantown, West Virginia 26506-6315 (United States)

2011-11-15T23:59:59.000Z

22

Atomic processes in high-density plasmas  

SciTech Connect (OSTI)

This review covers dense atomic plasmas such as that produced in inertial confinement fusion. The target implosion physics along with the associated atomic physics, i.e., free electron collision phenomena, electron states I, electron states II, and nonequilibrium plasma states are described. (MOW)

More, R.M.

1982-12-21T23:59:59.000Z

23

Robotics Science & Technology for Burning Plasma Experiments  

E-Print Network [OSTI]

Robotics Science & Technology for Burning Plasma Experiments J. N. Herndon, T. W. Burgess, M. M, General Atomics, San Diego, California. #12;Robotics Challenges in Burning Plasma Experiments · Control x x x x x x earthmoving equipment electric robots Conventional Machines DMHP Machines x x x x

24

Measurements of neutral helium density in helicon plasmas  

SciTech Connect (OSTI)

Laser-induced-fluorescence (LIF) is used to measure the density of helium atoms in a helicon plasma source. For a pump wavelength of 587.725 nm (vacuum) and laser injection along the magnetic field, the LIF signal exhibits a signal decrease at the Doppler shifted central wavelength. The drop in signal results from the finite optical depth of the plasma and the magnitude of the decrease is proportional to the density of excited state neutral atoms. Using Langmuir probe measurements of plasma density and electron temperature and a collisional-radiative model, the absolute ground state neutral density is calculated from the optical depth measurements. Optimal plasma performance, i.e., the largest neutral depletion on the axis of the system, is observed for antenna frequencies of 13.0 and 13.5 MHz and magnetic field strengths of 550-600 G.

Houshmandyar, Saeid; Sears, Stephanie H.; Thakur, Saikat Chakraborty; Carr, Jerry Jr.; Galante, Matthew E.; Scime, Earl E. [Department of Physics, West Virginia University, Morgantown, West Virginia 26506-6315 (United States)

2010-10-15T23:59:59.000Z

25

Basic Plasma Science | Princeton Plasma Physics Lab  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May Jun Jul(Summary)morphinanInformation InInformationCenterResearch HighlightsToolsBES ReportsExperimentBasic Energy Sciences

26

Relation between plasma plume density and gas flow velocity in atmospheric pressure plasma  

SciTech Connect (OSTI)

We have studied atmospheric pressure plasma generated using a quartz tube, helium gas, and copper foil electrode by applying RF high voltage. The atmospheric pressure plasma in the form of a bullet is released as a plume into the atmosphere. To study the properties of the plasma plume, the plasma plume current is estimated from the difference in currents on the circuit, and the drift velocity is measured using a photodetector. The relation of the plasma plume density n{sub plu}, which is estimated from the current and the drift velocity, and the gas flow velocity v{sub gas} is examined. It is found that the dependence of the density on the gas flow velocity has relations of n{sub plu} ? log(v{sub gas}). However, the plasma plume density in the laminar flow is higher than that in the turbulent flow. Consequently, in the laminar flow, the density increases with increasing the gas flow velocity.

Yambe, Kiyoyuki; Taka, Shogo; Ogura, Kazuo [Graduate School of Science and Technology, Niigata University, Niigata 950-2181 (Japan)] [Graduate School of Science and Technology, Niigata University, Niigata 950-2181 (Japan)

2014-04-15T23:59:59.000Z

27

Measurements of plasma bremsstrahlung and plasma energy density produced by electron cyclotron resonance ion source plasmas  

E-Print Network [OSTI]

high temperature plasma diagnostics used to study high en-high temperature plasma diagnostic. Plasma bremsstrahlungand J Ärje. Plasma breakdown diagnostics with the biased

Noland, Jonathan David

2011-01-01T23:59:59.000Z

28

Tunable Laser Plasma Accelerator based on Longitudinal Density Tailoring  

SciTech Connect (OSTI)

Laser plasma accelerators have produced high-quality electron beams with GeV energies from cm-scale devices and are being investigated as hyperspectral fs light sources producing THz to {gamma}-ray radiation and as drivers for future high-energy colliders. These applications require a high degree of stability, beam quality and tunability. Here we report on a technique to inject electrons into the accelerating field of a laser-driven plasma wave and coupling of this injector to a lower-density, separately tunable plasma for further acceleration. The technique relies on a single laser pulse powering a plasma structure with a tailored longitudinal density profile, to produce beams that can be tuned in the range of 100-400 MeV with percent-level stability, using laser pulses of less than 40 TW. The resulting device is a simple stand-alone accelerator or the front end for a multistage higher-energy accelerator.

Gonsalves, Anthony; Nakamura, Kei; Lin, Chen; Panasenko, Dmitriy; Shiraishi, Satomi; Sokollik, Thomas; Benedetti, Carlo; Schroeder, Carl; Geddes, Cameron; Tilborg, Jeroen van; Osterhoff, Jens; Esarey, Eric; Toth, Csaba; Leemans, Wim

2011-07-15T23:59:59.000Z

29

Stable laser–plasma accelerators at low densities  

SciTech Connect (OSTI)

We report stable laser wakefield acceleration using 17–50 TW laser pulses interacting with 4?mm-long helium gas jet. The initial laser spot size was relatively large (28??m) and the plasma densities were 0.48–2.0?×?10{sup 19?}cm{sup ?3}. High-quality 100–MeV electron beams were generated at the plasma density of 7.5?×?10{sup 18?}cm{sup ?3}, at which the beam parameters (pointing angle, energy spectrum, charge, and divergence angle) were measured and stabilized. At higher densities, filamentation instability of the laser-plasma interaction was observed and it has led to multiple wakefield accelerated electron beams. The experimental results are supported by 2D particle-in-cell simulations. The achievement presented here is an important step toward the use of laser-driven accelerators in real applications.

Li, Song; Hafz, Nasr A. M., E-mail: nasr@sjtu.edu.cn; Mirzaie, Mohammad; Ge, Xulei; Sokollik, Thomas; Chen, Min; Sheng, Zhengming; Zhang, Jie, E-mail: jzhang1@sjtu.edu.cn [Key Laboratory for Laser Plasmas (Ministry of Education) and Department of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240 (China)

2014-07-28T23:59:59.000Z

30

Observation of low magnetic field density peaks in helicon plasma  

SciTech Connect (OSTI)

Single density peak has been commonly observed in low magnetic field (<100 G) helicon discharges. In this paper, we report the observations of multiple density peaks in low magnetic field (<100 G) helicon discharges produced in the linear helicon plasma device [Barada et al., Rev. Sci. Instrum. 83, 063501 (2012)]. Experiments are carried out using argon gas with m = +1 right helical antenna operating at 13.56 MHz by varying the magnetic field from 0 G to 100 G. The plasma density varies with varying the magnetic field at constant input power and gas pressure and reaches to its peak value at a magnetic field value of {approx}25 G. Another peak of smaller magnitude in density has been observed near 50 G. Measurement of amplitude and phase of the axial component of the wave using magnetic probes for two magnetic field values corresponding to the observed density peaks indicated the existence of radial modes. Measured parallel wave number together with the estimated perpendicular wave number suggests oblique mode propagation of helicon waves along the resonance cone boundary for these magnetic field values. Further, the observations of larger floating potential fluctuations measured with Langmuir probes at those magnetic field values indicate that near resonance cone boundary; these electrostatic fluctuations take energy from helicon wave and dump power to the plasma causing density peaks.

Barada, Kshitish K.; Chattopadhyay, P. K.; Ghosh, J.; Kumar, Sunil; Saxena, Y. C. [Institute for Plasma Research, Bhat, Gandhinagar 382428 (India)

2013-04-15T23:59:59.000Z

31

Two-dimensional-spatial distribution measurement of electron temperature and plasma density in low temperature plasmas  

SciTech Connect (OSTI)

A real-time measurement method for two-dimensional (2D) spatial distribution of the electron temperature and plasma density was developed. The method is based on the floating harmonic method and the real time measurement is achieved with little plasma perturbation. 2D arrays of the sensors on a 300 mm diameter wafer-shaped printed circuit board with a high speed multiplexer circuit were used. Experiments were performed in an inductive discharge under various external conditions, such as powers, gas pressures, and different gas mixing ratios. The results are consistent with theoretical prediction. Our method can measure the 2D spatial distribution of plasma parameters on a wafer-level in real-time. This method can be applied to plasma diagnostics to improve the plasma uniformity of plasma reactors for plasma processing.

Kim, Young-Cheol [Department of Nanoscale Semiconductor Engineering, Hanyang University, 17 Haengdang-dong, Seongdong-gu, Seoul 133-791 (Korea, Republic of); Jang, Sung-Ho; Oh, Se-Jin; Lee, Hyo-Chang; Chung, Chin-Wook [Department of Electrical Engineering, Hanyang University, 17 Haengdang-dong, Seongdong-gu, Seoul 133-791 (Korea, Republic of)

2013-05-15T23:59:59.000Z

32

MICROCAVITYMICROCAVITY PLASMA SCIENCE AND RECENTPLASMA SCIENCE AND RECENT APPLICATIONS: BOUNDAPPLICATIONS: BOUND--FREE COUPLING, TRANSISTORFREE COUPLING, TRANSISTOR  

E-Print Network [OSTI]

Plasma Surface Treatment High Intensity Plasma Arc Lamp Spark Gap Plasma Display (150 inch Panasonic Electrode Glass6 mm 250 m LED Backlight Microcavity Lamp #12;OPERATION OF MICROCAVITY PLASMA DEVICESMICROCAVITYMICROCAVITY PLASMA SCIENCE AND RECENTPLASMA SCIENCE AND RECENT APPLICATIONS

Shyy, Wei

33

1004 IEEE TRANSACTIONS ON PLASMA SCIENCE, VOL. 34, NO. 3, JUNE 2006 Microwave Diagnostics of a Repetitive,  

E-Print Network [OSTI]

1004 IEEE TRANSACTIONS ON PLASMA SCIENCE, VOL. 34, NO. 3, JUNE 2006 Microwave Diagnostics--A microwave-transmission-based diagnostic method is presented here, applicable to plasmas having electron. Index Terms--Air, electron collision frequency, electron number density, microwave diagnostics, plasma

Miles, Richard

34

IEEE TRANSACTIONS ON PLASMA SCIENCE, VOL. 32, NO. 2, APRIL 2004 813 Characterization of Laser Produced Tetrakis  

E-Print Network [OSTI]

an electrodeless UV laser preionization of TMAE to initiate a plasma seeded in atmospheric pressure gases that can the initiation RF power budget. A large volume (500 cc), high-density ( 1013 cm 3), electrodeless plasmaIEEE TRANSACTIONS ON PLASMA SCIENCE, VOL. 32, NO. 2, APRIL 2004 813 Characterization of Laser

Scharer, John E.

35

Plasma density gradient injection of low absolute momentum spread electron bunches  

E-Print Network [OSTI]

t to the plasma density indicates the laser focus positionplasma exit. Scanning the jet position relative to the laser focus (

Geddes, C.G.R.

2008-01-01T23:59:59.000Z

36

The expansion of a collisionless plasma into a plasma of lower density  

SciTech Connect (OSTI)

This paper considers the asymptotic and numerical solution of a simple model for the expansion of a collisionless plasma into a plasma of lower density. The dependence on the density ratio of qualitative and quantitative features of solutions of the well-known cold-ion model is explored. In the cold-ion limit, we find that a singularity develops in the ion density in finite time unless the density ratio is zero or close to unity. The classical cold-ion model may cease to be valid when such a singularity occurs and we then regularize the model by the finite ion-temperature Vlasov-Poisson system. Numerical evidence suggests the emergence of a multi-modal velocity distribution.

Perego, M.; Gunzburger, M. D. [Department of Scientific Computing, Florida State University, Tallahassee, Florida 32306 (United States)] [Department of Scientific Computing, Florida State University, Tallahassee, Florida 32306 (United States); Howell, P. D.; Ockendon, J. R.; Allen, J. E. [OCIAM, Mathematical Institute, Oxford University, 24-29 St Giles, OX1 3LB Oxford (United Kingdom)] [OCIAM, Mathematical Institute, Oxford University, 24-29 St Giles, OX1 3LB Oxford (United Kingdom)

2013-05-15T23:59:59.000Z

37

Disruption Science Issues and Opportunities for a Burning Plasma Science Experiment  

E-Print Network [OSTI]

Disruption Science Issues and Opportunities for a Burning Plasma Science Experiment Prepared and presented by: John Wesley General Atomics San Diego, California With recent disruption science results University Fusion Association Workshop on Burning Plasma Science 11-13 December 2000 Austin, Texas QTYUIOP BP

38

Potential Materials Science Benefits from a Burning Plasma  

E-Print Network [OSTI]

Potential Materials Science Benefits from a Burning Plasma Science Experiment S.J. Zinkle Oak Ridge;Introduction · The main materials science advances from a BPSX would occur during the R&D phase prior to construction ­e.g., CIT/BPX, ITER · Materials science opportunities during operation of a BPSX would likely

39

THE SCIENCE FRONTIER OF MFE BURNING PLASMA PHYSICS  

E-Print Network [OSTI]

THE SCIENCE FRONTIER OF MFE BURNING PLASMA PHYSICS Gerald Navratil Columbia University Fusion Power Associates Annual Meeting and Symposium Frontiers in Fusion Research Washington, DC 25-26 September 2001 #12;Columbia University OUTLINE · INTRODUCTION TO BURNING PLASMAS · EXAMPLES OF FRONTIER SCIENCE IN BURNING

40

Dusty plasma diagnostics methods for charge, electron temperature, and ion density  

E-Print Network [OSTI]

Dusty plasma diagnostics methods for charge, electron temperature, and ion density Bin Liu,1 J 2010; published online 7 May 2010 Diagnostic methods are developed to measure the microparticle charge Q and two plasma parameters, electron temperature Te, and ion density ni, in the main plasma region

Goree, John

Note: This page contains sample records for the topic "density plasma science" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


41

Approach for control of high-density plasma reactors through optimal pulse shaping*  

E-Print Network [OSTI]

Approach for control of high-density plasma reactors through optimal pulse shaping* Tyrone L and it relies on a physical model of the plasma reactor used in conjunction with an optimal control algorithm high-density plasma reactor. Optimal power input pulse shapes and pulsing frequencies are determined

Raja, Laxminarayan L.

42

Counter-facing plasma focus system as a repetitive and/or long-pulse high energy density plasma source  

SciTech Connect (OSTI)

A plasma focus system composed of a pair of counter-facing coaxial plasma guns is proposed as a long-pulse and/or repetitive high energy density plasma source. A proof-of-concept experiment demonstrated that with an assist of breakdown and outer electrode connections, current sheets evolved into a configuration for stable plasma confinement at the center of the electrodes. The current sheets could successively compress and confine the high energy density plasma every half period of the discharge current, enabling highly repetitive light emissions in extreme ultraviolet region with time durations in at least ten microseconds.

Aoyama, Yutaka; Nakajima, Mitsuo; Horioka, Kazuhiko [Department of Energy Sciences, Interdisciplinary Graduate School of Science and Engineering, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama 226-8502 (Japan)

2009-11-15T23:59:59.000Z

43

PLASMA FOCUSING OF HIGH ENERGY DENSITY ELECTRON AND POSITRON BEAMS \\Lambda  

E-Print Network [OSTI]

PLASMA FOCUSING OF HIGH ENERGY DENSITY ELECTRON AND POSITRON BEAMS \\Lambda J.S.T. Ng, P. Chen, W, for the first time, positron beams. We also discuss measure­ ments on plasma lens­induced synchrotron radiation and laser­ and beam­plasma interactions. 1 INTRODUCTION The plasma lens was proposed as a final focusing

44

Modeling of free electronic state density in hydrogenic plasmas based on nearest neighbor approximation  

SciTech Connect (OSTI)

Most conventional atomic models in a plasma do not treat the effect of the plasma on the free-electron state density. Using a nearest neighbor approximation, the state densities in hydrogenic plasmas for both bound and free electrons were evaluated and the effect of the plasma on the atomic model (especially for the state density of the free electron) was studied. The model evaluates the electron-state densities using the potential distribution formed by the superposition of the Coulomb potentials of two ions. The potential from one ion perturbs the electronic state density on the other. Using this new model, one can evaluate the free-state density without making any ad-hoc assumptions. The resulting contours of the average ionization degree, given as a function of the plasma temperature and density, are shifted slightly to lower temperatures because of the effect of the increasing free-state density.

Nishikawa, Takeshi, E-mail: nishikawa.takeshi@okayama-u.ac.jp [Graduate School of Natural Science and Technology, Okayama University, Okayama 700-8530 (Japan)

2014-07-15T23:59:59.000Z

45

Analysis of line integrated electron density using plasma position data on Korea Superconducting Tokamak Advanced Research  

SciTech Connect (OSTI)

A 280 GHz single-channel horizontal millimeter-wave interferometer system has been installed for plasma electron density measurements on the Korea Superconducting Tokamak Advanced Research (KSTAR) device. This system has a triangular beam path that does not pass through the plasma axis due to geometrical constraints in the superconducting tokamak. The term line density on KSTAR has a different meaning from the line density of other tokamaks. To estimate the peak density and the mean density from the measured line density, information on the position of the plasma is needed. The information has been calculated from tangentially viewed visible images using the toroidal symmetry of the plasma. Interface definition language routines have been developed for this purpose. The calculated plasma position data correspond well to calculation results from magnetic analysis. With the position data and an estimated plasma profile, the peak density and the mean density have been obtained from the line density. From these results, changes of plasma density themselves can be separated from effects of the plasma movements, so they can give valuable information on the plasma status.

Nam, Y. U.; Chung, J. [National Fusion Research Institute, Gwahangno 113, Daejeon 305-333 (Korea, Republic of)

2010-10-15T23:59:59.000Z

46

Effect of density changes on tokamak plasma confinement  

E-Print Network [OSTI]

A change of the particle density (by gas puff, pellets or impurity seeding) during the plasma discharge in tokamak produces a radial current and implicitly a torque and rotation that can modify the state of confinement. After ionization the newly born ions will evolve toward the periodic neoclassical orbits (trapped or circulating) but the first part of their excursion, which precedes the periodicity, is an effective radial current. It is short, spatially finite and unique for each new ion, but multiplied by the rate of ionization and it can produce a substantial total radial current. The associated torque induces rotation which modify the transport processes. We derive the magnitude of the radial current induced by ionization by three methods: the analysis of a simple physical picture, a numerical model and the neoclassical drift-kinetic treatment. The results of the three approaches are in agreement and show that the current can indeed be substantial. Many well known experimental observations can be reconsi...

Spineanu, F

2015-01-01T23:59:59.000Z

47

High energy density micro plasma bunch from multiple laser interaction with thin target  

SciTech Connect (OSTI)

Three-dimensional particle-in-cell simulation is used to investigate radiation-pressure driven acceleration and compression of small solid-density plasma by intense laser pulses. It is found that multiple impacts by presently available short-pulse lasers on a small hemispheric shell target can create a long-living tiny quasineutral monoenergetic plasma bunch of very high energy density.

Xu, Han [National Laboratory for Parallel and Distributed Processing, College of Computer Science, National University of Defense Technology, Changsha 410073 (China); Shanghai Institute of Optics and Fine Mechanics, Shanghai 201800 (China); Yu, Wei; Luan, S. X.; Xu, Z. Z. [Shanghai Institute of Optics and Fine Mechanics, Shanghai 201800 (China); Yu, M. Y., E-mail: myyu@zju.edu.cn [Physics Department, Institute for Fusion Theory and Simulation, Zhejiang University, Hangzhou 310027 (China); Institute for Theoretical Physics I, Ruhr University, Bochum D-44780 (Germany); Cai, H. B.; Zhou, C. T. [Institute of Applied Physics and Computational Mathematics, Beijing 100088 (China); Yang, X. H.; Yin, Y.; Zhuo, H. B. [College of Science, National University of Defense Technology, Changsha (China); Wang, J. W. [Shanghai Institute of Optics and Fine Mechanics, Shanghai 201800 (China); Institute of Laser Engineering, Osaka University, Osaka 565-0871 (Japan); Murakami, M. [Institute of Laser Engineering, Osaka University, Osaka 565-0871 (Japan)

2014-01-13T23:59:59.000Z

48

Plasma Facing Component Science and Technology for Burning Plasma Experiments  

E-Print Network [OSTI]

HeatFlux(MW/m2 ) Disruptions Reentry Vehicles Fusion Divertor Fusion First Wall Fast Breeder Fission Reactor Radiant Flux at Sun Surface Rocket Nozzles Comparison Relative Heat Fluxes Fusion Plasma #12;MAU prediction of disruptions about 50 ms before they occur with a >90% accuracy ­ Massive gas puffing

49

Radiation transport and density effects in non-equilibrium plasmas Vladimir I. Fisher*, Dimitri V. Fisher, Yitzhak Maron  

E-Print Network [OSTI]

Radiation transport and density effects in non-equilibrium plasmas Vladimir I. Fisher*, Dimitri V populations and the radiation field in transient non-equilibrium plasmas. In this model, the plasma density to a self-consistent treatment of the radiative transfer. For non-Maxwellian plasmas, the atomic

50

Influence of microwave driver coupling design on plasma density at Testbench for Ion sources Plasma Studies, a 2.45 GHz Electron Cyclotron Resonance Plasma Reactor  

SciTech Connect (OSTI)

A comparative study of two microwave driver systems (preliminary and optimized) for a 2.45 GHz hydrogen Electron Cyclotron Resonance plasma generator has been conducted. The influence on plasma behavior and parameters of stationary electric field distribution in vacuum, i.e., just before breakdown, along all the microwave excitation system is analyzed. 3D simulations of resonant stationary electric field distributions, 2D simulations of external magnetic field mapping, experimental measurements of incoming and reflected power, and electron temperature and density along the plasma chamber axis have been carried out. By using these tools, an optimized set of plasma chamber and microwave coupler has been designed paying special attention to the optimization of stationary electric field value in the center of the plasma chamber. This system shows a strong stability on plasma behavior allowing a wider range of operational parameters and even sustaining low density plasma formation without external magnetic field. In addition, the optimized system shows the capability to produce values of plasma density four times higher than the preliminary as a consequence of a deeper penetration of the magnetic resonance surface in relative high electric field zone by keeping plasma stability. The increment of the amount of resonance surface embedded in the plasma under high electric field is suggested as a key factor.

Megía-Macías, A.; Vizcaíno-de-Julián, A. [E.S.S. Bilbao, Edificio Cosimet, Landabarri 2, 48940-Leioa, Vizcaya (Spain)] [E.S.S. Bilbao, Edificio Cosimet, Landabarri 2, 48940-Leioa, Vizcaya (Spain); Cortázar, O. D., E-mail: dcortazar@essbilbao.org [E.S.S. Bilbao, Edificio Cosimet, Landabarri 2, 48940-Leioa, Vizcaya (Spain); Universidad de Castilla-La Mancha, ETSII, C.J. Cela s/n, 13170 Ciudad Real (Spain)

2014-03-15T23:59:59.000Z

51

Michigan Institute for Plasma Science and Engineering Fall 2011 Seminar Series  

E-Print Network [OSTI]

Michigan Institute for Plasma Science and Engineering Fall 2011 Seminar Series Date, Time EECS Dr. Joe Borovsky AOSS and Los Alamos National Laboratory The Solar Wind Plasma Wednesday

Shyy, Wei

52

COALITION FOR PLASMA SCIENCE Fusion Power Associates  

E-Print Network [OSTI]

· Materials: brochure, two-pagers, posters. · Web page (plasmacoalition.org): links to plasma sites, evaluated of the CPS web site ­ Ask for input on how to improve web page · Solicit for individual(s) to conduct

53

Advances and Challenges in Computational Plasma Science  

SciTech Connect (OSTI)

Scientific simulation, which provides a natural bridge between theory and experiment, is an essential tool for understanding complex plasma behavior. Recent advances in simulations of magnetically-confined plasmas are reviewed in this paper with illustrative examples chosen from associated research areas such as microturbulence, magnetohydrodynamics, and other topics. Progress has been stimulated in particular by the exponential growth of computer speed along with significant improvements in computer technology.

W.M. Tang; V.S. Chan

2005-01-03T23:59:59.000Z

54

Using Radio Waves to Control Fusion Plasma Density  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

heat goes to electrons instead of plasma ions, as would happen in the center of a self-sustaining fusion reaction. Supercomputer simulations run at the Department of Energy's...

55

Stationary self-focusing of intense laser beam in cold quantum plasma using ramp density profile  

SciTech Connect (OSTI)

By using a transient density profile, we have demonstrated stationary self-focusing of an electromagnetic Gaussian beam in cold quantum plasma. The paper is devoted to the prospects of using upward increasing ramp density profile of an inhomogeneous nonlinear medium with quantum effects in self-focusing mechanism of high intense laser beam. We have found that the upward ramp density profile in addition to quantum effects causes much higher oscillation and better focusing of laser beam in cold quantum plasma in comparison to that in the classical relativistic case. Our computational results reveal the importance and influence of formation of electron density profiles in enhancing laser self-focusing.

Habibi, M. [Department of Physics, Shirvan Branch, Islamic Azad University, Shirvan (Iran, Islamic Republic of); Ghamari, F. [Department of Physics, Khorramabad Branch, Islamic Azad University, Khorramabad (Iran, Islamic Republic of)

2012-10-15T23:59:59.000Z

56

Characterization of low-frequency density fluctuations in dipole-confined laboratory plasmas  

E-Print Network [OSTI]

Low-frequency fluctuations of plasma density, floating potential, ion saturation current, visible light intensity, and edge magnetic field are routinely observed in the Levitated Dipole Experiment (LDX). For the purposes ...

Ellsworth, Jennifer L

2010-01-01T23:59:59.000Z

57

Density profiles of plasmas confined by the field of a Levitating Dipole Magnet  

E-Print Network [OSTI]

A 4-channel microwave interferometer (center frequency: 60 GHz) has been constructed to measure the density profiles of plasmas confined within the Levitated Dipole Experiment (LDX). LDX is the first and only experiment ...

Boxer, Alexander C

2009-01-01T23:59:59.000Z

58

Electron density and temperature profile diagnostics for C-2 field reversed configuration plasmas  

SciTech Connect (OSTI)

The 9-point Thomson scattering diagnostic system for the C-2 field reversed configuration plasmas is improved and the measured electron temperature profiles are consistent with theoretical expectations. Rayleigh scattering revealed a finite line width of the ruby laser emission, which complicates density calibration. Taking advantage of the plasma wobble motion, density profile reconstruction accuracy from the 6-chord two-color CO{sub 2}/HeNe interferometer data is improved.

Deng, B. H.; Kinley, J. S.; Schroeder, J. [Tri Alpha Energy, Inc., Rancho Santa Margarita, California 92688 (United States)

2012-10-15T23:59:59.000Z

59

Plasma density inside a femtosecond laser filament in air: Strong dependence on external focusing  

E-Print Network [OSTI]

Plasma density inside a femtosecond laser filament in air: Strong dependence on external focusing­16 . The plasma generation balances the self-focusing effect and leads to a limited peak intensity 17­19 along, Germany Received 10 March 2006; published 27 September 2006 Our experiment shows that external focusing

Becker, Andreas

60

High Energy Density Science at the Linac Coherent Light Source  

SciTech Connect (OSTI)

High energy density science (HEDS), as a discipline that has developed in the United States from National Nuclear Security Agency (NNSA)-sponsored laboratory research programs, is, and will remain, a major component of the NNSA science and technology strategy. Its scientific borders are not restricted to NNSA. 'Frontiers in High Energy Density Physics: The X-Games of Contemporary Science' identified numerous exciting scientific opportunities in this field, while pointing to the need for a overarching interagency plan for its evolution. Meanwhile, construction of the first x-ray free-electron laser, the Office-of-Science-funded Linear Coherent Light Source-LCLS: the world's first free electron x-ray laser, with 100-fsec time resolution, tunable x-ray energies, a high rep rate, and a 10 order-of-magnitude increase in brightness over any other x-ray source--led to the realization that the scientific needs of NNSA and the broader scientific community could be well served by an LCLS HEDS endstation employing both short-pulse and high-energy optical lasers. Development of this concept has been well received in the community. NNSA requested a workshop on the applicability of LCLS to its needs. 'High Energy Density Science at the LCLS: NNSA Defense Programs Mission Need' was held in December 2006. The workshop provided strong support for the relevance of the endstation to NNSA strategic requirements. The range of science that was addressed covered a wide swath of the vast HEDS phase space. The unique possibilities provided by the LCLS in areas of intense interest to NNSA Defense Programs were discussed. The areas of focus included warm dense matter and equations of state, hot dense matter, and behavior of high-pressure materials under conditions of high strain-rate and extreme dynamic loading. Development of new and advanced diagnostic techniques was also addressed. This report lays out the relevant science, as brief summaries (Ch. II), expanded descriptions (Ch. V), and a more detailed plans for experiments (Ch. VI), highlighting the uniqueness the HEDS endstation will play in providing mission-relevant HED data and in the development of the field. One of the more exciting aspects of NNSA-relevant experiments on LCLS is that, given the extraordinary investment and consequent advances in accurate atomic-scale simulations of matter (to a large extent via the Accelerated Scientific Computing program sponsored by NNSA), the facility will provide a platform that, for the first time, will permit experiments in the regimes of interest at the time and spatial scales of the simulations. In Chapter III, the report places the potential of LCLS with an HED science endstation in the context of science required by NNSA, as well as explicating the relationship of NNSA and HED science in general. Chapter IV discusses 4th-generation light sources, like LCLS, in the context of other laboratory technologies presently utilized by NNSA. The report concludes, noting that an HED endstation on LCLS can provide access to data in regimes that are relevant to NNSA needs but no mechanism exists for providing such data. The endstation will also serve to build a broad-based community in the 'X-Games' of physics. The science generated by the facility will be a collaboration of NNSA-based laboratory scientists and university-based researchers. The LCLS endstation fulfills the need for an intermediate-scale facility capable of delivering fundamental advances and mission-relevant research in high energy density science.

Lee, R W

2007-10-19T23:59:59.000Z

Note: This page contains sample records for the topic "density plasma science" from the National Library of EnergyBeta (NLEBeta).
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they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
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61

518 IEEE TRANSACTIONS ON PLASMA SCIENCE, VOL. 33, NO. 2, APRIL 2005 Plasma Dynamics During Breakdown in  

E-Print Network [OSTI]

, lamp, modeling, plasma. METAL halide arc lamps are widely used sources of in- door and large area plasma hydrodynamics model was used to investigate breakdown in metal halide lamp. Images depicting518 IEEE TRANSACTIONS ON PLASMA SCIENCE, VOL. 33, NO. 2, APRIL 2005 Plasma Dynamics During

Kushner, Mark

62

IEEE TRANSACTIONS ON PLASMA SCIENCE, VOL. 26, NO. 6, DECEMBER 1998 1635 Velocity Distributions in Magnetron Sputter  

E-Print Network [OSTI]

by LG Electronics, the Basic Science Research Institute Program, Ministry of Education 1997, Project 97 profiles of plasma density, potential, and velocity distribution function, along with the electron and the global model. The velocity distribution function of electrons is Maxwellian, but that of ions is non

Lee, Hae June

63

Energy enhancement of proton acceleration in combinational radiation pressure and bubble by optimizing plasma density  

SciTech Connect (OSTI)

The combinational laser radiation pressure and plasma bubble fields to accelerate protons are researched through theoretical analysis and numerical simulations. The dephasing length of the accelerated protons bunch in the front of the bubble and the density gradient effect of background plasma on the accelerating phase are analyzed in detail theoretically. The radiation damping effect on the accelerated protons energy is also considered. And it is demonstrated by two-dimensional particle-in-cell simulations that the protons bunch energy can be increased by using the background plasma with negative density gradient. However, radiation damping makes the maximal energy of the accelerated protons a little reduction.

Bake, Muhammad Ali; Xie Baisong [Key Laboratory of Beam Technology and Materials Modification of the Ministry of Education, Beijing Normal University, Beijing 100875 (China); College of Nuclear Science and Technology, Beijing Normal University, Beijing 100875 (China); Shan Zhang [Department of Mathematics and Physics, Shijiazhuang Tiedao University, Shijiazhuang 050043 (China); Hong Xueren [College of Nuclear Science and Technology, Beijing Normal University, Beijing 100875 (China); College of Physics and Electronic Engineering, Northwest Normal University, Lanzhou 730070 (China); Wang Hongyu [Department of Physics, Anshan Normal University, Anshan 114005 (China); Shanghai Bright-Tech Information Technology Co. Ltd, Shanghai 200136 (China)

2012-08-15T23:59:59.000Z

64

Importance of Intermediate-scale Experiments in Discovery Plasma Science  

E-Print Network [OSTI]

· Core research team: C. Forest, J. Egedal, E. Zweibel (U. Wisconsin), major · Support: ­ Theory/modeling: CMSO ­ ConstrucEon: NSF-MRI ­ OperaEons: DOE, NSF? Pellet Injection #12;Basic Plasma Science Facility (BAPSF) · Core research team: UCLA

65

Path Integral Monte Carlo Simulation of the Low-Density Hydrogen Plasma B. Militzer y  

E-Print Network [OSTI]

Path Integral Monte Carlo Simulation of the Low-Density Hydrogen Plasma B. Militzer y Lawrence to calculate the equilibrium properties of hydrogen in the density and temperature range of 9:83 #2; 10 4 #20 surface. We calculate the equation of state and compare with other models for hydrogen valid

Militzer, Burkhard

66

Device and method for electron beam heating of a high density plasma  

DOE Patents [OSTI]

A device and method for relativistic electron beam heating of a high density plasma in a small localized region. A relativistic electron beam generator produces a high voltage electron beam which propagates along a vacuum drift tube and is modulated to initiate electron bunching within the beam. The beam is then directed through a low density gas chamber which provides isolation between the vacuum modulator and the relativistic electron beam target. The relativistic beam is then applied to a high density target plasma which typically comprises DT, DD, hydrogen boron or similar thermonuclear gas at a density of 10.sup.17 to 10.sup.20 electrons per cubic centimeter. The target plasma is ionized prior to application of the electron beam by means of a laser or other preionization source. Utilizing a relativistic electron beam with an individual particle energy exceeding 3 MeV, classical scattering by relativistic electrons passing through isolation foils is negligible. As a result, relativistic streaming instabilities are initiated within the high density target plasma causing the relativistic electron beam to efficiently deposit its energy into a small localized region within the high density plasma target.

Thode, Lester E. (Los Alamos, NM)

1981-01-01T23:59:59.000Z

67

Extreme ultraviolet source at 6.7 nm based on a low-density plasma  

SciTech Connect (OSTI)

We demonstrate an efficient extreme ultraviolet (EUV) source for operation at {lambda} = 6.7 nm by optimizing the optical thickness of gadolinium (Gd) plasmas. Using low initial density Gd targets and dual laser pulse irradiation, we observed a maximum EUV conversion efficiency (CE) of 0.54% for 0.6% bandwidth (BW) (1.8% for 2% BW), which is 1.6 times larger than the 0.33% (0.6% BW) CE produced from a solid density target. Enhancement of the EUV CE by use of a low-density plasma is attributed to the reduction of self-absorption effects.

Higashiguchi, Takeshi; Yugami, Noboru [Department of Advanced Interdisciplinary Sciences, Center for Optical Research and Education (CORE), and Optical Technology Innovation Center (OpTIC), Utsunomiya University, Yoto 7-1-2, Utsunomiya, Tochigi 321-8585 (Japan); Japan Science and Technology Agency, CREST, 4-1-8 Honcho, Kanagawa, Saitama 332-0012 (Japan); Otsuka, Takamitsu [Department of Advanced Interdisciplinary Sciences, Center for Optical Research and Education (CORE), and Optical Technology Innovation Center (OpTIC), Utsunomiya University, Yoto 7-1-2, Utsunomiya, Tochigi 321-8585 (Japan); Jiang, Weihua [Department of Electrical Engineering, Nagaoka University of Technology, Kami-tomiokamachi 1603-1, Nagaoka, Niigata 940-2188 (Japan); Endo, Akira [Research Institute for Science and Engineering, Waseda University, Okubo 3-4-1, Shinjuku, Tokyo 169-8555 (Japan); Li Bowen; Kilbane, Deirdre; Dunne, Padraig; O'Sullivan, Gerry [School of Physics, University College Dublin, Belfield, Dublin 4 (Ireland)

2011-11-07T23:59:59.000Z

68

PLASMA DYNAMICS AND PLASMA WALL INTERACTION 130 Problems of Atomic Science and Technology. 2006, 6. Series: Plasma Physics (12), p. 130-134  

E-Print Network [OSTI]

PLASMA DYNAMICS AND PLASMA WALL INTERACTION 130 Problems of Atomic Science and Technology. 2006, 6. Series: Plasma Physics (12), p. 130-134 SIMULATION OF HIGH POWER DEPOSITION ON TARGET MATERIALS: APPLICATIONS IN MAGNETIC, INERTIAL FUSION, AND HIGH POWER PLASMA LITHOGRAPHY DEVICES Ahmed Hassanein Argonne

Harilal, S. S.

69

On the breaking of a plasma wave in a thermal plasma. I. The structure of the density singularity  

SciTech Connect (OSTI)

The structure of the singularity that is formed in a relativistically large amplitude plasma wave close to the wave breaking limit is found by using a simple waterbag electron distribution function. The electron density distribution in the breaking wave has a typical 'peakon' form. The maximum value of the electric field in a thermal breaking plasma is obtained and compared to the cold plasma limit. The results of computer simulations for different initial electron distribution functions are in agreement with the theoretical conclusions. The after-wavebreak regime is then examined, and a semi-analytical model of the density evolution is constructed. Finally the results of two dimensional particle in cell simulations for different initial electron distribution functions are compared, and the role of thermal effects in enhancing particle injection is noted.

Bulanov, Sergei V.; Esirkepov, Timur Zh.; Kando, Masaki; Koga, James K.; Pirozhkov, Alexander S.; Nakamura, Tatsufumi [QuBS, Japan Atomic Energy Agency, 1-8-7 Umemidai, Kizugawa, Kyoto 619-0215 (Japan); Bulanov, Stepan S. [University of California, Berkeley, California 94720 (United States); Schroeder, Carl B.; Esarey, Eric [Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Califano, Francesco; Pegoraro, Francesco [Physics Department, University of Pisa, Pisa 56127 (Italy)

2012-11-15T23:59:59.000Z

70

2013 Science Bowl | Princeton Plasma Physics Lab  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsrucLasDelivered‰PNGExperience hands-onASTROPHYSICS H. I.Plasma Camp View larger imageUS

71

Plasma behaviour at high beta and high density in the Madison Symmetric Torus RFP  

SciTech Connect (OSTI)

Pellet fuelling of improved confinement Madison Symmetric Torus (MST) plasmas has resulted in high density and high plasma beta. The density in improved confinement discharges has been increased fourfold, and a record plasma beta (beta(tot) = 26%) for the improved confinement reversed-field pinch (RFP) has been achieved. At higher beta, a new regime for instabilities is accessed in which local interchange and global tearing instabilities are calculated to be linearly unstable, but experimentally, no severe effect, e. g., a disruption, is observed. The tearing instability, normally driven by the current gradient, is driven by the pressure gradient in this case, and there are indications of increased energy transport ( as compared with low-density improved confinement). Pellet fuelling is also compared with enhanced edge fuelling of standard confinement RFP discharges for the purpose of searching for a density limit in MST. In standard-confinement discharges, pellet fuelling peaks the density profile where edge fuelling cannot, but transport appears unchanged. For a limited range of plasma current, MST discharges with edge fuelling are constrained to a maximum density corresponding to the Greenwald limit. This limit is surpassed in pellet-fuelled improved confinement discharges.

Wyman, M. [University of Wisconsin, Madison; Chapman, B. E. [University of Wisconsin, Madison; Ahn, J. W. [University of Wisconsin, Madison; Almagri, A. F. [University of Wisconsin, Madison; Anderson, J. [University of Wisconsin, Madison; Bonomo, F. [Consorzio RFX, Italy; Bower, D L [University of California, Los Angeles; Combs, Stephen Kirk [ORNL; Craig, D. [University of Wisconsin, Madison; Foust, Charles R [ORNL

2009-01-01T23:59:59.000Z

72

Science Education | Princeton Plasma Physics Lab  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May Jun Jul(Summary)morphinanInformation Desert Southwest RegionatSearchScheduled System Outages NERSCScience BriefsScience2015 About

73

About Science Education | Princeton Plasma Physics Lab  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsruc Documentation RUCProductstwrmrAre the Effects ofAbout Science Education Our Mission Using the

74

Science Education Blog | Princeton Plasma Physics Lab  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsrucLas ConchasPassiveSubmitted for USMaterialstheterahertzonExploreStudies » Science DMZ April

75

Science Education Lab | Princeton Plasma Physics Lab  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsrucLas ConchasPassiveSubmitted for USMaterialstheterahertzonExploreStudies » Science DMZ

76

Science Education Programs | Princeton Plasma Physics Lab  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsrucLas ConchasPassiveSubmitted for USMaterialstheterahertzonExploreStudies » Science DMZ

77

Science Education | Princeton Plasma Physics Lab  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsrucLas ConchasPassiveSubmitted for USMaterialstheterahertzonExploreStudies » Science Events

78

Science literacy | Princeton Plasma Physics Lab  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsrucLas ConchasPassiveSubmitted forHighlights Nuclear Physics (NP) NP HomeHasan Below is aScience

79

Nonlocal theory of electromagnetic wave decay into two electromagnetic waves in a rippled density plasma channel  

SciTech Connect (OSTI)

Parametric decay of a large amplitude electromagnetic wave into two electromagnetic modes in a rippled density plasma channel is investigated. The channel is taken to possess step density profile besides a density ripple of axial wave vector. The density ripple accounts for the momentum mismatch between the interacting waves and facilitates nonlinear coupling. For a given pump wave frequency, the requisite ripple wave number varies only a little w.r.t. the frequency of the low frequency decay wave. The radial localization of electromagnetic wave reduces the growth rate of the parametric instability. The growth rate decreases with the frequency of low frequency electromagnetic wave.

Sati, Priti; Tripathi, V. K. [Indian Institute of Technology, Hauz Khas, Delhi 110054 (India)

2012-12-15T23:59:59.000Z

80

IEEE TRANSACTIONS ON PLASMA SCIENCE, VOL. 34, NO. 3, JUNE 2006 755 Nonequilibrium EEDF in Gas Discharge Plasmas  

E-Print Network [OSTI]

­ion creation and gas excitation are due to the impact of fast elec- trons in the plasma volume, while electron discharges. This paper is organized as follows. Basic processes in gas dis- charge plasmas when EEDF and thusIEEE TRANSACTIONS ON PLASMA SCIENCE, VOL. 34, NO. 3, JUNE 2006 755 Nonequilibrium EEDF in Gas

Kaganovich, Igor

Note: This page contains sample records for the topic "density plasma science" from the National Library of EnergyBeta (NLEBeta).
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they are not comprehensive nor are they the most current set.
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to obtain the most current and comprehensive results.


81

Photoemission rate of strongly interacting quark-gluon plasma at finite density  

SciTech Connect (OSTI)

We calculate the thermal spectral function of strongly interacting Yang-Mills plasma with finite density using the holographic technique. The gravity dual of the finite temperature and density is taken as the Reissner-Nordstroem-anti-de Sitter black hole. In the presence of charge, linearized vector modes of gravitational and electromagnetic perturbation are coupled with each other. By introducing master variables for these modes, we solve the coupled system and calculate spectral function. The spectral function gets a new peak due to the density effect, which is most dramatic in the momentum plot with fixed frequency. We also calculate the photoemission rate of our gauge theory plasma from the spectral function for lightlike momentum. AC, dc conductivity, and their density dependence is also computed.

Jo, Kwanghyun; Sin, Sang-Jin [Department of Physics, Hanyang University, Seoul 133-791 (Korea, Republic of)

2011-01-15T23:59:59.000Z

82

The formation of reverse shocks in magnetized high energy density supersonic plasma flows  

SciTech Connect (OSTI)

A new experimental platform was developed, based on the use of supersonic plasma flow from the ablation stage of an inverse wire array z-pinch, for studies of shocks in magnetized high energy density physics plasmas in a well-defined and diagnosable 1-D interaction geometry. The mechanism of flow generation ensures that the plasma flow (Re{sub M}???50, M{sub S}???5, M{sub A}???8, V{sub flow}???100?km/s) has a frozen-in magnetic field at a level sufficient to affect shocks formed by its interaction with obstacles. It is found that in addition to the expected accumulation of stagnated plasma in a thin layer at the surface of a planar obstacle, the presence of the magnetic field leads to the formation of an additional detached density jump in the upstream plasma, at a distance of ?c/?{sub pi} from the obstacle. Analysis of the data obtained with Thomson scattering, interferometry, and local magnetic probes suggests that the sub-shock develops due to the pile-up of the magnetic flux advected by the plasma flow.

Lebedev, S. V., E-mail: s.lebedev@imperial.ac.uk, E-mail: l.suttle10@imperial.ac.uk; Suttle, L.; Swadling, G. F.; Bennett, M.; Bland, S. N.; Burdiak, G. C.; Chittenden, J. P.; Grouchy, P. de; Hall, G. N.; Hare, J. D.; Kalmoni, N.; Niasse, N.; Patankar, S.; Smith, R. A.; Suzuki-Vidal, F. [Blackett Laboratory, Imperial College, London SW7 2BW (United Kingdom)] [Blackett Laboratory, Imperial College, London SW7 2BW (United Kingdom); Burgess, D.; Clemens, A. [Astronomy Unit, School of Physics and Astronomy, Queen Mary University of London, London E1 4NS (United Kingdom)] [Astronomy Unit, School of Physics and Astronomy, Queen Mary University of London, London E1 4NS (United Kingdom); Ciardi, A. [LERMA, Observatoire de Paris and École Normale Supérieure Université Pierre et Marie Curie, UMR 8112 CNRS, 75231 Paris (France)] [LERMA, Observatoire de Paris and École Normale Supérieure Université Pierre et Marie Curie, UMR 8112 CNRS, 75231 Paris (France); Sheng, L. [Blackett Laboratory, Imperial College, London SW7 2BW (United Kingdom) [Blackett Laboratory, Imperial College, London SW7 2BW (United Kingdom); Northwest Institute of Nuclear Technology, Xi'an 710024 (China); Yuan, J. [Blackett Laboratory, Imperial College, London SW7 2BW (United Kingdom) [Blackett Laboratory, Imperial College, London SW7 2BW (United Kingdom); Institute of Fluid Physics, China Academy of Engineering Physics, Mianyang 621900 (China); and others

2014-05-15T23:59:59.000Z

83

J. L. Ellsworth, J. Kesner MIT Plasma Science and Fusion Center  

E-Print Network [OSTI]

of Plasma Physics Annual Meeting 2003 Albuquerque, New Mexico 27 October 2003 X-Ray Diagnostics electron plasma means that plasma temperature can be diagnosed with bremsstrahlung diagnostics. · MeasureJ. L. Ellsworth, J. Kesner MIT Plasma Science and Fusion Center D.T. Garnier, A.K. Hansen, M

84

Effect of electron density profile on power absorption of high frequency electromagnetic waves in plasma  

SciTech Connect (OSTI)

Considering different typical electron density profiles, a multi slab approximation model is built up to study the power absorption of broadband (0.75-30 GHz) electromagnetic waves in a partially ionized nonuniform magnetized plasma layer. Based on the model, the power absorption spectra for six cases are numerically calculated and analyzed. It is shown that the absorption strongly depends on the electron density fluctuant profile, the background electron number density, and the collision frequency. A potential optimum profile is also analyzed and studied with some particular parameters.

Xi Yanbin; Liu Yue [MOE Key Laboratory of Materials Modification by Laser, Electron, and Ion Beams, School of Physics and Optoelectronic Technology, Dalian University of Technology, Dalian 116024 (China)

2012-07-15T23:59:59.000Z

85

Effects of a random spatial variation of the plasma density on the mode conversion in cold, unmagnetized, and stratified plasmas  

SciTech Connect (OSTI)

We study the effects of a random spatial variation of the plasma density on the mode conversion of electromagnetic waves into electrostatic oscillations in cold, unmagnetized, and stratified plasmas. Using the invariant imbedding method, we calculate precisely the electromagnetic field distribution and the mode conversion coefficient, which is defined to be the fraction of the incident wave power converted into electrostatic oscillations, for the configuration where a numerically generated random density variation is added to the background linear density profile. We repeat similar calculations for a large number of random configurations and take an average of the results. We obtain a peculiar nonmonotonic dependence of the mode conversion coefficient on the strength of randomness. As the disorder increases from zero, the maximum value of the mode conversion coefficient decreases initially, then increases to a maximum, and finally decreases towards zero. The range of the incident angle in which mode conversion occurs increases monotonically as the disorder increases. We present numerical results suggesting that the decrease of mode conversion mainly results from the increased reflection due to the Anderson localization effect originating from disorder, whereas the increase of mode conversion of the intermediate disorder regime comes from the appearance of many resonance points and the enhanced tunneling between the resonance points and the cutoff point. We also find a very large local enhancement of the magnetic field intensity for particular random configurations. In order to obtain high mode conversion efficiency, it is desirable to restrict the randomness close to the resonance region.

Jung Yu, Dae [School of Space Research, Kyung Hee University, Yongin 446-701 (Korea, Republic of)] [School of Space Research, Kyung Hee University, Yongin 446-701 (Korea, Republic of); Kim, Kihong [Department of Energy Systems Research, Ajou University, Suwon 443-749 (Korea, Republic of)] [Department of Energy Systems Research, Ajou University, Suwon 443-749 (Korea, Republic of)

2013-12-15T23:59:59.000Z

86

Modelling of the internal dynamics and density in a tens of joules plasma focus device  

SciTech Connect (OSTI)

Using MHD theory, coupled differential equations were generated using a lumped parameter model to describe the internal behaviour of the pinch compression phase in plasma focus discharges. In order to provide these equations with appropriate initial conditions, the modelling of previous phases was included by describing the plasma sheath as planar shockwaves. The equations were solved numerically, and the results were contrasted against experimental measurements performed on the device PF-50J. The model is able to predict satisfactorily the timing and the radial electron density profile at the maximum compression.

Marquez, Ariel [CNEA and Instituto Balseiro, 8402 Bariloche (Argentina); Gonzalez, Jose [INVAP-CONICET and Instituto Balseiro, 8402 Bariloche, Argentina. (Argentina); Tarifeno-Saldivia, Ariel; Pavez, Cristian; Soto, Leopoldo [CCHEN, Comision Chilena de Energia Nuclear, Casilla 188-D, Santiago (Chile); Center for Research and Applications in Plasma Physics and Pulsed Power, P4 (Chile); Clausse, Alejandro [CNEA-CONICET and Universidad Nacional del Centro, 7000 Tandil (Argentina)

2012-01-15T23:59:59.000Z

87

Metrology Challenges for High Energy Density Science Target Manufacture  

SciTech Connect (OSTI)

Currently, High Energy Density Science (HEDS) experiments are used to support and qualify predictive physics models. These models assume ideal conditions such as energy (input) and device (target) geometry. The experiments rely on precision targets constructed from components with dimensions in the millimeter range, while having micrometer-scale, functional features, including planar steps, sine waves, and step-joint geometry on hemispherical targets. Future target designs will likely have features and forms that rival or surpass current manufacturing and characterization capability. The dimensional metrology of these features is important for a number of reasons, including qualification of sub-components prior to assembly, quantification of critical features on the as-built assemblies and as a feedback mechanism for fabrication process development. Variations in geometry from part to part can lead to functional limitations, such as unpredictable instabilities during an experiment and the inability to assemble a target from poorly matched sub-components. Adding to the complexity are the large number and variety of materials, components, and shapes that render any single metrology technique difficult to use with low uncertainty. Common materials include metal and glass foams, doped transparent and opaque plastics and a variety of deposited and wrought metals. A suite of metrology tools and techniques developed to address the many critical issues relevant to the manufacture of HEDS targets including interferometry, x-ray radiography and contact metrology are presented including two sided interferometry for absolute thickness metrology and low force probe technology for micrometer feature coordinate metrology.

Seugling, R M; Bono, M J; Davis, P

2009-02-19T23:59:59.000Z

88

Experimental and Computational Studies of High Energy Density Plasma Streams Ablated from Fine Wires  

SciTech Connect (OSTI)

Experimental and computational studies of high energy density plasma streams ablated from fine wires. Laboratory of Plasma Studies, School of Electrical and Computer Engineering, Cornell University. Principal Investigators: Dr. John B. Greenly and Dr. Charles E. Seyler. This report summarizes progress during the final year of this project to study the physics of high energy density (HED) plasma streams of 10^17-10^20/cm3 density and high velocity (~100-500 km/s). Such streams are produced from 5-250 micrometer diameter wires heated and ionized by a 1 MA, 250 ns current pulse on the COBRA pulsed power facility at Cornell University. Plasma is ablated from the wires and is driven away to high velocity by unbalanced JxB force. A wire, or an array of wires, can persist as an essentially stationary, continuous source of this streaming plasma for >200 ns, even with driving magnetic fields of many Tesla and peak current densities in the plasma of many MA/cm2. At the heart of the ablation stream generation is the continuous transport of mass from the relatively cold, near-solid-density wire "core" into current-carrying plasma within 1 mm of the wire, followed by the magnetic acceleration of that plasma and its trapped flux to form a directed stream. In the first two years of this program, an advancing understanding of ablation physics led to the discovery of several novel wire ablation experimental regimes. In the final year, one of these new HED plasma regimes has been studied in quantitative detail. This regime studies highly reproducible magnetic reconnection in strongly radiating plasma with supersonic and superalfvenic flow, and shock structures in the outflow. The key discovery is that very heavy wires, e.g. 250 micrometer diameter Al or 150 micrometer Cu, behave in a qualitatively different way than the lighter wires typically used in wire-array Z-pinches. Such wires can be configured to produce a static magnetic X-point null geometry that stores magnetic and thermal energy; reconnection and outflow are triggered when the current begins to decrease and the electric field reverses. The reconnecting flow is driven by both magnetic and thermal pressure forces, and it has been found to be possible to vary the configuration so that one or the other dominates. The magnetic null extends into a current sheet that is heated and radiates strongly, with supersonic outflows. This is the first study of reconnection in this HED plasma regime. This compressible, radiative regime, and the triggering mechanism, may be relevant to solar and astrophysical processes. The PERSEUS extended MHD code has been developed for simulation of these phenomena, and will continue to be used and further developed to help interpret and understand experimental results, as well as to guide experimental design. The code is well-suited to simulations of shocks, and includes Hall and electron inertia physics that appear to be of importance in a number of ablation flow regimes, and definitely in the reconnection regime when gradient scales are comparable to the ion inertial scale. During the final year, our graduate student supported by this grant completed a new version of PERSEUS with the finite volume computational scheme replaced by a discontinuous Galerkin method that gives much less diffusive behavior and allows faster run time and higher spatial resolution. Thecode is now being used to study shock structures produced in the outflow region of the reconnection regime.

Greenly, John B. [Cornell University; Seyler, Charles [Cornell University

2014-03-30T23:59:59.000Z

89

Current initiation in low-density foam z-pinch plasmas  

SciTech Connect (OSTI)

Low density agar and aerogel foams were tested as z-pinch loads on the SATURN accelerator. In these first experiments, we studied the initial plasma conditions by measuring the visible emission at early times with a framing camera and 1-D imaging. At later time, near the stagnation when the plasma is hotter, x-ray imaging and spectral diagnostics were used to characterize the plasma. Filamentation and arcing at the current contacts was observed. None of the implosions were uniform along the z-axis. The prime causes of these problems are believed to be the electrode contacts and the current return configuration and these are solvable. Periodic phenomena consistent with the formation of instabilities were observed on one shot, not on others, implying that there may be a way of controlling instabilities in the pinch. Many of the issues involving current initiation may be solvable. Solutions are discussed.

Derzon, M.; Nash, T.; Allshouse, G. [and others

1996-07-01T23:59:59.000Z

90

Density Diagnostics of the Hot Plasma in AE Aquarii with XMM-Newton  

E-Print Network [OSTI]

High resolution spectroscopy of AE Aquarii with the XMM-Newton RGS has enabled us to measure the electron number density of the X-ray-emitting hot plasma to be ~1E11/cm**-3 by means of intensity ratios of the He-like triplet of Nitrogen and Oxygen. Incorporating with the emission measure evaluated by the EPIC cameras, we have also found a linear scale of the plasma to be ~5E10 cm. Both these values, obtained model-independently, are incompatible with a standard post-shock accretion column of a magnetized white dwarf, but are naturally interpreted as the plasma being formed through interaction between an accretion flow and the magnetosphere of the white dwarf. Our results provide another piece of evidence of the magnetic propeller effect being at work in AE Aqr.

Kei Itoh; Manabu Ishida; Hideyo Kunieda

2004-12-21T23:59:59.000Z

91

Laser-driven hole boring and gamma-ray emission in high-density plasmas  

E-Print Network [OSTI]

Ion acceleration in laser-produced dense plasmas is a key topic of many recent investigations thanks to its potential applications. Besides, at forthcoming laser intensities ($I \\gtrsim 10^{23} \\text{W}\\,\\text{cm}^{-2}$) interaction of laser pulses with plasmas can be accompanied by copious gamma-ray emission. Here we demonstrate the mutual influence of gamma-ray emission and ion acceleration during relativistic hole boring in high-density plasmas with ultra-intense laser pulses. If gamma-ray emission is abundant, laser pulse reflection and hole-boring velocity are lower and gamma-ray radiation pattern is narrower than in the case of low emission. Conservation of energy and momentum allows one to elucidate the effects of gamma-ray emission which are more pronounced at higher hole-boring velocities.

Nerush, Evgeny

2014-01-01T23:59:59.000Z

92

Electron density and temperature measurement by continuum radiation emitted from weakly ionized atmospheric pressure plasmas  

SciTech Connect (OSTI)

The electron-atom neutral bremsstrahlung continuum radiation emitted from weakly ionized plasmas is investigated for electron density and temperature diagnostics. The continuum spectrum in 450–1000?nm emitted from the argon atmospheric pressure plasma is found to be in excellent agreement with the neutral bremsstrahlung formula with the electron-atom momentum transfer cross-section given by Popovi?. In 280–450?nm, however, a large discrepancy between the measured and the neutral bremsstrahlung emissivities is observed. We find that without accounting for the radiative H{sub 2} dissociation continuum, the temperature, and density measurements would be largely wrong, so that it should be taken into account for accurate measurement.

Park, Sanghoo; Choe, Wonho, E-mail: wchoe@kaist.ac.kr [Department of Physics, Korea Advanced Institute of Science and Technology, 291 Daehak-ro, Yuseong-gu, Daejeon 305-701 (Korea, Republic of); Youn Moon, Se [High-enthalpy Plasma Research Center, Chonbuk National University, 567 Baekje-daero, Deokjin-gu, Jeonju 561-756 (Korea, Republic of); Park, Jaeyoung [5771 La Jolla Corona Drive, La Jolla, CA 92037 (United States)

2014-02-24T23:59:59.000Z

93

Quasilinear dynamics of a cloud of hot electrons propagating through a plasma with decreasing density and temperature  

SciTech Connect (OSTI)

The effects of plasma inhomogeneities on the propagation of a cloud of hot electrons through a cold background plasma and generation of Langmuir waves are investigated using numerical simulations of the quasilinear equations. It is found that in a plasma with decreasing density the quasilinear relaxation of the electron distribution in velocity space is accelerated and the levels of the generated Langmuir waves are enhanced. The magnitude of the induced emission rate is increased and its maximum value moves to lower velocities. Due to density gradient the height of plateau shows an increase at small distances and a corresponding decrease at large distances. It is also found that in a plasma with decreasing temperature, the relaxation of the beam is retarded, the spectral density of Langmuir waves is broadened, and the height of the plateau decreases below its value in a uniform plasma. In the presence of both density and temperature gradients, at given position, the height and upper boundary of the plateau and the level of Langmuir waves are all increased at small velocities. The spatial expansion of the beam is increased by the plasma inhomogeneities, but its average velocity of propagation decreases. Initially, at a given position, the velocity at the upper boundary of the plateau is smaller in the presence of the density gradient than in the uniform plasma but the reverse is true at longer times. Due to temperature gradient, at large times and small distances, the upper boundary of the plateau is increased above its value in the uniform plasma. Because of fast relaxation, the value of the lower boundary of the plateau in the plasma with decreasing density is always less than its value in the uniform plasma. It is found that the local velocity of the beam decreases when the density gradient is present. The local velocity spread of the beam remains unchanged during the propagation of the beam in the uniform plasma, but increases in the presence of inhomogeneities.

Foroutan, G. [Department of Physics, Faculty of Science, Sahand University of Technology, Tabriz 51335-1996 (Iran, Islamic Republic of); School of Physics, The University of Sydney, Sydney NSW 2006 (Australia); Khalilpour, H.; Moslehi-Fard, M. [Faculty of Physics, Tabriz University, Tabriz 51664 (Iran, Islamic Republic of); Li, B.; Robinson, P. A. [School of Physics, University of Sydney, Sydney NSW 2006 (Australia)

2008-12-15T23:59:59.000Z

94

COLD BUBBLE FORMATION DURING TOKAMAK DENSITY LIMIT DISRUPTIONS  

E-Print Network [OSTI]

COLD BUBBLE FORMATION DURING TOKAMAK DENSITY LIMIT DISRUPTIONS J. HOWARD, M. PERSSON* Plasma Research Laboratory, Research School of Physical Sciences, Australian National University, Canberra

Howard, John

95

Materials Science and Engineering A297 (2001) 235243 Plasma-sprayed ceramic coatings: anisotropic elastic and  

E-Print Network [OSTI]

anisotropic elastic stiffnesses and thermal conductivities of the plasma sprayed ceramic coatingMaterials Science and Engineering A297 (2001) 235­243 Plasma-sprayed ceramic coatings: anisotropic are derived. © 2001 Elsevier Science S.A. All rights reserved. Keywords: Thermal spray; Elastic properties

Sevostianov, Igor

96

IEEE TRANSACTIONSON PLASMA SCIENCE,VOL. 21, NO. 1, FEBRUARY 1993 Phase-Matched Third Harmonic  

E-Print Network [OSTI]

IEEE TRANSACTIONSON PLASMA SCIENCE,VOL. 21, NO. 1, FEBRUARY 1993 ~ 105 Phase-Matched Third Harmonic Generation in a Plasma J. M. Rax and N. J. Fisch Abstract-Relativistic third harmonic generationin a plasma is investigated. The growth of a third harmonic wave is limited by the difference between the phase velocity

97

Plasma-Density Determination from X-Ray Radiography of Laser-Driven Spherical Implosions F. J. Marshall, P. W. McKenty, J. A. Delettrez, R. Epstein, J. P. Knauer, and V. A. Smalyuk  

E-Print Network [OSTI]

to sampling the areal density at the time of fusion particle production. In non-igniting capsules, the cold, R. D. Petrasso, and F. H. Se´guin Plasma Science and Fusion Center, Massachusetts Institute confinement fusion (ICF) relies on the com- pression of spherical targets by means of a high power driver

98

Organization by Gordon Research Conferences of the 2012 Plasma Processing Science Conference 22-27 July 2012  

SciTech Connect (OSTI)

The 2012 Gordon Research Conference on Plasma Processing Science will feature a comprehensive program that will highlight the most cutting edge scientific advances in plasma science and technology as well as explore the applications of this nonequilibrium medium in possible approaches relative to many grand societal challenges. Fundamental science sessions will focus on plasma kinetics and chemistry, plasma surface interactions, and recent trends in plasma generation and multi-phase plasmas. Application sessions will explore the impact of plasma technology in renewable energy, the production of fuels from renewable feedstocks and carbon dioxide neutral solar fuels (from carbon dioxide and water), and plasma-enabled medicine and sterilization.

Jane Chang

2012-07-27T23:59:59.000Z

99

Application of soft X-ray lasers for probing high density plasmas  

SciTech Connect (OSTI)

The reliability and characteristics of collisionally pumped soft x-ray lasers make them ideal for a wide variety of plasma diagnostics. These systems now operate over a wavelength range extending from 35 to 400 {Angstrom} and have output energies as high as 10 mJ in 150 ps pulses. The beam divergence of these lasers is less than 15 mrad and they have a typical linewidth of {Delta}{lambda}/{lambda} {approximately} 10{sup -4} making them the brightest xuv sources available. In this paper we will describe the use of x-ray lasers to probe high density plasmas using a variety of diagnostic techniques. Using an x-ray laser and a multilayer mirror imaging system we have studied hydrodynamic imprinting of laser speckle pattern on directly driven thin foils with 1-2 {mu}m spatial resolution. Taking advantage of recently developed multilayer beamsplitters we have constructed and used a Mach-Zehnder interferometer operating at 155 {Angstrom} to probe 1-3 mm size laser produced plasmas with peak electron densities of 4 x 10{sup 21} cm{sup -3}. A comparison of our results with computer simulations will be presented.

Da Silva, L.B.; Barbee, T.W. Jr.; Cauble, R. [and others

1996-08-01T23:59:59.000Z

100

Device and method for relativistic electron beam heating of a high-density plasma to drive fast liners  

DOE Patents [OSTI]

A device and method for relativistic electron beam heating of a high-density plasma in a small localized region. A relativistic electron beam generator or accelerator produces a high-voltage electron beam which propagates along a vacuum drift tube and is modulated to initiate electron bunching within the beam. The beam is then directed through a low-density gas chamber which provides isolation between the vacuum modulator and the relativistic electron beam target. The relativistic beam is then applied to a high-density target plasma which typically comprises DT, DD, hydrogen boron or similar thermonuclear gas at a density of 10.sup.17 to 10.sup.20 electrons per cubic centimeter. The target gas is ionized prior to application of the electron beam by means of a laser or other preionization source to form a plasma. Utilizing a relativistic electron beam with an individual particle energy exceeding 3 MeV, classical scattering by relativistic electrons passing through isolation foils is negligible. As a result, relativistic streaming instabilities are initiated within the high-density target plasma causing the relativistic electron beam to efficiently deposit its energy and momentum into a small localized region of the high-density plasma target. Fast liners disposed in the high-density target plasma are explosively or ablatively driven to implosion by a heated annular plasma surrounding the fast liner which is generated by an annular relativistic electron beam. An azimuthal magnetic field produced by axial current flow in the annular plasma, causes the energy in the heated annular plasma to converge on the fast liner.

Thode, Lester E. (Los Alamos, NM)

1981-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "density plasma science" from the National Library of EnergyBeta (NLEBeta).
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101

Efficient plasma production by intense laser irradiation of low density foam targets  

SciTech Connect (OSTI)

Experimental investigations conducted on low density structured materials, such as foams have been presented in this paper. These low density foam targets having a density greater than the critical density of the laser produced plasma ({rho}{sub cr{approx_equal}}3 mg{center_dot}cm{sup -3} at laser wavelength 1.06 {mu}m) have been envisaged to have enhanced laser absorption. Experiments were done with an indigenously developed, focused 15 Joule/500 ps Nd: Glass laser at {lambda} = 1064 nm. The focused laser intensity on the target was in the range of I{approx_equal}10{sup 13}-2x10{sup 14} W/cm{sup 2}. Laser absorption was determined by energy balance experiments. Laser energy absorption was observed to be higher than 85%. In another set of experiments, low density carbon foam targets of density 150 mg/cc were compared with the solid carbon targets. The x-ray emission in the soft x-ray region was observed to increase in foam target by about 1.8 times and 2.3 times in carbon foam and Pt doped foam as compared to solid carbon. Further, investigations were also carried out to measure the energy transmitted through the sub-critical density TAC foam targets having a density less than 3 mg/cc. Such targets have been proposed to be used for smoothening of intensity ripples in a high power laser beam profile. Transmission exceeding 1.87% has been observed and consistent with results from other laboratories.

Tripathi, S.; Chaurasia, S.; Munda, D. S.; Gupta, N. K.; Dhareshwar, L. J. [Laser and Neutron Physics Division, Bhabha Atomic Research Centre, Mumbai 85 (India); Nataliya, B. [Lebedev Physical Institute, Moscow (Russian Federation)

2010-12-01T23:59:59.000Z

102

Test particle simulation of direct laser acceleration in a density-modulated plasma waveguide  

SciTech Connect (OSTI)

Direct laser acceleration (DLA) of electrons by the use of the intense axial electric field of an ultrafast radially polarized laser pulse is a promising technique for future compact accelerators. Density-modulated plasma waveguides can be implemented for guiding the propagation of the laser pulse to extend the acceleration distance and for the quasi-phase-matching between the accelerated electrons and the laser pulse. A test particle model is developed to study the optimal axial density modulation structure of plasma waveguides for laser pulses to efficiently accelerate co-propagating electrons. A simple analytical approach is also presented, which can be used to estimate the energy gain in DLA. The analytical model is validated by the test particle simulation. The effect of injection phase and acceleration of electrons injected at various radial positions are studied. The results indicate that a positively chirped density modulation of the waveguide structure is required to accelerate electron with low initial energies, and can be effectively optimized. A wider tolerance on the injection phase and radial distance from the waveguide axis exists for electrons injected with a higher initial energy.

Lin, M.-W.; Jovanovic, I. [Department of Mechanical and Nuclear Engineering, Pennsylvania State University, University Park, Pennsylvania 16802 (United States)

2012-11-15T23:59:59.000Z

103

Two photon absorption laser induced fluorescence measurements of neutral density in a helicon plasma  

SciTech Connect (OSTI)

We have developed a new diagnostic based on two-photon absorption laser induced fluorescence (TALIF). We use a high intensity (5?MW/cm{sup 2}), narrow bandwidth (0.1?cm{sup ?1}) laser to probe the ground state of neutral hydrogen, deuterium and krypton with spatial resolution better than 0.2?cm, a time resolution of 10?ns, and a measurement cadence of 20?Hz. Here, we describe proof-of-principle measurements in a helicon plasma source that demonstrate the TALIF diagnostic is capable of measuring neutral densities spanning four orders of magnitude; comparable to the edge neutral gradients predicted in the DIII-D tokamak pedestal. The measurements are performed in hydrogen and deuterium plasmas and absolute calibration is accomplished through TALIF measurements in neutral krypton. The optical configuration employed is confocal, i.e., both light injection and collection are accomplished with a single lens through a single optical port in the vacuum vessel. The wavelength resolution of the diagnostic is sufficient to separate hydrogen and deuterium spectra and we present measurements from mixed hydrogen and deuterium plasmas that demonstrate isotopic abundance measurements are feasible. Time resolved measurements also allow us to explore the evolution of the neutral hydrogen density and temperature and effects of wall recycling. We find that the atomic neutral density grows rapidly at the initiation of the discharge, reaching the steady-state value within 1?ms. Additionally, we find that neutral hydrogen atoms are born with 0.08?eV temperatures, not 2?eV as is typically assumed.

Galante, M. E.; Magee, R. M.; Scime, E. E. [Department of Physics, West Virginia University, Morgantown, West Virginia 26506 (United States)] [Department of Physics, West Virginia University, Morgantown, West Virginia 26506 (United States)

2014-05-15T23:59:59.000Z

104

Electron density diagnostic for hot plasmas in coronal regime by using B-like ions  

E-Print Network [OSTI]

Line ratio of $3d-2p$ transition lines in boron-like spectra of Si X, S XII, Ar XIV and Fe XXII has been investigated. Collisional-radiative model calculations reveal that the line ratio is sensitive to the electron density in ranges of $n_{\\rm e}=4.0\\times10^7-3.0\\times10^{10}$ cm$^{-3}$, $4.0\\times10^8-3.0\\times10^{11}$ cm$^{-3}$, $3.0\\times10^9-4.0\\times10^{12}$ cm$^{-3}$ and $2.0\\times10^{12}-3.0\\times10^{15}$ cm$^{-3}$, respectively. This complements the K-shell diagnostics of helium-like ions. By comparison between the prediction and the measured values, effective electron densities in the electron beam ion trap (EBIT) plasmas performed by Lepson and collaborators at Lawrence Livermore EBIT, are estimated to be $n_{\\rm e}=3.4^{+0.8}_{-0.6}\\times10^{10}$ cm$^{-3}$ and $5.6^{+1.0}_{-1.1}\\times10^{10}$ cm$^{-3}$ for sulphur and argon plasmas. In case of argon, a good agreement is shown with the actual electron density derived from N VI K-shell spectrum. We further explore the $3d-2p$ transition lines of Si X and S XII in the stellar coronal spectra measured with the Low Energy Transmission Grating Spectrometer combined with High Resolution Camera on board the {\\it Chandra X-ray Observatory}. The constrained electron densities show a good agreement with the those determined from C V and O VII K-shell spectra.

Guiyun Liang; Gang Zhao

2008-03-14T23:59:59.000Z

105

Effect of shockwave-induced density jump on laser plasma interactions in low-pressure ambient air  

E-Print Network [OSTI]

1 Effect of shockwave-induced density jump on laser plasma interactions in low-pressure ambient air jump were investigated in low- pressure ambient air during the laser pulse using an optical interferometer. A tiny shockwave-induced density jump could be observed clearly in ambient air with pressure

Tillack, Mark

106

Comparison of surface vacuum ultraviolet emissions with resonance level number densities. I. Argon plasmas  

SciTech Connect (OSTI)

Vacuum ultraviolet (VUV) photons emitted from excited atomic states are ubiquitous in material processing plasmas. The highly energetic photons can induce surface damage by driving surface reactions, disordering surface regions, and affecting bonds in the bulk material. In argon plasmas, the VUV emissions are due to the decay of the 1s{sub 4} and 1s{sub 2} principal resonance levels with emission wavelengths of 104.8 and 106.7?nm, respectively. The authors have measured the number densities of atoms in the two resonance levels using both white light optical absorption spectroscopy and radiation-trapping induced changes in the 3p{sup 5}4p?3p{sup 5}4s branching fractions measured via visible/near-infrared optical emission spectroscopy in an argon inductively coupled plasma as a function of both pressure and power. An emission model that takes into account radiation trapping was used to calculate the VUV emission rate. The model results were compared to experimental measurements made with a National Institute of Standards and Technology-calibrated VUV photodiode. The photodiode and model results are in generally good accord and reveal a strong dependence on the neutral gas temperature.

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

2014-03-15T23:59:59.000Z

107

Transition from order to chaos, and density limit, in magnetized plasmas  

E-Print Network [OSTI]

It is known that a plasma in a magnetic field, conceived microscopically as a system of point charges, can exist in a magnetized state, and thus remain confined, inasmuch as it is in an ordered state of motion, with the charged particles performing gyrational motions transverse to the field. Here we give an estimate of a threshold, beyond which transverse motion become chaotic, the electrons being unable to perform even one gyration, so that a breakdown should occur, with complete loss of confinement. The estimate is obtained by the methods of perturbation theory, taking as perturbing force acting on each electron that due to the so--called microfield, i.e., the electric field produced by all the other charges. We first obtain a general relation for the threshold, which involves the fluctuations of the microfield. Then, taking for such fluctuations the fomula given by Iglesias, Lebowitz and MacGowan for the model of a one component plasma with neutralizing background, we obtain a definite formula for the threshold, which corresponds to a density limit increasing as the square of the imposed magnetic field. Such a theoretical density limit is found to fit pretty well the empirical data for collapses of fusion machines.

A. Carati; M. Zuin; A. Maiocchi; M. Marino; E. Martines; L. Galgani

2012-02-17T23:59:59.000Z

108

Sean Finnegan & Ann Satsangi Fusion Energy Sciences  

E-Print Network [OSTI]

Energy (IFE) science. #12;HEDLP definition "High-energy-density laboratory plasma (HEDLP) physicsSean Finnegan & Ann Satsangi Fusion Energy Sciences Program Management Team for HEDLP Fusion Power Associates15 December 2011 Comments on the DOE-SC Program in High Energy Density Laboratory Plasma Science

109

Diagnosing ions and neutrals via n=2 excited hydrogen atoms in plasmas with high electron density and low electron temperature  

SciTech Connect (OSTI)

Ion and neutral parameters are determined in the high electron density, magnetized, hydrogen plasma beam of an ITER divertor relevant plasma via measurements of the n=2 excited neutrals. Ion rotation velocity (up to 7 km/s) and temperature (2-3 eV{approx}T{sub e}) are obtained from analysis of H{alpha} spectra measured close to the plasma source. The methodology for neutral density determination is explained whereby measurements in the linear plasma beam of Pilot-PSI are compared to modeling. Ground-state atomic densities are obtained via the production rate of n=2 and the optical thickness of the Lyman-{alpha} transition (escape factor {approx}0.6) and yield an ionization degree >85% and dissociation degree in the residual gas of {approx}4%. A 30% proportion of molecules with a rovibrational excitation of more than 2 eV is deduced from the production rate of n=2 atoms. This proportion increases by more than a factor of 4 for a doubling of the electron density in the transition to ITER divertor relevant electron densities, probably because of a large increase in the production and confinement of ground-state neutrals. Measurements are made using laser-induced fluorescence (LIF) and absorption, the suitability of which are evaluated as diagnostics for this plasma regime. Absorption is found to have a much better sensitivity than LIF, mainly owing to competition with background emission.

Shumack, A. E.; Schram, D. C.; Biesheuvel, J.; Goedheer, W. J.; Rooij, G. J. van [FOM-Institute for Plasma Physics Rijnhuizen, Association EURATOM-FOM, Trilateral Euregio Cluster, Nieuwegein (Netherlands)

2011-03-15T23:59:59.000Z

110

Porkolab_FPA_12.4.2008 Plasma Science and Fusion Center  

E-Print Network [OSTI]

engineers, 1 technician and 4 graduate students #12;Porkolab_FPA_12.4.2008 The LDX is located at MITPorkolab_FPA_12.4.2008 Plasma Science and Fusion Center Highlights of Some Research Activities and the C-Mod Team Compact high- performance divertor tokamak research to establish the plasma physics

111

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  

SciTech Connect (OSTI)

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 inadequate 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.

None

2008-09-01T23:59:59.000Z

112

Science on Saturday Archive | Princeton Plasma Physics Lab  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Science on Saturday Archive 2014 Science on Saturday: Containing A Star On Earth: Understanding Turbulence At 100 Million Degrees January 11, 2014 Dr. Walter Guttenfelder, PPPL...

113

Measurements of electron density and temperature in the H-1 heliac plasma by helium line intensity ratios  

SciTech Connect (OSTI)

Electron density and temperature distributions in the H-1 heliac plasma are measured using the helium line intensity ratio technique based on a collisional-radiative model. An inversion approach with minimum Fisher regularization is developed to reconstruct the ratios of the local emission radiances from detected line-integrated intensities. The electron density and temperature inferred from the He I 667.8/728.1 and He I 728.1/706.5 nm line ratios are in good agreement with those from other diagnostic techniques in the inner region of the plasma. The electron density and temperature values appear to be a little high in the outer region of the plasma. Some possible causes of the discrepancy in the outer region are discussed.

Ma Shuiliang; Howard, John; Blackwell, Boyd D.; Thapar, Nandika [Plasma Research Laboratory, Australian National University, Canberra ACT 0200 (Australia)

2012-03-15T23:59:59.000Z

114

DENSITY AND MAGNETIC FIELD MEASUREMENTS IN THE TORMAC IV-c PLASMA  

E-Print Network [OSTI]

1974). R.B. Lovberg, in Plasma Diagnostic Techniques, R.H.the plasma using "non-ambiguous" diagnostics. There has beenand the plasma in contact with the wall. Diagnostics Tonnac

Coonrod Jr., John Walter

2011-01-01T23:59:59.000Z

115

Wavefront-sensor-based electron density measurements for laser-plasma accelerators  

E-Print Network [OSTI]

for laser-plasma accelerators G. R. Plateau, ? N. H. Matlis,driven plasma-wake?eld accelerator depends on the plasmaof the laser-plasma accelerator. It is shown that direct

Plateau, Guillaume

2010-01-01T23:59:59.000Z

116

2354 IEEE TRANSACTIONS ON PLASMA SCIENCE, VOL. 39, NO. 11, NOVEMBER 2011 Laser Diagnostic Imaging of Energetically Enhanced  

E-Print Network [OSTI]

2354 IEEE TRANSACTIONS ON PLASMA SCIENCE, VOL. 39, NO. 11, NOVEMBER 2011 Laser Diagnostic Imaging of Energetically Enhanced Flames Using Direct Microwave Plasma Coupling Xing Rao, Stephen Hammack, Campbell Carter in plasma-enhanced flames, where a nonthermal microwave plasma discharge is coupled di- rectly

Lee, Tonghun

117

Measurements of neutral density profiles using a deuterium Balmer-alpha diagnostic in the C-2 FRC plasma  

SciTech Connect (OSTI)

In C-2 field-reversed configuration (FRC) device, low neutral density outside the FRC separatrix is required to minimize the charge exchange loss of fast particles. Titanium gettering is used in C-2 to reduce the wall recycling and keep the neutral density low in plasma edge. The measurements of neutral density radial profile are desirable to understand the plasma recycling and the effects of titanium gettering. These measurements are also needed to study the interaction of neutral beams with FRC plasma and confinement of fast ions. Diagnostic based on absolute deuterium Balmer-alpha (D-alpha) radiation measurements is developed and deployed on C-2 device to measure the radial profile of neutral density. Simultaneous measurements of electron density and temperature are done using CO{sub 2} interferometer, Thomson scattering, and triple probes diagnostics along with absolute D-alpha radiation. Abel inversion was performed to get the time dependent radial profile of the local D-alpha emission density. Neutral density profiles are obtained under different machine conditions of titanium deposition.

Gupta, Deepak K.; Deng, B. H.; Knapp, K.; Sun, X.; Thompson, M. C. [Tri Alpha Energy, Rancho Santa Margarita, California 92688 (United States)

2012-10-15T23:59:59.000Z

118

DRAFT -FOR COMMENT -26 February 2001 Workshop on Burning Plasma Science  

E-Print Network [OSTI]

the Fusion Science Frontier 11-13 December 2000, Austin, TX [http seek to identify the scientific issues which would be at the frontier of fusion science and form are under study in the present generation of deuterium plasma experiments in the US and abroad. While

119

Wavefront-sensor-based electron density measurements for laser-plasma accelerators  

E-Print Network [OSTI]

After imaging the plasma to a primary focus shortly afterfocus was 1 mm above the nozzle. The laser pulse excited a plasma

Plateau, Guillaume

2010-01-01T23:59:59.000Z

120

Materials Science and Engineering A 445446 (2007) 186192 Plastic instabilities and dislocation densities during plastic  

E-Print Network [OSTI]

Materials Science and Engineering A 445­446 (2007) 186­192 Plastic instabilities and dislocation densities during plastic deformation in Al­Mg alloys Gyozo Horv´ath, Nguyen Q. Chinh, Jeno Gubicza, J 2006 Abstract Plastic deformation of Al­Mg alloys were investigated by analyzing the stress

Gubicza, Jenõ

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121

A passive measurement of dissociated atom densities in atmospheric pressure air discharge plasmas using vacuum ultraviolet self-absorption spectroscopy  

SciTech Connect (OSTI)

We demonstrate a method for determining the dissociation degree of atmospheric pressure air discharges by measuring the self-absorption characteristics of vacuum ultraviolet radiation from O and N atoms in the plasma. The atom densities are determined by modeling the amount of radiation trapping present in the discharge, without the use of typical optical absorption diagnostic techniques which require external sources of probing radiation into the experiment. For an 8.0?mm spark discharge between needle electrodes at atmospheric pressure, typical peak O atom densities of 8.5?×?10{sup 17}?cm{sup ?3} and peak N atom densities of 9.9?×?10{sup 17}?cm{sup ?3} are observed within the first ?1.0?mm of plasma near the anode tip by analyzing the OI and NI transitions in the 130.0–132.0?nm band of the vacuum ultraviolet spectrum.

Laity, George [Center for Pulsed Power and Power Electronics, Department of Electrical and Computer Engineering and Department of Physics, Texas Tech University, Lubbock, Texas 79409 (United States); Applied Science and Technology Maturation Department, Sandia National Laboratories, Albuquerque, New Mexico 87123 (United States); Fierro, Andrew; Dickens, James; Neuber, Andreas [Center for Pulsed Power and Power Electronics, Department of Electrical and Computer Engineering and Department of Physics, Texas Tech University, Lubbock, Texas 79409 (United States); Frank, Klaus [Erlangen Centre for Astroparticle Physics, Department of Physics, Friedrich–Alexander University at Erlangen-Nürnberg, 91058 Erlangen (Germany)

2014-03-28T23:59:59.000Z

122

Presented at UFA Burning Plasma Science Workshop II  

E-Print Network [OSTI]

Idaho National Engineering Laboratory Lawrence Livermore National Laboratory Massachusetts Institute, Madison, WI · Charge for First and Second meetings Scientific value of a Burning Plasma experiment Scientific readiness to proceed with such an experiment Is the FIRE mission scientifically appropriate

123

Increase in the energy density of the pinch plasma in 3D implosion of quasi-spherical wire arrays  

SciTech Connect (OSTI)

Results are presented from experimental studies of the characteristics of the soft X-ray (SXR) source formed in the implosion of quasi-spherical arrays made of tungsten wires and metalized kapron fibers. The experiments were carried out at the Angara-5-1 facility at currents of up to 3 MA. Analysis of the spatial distribution of hard X-ray emission with photon energies above 20 keV in the pinch images taken during the implosion of quasi-spherical tungsten wire arrays (QTWAs) showed that a compact quasi-spherical plasma object symmetric with respect to the array axis formed in the central region of the array. Using a diffraction grazing incidence spectrograph, spectra of SXR emission with wavelengths of 20–400 Å from the central, axial, and peripheral regions of the emission source were measured with spatial resolutions along the array radius and height in the implosion of QTWAs. It is shown that the emission spectra of the SXR sources formed under the implosion of quasi-spherical and cylindrical tungsten wire arrays at currents of up to 3 MA have a maximum in the wavelength range of 50–150 Å. It is found that, during the implosion of a QTWA with a profiled linear mass, a redistribution of energy in the emission spectrum takes place, which indicates that, during 3D implosion, the energy of longitudinal motion of the array material additionally contributes to the radiation energy. It is also found that, at close masses of the arrays and close values of the current in the range of 2.4{sup ?3} MA, the average energy density in the emission source formed during the implosion of a quasi-spherical wire array is larger by a factor of 7 than in the source formed during the implosion of a cylindrical wire array. The experimental data were compared with results of 3D simulations of plasma dynamics and radiation generation during the implosion of quasi-spherical wire arrays with a profiled mass by using the MARPLE-3D radiative magnetohydrodynamic code, developed at the Keldysh Institute of Applied Mathematics, Russian Academy of Sciences.

Aleksandrov, V. V., E-mail: alexvv@triniti.ru [Troitsk Institute for Innovation and Fusion Research (Russian Federation); Gasilov, V. A. [Russian Academy of Sciences, Keldysh Institute of Applied Mathematics (Russian Federation); Grabovski, E. V.; Gritsuk, A. N., E-mail: griar@triniti.ru; Laukhin, Ya. N.; Mitrofanov, K. N.; Oleinik, G. M. [Troitsk Institute for Innovation and Fusion Research (Russian Federation); Ol’khovskaya, O. G. [Russian Academy of Sciences, Keldysh Institute of Applied Mathematics (Russian Federation); Sasorov, P. V.; Smirnov, V. P.; Frolov, I. N. [Troitsk Institute for Innovation and Fusion Research (Russian Federation); Shevel’ko, A. P. [Russian Academy of Sciences, Lebedev Physical Institute (Russian Federation)

2014-12-15T23:59:59.000Z

124

CO{sub 2} laser-based dispersion interferometer utilizing orientation-patterned gallium arsenide for plasma density measurements  

SciTech Connect (OSTI)

A dispersion interferometer based on the second-harmonic generation of a carbon dioxide laser in orientation-patterned gallium arsenide has been developed for measuring electron density in plasmas. The interferometer includes two nonlinear optical crystals placed on opposite sides of the plasma. This instrument has been used to measure electron line densities in a pulsed radio-frequency generated argon plasma. A simple phase-extraction technique based on combining measurements from two successive pulses of the plasma has been used. The noise-equivalent line density was measured to be 1.7 × 10{sup 17} m{sup ?2} in a detection bandwidth of 950 kHz. One of the orientation-patterned crystals produced 13 mW of peak power at the second-harmonic wavelength from a carbon dioxide laser with 13 W of peak power. Two crystals arranged sequentially produced 58 mW of peak power at the second-harmonic wavelength from a carbon dioxide laser with 37 W of peak power.

Bamford, D. J.; Cummings, E. A.; Panasenko, D. [Physical Sciences Inc., 6652 Owens Drive, Pleasanton, California 94588 (United States)] [Physical Sciences Inc., 6652 Owens Drive, Pleasanton, California 94588 (United States); Fenner, D. B.; Hensley, J. M. [Physical Sciences Inc., 20 New England Business Center, Andover, Massachusetts 01810 (United States)] [Physical Sciences Inc., 20 New England Business Center, Andover, Massachusetts 01810 (United States); Boivin, R. L.; Carlstrom, T. N.; Van Zeeland, M. A. [General Atomics, P.O. Box 85608, San Diego, California 92186 (United States)] [General Atomics, P.O. Box 85608, San Diego, California 92186 (United States)

2013-09-15T23:59:59.000Z

125

Helicon plasma generator-assisted surface conversion ion source for the production of H{sup -} ion beams at the Los Alamos Neutron Science Center  

SciTech Connect (OSTI)

The converter-type negative ion source currently employed at the Los Alamos Neutron Science Center (LANSCE) is based on cesium enhanced surface production of H{sup -} ion beams in a filament-driven discharge. In this kind of an ion source the extracted H{sup -} beam current is limited by the achievable plasma density which depends primarily on the electron emission current from the filaments. The emission current can be increased by increasing the filament temperature but, unfortunately, this leads not only to shorter filament lifetime but also to an increase in metal evaporation from the filament, which deposits on the H{sup -} converter surface and degrades its performance. Therefore, we have started an ion source development project focused on replacing these thermionic cathodes (filaments) of the converter source by a helicon plasma generator capable of producing high-density hydrogen plasmas with low electron energy. In our studies which have so far shown that the plasma density of the surface conversion source can be increased significantly by exciting a helicon wave in the plasma, and we expect to improve the performance of the surface converter H{sup -} ion source in terms of beam brightness and time between services. The design of this new source and preliminary results are presented, along with a discussion of physical processes relevant for H{sup -} ion beam production with this novel design. Ultimately, we perceive this approach as an interim step towards our long-term goal, combining a helicon plasma generator with an SNS-type main discharge chamber, which will allow us to individually optimize the plasma properties of the plasma cathode (helicon) and H{sup -} production (main discharge) in order to further improve the brightness of extracted H{sup -} ion beams.

Tarvainen, O.; Rouleau, G.; Keller, R.; Geros, E.; Stelzer, J.; Ferris, J. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)

2008-02-15T23:59:59.000Z

126

Heavy Ion Fusion Science Virtual National Laboratory 1st Quarter FY08 Milestone Report: Report Initial Work on Developing Plasma Modeling Capability in WARP for NDCX Experiments Report Initial work on developing Plasma Modeling Capability in WARP for NDCX Experiments  

E-Print Network [OSTI]

plasma and (b) just past the time of peak compression and focus.plasma simulation models in Warp is to enable simulations of neutralized longitudinal compression and focuscm -3 at focus. The base case examined has a plasma density

Friedman, A.

2008-01-01T23:59:59.000Z

127

Wall current probe: A non-invasive in situ plasma diagnostic for space and time resolved current density distribution measurement  

SciTech Connect (OSTI)

In the context of low temperature plasma research, we propose a wall current probe to determine the local charged particle fluxes flowing to the chamber walls. This non-intrusive planar probe consists of an array of electrode elements which can be individually biased and for which the current can be measured separately. We detail the probe properties and present the ability of the diagnostic to be used as a space and time resolved measurement of the ion and electron current density at the chamber walls. This diagnostic will be relevant to study the electron transport in magnetized low-pressure plasmas.

Baude, R.; Gaboriau, F.; Hagelaar, G. J. M. [Université de Toulouse, UPS, INPT, LAPLACE (Laboratoire Plasma et Conversion d’énergie), 118 route de Narbonne, F-31062 Toulouse Cedex 9, France and CNRS, LAPLACE, F-31062, Toulouse (France)] [Université de Toulouse, UPS, INPT, LAPLACE (Laboratoire Plasma et Conversion d’énergie), 118 route de Narbonne, F-31062 Toulouse Cedex 9, France and CNRS, LAPLACE, F-31062, Toulouse (France)

2013-08-15T23:59:59.000Z

128

High repetition rate plasma mirror device for attosecond science  

SciTech Connect (OSTI)

This report describes an active solid target positioning device for driving plasma mirrors with high repetition rate ultra-high intensity lasers. The position of the solid target surface with respect to the laser focus is optically monitored and mechanically controlled on the nm scale to ensure reproducible interaction conditions for each shot at arbitrary repetition rate. We demonstrate the target capabilities by driving high-order harmonic generation from plasma mirrors produced on glass targets with a near-relativistic intensity few-cycle pulse laser system operating at 1 kHz. During experiments, residual target surface motion can be actively stabilized down to 47?nm (root mean square), which ensures sub-300-as relative temporal stability of the plasma mirror as a secondary source of coherent attosecond extreme ultraviolet radiation in pump-probe experiments.

Borot, A.; Douillet, D.; Iaquaniello, G.; Lefrou, T.; Lopez-Martens, R. [Laboratoire d'Optique Appliquée, ENSTA-ParisTech, CNRS, Ecole Polytechnique, UMR 7639, 91761 Palaiseau (France)] [Laboratoire d'Optique Appliquée, ENSTA-ParisTech, CNRS, Ecole Polytechnique, UMR 7639, 91761 Palaiseau (France); Audebert, P.; Geindre, J.-P. [Laboratoire pour l'Utilisation des Lasers Intenses, Ecole Polytechnique, CNRS, 91128 Palaiseau Cedex (France)] [Laboratoire pour l'Utilisation des Lasers Intenses, Ecole Polytechnique, CNRS, 91128 Palaiseau Cedex (France)

2014-01-15T23:59:59.000Z

129

92 IEEE TRANSACTIONS ON PLASMA SCIENCE, VOL. 30, NO. 1, FEBRUARY 2002 Formation of Coulomb Crystals in a  

E-Print Network [OSTI]

sheaths. DUST PARTICLE transport in partially ionized plasmas has been the focus of many recent92 IEEE TRANSACTIONS ON PLASMA SCIENCE, VOL. 30, NO. 1, FEBRUARY 2002 Formation of Coulomb Crystals in a Capacitively Coupled Plasma Vivek Vyas and Mark J. Kushner, Fellow, IEEE Abstract--Dust particle transport

Kushner, Mark

130

Increasing the upper-limit intensity and temperature range for thermal self-focusing of a laser beam by using plasma density ramp-up  

SciTech Connect (OSTI)

This work is devoted to improving relativistic and ponderomotive thermal self-focusing of the intense laser beam in an underdense plasma. It is shown that the ponderomotive nonlinearity induces a saturation mechanism for thermal self-focusing. Therefore, in addition to the well-known lower-limit critical intensity, there is an upper-limit intensity for thermal self-focusing above which the laser beam starts to experience ponderomotive defocusing. It is indicated that the upper-limit intensity value is dependent on plasma and laser parameters such as the plasma electron temperature, plasma density, and laser spot size. Furthermore, the effect of the upward plasma density ramp profile on the thermal self-focusing is studied. Results show that by using the plasma density ramp-up, the upper-limit intensity increases and the self-focusing temperature range expands.

Bokaei, B.; Niknam, A. R., E-mail: a-niknam@sbu.ac.ir [Laser and Plasma Research Institute, Shahid Beheshti University, G.C., Tehran (Iran, Islamic Republic of)

2014-03-15T23:59:59.000Z

131

Multichannel microwave interferometer with an antenna switching system for electron density measurement in a laboratory plasma experiment  

SciTech Connect (OSTI)

This study presents a simple and powerful technique for multichannel measurements of the density profile in laboratory plasmas by microwave interferometry. This technique uses electromechanical microwave switches to temporally switch the connection between multiple receiver antennas and one phase-detection circuit. Using this method, the phase information detected at different positions is rearranged into a time series that can be acquired from a minimum number of data acquisition channels (e.g., two channels in the case of quadrature detection). Our successfully developed multichannel microwave interferometer that uses the antenna switching method was applied to measure the radial electron density profiles in a magnetized plasma experiment. The advantage of the proposed method is its compactness and scalability to multidimensional measurement systems at low cost.

Kawamori, Eiichirou; Lin, Yu-Hsiang [Institute of Space and Plasma Sciences, National Cheng Kung University, Tainan 70101, Taiwan (China)] [Institute of Space and Plasma Sciences, National Cheng Kung University, Tainan 70101, Taiwan (China); Mase, Atsushi [Art, Science and Technology Center for Cooperative Research, Kyushu University, Kasuga 816-8580 (Japan)] [Art, Science and Technology Center for Cooperative Research, Kyushu University, Kasuga 816-8580 (Japan); Nishida, Yasushi; Cheng, C. Z. [Institute of Space and Plasma Sciences, National Cheng Kung University, Tainan 70101, Taiwan (China) [Institute of Space and Plasma Sciences, National Cheng Kung University, Tainan 70101, Taiwan (China); Plasma and Space Science Center, National Cheng Kung University, Tainan 70101, Taiwan (China)

2014-02-15T23:59:59.000Z

132

INSTITUTE OF PHYSICS PUBLISHING PLASMA SOURCES SCIENCE AND TECHNOLOGY Plasma Sources Sci. Technol. 12 (2003) 821 PII: S0963-0252(03)55523-2  

E-Print Network [OSTI]

as multi-atmosphere thermal arcs, during their starting phase the lamps are moderate pressure glowINSTITUTE OF PHYSICS PUBLISHING PLASMA SOURCES SCIENCE AND TECHNOLOGY Plasma Sources Sci. Technol. 12 (2003) 8­21 PII: S0963-0252(03)55523-2 Breakdown processes in metal halide lamps Brian Lay1

Kushner, Mark

133

MIT Plasma Fusion Sciences Center IAP Seminar! Jan 10th, 2012!  

E-Print Network [OSTI]

MIT Plasma Fusion Sciences Center IAP Seminar! Jan 10th, 2012! ! ! ! ! ! Otto Landen! Associate-07NA27344 Inertial Confinement Fusion Physics and Challenges*! #12;The NIF ignition experiments-degenerate fuel Spherical collapse of the shell produces a central hot spot surrounded by cold, dense main fuel

134

Results from the Levitated Dipole Experiment MIT Plasma Science and Fusion Center  

E-Print Network [OSTI]

research: earth, Jupiter... · Dipole is simplest confinement field · Naturally occurring high- plasma ( ~ 2 lead naturally to breadth in science and technology · Example: Confinement in the field of a levitated (radiation belts) · Adriani et al. (2011): Discovery of geo- magnetically trapped cosmic-ray antiprotons #12

135

Numerical solutions of sheath structures in front of an electron-emitting electrode immersed in a low-density plasma  

SciTech Connect (OSTI)

The exact theoretical expressions involved in the formation of sheath in front of an electron emitting electrode immersed in a low-density plasma have been derived. The potential profile in the sheath region has been calculated for subcritical, critical, and supercritical emissions. The potential profiles of critical and supercritical emissions reveals that we must take into account a small, instead of zero, electric field at the sheath edge to satisfy the boundary conditions used to integrate the Poisson's equation. The I-V curves for critical emission shows that only high values of plasma-electron to emitted-electron temperature ratio can meet the floating potential of the emissive electrode. A one-dimensional fluid like model is assumed for ions, while the electron species are treated as kinetic. The distribution of emitted-electron from the electrode is assumed to be half Maxwellian. The plasma-electron enters the sheath region at sheath edge with half Maxwellian velocity distribution, while the reflected ones have cut-off velocity distribution due to the absorption of super thermal electrons by the electrode. The effect of varying emitted-electron current on the sheath structure has been studied with the help of a parameter G (the ratio of emitted-electron to plasma-electron densities)

Din, Alif [Theoretical Plasma Physics Division, PINSTECH, P. O. Nilore, 44000 Islamabad (Pakistan)] [Theoretical Plasma Physics Division, PINSTECH, P. O. Nilore, 44000 Islamabad (Pakistan)

2013-09-15T23:59:59.000Z

136

Temperature and density evolution during decay in a 2.45 GHz hydrogen electron cyclotron resonance plasma: Off-resonant and resonant cases  

SciTech Connect (OSTI)

Time resolved electron temperature and density measurements during the decay stage in a hydrogen electron cyclotron resonance (ECR) plasma are presented for a resonance and off-resonance magnetic field configurations. The measurements are conducted on a ECR plasma generator excited at 2.45 GHz denominated test-bench for ion-sources plasma studies at ESS Bilbao. The plasma parameters evolution is studied by Langmuir probe diagnostic with synchronized sample technique developed for repetitive pulsed plasmas with a temporal resolution of 200 ns in typical decay processes of about 40 ?s. An afterglow transient is clearly observed in the reflected microwave power signal from the plasma. Simultaneously, the electron temperature evolution shows rebounding peaks that may be related to the interplay between density drop and microwave coupling with deep impact on the Electron Energy Distribution Function. The correlation of such structures with the plasma absorbed power and the coupling quality is also reported.

Cortázar, O. D. [ESS Bilbao, Edificio Cosimet, Landabarri 2, 48940-Leioa, Vizcaya (Spain) [ESS Bilbao, Edificio Cosimet, Landabarri 2, 48940-Leioa, Vizcaya (Spain); Universidad de Castilla-La Mancha, ETSII, C.J. Cela s/n, 13170 Ciudad Real (Spain); Megía-Macías, A.; Vizcaíno-de-Julián, A. [ESS Bilbao, Edificio Cosimet, Landabarri 2, 48940-Leioa, Vizcaya (Spain)] [ESS Bilbao, Edificio Cosimet, Landabarri 2, 48940-Leioa, Vizcaya (Spain)

2013-09-15T23:59:59.000Z

137

Simulating x-ray Thomson scattering signals from high-density, millimetre-scale plasmas at the National Ignition Facility  

SciTech Connect (OSTI)

We have developed a model for analysing x-ray Thomson scattering data from high-density, millimetre-scale inhomogeneous plasmas created during ultra-high pressure implosions at the National Ignition Facility in a spherically convergent geometry. The density weighting of the scattered signal and attenuation of the incident and scattered x-rays throughout the target are included using radial profiles of the density, opacity, ionization state, and temperature provided by radiation-hydrodynamics simulations. These simulations show that the scattered signal is strongly weighted toward the bulk of the shocked plasma and the Fermi degenerate material near the ablation front. We show that the scattered signal provides a good representation of the temperature of this highly nonuniform bulk plasma and can be determined to an accuracy of ca. 15% using typical data analysis techniques with simple 0D calculations. On the other hand, the mean ionization of the carbon in the bulk is underestimated. We suggest that this discrepancy is due to the convolution of scattering profiles from different regions of the target. Subsequently, we discuss modifications to the current platform to minimise the impact of inhomogeneities, as well as opacity, and also to enable probing of conditions more strongly weighted toward the compressed core.

Chapman, D. A., E-mail: david.chapman@awe.co.uk [Plasma Physics Group, Radiation Physics Department, AWE plc, Reading RG7 4PR (United Kingdom); Centre for Fusion, Space and Astrophysics, University of Warwick, Coventry CV4 7AL (United Kingdom); Kraus, D.; Falcone, R. W. [Department of Physics, University of California, Berkeley, California 94720 (United States); Kritcher, A. L.; Bachmann, B.; Collins, G. W.; Gaffney, J. A.; Hawreliak, J. A.; Landen, O. L.; Le Pape, S.; Ma, T.; Nilsen, J.; Pak, A.; Swift, D. C.; Döppner, T. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States); Gericke, D. O. [Centre for Fusion, Space and Astrophysics, University of Warwick, Coventry CV4 7AL (United Kingdom); Glenzer, S. H. [SLAC National Accelerator Laboratory, Menlo Park, California 94309 (United States); Guymer, T. M. [Plasma Physics Group, Radiation Physics Department, AWE plc, Reading RG7 4PR (United Kingdom); Neumayer, P. [Gesellschaft für Schwerionenforschung, 64291 Darmstadt (Germany); Redmer, R. [Institut für Physik, Universität Rostock, 18051 Rostock (Germany); and others

2014-08-15T23:59:59.000Z

138

Science on Saturday starts Jan. 11 | Princeton Plasma Physics Lab  

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139

Plasma Materials Interaction Issues For Burning Plasma Experiments  

E-Print Network [OSTI]

­ Resistance to neutron damage #12;MAU 5 11/15/2001 The FIRE Burning Plasma Device · A compact high field surface sees high density and temperature plasma · Key issues are hydrogen trapping, erosion, and thermal trapping and release, surface segregation · Materials science for nuclear radiation damage, thermal fatigue

140

Plasma-Density Determination from X-Ray Radiography of Laser-Driven Spherical Implosions  

E-Print Network [OSTI]

The fuel layer density of an imploding laser-driven spherical shell is inferred from framed x-ray radiographs. The density distribution is determined by using Abel inversion to compute the radial distribution of the opacity ...

Frenje, Johan A.

Note: This page contains sample records for the topic "density plasma science" from the National Library of EnergyBeta (NLEBeta).
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they are not comprehensive nor are they the most current set.
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141

2013 Science on Saturday Lecture Series | Princeton Plasma Physics Lab  

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142

DOE New Jersey Regional Middle School Science Bowl | Princeton Plasma  

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143

PLASMA PHYSICS:Turbulence and Sheared Flow --Burrell 281 (5384): 1816 --Science q My Science  

E-Print Network [OSTI]

the loss of energy from the plasma. One of the success stories of magnetic fusion research over the past. Burrell* In the quest for fusion energy, a continuing theme is the search for ways to improve energy. When present, these global MHD instabilities can typically tear apart in microseconds a plasma whose

Lin, Zhihong

144

Study of density fluctuations and particle transport at the edge of I-mode plasmas  

E-Print Network [OSTI]

The wide range of plasma parameters available on Alcator C-Mod has led to the accessibility of many regimes of operation. Since its commissioning, C-Mod has accessed the Linear ohmic confinement, Saturated ohmic confinement, ...

Dominguez, Arturo, Ph. D. Massachusetts Institute of Technology

2012-01-01T23:59:59.000Z

145

5. Kodama, R. et al. Fast heating of ultrahigh-density plasma as a step towards laser fusion ignition. Nature 412, 798802 (2001).  

E-Print Network [OSTI]

5. Kodama, R. et al. Fast heating of ultrahigh-density plasma as a step towards laser fusion. J. Geophys. Res. 100, 23567­23581 (1995). 13. Hirahara, M. et al. Acceleration and heating of cold

Davis, James C.

146

COLLOQUIUM: The Promise of Urban Science | Princeton Plasma Physics Lab  

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147

Science On Saturday Archive | Princeton Plasma Physics Lab  

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148

Science Education Upcoming Events | Princeton Plasma Physics Lab  

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149

Multi-dimensional collective effects in high-current relativistic beams relevant to High Density Laboratory Plasmas  

SciTech Connect (OSTI)

In summary, an analytical model describing the self-pinching of a relativistic charge-neutralized electron beam undergoing the collisionless Weibel instability in an overdense plasma has been developed. The model accurately predicts the final temperature and size of the self-focused filament. It is found that the final temperature is primarily defined by the total beam’s current, while the filament’s radius is shown to be smaller than the collisionless skin depth in the plasma and primarily determined by the beam’s initial size. The model also accurately predicts the repartitioning ratio of the initial energy of the beam’s forward motion into the magnetic field energy and the kinetic energy of the surrounding plasma. The density profile of the final filament is shown to be a superposition of the standard Bennett pinch profile and a wide halo surrounding the pinch, which contains a significant fraction of the beam’s electrons. PIC simulations confirm the key assumption of the analytic theory: the collisionless merger of multiple current filaments in the course of the Weibel Instability provides the mechanism for Maxwellization of the beam’s distribution function. Deviations from the Maxwell-Boltzmann distribution are explained by incomplete thermalization of the deeply trapped and halo electrons. It is conjectured that the simple expression derived here can be used for understanding collsionless shock acceleration and magnetic field amplification in astrophysical plasmas.

Shvets, Gennady

2014-05-09T23:59:59.000Z

150

Nanoparticle manipulation in the near-substrate areas of low-temperature, high-density rf plasmas  

SciTech Connect (OSTI)

Manipulation of a single nanoparticle in the near-substrate areas of high-density plasmas of low-temperature glow discharges is studied. It is shown that the nanoparticles can be efficiently manipulated by the thermophoretic force controlled by external heating of the substrate stage. Particle deposition onto or repulsion from nanostructured carbon surfaces critically depends on the values of the neutral gas temperature gradient in the near-substrate areas, which is directly measured in situ in different heating regimes by originally developed temperature gradient probe. The measured values of the near-surface temperature gradient are used in the numerical model of nanoparticle dynamics in a variable-length presheath. Specific conditions enabling the nanoparticle to overcome the repulsive potential and deposit on the substrate during the discharge operation are investigated. The results are relevant to fabrication of various nanostructured films employing structural incorporation of the plasma-grown nanoparticles, in particular, to nanoparticle deposition in the plasma-enhanced chemical-vapor deposition of carbon nanostructures in hydrocarbon-based plasmas.

Rutkevych, P.P.; Ostrikov, K.; Xu, S. [Plasma Sources and Applications Center, National Institute of Education (NIE), Nanyang Technological University, 1 Nanyang Walk, Singapore 637616 (Singapore); School of Physics, The University of Sydney, Sydney, New South Wales 2006 (Australia); Plasma Sources and Applications Center, National Institute of Education (NIE), Nanyang Technological University, 1 Nanyang Walk, Singapore 637616 (Singapore)

2005-10-01T23:59:59.000Z

151

MIT's Plasma Science Fusion Center: Tokamak Experiments Come Clean about  

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152

Propagation of a cloud of hot electrons through a plasma in the presence of Langmuir scattering by ambient density fluctuations  

SciTech Connect (OSTI)

Gas-dynamic theory is generalized to incorporate the effects of beam-driven Langmuir waves scattering off ambient density fluctuations, and the consequent effects on the propagation of a cloud of hot electrons in an inhomogeneous plasma. Assuming Langmuir scattering as the limit of nonlinear three-wave interactions with fluctuations that are weak, low-frequency, long-wavelength ion-sound waves, the net effect of scattering is equivalent to effective damping of the Langmuir waves. Under the assumption of self-similarity in the evolution of the beam and Langmuir wave distribution functions, gas-dynamic theory shows that the effects of Langmuir scattering on the beam distribution are equivalent to a perturbation in the injection profile of the beam. Analytical expressions are obtained for the height of the plateau of the beam distribution function, wave spectral number density, total wave and particle energy density, and the beam number density. The main results of gas-dynamic theory are then compared with simulation results from numerical solutions of quasilinear equations. The relaxation of the beam in velocity space is retarded in the presence of density fluctuations and the magnitude of the upper velocity boundary is less than that in the absence of fluctuations. There are four different regimes for the height of the plateau, corresponding to different stages of relaxation of the beam in velocity space. Moreover, Langmuir scattering results in transfer of electrons from moderate velocity to low velocity; this effect produces an enhancement in the beam number density at small distances near the injection site and a corresponding decrease at large distances. There are sharp decreases in the profiles of the beam and total wave energy densities, which are related to dissipation of energy at large phase velocities. Due to a slower velocity space diffusion of the beam distribution in the presence of scattering effects, the spatial width of the beam is reduced while its mean velocity of propagation increases slightly.

Foroutan, G. R.; Robinson, P. A.; Sobhanian, S.; Moslehi-Fard, M.; Li, B.; Cairns, I. H. [School of Physics, University of Sydney, NSW 2006, Sydney (Australia); Research Institute for Astronomy and Astrophysics of Maragha, P.O. Box 55134-441 Maragha (Iran, Islamic Republic of) and Physics Department, Faculty of Science, Sahand University of Technology, 51335-1996 Tabriz (Iran); School of Physics, University of Sydney, NSW 2006, Sydney (Australia); Research Institute for Astronomy and Astrophysics of Maragha, P.O. Box 55134-441 Maragha (Iran, Islamic Republic of) and Faculty of Physics, Tabriz University, Tabriz 51664 (Iran); Faculty of Physics, Tabriz University, Tabriz 51664 (Iran, Islamic Republic of); School of Physics, University of Sydney, NSW 2006, Sydney (Australia)

2007-01-15T23:59:59.000Z

153

Influence of ambient gas on the temperature and density of laser produced carbon plasma  

E-Print Network [OSTI]

; accepted for publication 11 November 1997 The effect of ambient gas on the dynamics of the plasma generated In moderate or high pressures, a blast wave model is found to describe accurately the plume propagation the maximum plume length with considerable accuracy.7,13 In this letter we report the effect of ambient

Harilal, S. S.

154

718 IEEE TRANSACTIONS ON PLASMA SCIENCE, VOL. 34, NO. 3, JUNE 2006 Nonlinear Effects and Anomalous Transport  

E-Print Network [OSTI]

plasmas, and techniques learned from high-temperature, fusion research are used to solve them. Low-temperature Identifier 10.1109/TPS.2006.874851 Fig. 1. Radial profiles of density, electron temperature, and the RF B. They are one of the main plasma devices used in producing computer chips and are, therefore, highly developed

Kaganovich, Igor

155

Radiation from Ag high energy density Z-pinch plasmas and applications to lasing  

SciTech Connect (OSTI)

Silver (Ag) wire arrays were recently introduced as efficient x-ray radiators and have been shown to create L-shell plasmas that have the highest electron temperature (>1.8?keV) observed on the Zebra generator so far and upwards of 30?kJ of energy output. In this paper, results of single planar wire arrays and double planar wire arrays of Ag and mixed Ag and Al that were tested on the UNR Zebra generator are presented and compared. To further understand how L-shell Ag plasma evolves in time, a time-gated x-ray spectrometer was designed and fielded, which has a spectral range of approximately 3.5–5.0?Å. With this, L-shell Ag as well as cold L{sub ?} and L{sub ?} Ag lines was captured and analyzed along with photoconducting diode (PCD) signals (>0.8?keV). Along with PCD signals, other signals, such as filtered XRD (>0.2?keV) and Si-diodes (SiD) (>9?keV), are analyzed covering a broad range of energies from a few eV to greater than 53?keV. The observation and analysis of cold L{sub ?} and L{sub ?} lines show possible correlations with electron beams and SiD signals. Recently, an interesting issue regarding these Ag plasmas is whether lasing occurs in the Ne-like soft x-ray range, and if so, at what gains? To help answer this question, a non-local thermodynamic equilibrium (LTE) kinetic model was utilized to calculate theoretical lasing gains. It is shown that the Ag L-shell plasma conditions produced on the Zebra generator at 1.7 maximum current may be adequate to produce gains as high as 6?cm{sup ?1} for various 3p???3s transitions. Other potential lasing transitions, including higher Rydberg states, are also included in detail. The overall importance of Ag wire arrays and plasmas is discussed.

Weller, M. E., E-mail: mweller@unr.edu; Safronova, A. S.; Kantsyrev, V. L.; Esaulov, A. A.; Shrestha, I.; Stafford, A.; Keim, S. F.; Shlyaptseva, V. V.; Osborne, G. C.; Petkov, E. E. [Physics Department, University of Nevada, Reno, Nevada 89557 (United States)] [Physics Department, University of Nevada, Reno, Nevada 89557 (United States); Apruzese, J. P.; Giuliani, J. L. [Naval Research Laboratory, Washington, District of Columbia 20375 (United States)] [Naval Research Laboratory, Washington, District of Columbia 20375 (United States); Chuvatin, A. S. [Ecole Polytechnique, 91128 Palaiseau (France)] [Ecole Polytechnique, 91128 Palaiseau (France)

2014-03-15T23:59:59.000Z

156

Computational Support for Alternative Confinement Concepts Basic Plasma Science  

SciTech Connect (OSTI)

This is the final report for contract DE-FG03-99ER54528, ''Computational Support for Alternative Confinement Concepts''. Progress was made in the following areas of investigation: (1) Extensive studies of the confinement properties of conventional Reversed-field Pinch (RFP) configurations (i.e., without current profile control) were performed in collaboration with the Royal Institute of Technology (KTH) in Stockholm, Sweden. These studies were carried out using the full 3-dimensional, finite-{beta}, resistive MHD model in the DEBS code, including ohmic heating and anisotropic heat conduction, and thus for the first time included the self-consistent effects of the dynamo magnetic fluctuations on the confinement properties of the RFP. By using multi-variant regression analysis of these results, scaling laws for various properties characterizing the conventional RFP were obtained. In particular, it was found that the, for constant ratio of I/N (where I is the current and N = na{sup 2} is the line density), and over a range of Lundquist numbers S that approaches 10{sup 6}, the fluctuations scale as {delta}B/B {approx} S{sup -0.14}, the temperature scales as T {approx} I{sup 0.56}, the poloidal beta scales as {beta}{sub {theta}} {approx} I{sup -0.4}, and the energy confinement time scales as {tau}{sub E} {approx} I{sup 0.34}. The degradation of poloidal beta with current is a result of the weak scaling of the fluctuation level with the Lundquist number, and leads to the unfavorable scaling laws for temperature and energy confinement time. These results compare reasonably well with experimental data, and emphasize the need for external control of the dynamo fluctuations in the RFP. (2) Studies of feedback stabilization of resistive wall modes in the RFP were performed with the DEBS code in collaboration with the CNR/RFX group in Padua, Italy. The ideal growth rates are ''passively'' reduced by the presence of a resistive wall within the radius for perfectly conducting wall stabilization of these modes. In this work we consider cases with up to two resistive walls. Moreover the feedback system is assumed to react to any given Fourier harmonic with an ideal response, in the sense that no spurious harmonics are generated. Successful feedback schemes are shown to be possible. However, a careful choice of the gains, along with the simultaneous feedback on at least 4 or 5 modes, is found to be necessary. (3) Studies of a stable rampdown operating regime for the RFP were performed in collaboration with Los Alamos National Laboratory and the University of Wisconsin. It was found that completely stable mean profiles can be obtained by properly tailoring the decaying time dependence of the toroidal current and magnetic flux. Deviations from optimal decay rates were shown to lead to single helicity (SH) and quasi-single helicity (QSH) states. In all cases the prospects for improved confinement properties were obtained. These results may account for the experimental observation of QSH states when the toroidal current is allowed to decay.

Dalton D. Schnack

2002-12-09T23:59:59.000Z

157

Inertial Confinement Fusion, High Energy Density Plasmas and an Energy Source on Earth  

E-Print Network [OSTI]

Lawrence Livermore National Laboratory American Association for the Advancement of Science February 13 Lawrence Livermore National Laboratory under contract No. W-7405-Eng-48. #12;Tabak Snowmass We are making be tested at the National Ignition Facility(NIF) · NIF is scheduled for completion by 2009 ­ Physics

158

Electron density inside Enceladus plume inferred from plasma oscillations excited by dust impacts  

E-Print Network [OSTI]

1 Department of Physics and Astronomy, University of Iowa, Iowa City, Iowa, USA, 2 LASP, University and electron spectrometers [Jones et al., 2009; Hill et al., 2012]. The nanoparticles appear as high-energy a sweeping voltage, and the ion and electron density can be inferred from the current balance. It is found

Gurnett, Donald A.

159

Electron density estimations derived from spacecraft potential measurements on Cluster in tenuous plasma regions  

E-Print Network [OSTI]

in the solar wind, the magnetosheath, and the plasmashere by the use of CIS ion density and WHISPER electron, in operation from early 2001 in a high inclination orbit, have provided data over nearly half of the 11-year are in the magnetotail from approximately beginning of July to end of October, and the high inclination orbit makes

California at Berkeley, University of

160

A high-resolution imaging x-ray crystal spectrometer for high energy density plasmas  

SciTech Connect (OSTI)

Adapting a concept developed for magnetic confinement fusion experiments, an imaging crystal spectrometer has been designed and tested for HED plasmas. The instrument uses a spherically bent quartz [211] crystal with radius of curvature of 490.8 mm. The instrument was tested at the Titan laser at Lawrence Livermore National Laboratory by irradiating titanium slabs with laser intensities of 10{sup 19}–10{sup 20} W/cm{sup 2}. He-like and Li-like Ti lines were recorded, from which the spectrometer performance was evaluated. This spectrometer provides very high spectral resolving power (E/dE > 7000) while acquiring a one-dimensional image of the source.

Chen, Hui, E-mail: chen33@llnl.gov, E-mail: bitter@pppl.gov; Magee, E.; Nagel, S. R.; Park, J.; Schneider, M. B.; Stone, G.; Williams, G. J.; Beiersdorfer, P. [Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550-9234 (United States); Bitter, M., E-mail: chen33@llnl.gov, E-mail: bitter@pppl.gov; Hill, K. W. [Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543 (United States); Kerr, S. [Department of Applied Science, University of Alberta, Edmonton, Alberta T6G 2R3 (Canada)

2014-11-15T23:59:59.000Z

Note: This page contains sample records for the topic "density plasma science" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


161

Present Status and Future Prospects of Laser Fusion and Related High Energy Density Plasma Research  

SciTech Connect (OSTI)

The present status and future prospects of the laser fusion research and related laser plasma physics are reviewed. In laser fusion research, giant lasers for ignition and burn by imploding DT fuel pellets are under construction at LLNL (Lawrence Livermore National Laboratory) and CEA, France. In Japan , the Gekko XII and the Peta Watt laser system have been operated to investigate the implosion hydrodynamics, fast ignition, and the relativistic laser plasma interactions and a new project; FIREX( Fast Ignition Realization Experiment) had started toward the ignition and burn at the Institute of laser Engineering of Osaka University. Recently, heating experiments with cone shell target have been carried out. The thermal neutron yield is found to increase by three orders of magnitude by the peta watt laser injection to the cone shell target. The FIREX-I is planned according to this experimental results, where multi 10kJ peta watt laser is used to heat compressed DT fuel to the ignition temperature. The FIREX-II will follow for demonstrating ignition and burn, in which the implosion laser and heating laser are up-graded.

Mima, Kunioki [Institute of Laser Engineering, Osaka University, 2-6 Yamada-oka, Suita , Osaka, 565-0871 (Japan)

2004-12-01T23:59:59.000Z

162

Science on Saturday attracts science fans of all ages | Princeton Plasma  

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163

Imaging spectroscopy diagnosis of internal electron temperature and density distributions of plasma cloud surrounding hydrogen pellet in the Large Helical Device  

SciTech Connect (OSTI)

To investigate the behavior of hydrogen pellet ablation, a novel method of high-speed imaging spectroscopy has been used in the Large Helical Device (LHD) for identifying the internal distribution of the electron density and temperature of the plasma cloud surrounding the pellet. This spectroscopic system consists of a five-branch fiberscope and a fast camera, with each objective lens having a different narrow-band optical filter for the hydrogen Balmer lines and the background continuum radiation. The electron density and temperature in the plasma cloud are obtained, with a spatial resolution of about 6 mm and a temporal resolution of 5 Multiplication-Sign 10{sup -5} s, from the intensity ratio measured through these filters. To verify the imaging, the average electron density and temperature also have been measured from the total emission by using a photodiode, showing that both density and temperature increase with time during the pellet ablation. The electron density distribution ranging from 10{sup 22} to 10{sup 24} m{sup -3} and the temperature distribution around 1 eV have been observed via imaging. The electron density and temperature of a 0.1 m plasma cloud are distributed along the magnetic field lines and a significant electron pressure forms in the plasma cloud for typical experimental conditions of the LHD.

Motojima, G.; Sakamoto, R.; Goto, M.; Matsuyama, A.; Yamada, H. [National Institute for Fusion Science, 322-6, Oroshi-cho, Toki-City, Gifu 509-5292 (Japan); Mishra, J. S. [Graduate University for Advanced Studies, 322-6, Oroshi-cho, Toki-City, Gifu 509-5292 (Japan)

2012-09-15T23:59:59.000Z

164

Scattering of Radio Frequency Waves by Edge Density Blobs in Tokamak Plasmas  

SciTech Connect (OSTI)

The density blobs and fluctuations present in the edge region of magnetic fusion devices can scatter radio frequency (RF) waves through refraction and diffraction. The scattering can diffuse the rays in space and in wave-vector space. The diffusion in space can make the rays miss their intended target region, while the diffusion in wave-vector space can broaden the wave spectrum and modify the wave damping and current profile.

Ram, A. K. [Plasma Science and Fusion Center, Massachusetts Institute of Technology, Cambridge, MA 02139 (United States); Hizanidis, K.; Kominis, Y. [National Technical University of Athens, Association EURATOM-Hellenic Republic, Zografou, Athens 15773 (Greece)

2011-12-23T23:59:59.000Z

165

Amplifying Magnetic Fields in High Energy Density Plasmas | U.S. DOE Office  

Office of Science (SC) Website

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166

Laser-induced fluorescence measurements on plasma science experiments at PPPL  

SciTech Connect (OSTI)

Collaborative research between WVU and PPPL was carried out at WVU for the purpose of incorporating the sophisticated diagnostic technique known as laser-induced fluorescence (LIF) in the Paul-Trap Simulation Experiment (PTSX) at PPPL. WVU assembled a LIF system at WVU, transported it to PPPL, helped make LIF experiments on the PTSX device, participated in PTSX science, and trained PPPL staff in LIF techniques. In summary, WVU refurbished a non-operational LIF system being loaned from University of Maryland to PPPL and, by doing so, provided PPPL with additional diagnostic capability for its PTSX device and other General Plasma Science experiments. WVU students, staff, and faculty will visit PPPL to collaborate on PTSX experiments in the future.

Koepke, Mark

2011-12-20T23:59:59.000Z

167

Heavy ion fusion science research for high energy density physics and fusion applications  

E-Print Network [OSTI]

long final-focus solenoid filled with plasma was modeled (final-focus solenoid. In this simulation, plasma is assumedplasma source (FEPS) which neutralizes the longitudinal drift compression region, 5T final focus

Logan, B.G.

2007-01-01T23:59:59.000Z

168

E-Print Network 3.0 - arc plasma science Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Mathematics 35 PLASMA PROCESSING UPDATE A newsletter from the Summary: for Plasma Research , Gujarat DST-PSSI Interaction Meet Dr. S. Mukherjee Popularizing Plasma...

169

Demonstration of x-ray fluorescence imaging of a high-energy-density plasma  

SciTech Connect (OSTI)

Experiments at the Trident Laser Facility have successfully demonstrated the use of x-ray fluorescence imaging (XRFI) to diagnose shocked carbonized resorcinol formaldehyde (CRF) foams doped with Ti. One laser beam created a shock wave in the doped foam. A second laser beam produced a flux of vanadium He-? x-rays, which in turn induced Ti K-shell fluorescence within the foam. Spectrally resolved 1D imaging of the x-ray fluorescence provided shock location and compression measurements. Additionally, experiments using a collimator demonstrated that one can probe specific regions within a target. These results show that XRFI is a capable alternative to path-integrated measurements for diagnosing hydrodynamic experiments at high energy density.

MacDonald, M. J., E-mail: macdonm@umich.edu; Gamboa, E. J. [Department of Atmospheric, Oceanic, and Space Sciences, University of Michigan, Ann Arbor, Michigan 48109 (United States); SLAC National Accelerator Laboratory, Menlo Park, California 94025 (United States); Keiter, P. A.; Fein, J. R.; Klein, S. R.; Kuranz, C. C.; LeFevre, H. J.; Manuel, M. J.-E.; Wan, W. C.; Drake, R. P. [Department of Atmospheric, Oceanic, and Space Sciences, University of Michigan, Ann Arbor, Michigan 48109 (United States); Montgomery, D. S. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Biener, M. M.; Fournier, K. B. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States); Streit, J. [Schafer Corporation, Livermore, California 94551 (United States)

2014-11-15T23:59:59.000Z

170

Quark spectral density and a strongly-coupled quark-gluon plasma.  

SciTech Connect (OSTI)

The maximum entropy method is used to compute the dressed-quark spectral density from the self-consistent numerical solution of a rainbow truncation of QCD's gap equation at temperatures above that for which chiral symmetry is restored. In addition to the normal and plasmino modes, the spectral function also exhibits an essentially nonperturbative zero mode for temperatures extending to 1.4-1.8 times the critical temperature, T{sub c}. In the neighborhood of T{sub c}, this long-wavelength mode contains the bulk of the spectral strength and as long as this mode persists, the system may fairly be described as a strongly-coupled state of matter.

Qin, S.; Chang, L.; Liu, Y.; Roberts, C. D. (Physics); (Peking Univ.); (Inst. of Applied Physics and Computational Mathematics); (National Lab. of Heavy Ion Accelerator)

2011-07-13T23:59:59.000Z

171

694 IEEE TRANSACTIONS ON PLASMA SCIENCE, VOL. 34, NO. 3, JUNE 2006 Guest Editorial  

E-Print Network [OSTI]

-temperature, fu- sion plasmas and low-temperature, gas discharge plasmas. Such low-pressure plasmas have dynamics in plasmas, particularly in glow discharges, plasma sources for material processing, and plasma. Therefore, it is important to summarize the current state-of-the-art for both communities in one volume. Low

Kaganovich, Igor

172

Absolute atomic oxygen and nitrogen densities in radio-frequency driven atmospheric pressure cold plasmas: Synchrotron vacuum ultra-violet high-resolution Fourier-transform absorption measurements  

SciTech Connect (OSTI)

Reactive atomic species play a key role in emerging cold atmospheric pressure plasma applications, in particular, in plasma medicine. Absolute densities of atomic oxygen and atomic nitrogen were measured in a radio-frequency driven non-equilibrium plasma operated at atmospheric pressure using vacuum ultra-violet (VUV) absorption spectroscopy. The experiment was conducted on the DESIRS synchrotron beamline using a unique VUV Fourier-transform spectrometer. Measurements were carried out in plasmas operated in helium with air-like N{sub 2}/O{sub 2} (4:1) admixtures. A maximum in the O-atom concentration of (9.1 {+-} 0.7) Multiplication-Sign 10{sup 20} m{sup -3} was found at admixtures of 0.35 vol. %, while the N-atom concentration exhibits a maximum of (5.7 {+-} 0.4) Multiplication-Sign 10{sup 19} m{sup -3} at 0.1 vol. %.

Niemi, K.; O'Connell, D.; Gans, T. [York Plasma Institute, Department of Physics, University of York, York YO10 5DD (United Kingdom); Oliveira, N. de; Joyeux, D.; Nahon, L. [Synchrotron Soleil, l'Orme des Merisiers, St. Aubin BP 48, 91192 Gif sur Yvette Cedex (France); Booth, J. P. [Laboratoire de Physique des Plasmas-CNRS, Ecole Polytechnique, 91128 Palaiseau (France)

2013-07-15T23:59:59.000Z

173

Reduction of plasma density in the Helicity Injected Torus with Steady Inductance experiment by using a helicon pre-ionization source  

SciTech Connect (OSTI)

A helicon based pre-ionization source has been developed and installed on the Helicity Injected Torus with Steady Inductance (HIT-SI) spheromak. The source initiates plasma breakdown by injecting impurity-free, unmagnetized plasma into the HIT-SI confinement volume. Typical helium spheromaks have electron density reduced from (2–3) × 10{sup 19} m{sup ?3} to 1 × 10{sup 19} m{sup ?3}. Deuterium spheromak formation is possible with density as low as 2 × 10{sup 18} m{sup ?3}. The source also enables HIT-SI to be operated with only one helicity injector at injector frequencies above 14.5 kHz. A theory explaining the physical mechanism driving the reduction of breakdown density is presented.

Hossack, Aaron C.; Jarboe, Thomas R.; Victor, Brian S. [Department of Aeronautics and Astronautics, University of Washington, Seattle, Washington 98195 (United States)] [Department of Aeronautics and Astronautics, University of Washington, Seattle, Washington 98195 (United States); Firman, Taylor; Prager, James R.; Ziemba, Timothy [Eagle Harbor Technologies, Inc., 119 W. Denny Way, Suite 210, Seattle, Washington 98119 (United States)] [Eagle Harbor Technologies, Inc., 119 W. Denny Way, Suite 210, Seattle, Washington 98119 (United States); Wrobel, Jonathan S. [979B West Moorhead Circle, Boulder, Colorado 80305 (United States)] [979B West Moorhead Circle, Boulder, Colorado 80305 (United States)

2013-10-15T23:59:59.000Z

174

The National Ignition Facility: The Path to Ignition, High Energy Density Science and Inertial Fusion Energy  

SciTech Connect (OSTI)

The National Ignition Facility (NIF) at the Lawrence Livermore National Laboratory (LLNL) in Livermore, CA, is a Nd:Glass laser facility capable of producing 1.8 MJ and 500 TW of ultraviolet light. This world's most energetic laser system is now operational with the goals of achieving thermonuclear burn in the laboratory and exploring the behavior of matter at extreme temperatures and energy densities. By concentrating the energy from its 192 extremely energetic laser beams into a mm{sup 3}-sized target, NIF can produce temperatures above 100 million K, densities of 1,000 g/cm{sup 3}, and pressures 100 billion times atmospheric pressure - conditions that have never been created in a laboratory and emulate those in the interiors of planetary and stellar environments. On September 29, 2010, NIF performed the first integrated ignition experiment which demonstrated the successful coordination of the laser, the cryogenic target system, the array of diagnostics and the infrastructure required for ignition. Many more experiments have been completed since. In light of this strong progress, the U.S. and the international communities are examining the implication of achieving ignition on NIF for inertial fusion energy (IFE). A laser-based IFE power plant will require a repetition rate of 10-20 Hz and a 10% electrical-optical efficiency laser, as well as further advances in large-scale target fabrication, target injection and tracking, and other supporting technologies. These capabilities could lead to a prototype IFE demonstration plant in 10- to 15-years. LLNL, in partnership with other institutions, is developing a Laser Inertial Fusion Energy (LIFE) baseline design and examining various technology choices for LIFE power plant This paper will describe the unprecedented experimental capabilities of the NIF, the results achieved so far on the path toward ignition, the start of fundamental science experiments and plans to transition NIF to an international user facility providing access to researchers around the world. The paper will conclude with a discussion of LIFE, its development path and potential to enable a carbon-free clean energy future.

Moses, E

2011-03-25T23:59:59.000Z

175

Ultrafast dynamics of a near-solid-density layer in an intense femtosecond laser-excited plasma  

SciTech Connect (OSTI)

We report on the picosecond dynamics of a near-solid-density plasma generated by an intense, infrared (??=?800?nm) femtosecond laser using time-resolved pump-probe Doppler spectrometry. An initial red-shift is observed in the reflected third harmonic (??=?266?nm) probe pulse, which gets blue-shifted at longer probe-delays. A combination of particle-in-cell and radiation-hydrodynamics modelling is performed to model the pump laser interaction with the solid target. The results are post-processed to predict the Doppler shift. An excellent agreement is found between the results of such modelling and the experiment. The modelling suggests that the initial inward motion of the critical surface observed in the experiment is due to the passage of a shock-wave-like disturbance, launched by the pump interaction, propagating into the target. Furthermore, in order to achieve the best possible fit to the experimental data, it was necessary to incorporate the effects of bulk ion-acceleration resulting from the electrostatic field set up by the expulsion of electrons from the laser envelope. We also present results of time-resolved pump-probe reflectometry, which are corroborated with the spectrometry results using a 1-D reflectivity model.

Adak, Amitava; Chatterjee, Gourab; Kumar Singh, Prashant; Lad, Amit D.; Brijesh, P.; Kumar, G. Ravindra, E-mail: grk@tifr.res.in [Tata Institute of Fundamental Research, Dr. Homi Bhabha Road, Colaba, Mumbai 400005 (India); Blackman, David R. [York Plasma Institute, University of York, Heslington, York YO10 5DQ (United Kingdom); Robinson, A. P. L. [Central Laser Facility, Rutherford-Appleton Laboratory, Chilton, Didcot OX10 0QX (United Kingdom); Pasley, John [York Plasma Institute, University of York, Heslington, York YO10 5DQ (United Kingdom); Central Laser Facility, Rutherford-Appleton Laboratory, Chilton, Didcot OX10 0QX (United Kingdom)

2014-06-15T23:59:59.000Z

176

862 IEEE TRANSACTIONS ON PLASMA SCIENCE, VOL. 36, NO. 4, AUGUST 2008 Guest Editorial  

E-Print Network [OSTI]

including high-temperature plasmas, laser-produced plasmas, plasma material processing, plasma lighting- cial Issue also emphasizes the increasing interest in atmospheric and high-pressure discharges: from to the expanse of ionosphere and space Digital Object Identifier 10.1109/TPS.2008.925808 plasmas. The temporal

Kushner, Mark

177

Al{sub 2}O{sub 3} multi-density layer structure as a moisture permeation barrier deposited by radio frequency remote plasma atomic layer deposition  

SciTech Connect (OSTI)

Al{sub 2}O{sub 3} films deposited by remote plasma atomic layer deposition have been used for thin film encapsulation of organic light emitting diode. In this study, a multi-density layer structure consisting of two Al{sub 2}O{sub 3} layers with different densities are deposited with different deposition conditions of O{sub 2} plasma reactant time. This structure improves moisture permeation barrier characteristics, as confirmed by a water vapor transmission rate (WVTR) test. The lowest WVTR of the multi-density layer structure was 4.7 × 10{sup ?5} gm{sup ?2} day{sup ?1}, which is one order of magnitude less than WVTR for the reference single-density Al{sub 2}O{sub 3} layer. This improvement is attributed to the location mismatch of paths for atmospheric gases, such as O{sub 2} and H{sub 2}O, in the film due to different densities in the layers. This mechanism is analyzed by high resolution transmission electron microscopy, elastic recoil detection, and angle resolved X-ray photoelectron spectroscopy. These results confirmed that the multi-density layer structure exhibits very good characteristics as an encapsulation layer via location mismatch of paths for H{sub 2}O and O{sub 2} between the two layers.

Jung, Hyunsoo [Division of Materials Science and Engineering, Hanyang University, Seoul 133-791 (Korea, Republic of); Samsung Display Co. Ltd., Tangjeong, Chungcheongnam-Do 336-741 (Korea, Republic of); Jeon, Heeyoung [Department of Nano-scale Semiconductor Engineering, Hanyang University, Seoul 133-791 (Korea, Republic of); Choi, Hagyoung; Ham, Giyul; Shin, Seokyoon [Division of Materials Science and Engineering, Hanyang University, Seoul 133-791 (Korea, Republic of); Jeon, Hyeongtag, E-mail: hjeon@hanyang.ac.kr [Division of Materials Science and Engineering, Hanyang University, Seoul 133-791 (Korea, Republic of); Department of Nano-scale Semiconductor Engineering, Hanyang University, Seoul 133-791 (Korea, Republic of)

2014-02-21T23:59:59.000Z

178

Departures from local thermodynamic equilibrium in cutting arc plasmas derived from electron and gas density measurements using a two-wavelength quantitative Schlieren technique  

SciTech Connect (OSTI)

A two-wavelength quantitative Schlieren technique that allows inferring the electron and gas densities of axisymmetric arc plasmas without imposing any assumption regarding statistical equilibrium models is reported. This technique was applied to the study of local thermodynamic equilibrium (LTE) departures within the core of a 30 A high-energy density cutting arc. In order to derive the electron and heavy particle temperatures from the inferred density profiles, a generalized two-temperature Saha equation together with the plasma equation of state and the quasineutrality condition were employed. Factors such as arc fluctuations that influence the accuracy of the measurements and the validity of the assumptions used to derive the plasma species temperature were considered. Significant deviations from chemical equilibrium as well as kinetic equilibrium were found at elevated electron temperatures and gas densities toward the arc core edge. An electron temperature profile nearly constant through the arc core with a value of about 14000-15000 K, well decoupled from the heavy particle temperature of about 1500 K at the arc core edge, was inferred.

Prevosto, L.; Mancinelli, B. [Grupo de Descargas Electricas, Departamento Ing. Electromecanica, Facultad Regional Venado Tuerto (UTN), Laprida 651, Venado Tuerto 2600, Santa Fe (Argentina); Artana, G. [Laboratorio de Fluidodinamica, Departamento Ing. Mecanica, Facultad de Ingenieria (UBA), Paseo Colon 850, C1063ACV, Buenos Aires (Argentina); Kelly, H. [Grupo de Descargas Electricas, Departamento Ing. Electromecanica, Facultad Regional Venado Tuerto (UTN), Laprida 651, Venado Tuerto 2600, Santa Fe (Argentina); Departamento de Fisica, Facultad de Ciencias Exactas y Naturales (UBA), Instituto de Fisica del Plasma (CONICET), Ciudad Universitaria, Pab. I, 1428 Buenos Aires (Argentina)

2011-03-15T23:59:59.000Z

179

IEEE TRANSACTIONS ON PLASMA SCIENCE, VOL. 34, NO. 3, JUNE 2006 855 Kinetics of Plasma Particles and Electron Transport  

E-Print Network [OSTI]

in the interelectrode gap. In a low-pressure gas, a high-current density discharge can be supported if the density Identifier 10.1109/TPS.2006.873250 In ablative wall discharges (e.g., metallic electrode ablation in arcs[2 of the vapor particles. The hydrodynamic pa- rameters (temperature, density, velocity) in the Knudsen layer

Kaganovich, Igor

180

Heavy ion fusion science research for high energy density physics and fusion applications  

E-Print Network [OSTI]

cost direct plasma MHD direct conversion [38], as well as toT-lean targets and direct conversion for heavy ion fusion. [conversion loss of beam energy into x-rays. High ablation velocities with heavy ion direct

Logan, B.G.

2007-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "density plasma science" from the National Library of EnergyBeta (NLEBeta).
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181

Relativistic self-focusing of ultra-high intensity X-ray laser beams in warm quantum plasma with upward density profile  

SciTech Connect (OSTI)

The results of a numerical study of high-intensity X-ray laser beam interaction with warm quantum plasma (WQP) are presented. By means of an upward ramp density profile combined with quantum factors specially the Fermi velocity, we have demonstrated significant relativistic self-focusing (RSF) of a Gaussian electromagnetic beam in the WQP where the Fermi temperature term in the dielectric function is important. For this purpose, we have considered the quantum hydrodynamics model that modifies refractive index of inhomogeneous WQPs with the inclusion of quantum correction through the quantum statistical and diffraction effects in the relativistic regime. Also, to better illustration of the physical difference between warm and cold quantum plasmas and their effect on the RSF, we have derived the envelope equation governing the spot size of X-ray laser beam in Q-plasmas. In addition to the upward ramp density profile, we have found that the quantum effects would be caused much higher oscillation and better focusing of X-ray laser beam in the WQP compared to that of cold quantum case. Our computational results reveal the importance of the use of electrons density profile and Fermi speed in enhancing self-focusing of laser beam.

Habibi, M., E-mail: habibi.physics@gmail.com [Young Researchers and Elite Club, Shirvan Branch, Islamic Azad University, Shirvan (Iran, Islamic Republic of); Ghamari, F. [Young Researchers and Elite Club, Khorramabad Branch, Islamic Azad University, Khorramabad (Iran, Islamic Republic of)

2014-05-15T23:59:59.000Z

182

Dust density effect on complex plasma decay L. Couedel a,b, A.A. Samarian a  

E-Print Network [OSTI]

and supported by comparison to existing experimental data. Key words: Complex plasma, dust, afterglow, decay (PECVD, etching, fusion reactor,etc). The dust particles are charged due to their interactions, the dust particles can be either grown directly in the plasma chamber (by sputtering [6,7] or using

Paris-Sud XI, Université de

183

Influence of the reactor wall composition on radicals' densities and total pressure in Cl{sub 2} inductively coupled plasmas: II. During silicon etching  

SciTech Connect (OSTI)

In an industrial inductively coupled plasma reactor dedicated to silicon etching in chlorine-based chemistry, the density of Cl{sub 2} molecules and the gas temperature are measured by means of laser absorption techniques, the density of SiCl{sub x} (x{<=}2) radicals by broadband absorption spectroscopy, the density of SiCl{sub 4} and ions by mass spectrometry, and the total gas pressure with a capacitance gauge. These measurements permit us to estimate the mole fractions of Cl, SiCl{sub 4}, and etch product radicals when etching a 200 mm diameter silicon wafer. The pure Cl{sub 2} plasma is operated in well prepared chamber wall coating with a thin film of SiOCl, AlF, CCl, or TiOCl. The impact of the chemical nature of the reactor wall's coatings on these mole fractions is studied systematically. We show that the reactor wall coatings have a huge influence on the radicals densities, but this is not only from the difference on Cl-Cl recombination coefficient on different surfaces. During silicon etching, SiCl{sub x} radicals sticking on the reactor walls are etched by Cl atoms and recycled into the plasma by forming volatile SiCl{sub 4}. Hence, the loss of Cl atoms in etching the wall deposited silicon is at least as important as their wall recombination in controlling the Cl atoms density. Furthermore, because SiCl{sub 4} is produced at high rate by both the wafer and reactor walls, it is the predominant etching product in the gas phase. However, the percentage of redeposited silicon that can be recycled into the plasma depends on the amount of oxygen present in the plasma: O atoms produced by etching the quartz roof window fix Si on the reactor walls by forming a SiOCl deposit. Hence, the higher the O density is, the lower the SiCl{sub 4} density will be, because silicon is pumped by the reactor walls and the SiOCl layer formed is not isotropically etched by chlorine. As a result, in the same pure Cl{sub 2} plasma at 20 mTorr, the SiCl{sub x} mole fraction can vary from 18% in a SiOCl-coated reactor, where the O density is the highest, to 62% in a carbon-coated reactor, where there is no O. In the latter case, most of the Cl mass injected in the reactor is stored in SiCl{sub 4} molecules, which results in a low silicon etch rate. In this condition, the Cl mass balance is verified within 10%, and from the silicon mass balance we concluded that SiCl{sub x} radicals have a high surface loss probability. The impact of the reactor wall coating on the etching process is thus important, but the mechanisms by which the walls control the plasma chemistry is much more complicated than a simple control through recombination reaction of halogen atoms on these surfaces.

Cunge, G.; Sadeghi, N.; Ramos, R. [Laboratoire des Technologies de la Microelectronique, CNRS, 17 rue des Martyrs (c/o CEA-LETI), 38054 Grenoble Cedex 9 (France); Laboratoire de Spectrometrie Physique (UMR 5588), Universite Joseph Fourier-Grenoble, and CNRS, BP 87, 38402 St. Martin d'Heres (France); Laboratoire des Technologies de la Microelectronique, CNRS, 17 rue des Martyrs (c/o CEA-LETI), 38054 Grenoble Cedex 9 (France)

2007-11-01T23:59:59.000Z

184

Space and time resolved spectroscopy of laser-produced plasmas: A study of density-sensitive x-ray transitions in helium-like and neon-like ions  

SciTech Connect (OSTI)

The determination of level populations and detailed population mechanisms in dense plasmas has become an increasingly important problem in atomic physics. In this work, the density variation of line intensities and level populations in aluminum K-shell and molybdenum and silver L-shell emission spectra have been measured from high-powered, laser-produced plasmas. For each case, the density dependence of the observed line emission is due to the effect of high frequency electron-ion collisions on metastable levels. The density dependent line intensities vary greatly in laser-produced plasmas and can be used to extract detailed information concerning the population kinetics and level populations of the ions. The laser-plasmas had to be fully characterized in order to clearly compare the observed density dependence with atomic theory predictions. This has been achieved through the combined use of new diagnostic instruments and microdot targets which provided simultaneously space, time, and spectrally resolved data. The plasma temperatures were determined from the slope of the hydrogen-like recombination continuum. The time resolved electron density profiles were measured using multiple frame holographic interferometry. Thus, the density dependence of K-shell spectral lines could be clearly examined, independent of assumptions concerning the dynamics of the plasma. In aluminum, the electron density dependence of various helium-like line intensity ratios were measured. Standard collisional radiative equilibrium models fail to account for the observed density dependence measured for the ''He/sub ..cap alpha..//IC'' ratio. Instead, a quasi-steady state atomic model based on a purely recombining plasma is shown to accurately predict the measured density dependence. This same recombining plasma calculation successfully models the density dependence of the high-n ''He/sub ..gamma..//He/sub ..beta../'' and ''He/sub delta//He/sub ..beta../'' helium-like resonance line intensity ratios.

Young, Bruce Kai Fong

1988-09-01T23:59:59.000Z

185

104 IEEE TRANSACTIONS ON PLASMA SCIENCE, VOL. 31, NO. 1, FEBRUARY 2003 Modeling Plasma Immersion Ion Implantation  

E-Print Network [OSTI]

Ion Implantation Under Trapezoidal Voltage Pulses Joaquim José Barroso, Jóse Osvaldo Rossi, and Mário Research, S.J. Campos, SP 12201-970, Brazil (e-mail: barroso@plasma.inpe.br). Digital Object Identifier 10

186

10 IEEE TRANSACTIONS ON PLASMA SCIENCE, VOL. 30, NO. 1, FEBRUARY 2002 Study of Magnetic Helicity Injection via Plasma  

E-Print Network [OSTI]

, spheromak. MAGNETIC helicity [1] is a quantity which describes the amount of twist or writhe in the magnetic-confined plasmas in fusion research (e.g., spheromaks) must be sustained somehow, i.e., via helicity injection a schematic of the experimental setup. A coaxial spheromak gun with large planar geometry is installed on one

Hsu, Scott

187

IEEE TRANSACTIONS ON PLASMA SCIENCE, VOL. 34, NO. 3, JUNE 2006 825 Nonlocal Effects in a Bounded Afterglow Plasma  

E-Print Network [OSTI]

excitation, supply additional heating to slow electrons and reduce their diffu- sion cooling rate. Altering research and technical applications. Index Terms--Afterglow plasma, diffusion cooling, electron energy and diffusion cooling, much faster than the characteristic recombination time of the electrons. Due

Kaganovich, Igor

188

576 IEEE TRANSACTIONS ON PLASMA SCIENCE, VOL. 28, NO. 3, JUNE 2000 A Comparison of L-Band Helix TWT Experiments  

E-Print Network [OSTI]

576 IEEE TRANSACTIONS ON PLASMA SCIENCE, VOL. 28, NO. 3, JUNE 2000 A Comparison of L-Band Helix TWT. Publisher Item Identifier S 0093-3813(00)05375-3. With the projected growth of the telecommunications market

Hassam, Adil

189

Influence of the reactor wall composition on radicals' densities and total pressure in Cl{sub 2} inductively coupled plasmas: I. Without silicon etching  

SciTech Connect (OSTI)

Laser absorption at 355 nm is used to monitor the time variations of the Cl{sub 2} density in high-density industrial inductively coupled plasma. This technique is combined with the measurement of the gas temperature from the Doppler width of the 811.5 nm line of argon, added as a trace gas and with the measurement of the total gas pressure with a Baratron gauge. These measurements permit to estimate the mole fractions of Cl{sub 2} and Cl species in Cl{sub 2} inductively coupled plasmas in a waferless reactor. The impact of the chemical nature of the reactor wall coatings on the Cl and Cl{sub 2} mole fractions is studied systematically. We show that under otherwise identical plasma conditions, the Cl mole fraction is completely different when the plasma is operated in SiOCl, AlF, CCl, or TiOCl coated reactors, because the homogeneous recombination probability of Cl atoms is strongly surface dependant. The Cl atom mole fraction reached at 100 W radiofrequency power in SiOCl coated reactor (80%) is much higher than that obtained at 900 W in a ''clean'' AlF reactor (40%). A simple zero-dimensional model permits to provide the recombination coefficient of Cl atoms, {gamma}{sub rec}: 0.005 on SiOCl film and about 0.3 on the other three coatings. It is proposed to get benefit of this very high sensitivity of Cl{sub 2} dissociation rate to the wall coating for the control of the chamber wall status from the Cl{sub 2} density measurements in standard conditions.

Cunge, G.; Sadeghi, N.; Ramos, R. [Laboratoire des Technologies de la Microelectronique, CNRS, 17 rue des Martyrs (c/o CEA-LETI), 38054 Grenoble Cedex 9 (France); Laboratoire de Spectrometrie Physique (UMR 5588), Universite Joseph Fourier-Grenoble, and CNRS, BP 87, 38402 St. Martin d'Heres (France); Laboratoire des Technologies de la Microelectronique, CNRS, 17 rue des Martyrs (c/o CEA-LETI), 38054 Grenoble Cedex 9 (France)

2007-11-01T23:59:59.000Z

190

Quantitative studies of transfer in vivo of low density, Sf 12-60, and Sf 60-400 lipoproteins between plasma and arterial intima in humans  

SciTech Connect (OSTI)

To assess the potential of various plasma lipoprotein classes to contribute to the lipid content of the arterial intima, influx and efflux of these plasma lipoprotein fractions into and from the intima of human carotid arteries were measured in vivo. While low density lipoprotein (LDL) is known to transfer from plasma into the arterial wall, there is less information on the atherogenic potential of lipoproteins of intermediate density (Sf 12-60) or of very low density (Sf 60-400). Aliquots of the same lipoprotein (LDL, Sf 12-60 lipoprotein particles, or Sf 60-400 lipoprotein particles) iodinated with iodine-125 and iodine-131 were injected intravenously 18-29 hours and 3-6 hours, respectively, before elective surgical removal of atheromatous arterial tissue, and the intimal clearance of lipoproteins, lipoprotein influx, and fractional loss of newly entered lipoproteins were calculated. Intimal clearance of Sf 60-400 particles was not detectable (less than 0.3 microliter x hr-1 x cm-2), whereas the average value for both LDL and Sf 12-60 lipoprotein particles was 0.9 microliter x hr-1 x cm-2. Since the fractional loss of newly entered LDL and Sf 12-60 lipoprotein particles was also similar, the results suggest similar modes of entry and exit for these two particles. However, due to lower plasma concentrations of Sf 12-60 lipoproteins as compared with LDL, the mass influx of cholesterol in the Sf 12-60 particles was on the order of one 10th of that in LDL, and that of apolipoprotein B was about one 20th.

Shaikh, M.; Wootton, R.; Nordestgaard, B.G.; Baskerville, P.; Lumley, J.S.; La Ville, A.E.; Quiney, J.; Lewis, B. (Guys Hospital, London, (United Kingdom))

1991-05-01T23:59:59.000Z

191

INSTITUTE OF PHYSICS PUBLISHING PLASMA SOURCES SCIENCE AND TECHNOLOGY Plasma Sources Sci. Technol. 16 (2007) 233239 doi:10.1088/0963-0252/16/2/004  

E-Print Network [OSTI]

-pinch [3], spheromak [4] and plasma opening switch [5]. The plasma source used here is very repeatable [6

Choueiri, Edgar

192

Fusion Energy Sciences  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

from discovery plasma science to high-power, long-pulse, and foundational burning plasma research. Current major collaborations include: divertor and edge plasma diagnostics on...

193

Diagnosing collisions of magnetized, high energy density plasma flows using a combination of collective Thomson scattering, Faraday rotation, and interferometry (invited)  

SciTech Connect (OSTI)

A suite of laser based diagnostics is used to study interactions of magnetised, supersonic, radiatively cooled plasma flows produced using the Magpie pulse power generator (1.4 MA, 240 ns rise time). Collective optical Thomson scattering measures the time-resolved local flow velocity and temperature across 7–14 spatial positions. The scattering spectrum is recorded from multiple directions, allowing more accurate reconstruction of the flow velocity vectors. The areal electron density is measured using 2D interferometry; optimisation and analysis are discussed. The Faraday rotation diagnostic, operating at 1053 nm, measures the magnetic field distribution in the plasma. Measurements obtained simultaneously by these diagnostics are used to constrain analysis, increasing the accuracy of interpretation.

Swadling, G. F., E-mail: swadling@imperial.ac.uk; Lebedev, S. V.; Hall, G. N.; Patankar, S.; Stewart, N. H.; Smith, R. A.; Burdiak, G. C.; Grouchy, P. de; Skidmore, J.; Suttle, L.; Suzuki-Vidal, F.; Bland, S. N.; Kwek, K. H.; Pickworth, L.; Bennett, M.; Hare, J. D. [Plasma Physics Group, Imperial College, London SW6 7LZ (United Kingdom); Harvey-Thompson, A. J. [Sandia National Laboratory, Albuquerque, New Mexico 87185-1193 (United States); Rozmus, W. [Department of Physics, University of Alberta, Edmonton, Alberta T6G 2J1 (Canada); Yuan, J. [Key Laboratory of Pulsed Power, Institute of Fluid Physics, CAE, Mianyang 621900 (China)

2014-11-15T23:59:59.000Z

194

On the program, vision, and budget for the fusion and plasma sciences  

E-Print Network [OSTI]

relevant to clean energy with near-term payoff. With this as backdrop, the Administration affirms a strong Director, Office of Science For Fusion Energy Sciences U.S. Department of Energy Presented to the Fusion Energy Sciences Advisory Committee February 28, 2012 #12;The science at the heart of fusion energy is far

195

Multi-Megajoule NIF: Ushering In a New Era in High Energy Density Science  

SciTech Connect (OSTI)

This paper describes the status of the stadium-sized National Ignition Facility (NIF), the world's largest laser system and first operational multi-megajoule laser. The 192-beam NIF, located at Lawrence Livermore National Laboratory (LLNL), is 96% complete and scheduled for completion in March 2009. The NIF laser will produce nanosecond laser pulses with energies up to approximately 4 MJ in the infrared (laser wavelength = 1.053-{micro}m) and 2MJ in the ultraviolet (laser wavelength = 0.35-{micro}m). With these energies NIF will access conditions of pressure and temperature not previously available on earth, allowing it to conduct experiments in support of the nation's national security, energy, and fundamental science goals. First ignition experiments at NIF are scheduled for FY2010. This paper will provide an overview of the NIF laser and the ignition, energy, and fundamental science activities at NIF.

Keane, C; Moses, E I

2008-04-30T23:59:59.000Z

196

Plasma Wakefield Acceleration and FACET - Facilities for Accelerator Science and Experimental Test Beams at SLAC  

ScienceCinema (OSTI)

Plasma wakefield acceleration is one of the most promising approaches to advancing accelerator technology. This approach offers a potential 1,000-fold or more increase in acceleration over a given distance, compared to existing accelerators.  FACET, enabled by the Recovery Act funds, will study plasma acceleration, using short, intense pulses of electrons and positrons. In this lecture, the physics of plasma acceleration and features of FACET will be presented.  

Andrei Seryi

2010-01-08T23:59:59.000Z

197

Far-from-equilibrium dynamics of a strongly coupled non-Abelian plasma with non-zero charge density or external magnetic field  

E-Print Network [OSTI]

Using holography, we study the evolution of a spatially homogeneous, far from equilibrium, strongly coupled N=4 supersymmetric Yang-Mills plasma with a non-zero charge density or a background magnetic field. This gauge theory problem corresponds, in the dual gravity description, to an initial value problem in Einstein-Maxwell theory with homogeneous but anisotropic initial conditions. We explore the dependence of the equilibration process on different aspects of the initial departure from equilibrium and, while controlling for these dependencies, examine how the equilibration dynamics are affected by the presence of a non-vanishing charge density or an external magnetic field. The equilibration dynamics are remarkably insensitive to the addition of even large chemical potentials or magnetic fields; the equilibration time is set primarily by the form of the initial departure from equilibrium. For initial deviations from equilibrium which are well localized in scale, we formulate a simple model for equilibratio...

Fuini, John F

2015-01-01T23:59:59.000Z

198

Far-from-equilibrium dynamics of a strongly coupled non-Abelian plasma with non-zero charge density or external magnetic field  

E-Print Network [OSTI]

Using holography, we study the evolution of a spatially homogeneous, far from equilibrium, strongly coupled N=4 supersymmetric Yang-Mills plasma with a non-zero charge density or a background magnetic field. This gauge theory problem corresponds, in the dual gravity description, to an initial value problem in Einstein-Maxwell theory with homogeneous but anisotropic initial conditions. We explore the dependence of the equilibration process on different aspects of the initial departure from equilibrium and, while controlling for these dependencies, examine how the equilibration dynamics are affected by the presence of a non-vanishing charge density or an external magnetic field. The equilibration dynamics are remarkably insensitive to the addition of even large chemical potentials or magnetic fields; the equilibration time is set primarily by the form of the initial departure from equilibrium. For initial deviations from equilibrium which are well localized in scale, we formulate a simple model for equilibration times which agrees quite well with our results.

John F. Fuini III; Laurence G. Yaffe

2015-03-24T23:59:59.000Z

199

The impact of low-Z impurities on x-ray conversion efficiency from laser-produced plasmas of low-density gold foam targets  

SciTech Connect (OSTI)

It is an important approach to improve the x-ray conversion efficiency of laser-ablated high-Z plasmas by using low initial density materials for various applications. However, unavoidable low-Z impurities in the manufacture process of low-density high-Z foam targets will depress this effect. A general easy-to-use analytical model based on simulations was developed to evaluate the quantitative impact of impurities within the gold foam target on laser to x-ray conversion efficiency. In addition, the x-ray conversion efficiencies of 1 g/cm{sup 3} gold foams with two different initial contents of impurities were experimentally investigated. Good agreements have been achieved between the model results and experiments.

Dong, Yunsong [Research Center of Laser Fusion, China Academy of Engineering Physics, Mianyang 621900 (China) [Research Center of Laser Fusion, China Academy of Engineering Physics, Mianyang 621900 (China); Department of Engineering Physics, Tsinghua University, Beijing 100084 (China); Shang, Wanli; Yang, Jiamin; Zhang, Lu; Zhang, Wenhai; Li, Zhichao; Guo, Liang; Zhan, Xiayu; Du, Huabing; Deng, Bo [Research Center of Laser Fusion, China Academy of Engineering Physics, Mianyang 621900 (China)] [Research Center of Laser Fusion, China Academy of Engineering Physics, Mianyang 621900 (China); Pu, Yikang [Department of Engineering Physics, Tsinghua University, Beijing 100084 (China)] [Department of Engineering Physics, Tsinghua University, Beijing 100084 (China)

2013-12-15T23:59:59.000Z

200

Basic concept in plasma diagnostics  

E-Print Network [OSTI]

This paper presents the basic concept of various plasma diagnostics used for the study of plasma characteristics in different plasma experiments ranging from low temperature to high energy density plasma.

Rai, V N

2014-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "density plasma science" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


201

2780 IEEE TRANSACTIONS ON PLASMA SCIENCE, VOL. 39, NO. 11, NOVEMBER 2011 Jetlike Emission From Colliding  

E-Print Network [OSTI]

attractive applications in the field of X-ray lasers, pulsed-laser deposition (PLD), extreme ultraviolet Colliding Laser-Produced Plasmas Sivanandan S. Harilal, Mathew P. Polek, and Ahmed Hassanein, Member, IEEE Abstract--We report a large jetlike collimated emission feature from colliding laser-produced plasmas (LPPs

Harilal, S. S.

202

INSTITUTE OF PHYSICS PUBLISHING PLASMA SOURCES SCIENCE AND TECHNOLOGY Plasma Sources Sci. Technol. 15 (2006) 858864 doi:10.1088/0963-0252/15/4/032  

E-Print Network [OSTI]

temperature in pulsed fluorocarbon rf plasmas O Gabriel1 , S Stepanov, M Pfafferott and J Meichsner Institute in fluorocarbon plasmas is essential for a fundamental understanding of plasma chemical processes and plasma fluorocarbon radio frequency plasmas were successfully applied, e.g. for contact hole etching [1]. Furthermore

Greifswald, Ernst-Moritz-Arndt-Universität

203

Estimation of the electron density and radiative energy losses in a calcium plasma source based on an electron cyclotron resonance discharge  

SciTech Connect (OSTI)

The parameters of a calcium plasma source based on an electron cyclotron resonance (ECR) discharge were calculated. The analysis was performed as applied to an ion cyclotron resonance system designed for separation of calcium isotopes. The plasma electrons in the source were heated by gyrotron microwave radiation in the zone of the inhomogeneous magnetic field. It was assumed that, in such a combined trap, the energy of the extraordinary microwave propagating from the high-field side was initially transferred to a small group of resonance electrons. As a result, two electron components with different transverse temperatures-the hot resonance component and the cold nonresonance component-were created in the plasma. The longitudinal temperatures of both components were assumed to be equal. The entire discharge space was divided into a narrow ECR zone, where resonance electrons acquired transverse energy, and the region of the discharge itself, where the gas was ionized. The transverse energy of resonance electrons was calculated by solving the equations for electron motion in an inhomogeneous magnetic field. Using the law of energy conservation and the balance condition for the number of hot electrons entering the discharge zone and cooled due to ionization and elastic collisions, the density of hot electrons was estimated and the dependence of the longitudinal temperature T{sub e Parallel-To} of the main (cold) electron component on the energy fraction {beta} lost for radiation was obtained.

Potanin, E. P., E-mail: potanin@imp.kiae.ru; Ustinov, A. L. [National Research Centre Kurchatov Institute (Russian Federation)

2013-06-15T23:59:59.000Z

204

U.S. Department of Energy's Plasma Science Center holds third...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

May 22, 2012 Tweet Widget Google Plus One Share on Facebook Jeff Walker, a University of West Virginia graduate student, discussed his poster on dusty plasmas with PPPL physicist...

205

Atomic data of tungsten for current and future uses in fusion and plasma science  

SciTech Connect (OSTI)

Atomic physics has played an important role throughout the history of experimental plasma physics. For example, accurate knowledge of atomic properties has been crucial for understanding the plasma energy balance and for diagnostic development. With the shift in magnetic fusion research toward high-temperature burning plasmas like those expected to be produced in the ITER tokamak, the atomic physics of tungsten has become important. Tungsten will be a constituent of ITER plasmas because of its use as a plasma-facing material able to withstand high heat loads with lower tritium retention than other possible materials. Already, ITER diagnostics are being developed based on using tungsten radiation. In particular, the ITER Core Imaging X-ray Spectrometer (CIXS), which is designed to measure the core ion temperature and bulk plasma motion, is being based on the x-ray emission of neonlike tungsten ions (W{sup 64+}). In addition, tungsten emission will at ITER be measured by extreme ultraviolet (EUV) and optical spectrometers to determine its concentration in the plasma and to assess power loss and tungsten sputtering rates. On present-day tokamaks tungsten measurements are therefore being performed in preparation of ITER. Tungsten has very complex spectra and most are still unknown. The WOLFRAM project at Livermore aims to produce data for tungsten in various spectral bands: Lshell x-ray emission for CIXS development, soft x-ray and EUV M- and N-shell tungsten emission for understanding the edge radiation from ITER plasmas as well as from contemporary tokamaks, and O-shell emission for developing spectral diagnostics of the ITER divertor.

Clementson, J.; Beiersdorfer, P. [Physics Division, Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, CA 94551 (United States); Lennartsson, T. [Lund Observatory, Lund University, P.O. Box 43, SE-221 00 Lund (Sweden)

2013-04-19T23:59:59.000Z

206

Absolute CF{sub 2} density and gas temperature measurements by absorption spectroscopy in dual-frequency capacitively coupled CF{sub 4}/Ar plasmas  

SciTech Connect (OSTI)

Broadband ultraviolet absorption spectroscopy has been used to determine the CF{sub 2} radical density in dual-frequency capacitively coupled CF{sub 4}/Ar plasmas, using the CF{sub 2} A{sup ~1}B{sub 1}?X{sup ~1}A{sub 1} system of absorption spectrum. The rotational temperature of ground state CF{sub 2} and excited state CF was also estimated by using A{sup ~1}B{sub 1}?X{sup ~1}A{sub 1} system and B{sup 2}??X{sup 2}? system, respectively. The translational gas temperature was deduced from the Doppler width of the Ar{sup *}({sup 3}P{sub 2}) and Ar{sup *}({sup 3}P{sub 0}) metastable atoms absorption line by using the tunable diode laser absorption spectroscopy. The rotational temperatures of the excited state CF are about 100?K higher than those of ground state CF{sub 2}, and about 200?K higher than the translational gas temperatures. The dependences of the radical CF{sub 2} density, electron density, electron temperature, rotational temperature, and gas temperature on the high frequency power and pressure have been analyzed. Furthermore, the production and loss mechanisms of CF{sub 2} radical and the gas heating mechanisms have also been discussed.

Liu, Wen-Yao; Xu, Yong, E-mail: yongxu@dlut.edu.cn; Peng, Fei; Gong, Fa-Ping; Li, Xiao-Song; Zhu, Ai-Min [Key Laboratory of Materials Modification by Laser, Ion, and Electron Beams (Ministry of Education), School of Physics and Optoelectronic Technology, Dalian University of Technology, Dalian 116024 (China); Laboratory of Plasma Physical Chemistry, Dalian University of Technology, Dalian 116024 (China); Liu, Yong-Xin; Wang, You-Nian [Key Laboratory of Materials Modification by Laser, Ion, and Electron Beams (Ministry of Education), School of Physics and Optoelectronic Technology, Dalian University of Technology, Dalian 116024 (China)

2014-10-15T23:59:59.000Z

207

Computational Science Technical Note CSTN-172 Plasma Visualization in Parallel using Particle Systems on Graphical Processing  

E-Print Network [OSTI]

as particle systems that emit light are important in many interesting components of games, computer animated = {April}, publisher = {WorldComp}, institution = {Computer Science, Massey University, Auckland, New Ken Hawick, Computer Science, Massey University, Albany, North Shore 102-904, Auckland, New Zealand

Hawick, Ken

208

Issues in "Burning Plasma Science" S. J. Zweben, D. S. Darrow  

E-Print Network [OSTI]

development issues => big issue: local burn control in an AT · Our conclusions · Alternate path #12;Burning, not fusion energy development (i.e. reactor-relevance) General issues: What are the interesting plasma a viable fusion reactor (or, should it be)? #12;What are Fusion Energy Development Issues Which Could

209

Age distribution of scientists at the MIT Plasma Science and Fusion Center.  

E-Print Network [OSTI]

. #12;[1]Edward Thomas, Jr., et al., Fusion in the era of burning plasma studies: workforce planning engineering are rapidly declining. This situation is unfolding in the context of an aging US fusion workforce, retirement age. I believe the workforce distribution for the entire US fusion program is not very different

210

Physical Sciences 2007 Science & Technology Highlights  

SciTech Connect (OSTI)

The Physical Sciences Directorate applies frontier physics and technology to grand challenges in national security. Our highly integrated and multidisciplinary research program involves collaborations throughout Lawrence Livermore National Laboratory, the National Nuclear Security Administration, the Department of Energy, and with academic and industrial partners. The Directorate has a budget of approximately $150 million, and a staff of approximately 350 employees. Our scientists provide expertise in condensed matter and high-pressure physics, plasma physics, high-energy-density science, fusion energy science and technology, nuclear and particle physics, accelerator physics, radiation detection, optical science, biotechnology, and astrophysics. This document highlights the outstanding research and development activities in the Physical Sciences Directorate that made news in 2007. It also summarizes the awards and recognition received by members of the Directorate in 2007.

Hazi, A U

2008-04-07T23:59:59.000Z

211

Plasma Sources Science and Technology Plasma Sources Sci. Technol. 23 (2014) 044005 (6pp) doi:10.1088/0963-0252/23/4/044005  

E-Print Network [OSTI]

.1088/0963-0252/23/4/044005 Cross-field plasma lens for focusing of the Hall thruster plume Martin E Griswold, Yevgeny Raitses as a means to focus the thruster plume. In the PL, the plasma is nearly collisionless, with non from its ionization and acceleration using an external plasma lens (PL) to focus the beam after

212

DOE Science Showcase - DOE Plasma Research | OSTI, US Dept of Energy,  

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213

MIT Plasma Science & Fusion left: research>alctor>meetings scheduled  

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214

'Art of Science' exhibition on view thru November 2012 | Princeton Plasma  

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215

Princeton Plasma Physics Laboratory | U.S. DOE Office of Science (SC)  

Office of Science (SC) Website

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216

Princeton Plasma Physics Laboratory | U.S. DOE Office of Science (SC)  

Office of Science (SC) Website

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217

Princeton Plasma Physics Laboratory | U.S. DOE Office of Science (SC)  

Office of Science (SC) Website

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218

Princeton Plasma Physics Laboratory | U.S. DOE Office of Science (SC)  

Office of Science (SC) Website

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219

Study of electron acceleration and x-ray radiation as a function of plasma density in capillary-guided laser wakefield accelerators  

SciTech Connect (OSTI)

Laser wakefield electron acceleration in the blow-out regime and the associated betatron X-ray radiation were investigated experimentally as a function of the plasma density in a configuration where the laser is guided. Dielectric capillary tubes were employed to assist the laser keeping self-focused over a long distance by collecting the laser energy around its central focal spot. With a 40 fs, 16 TW pulsed laser, electron bunches with tens of pC charge were measured to be accelerated to an energy up to 300 MeV, accompanied by X-ray emission with a peak brightness of the order of 10{sup 21} ph/s/mm{sup 2}/mrad{sup 2}/0.1%BW. Electron trapping and acceleration were studied using the emitted X-ray beam distribution to map the acceleration process; the number of betatron oscillations performed by the electrons was inferred from the correlation between measured X-ray fluence and beam charge. A study of the stability of electron and X-ray generation suggests that the fluctuation of X-ray emission can be reduced by stabilizing the beam charge. The experimental results are in good agreement with 3D particle-in-cell (PIC) simulation.

Ju, J.; Döpp, A.; Cros, B. [Laboratoire de Physique des Gaz et des Plasmas, CNRS-Université Paris-Sud, 91405 Orsay (France)] [Laboratoire de Physique des Gaz et des Plasmas, CNRS-Université Paris-Sud, 91405 Orsay (France); Svensson, K.; Genoud, G.; Wojda, F.; Burza, M.; Persson, A.; Lundh, O.; Wahlström, C.-G. [Department of Physics, Lund University, P.O. Box 118, S-22100 Lund (Sweden)] [Department of Physics, Lund University, P.O. Box 118, S-22100 Lund (Sweden); Ferrari, H. [Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) and CNEA-CAB (Argentina)] [Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) and CNEA-CAB (Argentina)

2013-08-15T23:59:59.000Z

220

Computational accelerator science needs towards laser-plasma accelerators for future colliders  

E-Print Network [OSTI]

Laser plasma accelerators have the potential to reduce the size of future linacs for high energy physics by more than an order of magnitude, due to their high gradient. Research is in progress at current facilities, including the BELLA PetaWatt laser at LBNL, towards high quality 10 GeV beams and staging of multiple modules, as well as control of injection and beam quality. The path towards high-energy physics applications will likely involve hundreds of such stages, with beam transport, conditioning and focusing. Current research focuses on addressing physics and R&D challenges required for a detailed conceptual design of a future collider. Here, the tools used to model these accelerators and their resource requirements are summarized, both for current work and to support R&D addressing issues related to collider concepts.

Geddes, C G R; Schroeder, C B; Esarey, E; Leemans, W P

2013-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "density plasma science" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


221

The Ronald E. Hatcher SCIENCE ON SATURDAY Lecture Series | Princeton Plasma  

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222

The Ronald E. Hatcher SCIENCE ON SATURDAY Lecture Series | Princeton Plasma  

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223

INSTITUTE OF PHYSICS PUBLISHING PLASMA SOURCES SCIENCE AND TECHNOLOGY Plasma Sources Sci. Technol. 11 (2002) 426430 PII: S0963-0252(02)52640-2  

E-Print Network [OSTI]

. 11 (2002) 426­430 PII: S0963-0252(02)52640-2 Comparison of hollow cathode and Penning dischargesA, and a range of pressures, from 100 mTorr to 5 Torr, were investigated. This work is directed ultimately in many plasma applica- tions, including magnetic fusion reactors, plasma processing and inertial

Howard, John

224

INSTITUTE OF PHYSICS PUBLISHING PLASMA SOURCES SCIENCE AND TECHNOLOGY Plasma Sources Sci. Technol. 16 (2007) 9096 doi:10.1088/0963-0252/16/1/012  

E-Print Network [OSTI]

-dimensional simulation of the plasma reactor was coupled with a two-dimensional simulation of the sheath region overIEDisdeterminedbythedifferenceinpotentialbetweenthe plasma and the substrate, as well as ion collisions with the background neutral gas. For radio frequency were then neutralized to become fast neutrals in neutral beam applications [12,13]. In all

Economou, Demetre J.

2007-01-01T23:59:59.000Z

225

MIT Plasma Science & Fusion Center: research>alcator>  

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226

MIT Plasma Science & Fusion Center: research, alcator, pubs, CMod_2003.html  

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AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth7-1D: VegetationEquipment Surfaces and InterfacesAdministration -Lowell L.Fall Career FairEnergy- Density

227

MIT Plasma Science & Fusion Center: research, alcator, pubs, CMod_2004.html  

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228

MIT Plasma Science & Fusion Center: research>alcator>introduction  

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229

MIT Plasma Science & Fusion Center: research>alcator>publications &  

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230

MIT Plasma Science & Fusion Center: research>alcator>research program  

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231

MIT Plasma Science & Fusion Center:<research<alcator<publications &  

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232

MIT's Plasma Science Fusion Center: I-Mode Powers Up on Alcator C-Mod  

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233

Plasma Channel Diagnostic Based on Laser Centroid Oscillations  

E-Print Network [OSTI]

plasma density, plasma diagnostics PACS: 52.70.Kz, 52.38.Kd,Plasma Channel Diagnostic Based on Laser Centroid

Gonsalves, Anthony

2012-01-01T23:59:59.000Z

234

Laser Plasma Particle Accelerators: Large Fields for Smaller Facility Sources  

E-Print Network [OSTI]

of high- gradient, laser plasma particle accelerators.accelerators that use laser-driven plasma waves. Theseleft) showing the laser (red), plasma wake density (purple-

Geddes, Cameron G.R.

2010-01-01T23:59:59.000Z

235

High Energy Density Laboratory Plasmas  

E-Print Network [OSTI]

faciliBes 1st users of MECI in FY13 Recognize common interests NNSA/FES Compliment NNSA investments Stability ­ investments in HEDLP: people, departments

236

A NATIONAL COLLABORATORY TO ADVANCE THE SCIENCE OF HIGH TEMPERATURE PLASMA PHYSICS FOR MAGNETIC FUSION  

SciTech Connect (OSTI)

This report summarizes the work of the University of Utah, which was a member of the National Fusion Collaboratory (NFC) Project funded by the United States Department of Energy (DOE) under the Scientific Discovery through Advanced Computing Program (SciDAC) to develop a persistent infrastructure to enable scientific collaboration for magnetic fusion research. A five year project that was initiated in 2001, it the NFC built on the past collaborative work performed within the U.S. fusion community and added the component of computer science research done with the USDOE Office of Science, Office of Advanced Scientific Computer Research. The project was itself a collaboration, itself uniting fusion scientists from General Atomics, MIT, and PPPL and computer scientists from ANL, LBNL, and Princeton University, and the University of Utah to form a coordinated team. The group leveraged existing computer science technology where possible and extended or created new capabilities where required. The complete finial report is attached as an addendum. The In the collaboration, the primary technical responsibility of the University of Utah in the collaboration was to develop and deploy an advanced scientific visualization service. To achieve this goal, the SCIRun Problem Solving Environment (PSE) is used on FusionGrid for an advanced scientific visualization service. SCIRun is open source software that gives the user the ability to create complex 3D visualizations and 2D graphics. This capability allows for the exploration of complex simulation results and the comparison of simulation and experimental data. SCIRun on FusionGrid gives the scientist a no-license-cost visualization capability that rivals present day commercial visualization packages. To accelerate the usage of SCIRun within the fusion community, a stand-alone application built on top of SCIRun was developed and deployed. This application, FusionViewer, allows users who are unfamiliar with SCIRun to quickly create visualizations and perform analysis of their simulation data from either the MDSplus data storage environment or from locally stored HDF5 files. More advanced tools for visualization and analysis also were created in collaboration with the SciDAC Center for Extended MHD Modeling. Versions of SCIRun with the FusionViewer have been made available to fusion scientists on the Mac OS X, Linux, and other Unix based platforms and have been downloaded 1163 times. SCIRun has been used with NIMROD, M3D, BOUT fusion simulation data as well as simulation data from other SciDAC application areas (e.g., Astrophysics). The subsequent visualization results - including animations - have been incorporated into invited talks at multiple APS/DPP meetings as well as peer reviewed journal articles. As an example, SCIRun was used for the visualization and analysis of a NIMROD simulation of a disruption that occurred in a DIII-D experiment. The resulting animations and stills were presented as part of invited talks at APS/DPP meetings and the SC04 conference in addition to being highlighted in the NIH/NSF Visualization Research Challenges Report. By achieving its technical goals, the University of Utah played a key role in the successful development of a persistent infrastructure to enable scientific collaboration for magnetic fusion research. Many of the visualization tools developed as part of the NFC continue to be used by Fusion and other SciDAC application scientists and are currently being supported and expanded through follow-on up on SciDAC projects (Visualization and Analytics Center for Enabling Technology, and the Visualization and Analysis in Support of Fusion SAP).

Allen R. Sanderson; Christopher R. Johnson

2006-08-01T23:59:59.000Z

237

IOP PUBLISHING PLASMA SOURCES SCIENCE AND TECHNOLOGY Plasma Sources Sci. Technol. 21 (2012) 055003 (7pp) doi:10.1088/0963-0252/21/5/055003  

E-Print Network [OSTI]

7 May 2012, in final form 9 July 2012 Published 10 August 2012 Online at stacks.iop.org/PSST/21 of the produced plasma (e.g. absorption, mass ablation, emission, opacity, etc). Currently, significant effort

Harilal, S. S.

238

Impact of the energy loss spatial profile and shear viscosity to entropy density ratio for the Mach cone vs. head shock signals produced by a fast moving parton in a quark-gluon plasma  

E-Print Network [OSTI]

We compute the energy and momentum deposited by a fast moving parton in a quark-gluon plasma using linear viscous hydrodynamics with an energy loss per unit length profile proportional to the path length and with different values of the shear viscosity to entropy density ratio. We show that when varying these parameters, the transverse modes still dominate over the longitudinal ones and thus energy and momentum is preferentially deposited along the head-shock, as in the case of a constant energy loss per unit length profile and the lowest value for the shear viscosity to entropy density ratio.

Alejandro Ayala; Jorge David Castano-Yepes; Isabel Dominguez; Maria Elena Tejeda-Yeomans

2014-12-18T23:59:59.000Z

239

1014 IEEE TRANSACTIONS ON PLASMA SCIENCE, VOL. 36, NO. 4, AUGUST 2008 Dust-Cloud Dynamics in a Complex  

E-Print Network [OSTI]

is proposed. Index Terms--Charge, dust cloud, dusty plasma. ACOMPLEX (dusty) plasma is a partially ionized gas research program (FAST) under Contract FR060169. L. Couëdel is with the School of Physics, The University of the plasma are lost by diffusion to the walls of the reactor and by recombination on the dust

Boyer, Edmond

240

Thermionic energy conversion plasmas  

SciTech Connect (OSTI)

In this paper the history, application options, and ideal basic performance of the thermionic energy converter are outlined. The basic plasma types associated with various modes of converter operation are described, with emphasis on identification and semi-quantitative characterization of the dominant physical processes and utility of each plasma type. The frontier plasma science issues in thermionic converter applications are briefly summarized.

Rasor, N.S. (Rasor Associates, Inc., Sunnyvale, CA (United States))

1991-12-01T23:59:59.000Z

Note: This page contains sample records for the topic "density plasma science" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


241

Frontiers for Discovery in High Energy Density Physics  

SciTech Connect (OSTI)

The report is intended to identify the compelling research opportunities of high intellectual value in high energy density physics. The opportunities for discovery include the broad scope of this highly interdisciplinary field that spans a wide range of physics areas including plasma physics, laser and particle beam physics, nuclear physics, astrophysics, atomic and molecular physics, materials science and condensed matter physics, intense radiation-matter interaction physics, fluid dynamics, and magnetohydrodynamics

Davidson, R. C.; Katsouleas, T.; Arons, J.; Baring, M.; Deeney, C.; Di Mauro, L.; Ditmire, T.; Falcone, R.; Hammer, D.; Hill, W.; Jacak, B.; Joshi, C.; Lamb, F.; Lee, R.; Logan, B. G.; Melissinos, A.; Meyerhofer, D.; Mori, W.; Murnane, M.; Remington, B.; Rosner, R.; Schneider, D.; Silvera, I.; Stone, J.; Wilde, B.; Zajc. W.

2004-07-20T23:59:59.000Z

242

SCIENCE CHINA Technological Sciences  

E-Print Network [OSTI]

SCIENCE CHINA Technological Sciences © Science China Press and Springer-Verlag Berlin Heidelberg. Density-functional-theory formulation of classical and quantum Hooke's law. Sci China Tech Sci, 2014, 57- sider an equilibrium lattice without strain (=0), but elec- #12;Hu H, et al. Sci China Tech Sci April

Simons, Jack

243

Final report for the NSF/DOE partnership in basic plasma science grant DE-FG02-06ER54906 '?Laser-driven collisionless shocks in the Large Plasma Device'?  

SciTech Connect (OSTI)

We have performed several thousand high-energy laser shots in the LAPD to investigate the dynamics of an exploding laser-produced plasma in a large ambient magneto-plasma. Debris-ions expanding at super-Alfvenic velocity (up to MA=1.5) expel the ambient magnetic field, creating a large (> 20 cm) diamagnetic cavity. We observed field compressions of up to B/B{sub 0} = 1.5 at the edge of the bubble, consistent with the MHD jump conditions, as well as localized electron heating at the edge of the bubble. Two-dimensional hybrid simulations reproduce these measurements well and show that the majority of the ambient ions are energized by the magnetic piston to super-Alfvenic speeds and swept outside the bubble volume. Nonlinear shear-Alfven waves ({delta}B/B{sub 0} > 25%) are radiated from the cavity with a coupling efficiency of 70% from magnetic energy in the bubble to the wave. While the data is consistent with a weak magneto-sonic shock, the experiments were severely limited by the low ambient plasma densities (10{sup 12} cm{sup -3}). 2D hybrid simulations indicate that future experiments with the new LAPD plasma source and densities in excess of 10{sup 13} cm{sup -3} will drive full-blown collisionless shocks with MA>10 over several c/wpi and shocked Larmor radii. In a separate experiment at the LANL Trident laser facility we have performed a proof-of-principle experiment at higher densities to demonstrate key elements of collisionless shocks in laser-produced magnetized plasmas with important implications to NIF. Simultaneously we have upgraded the UCLA glass-laser system by adding two large amplitude disk amplifiers from the NOVA laser and boost the on-target energy from 30 J to up to 1 kJ, making this one of the world’s largest university-scale laser systems. We now have the infrastructure in place to perform novel and unique high-impact experiments on collision-less shocks at the LAPD.

Niemann, Christoph [UCLA, CA (United States); Gekelman, W. [UCLA, CA (United States); Winske, D. [LANL, NM (United States); Larsen, D. [LLNL, CA (United States)

2012-12-14T23:59:59.000Z

244

IOP PUBLISHING PLASMA SOURCES SCIENCE AND TECHNOLOGY Plasma Sources Sci. Technol. 18 (2009) 045003 (6pp) doi:10.1088/0963-0252/18/4/045003  

E-Print Network [OSTI]

uranium is produced by the gas centrifuge method [7], a significant number of isotopes are still produced of configurations for the separation of elements and isotopes [1­4]. Isotope separation has applications by calutrons due to their flexibility [8]. The idea to use rotating plasma to separate isotopes was first

245

Density Functional Theory Simulations Predict New Materials for Magnesium-Ion Batteries (Fact Sheet), NREL Highlights, Science  

SciTech Connect (OSTI)

Multivalence is identified in the light element, B, through structure morphology. Boron sheets exhibit highly versatile valence, and the layered boron materials may hold the promise of a high-energy-density magnesium-ion battery. Practically, boron is superior to previously known multivalence materials, especially transition metal compounds, which are heavy, expensive, and often not benign. Based on density functional theory simulations, researchers at the National Renewable Energy Laboratory (NREL) have predicted a series of stable magnesium borides, MgB{sub x}, with a broad range of stoichiometries, 2 < x < 16, by removing magnesium atoms from MgB{sub 2}. The layered boron structures are preserved through an in-plane topological transformation between the hexagonal lattice domains and the triangular domains. The process can be reversibly switched as the charge transfer changes with Mg insertion/extraction. The mechanism of such a charge-driven transformation originates from the versatile valence state of boron in its planar form. The discovery of these new physical phenomena suggests the design of a high-capacity magnesium-boron battery with theoretical energy density 876 mAh/g and 1550 Wh/L.

Not Available

2011-10-01T23:59:59.000Z

246

752 IEEE TRANSACTIONS ON PLASMA SCIENCE, VOL. 31, NO. 4, AUGUST 2003 Examining by the RayleighFourier Method the  

E-Print Network [OSTI]

­Fourier Method the Cylindrical Waveguide With Axially Rippled Wall Joaquim José Barroso, Joaquim Paulino Leite. J. Barroso and J. P. L. Neto are with the Associated Plasma Laboratory, National Institute for Space Research (INPE), 12201-970 São José dos Campos, Brazil (e-mail: barroso@plasma.inpe.br). K. G. Kostov

247

190 IEEE TRANSACTIONS ON PLASMA SCIENCE, VOL. 30, NO. 1, FEBRUARY 2002 Gap Closure in a Cold Metal Halide Lamp  

E-Print Network [OSTI]

lamp has been investigated using a two-dimensional, plasma transport model. Im- ages are presented- charge devices, lighting, plasma applications. METAL halide high-intensity-discharge (HID) lamps op- erate as high-pressure thermal arcs [1]. The cold fills of HID lamps are typically 50­100 torr of a rare

Kushner, Mark

248

Intense Magnetized Plasma-Wall Interaction  

SciTech Connect (OSTI)

This research project studied wall-plasma interactions relevant to fusion science. Such interactions are a critical aspect of Magneto-Inertial Fusion (MIF) because flux compression by a pusher material, in particular the metal for the liner approach to MIF, involves strong eddy current heating on the surface of the pusher, and probably interactions and mixing of the pusher with the interior fuel during the time when fusion fuel is being burned. When the pusher material is a metal liner, high-energy-density conditions result in fascinating behavior. For example, "warm dense matter" is produced, for which material properties such as resistivity and opacity are not well known. In this project, the transformation into plasma of metal walls subjected to pulsed megagauss magnetic fields was studied with an experiment driven by the UNR 1 MA Zebra generator. The experiment was numerically simulated with using the MHRDR code. This simple, fundamental high-energy-density physics experiment, in a regime appropriate to MIF, has stimulated an important and fascinating comparison of numerical modeling codes and tables with experiment. In addition, we participated in developing the FRCHX experiment to compress a field-reversed-configuration (FRC) plasma with a liner, in collaboration with researchers from Air Force Research Laboratory and Los Alamos National Lab, and we helped develop diagnostics for the Plasma Liner Experiment (PLX) at LANL. Last, but not least, this project served to train students in high-energy-density physics.

Bauer, Bruno S. [UNR] [UNR; Fuelling, Stephan [UNR] [UNR

2013-11-30T23:59:59.000Z

249

Analysis of plasma waves observed within local plasma injections seen in Saturn's magnetosphere  

E-Print Network [OSTI]

Analysis of plasma waves observed within local plasma injections seen in Saturn's magnetosphere J; published 17 May 2008. [1] Plasma injections or density depletion regions have been reported plasma in a cooler, locally produced plasma background. The injected plasma undergoes dispersion

Gurnett, Donald A.

250

Princeton Plasma Physics Laboratory  

SciTech Connect (OSTI)

This report discusses the following topics: principal parameters achieved in experimental devices fiscal year 1990; tokamak fusion test reactor; compact ignition tokamak; Princeton beta experiment- modification; current drive experiment-upgrade; international collaboration; x-ray laser studies; spacecraft glow experiment; plasma processing: deposition and etching of thin films; theoretical studies; tokamak modeling; international thermonuclear experimental reactor; engineering department; project planning and safety office; quality assurance and reliability; technology transfer; administrative operations; PPPL patent invention disclosures for fiscal year 1990; graduate education; plasma physics; graduate education: plasma science and technology; science education program; and Princeton Plasma Physics Laboratory reports fiscal year 1990.

Not Available

1990-01-01T23:59:59.000Z

251

An in-situ accelerator-based diagnostic for plasma-material interactions science in magnetic fusion devices  

E-Print Network [OSTI]

Plasma-material interactions (PMI) in magnetic fusion devices such as fuel retention, material erosion and redeposition, and material mixing present significant scientific and engineering challenges, particularly for the ...

Hartwig, Zachary Seth

2014-01-01T23:59:59.000Z

252

E-Print Network 3.0 - astrophysical plasma physics Sample Search...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Science 64 Michigan Institute for Plasma Science Summary: Methods for Plasma Physics Dr. Phillip Colella Lawrence Berkeley National Laboratory Tuesday, 8... Michigan Institute for...

253

E-Print Network 3.0 - atmospheric thermal plasmas Sample Search...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

particles in a plasma... D | 1 the laser senses plasma ... Source: Howard, John - Plasma Research Laboratory, Research School of Physical Sciences and Engineering, Australian...

254

E-Print Network 3.0 - atmospheric-pressure argon plasma Sample...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

ON PLASMA SCIENCE, VOL. 33, NO. 3, JUNE 2005 1061 Nonthermal Plasma Bio-Active Liquid Micro and Summary: plasma (Fig. 6.) IV. CONCLUSION Ignition of atmospheric pressure...

255

The evolution of ion charge states in cathodic vacuum arc plasmas: a review  

SciTech Connect (OSTI)

Cathodic vacuum arc plasmas are known to contain multiply charged ions. 20 years after “Pressure Ionization: its role in metal vapour vacuum arc plasmas and ion sources” appeared in vol. 1 of Plasma Sources Science and Technology, it is a great opportunity to re-visit the issue of pressure ionization, a non-ideal plasma effect, and put it in perspective to the many other factors that influence observable charge state distributions, such as the role of the cathode material, the path in the density-temperature phase diagram, the “noise” in vacuum arc plasma as described by a fractal model approach, the effects of external magnetic fields and charge exchange collisions with neutrals. A much more complex image of the vacuum arc plasma emerges putting decades of experimentation and modeling in perspective.

Anders, Andre

2011-12-18T23:59:59.000Z

256

E-Print Network 3.0 - argon plasmas measured Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

; Plasma Physics and Fusion 82 Approach for control of high-density plasma reactors through optimal pulse shaping* Summary: the accessible plasma parameter space over...

257

agricultural knowledge science: Topics by E-print Network  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Sciences Agricultural Economics Marine industry studies Corporate social Materials Science Plasma Physics Toxicology Aquatic ecosystems 12;Engineering Biological...

258

Fundamentals of Plasma Physics  

E-Print Network [OSTI]

of students (from physics, engineering physics, elec- trical engineering, nuclear engineering and other un;PREFACE Plasma physics is a relatively new branch of physics that became a mature science over the last). Thus, plasma physics has developed in large part as a branch of applied or engineering physics

Callen, James D.

259

Planetary and Space Science 55 (2007) 17721792 The Analyser of Space Plasmas and Energetic Atoms (ASPERA-4)  

E-Print Network [OSTI]

, Finland i Finnish Meteorological Institute, Box 503, FIN-00101 Helsinki, Finland j Space Physics Research objective of the ASPERA-4 (Analyser of Space Plasmas and Energetic Atoms) experiment is to study the solar flux (0.1­60 keV) with no mass and energy resolution but relatively high angular resolution

California at Berkeley, University of

260

728 IEEE TRANSACTIONS ON PLASMA SCIENCE, VOL. 34, NO. 3, JUNE 2006 The Electron Diffusion Coefficient in Energy  

E-Print Network [OSTI]

Coefficient in Energy in Bounded Collisional Plasmas Lev D. Tsendin Abstract--The electron energies in typical, the momentum relaxation in collisions with neutrals is sig- nificantly faster than the energy relaxation due be de- scribed by a diffusion coefficient in energy . Both collisional and stochastic heating mechanisms

Kaganovich, Igor

Note: This page contains sample records for the topic "density plasma science" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


261

564 IEEE TRANSACTIONS ON PLASMA SCIENCE, VOL. 33, NO. 2, APRIL 2005 Experimental and Numerical Study of External Plume  

E-Print Network [OSTI]

nonequilibrium high-pressure plasma discharges char- acterized by intense radiation and high gas temperatures filled with high-purity helium gas. The anode and cathode are connected to a direct current (dc) power.1109/TPS.2005.845290 optical emission from the discharge plume are obtained, which are then Abel

Raja, Laxminarayan L.

262

552 IEEE TRANSACTIONS ON PLASMA SCIENCE, VOL. 33, NO. 2, APRIL 2005 Visualizing Shear Alfvn Wave Currents Near the  

E-Print Network [OSTI]

of the device. The electron temperature is 6 eV and the confining magnetic field is 1.0 kG. The duration of the plasma is approximately 10 ms; this highly reproducible Manuscript received July 2, 2004; revised Angeles, CA 90095-1696 USA. Digital Object Identifier 10.1109/TPS.2005.845288 discharge is repeated once

California at Los Angles, University of

263

An in situ accelerator-based diagnostic for plasma-material interactions science on magnetic fusion devices  

SciTech Connect (OSTI)

This paper presents a novel particle accelerator-based diagnostic that nondestructively measures the evolution of material surface compositions inside magnetic fusion devices. The diagnostic's purpose is to contribute to an integrated understanding of plasma-material interactions in magnetic fusion, which is severely hindered by a dearth of in situ material surface diagnosis. The diagnostic aims to remotely generate isotopic concentration maps on a plasma shot-to-shot timescale that cover a large fraction of the plasma-facing surface inside of a magnetic fusion device without the need for vacuum breaks or physical access to the material surfaces. Our instrument uses a compact (?1 m), high-current (?1 milliamp) radio-frequency quadrupole accelerator to inject 0.9 MeV deuterons into the Alcator C-Mod tokamak at MIT. We control the tokamak magnetic fields – in between plasma shots – to steer the deuterons to material surfaces where the deuterons cause high-Q nuclear reactions with low-Z isotopes ?5 ?m into the material. The induced neutrons and gamma rays are measured with scintillation detectors; energy spectra analysis provides quantitative reconstruction of surface compositions. An overview of the diagnostic technique, known as accelerator-based in situ materials surveillance (AIMS), and the first AIMS diagnostic on the Alcator C-Mod tokamak is given. Experimental validation is shown to demonstrate that an optimized deuteron beam is injected into the tokamak, that low-Z isotopes such as deuterium and boron can be quantified on the material surfaces, and that magnetic steering provides access to different measurement locations. The first AIMS analysis, which measures the relative change in deuterium at a single surface location at the end of the Alcator C-Mod FY2012 plasma campaign, is also presented.

Hartwig, Zachary S.; Barnard, Harold S.; Lanza, Richard C.; Sorbom, Brandon N.; Stahle, Peter W.; Whyte, Dennis G. [Plasma Science and Fusion Center, Massachusetts Institute of Technology, 77 Massachusetts Ave, Cambridge Massachusetts 02139 (United States)] [Plasma Science and Fusion Center, Massachusetts Institute of Technology, 77 Massachusetts Ave, Cambridge Massachusetts 02139 (United States)

2013-12-15T23:59:59.000Z

264

108 IEEE TRANSACTIONS ON PLASMA SCIENCE, VOL. 27, NO. 1, FEBRUARY 1999 The Consequences of Remnant Surface Charges on  

E-Print Network [OSTI]

on the dielectric reduces the gap voltage at the position of the microdischarge to below self sustaining. As the electron density avalanches, the dielectric charges, removing voltage from the gap until the is below self sustaining. Electron attachment t

Kushner, Mark

265

PUBLISHED ONLINE: 17 NOVEMBER 2013 | DOI: 10.1038/NPHYS2795 A long-pulse high-confinement plasma  

E-Print Network [OSTI]

, Chinese Academy of Sciences, Hefei 230031, China, 2Tri Alpha Energy, Inc., PO Box 7010, Rancho Santa energy source with an abundant fuel supply. One of the most promising approaches to harnessing fusion degrees Celsius) plasma state with sufficient density and energy confinement time. Significant progress

Loss, Daniel

266

Nonlinear plasma waves excitation by intense ion beams in background plasma  

E-Print Network [OSTI]

describe the plasma perturbations well.5 Here, we focus on the general case where the plasma density hasNonlinear plasma waves excitation by intense ion beams in background plasma Igor D. Kaganovich, Edward A. Startsev, and Ronald C. Davidson Plasma Physics Laboratory, Princeton University, Princeton

Kaganovich, Igor

267

Extensive remote handling and conservative plasma conditions to enable fusion nuclear science R&D using a component testing facility  

E-Print Network [OSTI]

nuclear science R&D using a component testing facility Y.K.M. Peng 1), T.W. Burgess 1), A.J. Carroll 1), C. This use aims to test components in an integrated fusion nuclear environment, for the first time@ornl.gov Abstract. The use of a fusion component testing facility to study and establish, during the ITER era

Princeton Plasma Physics Laboratory

268

1956 IEEE TRANSACTIONS ON PLASMA SCIENCE, VOL. 28, NO. 6, DECEMBER 2000 An Adaptive MHD Method for Global Space Weather  

E-Print Network [OSTI]

to conditions at a particular place and time on the Sun and in the solar wind, magnetosphere, iono- sphere and Space Sciences, The Univer- sity of Michigan, Ann Arbor, MI 48109 USA (e-mail: darrens@umich.edu). C. P. G. Powell is with the Department of Aerospace Engineering, The Univer- sity of Michigan, Ann Arbor

Stout, Quentin F.

269

REPORT FROM THE PLANNING WORKSHOP FUSION ENERGY SCIENCES PROGRAM  

E-Print Network [OSTI]

research recognizes the utility of plasma research to the nation's science and technology base beyond

270

Michigan Institute Science and  

E-Print Network [OSTI]

Michigan Institute for Plasma Science and Engineering Seminar Onset of Fast Magnetic Reconnection's magnetosphere, and solar flares. These observations place strong constraints on theory, which must explain

Shyy, Wei

271

2566 IEEE TRANSACTIONS ON PLASMA SCIENCE, VOL. 36, NO. 5, OCTOBER 2008 Quantitative Analysis of Gas Circuit Breaker  

E-Print Network [OSTI]

, pressure waves. I. INTRODUCTION THE ARC zone of high-voltage self-blast gas circuit break- ers is challenging to diagnose directly due to the combina- tion of temperatures in the 30 000 K range and densities-mail: margarita.abrahamsson@ gmail.com). Digital Object Identifier 10.1109/TPS.2008.2004235 This paper

Basse, Nils Plesner

272

2034 IEEE TRANSACTIONS ON PLASMA SCIENCE, VOL. 36, NO. 5, OCTOBER 2008 Simulations of a Miniaturized Cylindrical  

E-Print Network [OSTI]

high propellant utilization efficiency is found to be due to doubly charged ions. Index Terms density. S Ionization source term. T Thrust. Te Electron temperature. U Fitting parameter (sheath@pppl.gov; asmirnov@trialphanenergy.com; fisch@princeton.edu). Digital Object Identifier 10.1109/TPS.2008

273

Science  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May Jun Jul(Summary)morphinanInformation Desert Southwest RegionatSearchScheduled System Outages NERSC Scheduled Systemresearch Science

274

Science  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsrucLas ConchasPassiveSubmitted for USMaterialstheterahertzonExplore by Subjectsupernova*Science

275

Development and Benchmarking of a Hybrid PIC Code For Dense Plasmas and Fast Ignition  

SciTech Connect (OSTI)

Radiation processes play an important role in the study of both fast ignition and other inertial confinement schemes, such as plasma jet driven magneto-inertial fusion, both in their effect on energy balance, and in generating diagnostic signals. In the latter case, warm and hot dense matter may be produced by the convergence of a plasma shell formed by the merging of an assembly of high Mach number plasma jets. This innovative approach has the potential advantage of creating matter of high energy densities in voluminous amount compared with high power lasers or particle beams. An important application of this technology is as a plasma liner for the flux compression of magnetized plasma to create ultra-high magnetic fields and burning plasmas. HyperV Technologies Corp. has been developing plasma jet accelerator technology in both coaxial and linear railgun geometries to produce plasma jets of sufficient mass, density, and velocity to create such imploding plasma liners. An enabling tool for the development of this technology is the ability to model the plasma dynamics, not only in the accelerators themselves, but also in the resulting magnetized target plasma and within the merging/interacting plasma jets during transport to the target. Welch pioneered numerical modeling of such plasmas (including for fast ignition) using the LSP simulation code. Lsp is an electromagnetic, parallelized, plasma simulation code under development since 1995. It has a number of innovative features making it uniquely suitable for modeling high energy density plasmas including a hybrid fluid model for electrons that allows electrons in dense plasmas to be modeled with a kinetic or fluid treatment as appropriate. In addition to in-house use at Voss Scientific, several groups carrying out research in Fast Ignition (LLNL, SNL, UCSD, AWE (UK), and Imperial College (UK)) also use LSP. A collaborative team consisting of HyperV Technologies Corp., Voss Scientific LLC, FAR-TECH, Inc., Prism Computational Sciences, Inc. and Advanced Energy Systems Inc. joined efforts to develop new physics and numerical models for LSP in several key areas to enhance the ability of LSP to model high energy density plasmas (HEDP). This final report details those efforts. Areas addressed in this research effort include: adding radiation transport to LSP, first in 2D and then fully 3D, extending the EMHD model to 3D, implementing more advanced radiation and electrode plasma boundary conditions, and installing more efficient implicit numerical algorithms to speed complex 2-D and 3-D computations. The new capabilities allow modeling of the dominant processes in high energy density plasmas, and further assist the development and optimization of plasma jet accelerators, with particular attention to MHD instabilities and plasma/wall interaction (based on physical models for ion drag friction and ablation/erosion of the electrodes). In the first funding cycle we implemented a solver for the radiation diffusion equation. To solve this equation in 2-D, we used finite-differencing and applied the parallelized sparse-matrix solvers in the PETSc library (Argonne National Laboratory) to the resulting system of equations. A database of the necessary coefficients for materials of interest was assembled using the PROPACEOS and ATBASE codes from Prism. The model was benchmarked against Prism's 1-D radiation hydrodynamics code HELIOS, and against experimental data obtained from HyperV's separately funded plasma jet accelerator development program. Work in the second funding cycle focused on extending the radiation diffusion model to full 3-D, continued development of the EMHD model, optimizing the direct-implicit model to speed up calculations, add in multiply ionized atoms, and improved the way boundary conditions are handled in LSP. These new LSP capabilities were then used, along with analytic calculations and Mach2 runs, to investigate plasma jet merging, plasma detachment and transport, restrike and advanced jet accelerator design. In addition, a strong linkage to diagnostic measureme

Witherspoon, F. Douglas [HyperV Technologies Corp.; Welch, Dale R. [Voss Scientific, LLC; Thompson, John R. [FAR-TECH, Inc.; MacFarlane, Joeseph J. [Prism Computational Sciences Inc.; Phillips, Michael W. [Advanced Energy Systems, Inc.; Bruner, Nicki [Voss Scientific, LLC; Mostrom, Chris [Voss Scientific, LLC; Thoma, Carsten [Voss Scientific, LLC; Clark, R. E. [Voss Scientific, LLC; Bogatu, Nick [FAR-TECH, Inc.; Kim, Jin-Soo [FAR-TECH, Inc.; Galkin, Sergei [FAR-TECH, Inc.; Golovkin, Igor E. [Prism Computational Sciences, Inc.; Woodruff, P. R. [Prism Computational Sciences, Inc.; Wu, Linchun [HyperV Technologies Corp.; Messer, Sarah J. [HyperV Technologies Corp.

2014-05-20T23:59:59.000Z

276

Nuclear Science & Engineering  

E-Print Network [OSTI]

. 1 Nuclear Science & Engineering Nuclear Energy Present and Future Ian H. Hutchinson Head, Department of Nuclear Science and Engineering CoPrincipal, Alcator Tokamak Project, Plasma Science and Fusion Science & Engineering Nuclear Power Plants Worldwide · US: 103 plants in operation, none under

277

Review: engineering particles using the aerosol-through-plasma method  

SciTech Connect (OSTI)

For decades, plasma processing of materials on the nanoscale has been an underlying enabling technology for many 'planar' technologies, particularly virtually every aspect of modern electronics from integrated-circuit fabrication with nanoscale elements to the newest generation of photovoltaics. However, it is only recent developments that suggest that plasma processing can be used to make 'particulate' structures of value in fields, including catalysis, drug delivery, imaging, higher energy density batteries, and other forms of energy storage. In this paper, the development of the science and technology of one class of plasma production of particulates, namely, aerosol-through-plasma (A-T-P), is reviewed. Various plasma systems, particularly RF and microwave, have been used to create nanoparticles of metals and ceramics, as well as supported metal catalysts. Gradually, the complexity of the nanoparticles, and concomitantly their potential value, has increased. First, unique two-layer particles were generated. These were postprocessed to create unique three-layer nanoscale particles. Also, the technique has been successfully employed to make other high-value materials, including carbon nanotubes, unsupported graphene, and spherical boron nitride. Some interesting plasma science has also emerged from efforts to characterize and map aerosol-containing plasmas. For example, it is clear that even a very low concentration of particles dramatically changes plasma characteristics. Some have also argued that the local-thermodynamic-equilibrium approach is inappropriate to these systems. Instead, it has been suggested that charged- and neutral-species models must be independently developed and allowed to 'interact' only in generation terms.

Phillips, Jonathan [Los Alamos National Laboratory; Luhrs, Claudia C [UNM; Richard, Monique [TEMA

2009-01-01T23:59:59.000Z

278

SciDAC Fusiongrid Project--A National Collaboratory to Advance the Science of High Temperature Plasma Physics for Magnetic Fusion  

SciTech Connect (OSTI)

This report summarizes the work of the National Fusion Collaboratory (NFC) Project funded by the United States Department of Energy (DOE) under the Scientific Discovery through Advanced Computing Program (SciDAC) to develop a persistent infrastructure to enable scientific collaboration for magnetic fusion research. A five year project that was initiated in 2001, it built on the past collaborative work performed within the U.S. fusion community and added the component of computer science research done with the USDOE Office of Science, Office of Advanced Scientific Computer Research. The project was a collaboration itself uniting fusion scientists from General Atomics, MIT, and PPPL and computer scientists from ANL, LBNL, Princeton University, and the University of Utah to form a coordinated team. The group leveraged existing computer science technology where possible and extended or created new capabilities where required. Developing a reliable energy system that is economically and environmentally sustainable is the long-term goal of Fusion Energy Science (FES) research. In the U.S., FES experimental research is centered at three large facilities with a replacement value of over $1B. As these experiments have increased in size and complexity, there has been a concurrent growth in the number and importance of collaborations among large groups at the experimental sites and smaller groups located nationwide. Teaming with the experimental community is a theoretical and simulation community whose efforts range from applied analysis of experimental data to fundamental theory (e.g., realistic nonlinear 3D plasma models) that run on massively parallel computers. Looking toward the future, the large-scale experiments needed for FES research are staffed by correspondingly large, globally dispersed teams. The fusion program will be increasingly oriented toward the International Thermonuclear Experimental Reactor (ITER) where even now, a decade before operation begins, a large portion of national program efforts are organized around coordinated efforts to develop promising operational scenarios. Substantial efforts to develop integrated plasma modeling codes are also underway in the U.S., Europe and Japan. As a result of the highly collaborative nature of FES research, the community is facing new and unique challenges. While FES has a significant track record for developing and exploiting remote collaborations, with such large investments at stake, there is a clear need to improve the integration and reach of available tools. The NFC Project was initiated to address these challenges by creating and deploying collaborative software tools. The original objective of the NFC project was to develop and deploy a national FES 'Grid' (FusionGrid) that would be a system for secure sharing of computation, visualization, and data resources over the Internet. The goal of FusionGrid was to allow scientists at remote sites to participate as fully in experiments and computational activities as if they were working on site thereby creating a unified virtual organization of the geographically dispersed U.S. fusion community. The vision for FusionGrid was that experimental and simulation data, computer codes, analysis routines, visualization tools, and remote collaboration tools are to be thought of as network services. In this model, an application service provider (ASP) provides and maintains software resources as well as the necessary hardware resources. The project would create a robust, user-friendly collaborative software environment and make it available to the US FES community. This Grid's resources would be protected by a shared security infrastructure including strong authentication to identify users and authorization to allow stakeholders to control their own resources. In this environment, access to services is stressed rather than data or software portability.

SCHISSEL, D.P.; ABLA, G.; BURRUSS, J.R.; FEIBUSH, E.; FREDIAN, T.W.; GOODE, M.M.; GREENWALD, M.J.; KEAHEY, K.; LEGGETT, T.; LI, K.; McCUNE, D.C.; PAPKA, M.E.; RANDERSON, L.; SANDERSON, A.; STILLERMAN, J.; THOMPSON, M.R.; URAM, T.; WALLACE, G.

2006-08-31T23:59:59.000Z

279

Michigan Institute Science and  

E-Print Network [OSTI]

. Kaita's present research interests focus on plasma-surface interactions and the use of liquid metalsMichigan Institute for Plasma Science and Engineering Seminar Up Against the Wall: Liquid Lithium for the Chamber Technology Challenge in Fusion Energy Dr. Robert Kaita Princeton Plasma Physics Laboratory 3:00 pm

Shyy, Wei

280

Energy in density gradient  

E-Print Network [OSTI]

Inhomogeneous plasmas and fluids contain energy stored in inhomogeneity and they naturally tend to relax into lower energy states by developing instabilities or by diffusion. But the actual amount of energy in such inhomogeneities has remained unknown. In the present work the amount of energy stored in a density gradient is calculated for several specific density profiles in a cylindric configuration. This is of practical importance for drift wave instability in various plasmas, and in particular in its application in models dealing with the heating of solar corona because the instability is accompanied with stochastic heating, so the energy contained in inhomogeneity is effectively transformed into heat. It is shown that even for a rather moderate increase of the density at the axis in magnetic structures in the corona by a factor 1.5 or 3, the amount of excess energy per unit volume stored in such a density gradient becomes several orders of magnitude greater than the amount of total energy losses per unit ...

Vranjes, J

2015-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "density plasma science" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


281

714 IEEE TRANSACTIONS ON PLASMA SCIENCE, VOL. 38, NO. 4, APRIL 2010 Interaction of a CO2 Laser Pulse With Tin-Based  

E-Print Network [OSTI]

Pulse With Tin-Based Plasma for an Extreme Ultraviolet Lithography Source Yezheng Tao, Mark S. Tillack

Najmabadi, Farrokh

282

Dynamics and manipulation of the dominant 13.5 nm in-band extreme ultraviolet emitting region of laser-produced Sn plasmas  

E-Print Network [OSTI]

Plasma Diagnostics ..Principles of plasma diagnostics Cambridge University Press,the laser pulse. Plasma Diagnostics 2.6.1. Electron Density

Yuspeh, Samuel Edward

2011-01-01T23:59:59.000Z

283

Integrating Experiment and Theory in Electrochemical Surface Science: Studies on the Molecular Adsorption on Noble-Metal Electrode Surfaces by Density Functional Theory, Electron Spectroscopy, and Electrochemistry  

E-Print Network [OSTI]

Computational techniques based on density functional theory (DFT) and experimental methods based on electrochemistry (EC), electrochemical scanning tunneling microscopy (EC-STM), and high-resolution electron energy loss spectroscopy (HREELS) were...

Javier, Alnald Caintic

2013-08-05T23:59:59.000Z

284

applications plasma rate-coefficients: Topics by E-print Network  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Websites Summary: Institute of Science, Rehovot 76100, Israel b Institute for Plasma Research, University of Maryland, College in plasmas have been developed, where the motion...

285

DENSITY LIMITS IN TOROIDAL PLASMAS MARTIN GREENWALD  

E-Print Network [OSTI]

;ACKNOWLEDGEMENTS · All people who have worked in this area over the years · Note particularly people who power scaling) (Axon 1980) #12;SCALING REFINED BY INCLUSION OF DATA FROM SHAPED TOKAMAKS · Greenwald

Greenwald, Martin

286

High-Energy-Density Plasmas, Fluids  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May Jun Jul(Summary)morphinanInformation Desert Southwest Region service area.

287

Plasma Physics and Fusion Energy Miklos Porkolab  

E-Print Network [OSTI]

Plasma Physics and Fusion Energy Miklos Porkolab MIT Plasma Science and Fusion Center Presented at the Fusion Power Associates Annual Meeting Washington, D.C. December 2-3, 2009 Porkolab_FPA_2009 #12;Proposed is sufficient physics to make ITER a success but much more to learn for DEMO grade plasmas See review talk

288

E-Print Network 3.0 - av accelerates plasma Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

for Plasma in the Laboratory and Astrophysics Collection: Physics ; Plasma Physics and Fusion 5 Lower hybrid current drive at densities required for thermonuclear reactors R....

289

AlGaN UV LED and Photodiodes Radiation Hardness and Space Qualifications and Their Applications in Space Science and High Energy Density Physics  

SciTech Connect (OSTI)

This presentation provides an overview of robust, radiation hard AlGaN optoelectronic devices and their applications in space exploration & high energy density physics. Particularly, deep UV LED and deep UV photodiodes are discussed with regard to their applications, radiation hardness and space qualification. AC charge management of UV LED satellite payload instruments, which were to be launched in late 2012, is covered.

Sun, K. X.

2011-05-31T23:59:59.000Z

290

Meter scale plasma source for plasma wakefield experiments  

SciTech Connect (OSTI)

High accelerating gradients generated by a high density electron beam moving through plasma has been used to double the energy of the SLAC electron beam [1]. During that experiment, the electron current density was high enough to generate its own plasma without significant head erosion. In the newly commissioned FACET facility at SLAC, the peak current will be lower and without pre-ionization, head erosion will be a significant challenge for the planned experiments. In this work we report on our design of a meter scale plasma source for these experiments to effectively avoid the problem of head erosion. The plasma source is based on a homogeneous metal vapor gas column that is generated in a heat pipe oven [2]. A lithium oven over 30 cm long at densities over 10{sup 17} cm{sup -3} has been constructed and tested at UCLA. The plasma is then generated by coupling a 10 TW short pulse Ti:Sapphire laser into the gas column using an axicon lens setup. The Bessel profile of the axicon setup creates a region of high intensity that can stretch over the full length of the gas column with approximately constant diameter. In this region of high intensity, the alkali metal vapor is ionized through multi-photon ionization process. In this manner, a fully ionized meter scale plasma of uniform density can be formed. Methods for controlling the plasma diameter and length will also be discussed.

Vafaei-Najafabadi, N.; Shaw, J. L.; Marsh, K. A.; Joshi, C.; Hogan, M. J. [Department of Electrical Engineering, University of California Los Angeles, Los Angeles, CA 90095 (United States); SLAC National Accelerator Laboratory, Menlo Park, CA 94025 (United States)

2012-12-21T23:59:59.000Z

291

Neutral depletion and the helicon density limit  

SciTech Connect (OSTI)

It is straightforward to create fully ionized plasmas with modest rf power in a helicon. It is difficult, however, to create plasmas with density >10{sup 20} m{sup ?3}, because neutral depletion leads to a lack of fuel. In order to address this density limit, we present fast (1 MHz), time-resolved measurements of the neutral density at and downstream from the rf antenna in krypton helicon plasmas. At the start of the discharge, the neutral density underneath the antenna is reduced to 1% of its initial value in 15 ?s. The ionization rate inferred from these data implies that the electron temperature near the antenna is much higher than the electron temperature measured downstream. Neutral density measurements made downstream from the antenna show much slower depletion, requiring 14 ms to decrease by a factor of 1/e. Furthermore, the downstream depletion appears to be due to neutral pumping rather than ionization.

Magee, R. M.; Galante, M. E.; Carr, J. Jr.; Lusk, G.; McCarren, D. W.; Scime, E. E. [West Virginia University, Morgantown, West Virginia 26506 (United States)] [West Virginia University, Morgantown, West Virginia 26506 (United States)

2013-12-15T23:59:59.000Z

292

PLASMA SCIENCE ADVANCED COMPUTING INTITUTE  

E-Print Network [OSTI]

, ... leading to ITER -- impact real decision-making in the large "scientific options space" -- harvest

293

australian nuclear science: Topics by E-print Network  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Volume6No.5 Science Magazine of the australian national Chen, Ying 3 Nuclear Science & Engineering Plasma Physics and Fusion Websites Summary: Center Massachusetts Institute of...

294

Control of focusing forces and emittances in plasma-based accelerators using near-hollow plasma channels  

SciTech Connect (OSTI)

A near-hollow plasma channel, where the plasma density in the channel is much less than the plasma density in the walls, is proposed to provide independent control over the focusing and accelerating forces in a plasma accelerator. In this geometry the low density in the channel contributes to the focusing forces, while the accelerating fields are determined by the high density in the channel walls. The channel also provides guiding for intense laser pulses used for wakefield excitation. Both electron and positron beams can be accelerated in a nearly symmetric fashion. Near-hollow plasma channels can effectively mitigate emittance growth due to Coulomb scattering for high energy physics applications.

Schroeder, Carl; Esarey, Eric; Benedetti, Carlo; Leemans, Wim

2013-08-06T23:59:59.000Z

295

Control of focusing forces and emittances in plasma-based accelerators using near-hollow plasma channels  

SciTech Connect (OSTI)

A near-hollow plasma channel, where the plasma density in the channel is much less than the plasma density in the walls, is proposed to provide independent control over the focusing and accelerating forces in a plasma accelerator. In this geometry the low density in the channel contributes to the focusing forces, while the accelerating fields are determined by the high density in the channel walls. The channel also provides guiding for intense laser pulses used for wakefield excitation. Both electron and positron beams can be accelerated in a nearly symmetric fashion. Near-hollow plasma channels can effectively mitigate emittance growth due to Coulomb scattering for high-energy physics applications.

Schroeder, C. B.; Esarey, E.; Benedetti, C.; Leemans, W. P. [Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States)] [Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States)

2013-08-15T23:59:59.000Z

296

Plasma Simulation Program  

SciTech Connect (OSTI)

Many others in the fusion energy and advanced scientific computing communities participated in the development of this plan. The core planning team is grateful for their important contributions. This summary is meant as a quick overview the Fusion Simulation Program's (FSP's) purpose and intentions. There are several additional documents referenced within this one and all are supplemental or flow down from this Program Plan. The overall science goal of the DOE Office of Fusion Energy Sciences (FES) Fusion Simulation Program (FSP) is to develop predictive simulation capability for magnetically confined fusion plasmas at an unprecedented level of integration and fidelity. This will directly support and enable effective U.S. participation in International Thermonuclear Experimental Reactor (ITER) research and the overall mission of delivering practical fusion energy. The FSP will address a rich set of scientific issues together with experimental programs, producing validated integrated physics results. This is very well aligned with the mission of the ITER Organization to coordinate with its members the integrated modeling and control of fusion plasmas, including benchmarking and validation activities. [1]. Initial FSP research will focus on two critical Integrated Science Application (ISA) areas: ISA1, the plasma edge; and ISA2, whole device modeling (WDM) including disruption avoidance. The first of these problems involves the narrow plasma boundary layer and its complex interactions with the plasma core and the surrounding material wall. The second requires development of a computationally tractable, but comprehensive model that describes all equilibrium and dynamic processes at a sufficient level of detail to provide useful prediction of the temporal evolution of fusion plasma experiments. The initial driver for the whole device model will be prediction and avoidance of discharge-terminating disruptions, especially at high performance, which are a critical impediment to successful operation of machines like ITER. If disruptions prove unable to be avoided, their associated dynamics and effects will be addressed in the next phase of the FSP.

Greenwald, Martin

2011-10-04T23:59:59.000Z

297

HEAVY ION FUSION SCIENCE VIRTUALNATIONAL LABORATORY 2nd QUARTER 2009 MILESTONE REPORT: Perform beam and target experiments with a new induction bunching module, extended FEPS plasma, and improved target diagnostic and positioning equipment on NDCX  

E-Print Network [OSTI]

FEPS plasma, and improved target diagnostic and positioningFEPS plasma, and improved target diagnostic and positioningoptical target diagnostic system, and FCAPS plasma injection

Bieniosek, F.M.

2010-01-01T23:59:59.000Z

298

Plasma generating apparatus for large area plasma processing  

DOE Patents [OSTI]

A plasma generating apparatus for plasma processing applications is based on a permanent magnet line-cusp plasma confinement chamber coupled to a compact single-coil microwave waveguide launcher. The device creates an electron cyclotron resonance (ECR) plasma in the launcher and a second ECR plasma is created in the line cusps due to a 0.0875 tesla magnetic field in that region. Additional special magnetic field configuring reduces the magnetic field at the substrate to below 0.001 tesla. The resulting plasma source is capable of producing large-area (20-cm diam), highly uniform (.+-.5%) ion beams with current densities above 5 mA/cm[sup 2]. The source has been used to etch photoresist on 5-inch diam silicon wafers with good uniformity. 3 figures.

Tsai, C.C.; Gorbatkin, S.M.; Berry, L.A.

1991-07-16T23:59:59.000Z

299

Plasma generating apparatus for large area plasma processing  

DOE Patents [OSTI]

A plasma generating apparatus for plasma processing applications is based on a permanent magnet line-cusp plasma confinement chamber coupled to a compact single-coil microwave waveguide launcher. The device creates an electron cyclotron resonance (ECR) plasma in the launcher and a second ECR plasma is created in the line cusps due to a 0.0875 tesla magnetic field in that region. Additional special magnetic field configuring reduces the magnetic field at the substrate to below 0.001 tesla. The resulting plasma source is capable of producing large-area (20-cm diam), highly uniform (.+-.5%) ion beams with current densities above 5 mA/cm.sup.2. The source has been used to etch photoresist on 5-inch diam silicon wafers with good uniformity.

Tsai, Chin-Chi (Oak Ridge, TN); Gorbatkin, Steven M. (Oak Ridge, TN); Berry, Lee A. (Oak Ridge, TN)

1991-01-01T23:59:59.000Z

300

Chemical simulation of hydrogen generation in a plasma fuel reformer  

E-Print Network [OSTI]

A model for a plasma fuel reformer or plasmatron has been developed. The model was based in a series of experiments realized at the Plasma Science and Fusion Center with such a plasmatron. The device is set up to produce ...

Margarit Bel, Nuria, 1977-

2004-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "density plasma science" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


301

Diagnostic technique for measuring plasma parameters near surfaces in radio frequency discharges  

E-Print Network [OSTI]

Diagnostic technique for measuring plasma parameters near surfaces in radio frequency discharges September 1998 A plasma diagnostic technique for measuring the electron density, electron temperature the plasma parameters. The technique is demonstrated by implementing the diagnostic in a computer model

Kushner, Mark

302

Fluorination mechanisms of Al{sub 2}O{sub 3} and Y{sub 2}O{sub 3} surfaces irradiated by high-density CF{sub 4}/O{sub 2} and SF{sub 6}/O{sub 2} plasmas  

SciTech Connect (OSTI)

Fluorination of Al{sub 2}O{sub 3} and Y{sub 2}O{sub 3} surfaces was investigated by irradiating high-density, helicon-wave CF{sub 4}/O{sub 2} and SF{sub 6}/O{sub 2} plasmas. The Al{sub 2}O{sub 3} surface bombarded by high-flux positive ions of the CF{sub 4}/O{sub 2} plasma was fluorinated significantly. On contrast, Y{sub 2}O{sub 3} was less fluorinated than Al{sub 2}O{sub 3} when they were irradiated by the same CF{sub 4}/O{sub 2} plasma. The analysis of the Al{sub 2}O{sub 3} surface irradiated by the CF{sub 4}/O{sub 2} plasma suggests that the fluorination is triggered by reactions between fluorocarbon deposit and Al-O bonding with the assistance of ion bombardment. On the other hand, irradiation of the SF{sub 6}/O{sub 2} plasma induced less significant fluorination on the Al{sub 2}O{sub 3} surface. This suggests a lower reaction probability between sulfur fluoride deposit and Al-O bonding. The difference in the fluorination of the Al{sub 2}O{sub 3} and Y{sub 2}O{sub 3} surfaces induced by the irradiations of the CF{sub 4}/O{sub 2} and SF{sub 6}/O{sub 2} plasmas is understood by comparing the bonding energies of C-O, S-O, Al-O, and Y-O.

Miwa, Kazuhiro; Takada, Noriharu; Sasaki, Koichi [Department of Electrical Engineering and Computer Science, Nagoya University, Nagoya, 464-8603 (Japan); Plasma Nanotechnology Research Center, Nagoya University, Nagoya 464-8603 (Japan)

2009-07-15T23:59:59.000Z

303

Aerodynamic Focusing Of High-Density Aerosols  

SciTech Connect (OSTI)

High-density micron-sized particle aerosols might form the basis for a number of applications in which a material target with a particular shape might be quickly ionized to form a cylindrical or sheet shaped plasma. A simple experimental device was built in order to study the properties of high-density aerosol focusing for 1#22; m silica spheres. Preliminary results recover previous findings on aerodynamic focusing at low densities. At higher densities, it is demonstrated that the focusing properties change in a way which is consistent with a density dependent Stokes number.

Ruiz, D. E.; Fisch, Nathaniel

2014-02-24T23:59:59.000Z

304

Nonequilibrium lighting plasmas  

SciTech Connect (OSTI)

In this paper the science of a variety of devices employing nonequilibrium lighting plasmas is reviewed. The devices include the fluorescent lamp, the low-pressure sodium lamp, the neon sign, ultraviolet lamps, glow indicators, and a variety of devices used by spectroscopists, such as the hollow cathode light source. The plasma conditions in representative commercial devices are described. Recent research on the electron gas, the role of heavy particles, spatial and temporal inhomogeneities, and new electrodeless excitation schemes is reviewed. Areas of future activity are expected to be in new applications of high-frequency electronics to commercial devices, new laser-based diagnostics of plasma conditions, and more sophisticated models requiring more reliable and extensive rate coefficient data.

Dakin, J.T. (GE Lighting, Nela Park, Cleveland, OH (US))

1991-12-01T23:59:59.000Z

305

axisymmetric tokamak plasmas: Topics by E-print Network  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Robert G. Kleva and Parvez N. Guzdar Materials Science Websites Summary: for Plasma Research, University of Maryland, College Park, Maryland 20770 Received 9 June 1999;...

306

ac plasma polymerisation: Topics by E-print Network  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Physics and Fusion Websites Summary: ons USBPO - Coordinates US burning plasma research, to advance scienfic understanding USBPO organizes the US Fusion Energy Science...

307

ac plasma electrolytic: Topics by E-print Network  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Physics and Fusion Websites Summary: ons USBPO - Coordinates US burning plasma research, to advance scienfic understanding USBPO organizes the US Fusion Energy Science...

308

ac plasma display: Topics by E-print Network  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Physics and Fusion Websites Summary: ons USBPO - Coordinates US burning plasma research, to advance scienfic understanding USBPO organizes the US Fusion Energy Science...

309

ac plasma polymerization: Topics by E-print Network  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Physics and Fusion Websites Summary: ons USBPO - Coordinates US burning plasma research, to advance scienfic understanding USBPO organizes the US Fusion Energy Science...

310

Positron plasma diagnostics and temperature control for antihydrogen production  

E-Print Network [OSTI]

Production of antihydrogen atoms by mixing antiprotons with a cold, confined, positron plasma depends critically on parameters such as the plasma density and temperature. We discuss non-destructive measurements, based on a novel, real-time analysis of excited, low-order plasma modes, that provide comprehensive characterization of the positron plasma in the ATHENA antihydrogen apparatus. The plasma length, radius, density, and total particle number are obtained. Measurement and control of plasma temperature variations, and the application to antihydrogen production experiments are discussed.

ATHENA Collaboration; M. Amoretti; C. Amsler; G. Bonomi; A. Bouchta; P. D. Bowe; C. Carraro; C. L. Cesar; M. Charlton; M. Doser; V. Filippini; A. Fontana; M. C. Fujiwara; R. Funakoshi; P. Genova; J. S. Hangst; R. S. Hayano; L. V. Jorgensen; V. Lagomarsino; R. Landua; D. Lindelof; E. Lodi Rizzini; M. Macri'; N. Madsen; G. Manuzio; P. Montagna; H. Pruys; C. Regenfus; A. Rotondi; G. Testera; A. Variola; D. P. van der Werf

2003-07-30T23:59:59.000Z

311

Michigan Institute Science and  

E-Print Network [OSTI]

Michigan Institute for Plasma Science and Engineering Seminar Universal Magnetic Structures Prof. Mark Moldwin Dept. of Atmospheric, Oceanic and Space Sciences University of Michigan Thursday, 19 Nov and provide examples on how thinking about discrete structures can add to our understanding of the solar

Shyy, Wei

312

ANALYSIS OF DATA FROM Z-PINCH MTF TARGET PLASMA EXPERIMENTS  

SciTech Connect (OSTI)

The Los Alamos National Laboratory Colt facility has been used to create target plasma for Magnetized Target Fusion (MTF). The primary results regarding magnetic field, plasma density, plasma temperature, and hot plasma lifetime are summarized and the suitability of these plasma targets for MTF is assessed.

F. WYSOCKI; J. TACCETTI; ET AL

1999-04-01T23:59:59.000Z

313

FUSION NUCLEAR SCIENCE PROGRAM & SUPPORTING FUSION NUCLEAR SCIENCE FACILITY (FNSF)  

E-Print Network [OSTI]

FUSION NUCLEAR SCIENCE PROGRAM & SUPPORTING FUSION NUCLEAR SCIENCE FACILITY (FNSF): UPDATE · It was well recognized there were also critical materials and technology issues that needed to be addressed in order to apply the knowledge we gained about burning plasma state #12;FUSION NUCLEAR SCIENCE PROGRAM

314

Boundary Plasma Turbulence Simulations for Tokamaks  

SciTech Connect (OSTI)

The boundary plasma turbulence code BOUT models tokamak boundary-plasma turbulence in a realistic divertor geometry using modified Braginskii equations for plasma vorticity, density (ni), electron and ion temperature (T{sub e}; T{sub i}) and parallel momenta. The BOUT code solves for the plasma fluid equations in a three dimensional (3D) toroidal segment (or a toroidal wedge), including the region somewhat inside the separatrix and extending into the scrape-off layer; the private flux region is also included. In this paper, a description is given of the sophisticated physical models, innovative numerical algorithms, and modern software design used to simulate edge-plasmas in magnetic fusion energy devices. The BOUT code's unique capabilities and functionality are exemplified via simulations of the impact of plasma density on tokamak edge turbulence and blob dynamics.

Xu, X; Umansky, M; Dudson, B; Snyder, P

2008-05-15T23:59:59.000Z

315

Characterization of BCl3/N-2 plasmas  

E-Print Network [OSTI]

Optical emission spectroscopy, quadrupole mass spectrometry, and electron density measurements were used to study the effect of the percentage of N-2 on the characteristics of BCl3/N-2 plasmas and their resulting etch ...

Sia, S. F.

2003-08-15T23:59:59.000Z

316

Plasma response to electron energy filter in large volume plasma device  

SciTech Connect (OSTI)

An electron energy filter (EEF) is embedded in the Large Volume Plasma Device plasma for carrying out studies on excitation of plasma turbulence by a gradient in electron temperature (ETG) described in the paper of Mattoo et al. [S. K. Mattoo et al., Phys. Rev. Lett. 108, 255007 (2012)]. In this paper, we report results on the response of the plasma to the EEF. It is shown that inhomogeneity in the magnetic field of the EEF switches on several physical phenomena resulting in plasma regions with different characteristics, including a plasma region free from energetic electrons, suitable for the study of ETG turbulence. Specifically, we report that localized structures of plasma density, potential, electron temperature, and plasma turbulence are excited in the EEF plasma. It is shown that structures of electron temperature and potential are created due to energy dependence of the electron transport in the filter region. On the other hand, although structure of plasma density has origin in the particle transport but two distinct steps of the density structure emerge from dominance of collisionality in the source-EEF region and of the Bohm diffusion in the EEF-target region. It is argued and experimental evidence is provided for existence of drift like flute Rayleigh-Taylor in the EEF plasma.

Sanyasi, A. K.; Awasthi, L. M.; Mattoo, S. K.; Srivastava, P. K.; Singh, S. K.; Singh, R.; Kaw, P. K. [Institute for Plasma Research, Gandhinagar, 382 428 Gujarat (India)] [Institute for Plasma Research, Gandhinagar, 382 428 Gujarat (India)

2013-12-15T23:59:59.000Z

317

HEAVY ION FUSION SCIENCE VIRTUAL NATIONAL LABORATORY 3nd QUARTER 2009 MILESTONE REPORT: Upgrade plasma source configuration and carry out initial experiments. Characterize improvements in focal spot beam intensity  

E-Print Network [OSTI]

FEPS plasma and the plasma in the final focus solenoid. TheI Final Focus Solenoid (FFS) in order to generate plasma onplasma sources (CAPS) streams from left to right into the final focus

Lidia, S.

2010-01-01T23:59:59.000Z

318

http://science.energy.gov/fes Establishing the scien.fic basis for fusion energy  

E-Print Network [OSTI]

http://science.energy.gov/fes Establishing the scien.fic basis for fusion energy and plasma science goals · Office of Science role regarding fusion energy: establish university engagement and leadership. Fusion materials science will be an increasing

319

Plasma Diagnostics and Plasma-Surface Interactions in Inductively Coupled Plasmas  

E-Print Network [OSTI]

Plasma Diagnostics and Plasma-Surface Interactions inLieberman Spring 2010 Plasma Diagnostics and Plasma-SurfaceJoy Titus Abstract Plasma Diagnostics and Plasma-Surface

Titus, Monica Joy

2010-01-01T23:59:59.000Z

320

Taylor/FESAC Priorities/July 18, 2012 Fusion Energy Science Program Priorities  

E-Print Network [OSTI]

Base Plasma science Engineering Science Innovative Experiments, Theory/modeling Students Workforce #12 materials fuel cycle ITER high gain BP Physics DEMO net electricity Excellent Science and Innovation are strengths of the U. S. Magnetic Fusion Program Strong Scientific Base Plasma science Engineering Science

Note: This page contains sample records for the topic "density plasma science" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


321

Waves generated in the plasma plume of helicon magnetic nozzle  

SciTech Connect (OSTI)

Experimental measurements have shown that the plasma plume created in a helicon plasma device contains a conical structure in the plasma density and a U-shaped double layer (US-DL) tightly confined near the throat where plasma begins to expand from the source. Recently reported two-dimensional particle-in-cell simulations verified these density and US-DL features of the plasma plume. Simulations also showed that the plasma in the plume develops non-thermal feature consisting of radial ion beams with large densities near the conical surface of the density structure. The plasma waves that are generated by the radial ion beams affecting the structure of the plasma plume are studied here. We find that most intense waves persist in the high-density regions of the conical density structure, where the transversely accelerated ions in the radial electric fields in the plume are reflected setting up counter-streaming. The waves generated are primarily ion Bernstein modes. The nonlinear evolution of the waves leads to magnetic field-aligned striations in the fields and the plasma near the conical surface of the density structure.

Singh, Nagendra; Rao, Sathyanarayan; Ranganath, Praveen [Department of Electrical and Computer Engineering, University of Alabama, Huntsville, Alabama 35899 (United States)

2013-03-15T23:59:59.000Z

322

Laser beat wave excitation of terahertz radiation in a plasma slab  

SciTech Connect (OSTI)

Terahertz (THz) radiation generation by nonlinear mixing of lasers, obliquely incident on a plasma slab is investigated. Two cases are considered: (i) electron density profile is parabolic but density peak is below the critical density corresponding to the beat frequency, (ii) plasma boundaries are sharp and density is uniform. In both cases, nonlinearity arises through the ponderomotive force that gives rise to electron drift at the beat frequency. In the case of inhomogeneous plasma, non zero curl of the nonlinear current density gives rise to electromagnetic THz generation. In case of uniform plasma, the sharp density variation at the plasma boundaries leads to radiation generation. In a slab width of less than a terahertz wavelength, plasma density one fourth of terahertz critical density, laser intensities ?10{sup 17?}W/cm{sup 2} at 1??m, one obtains the THz intensity ?1?GW/cm{sup 2} at 3 THz radiation frequency.

Chauhan, Santosh; Parashar, Jetendra, E-mail: j.p.parashar@gmail.com [Department of Applied Physics, Samrat Ashok Technological Institute, Vidisha 464001, Madhya Pradesh (India)

2014-10-15T23:59:59.000Z

323

Office of Science Summary Program and Financing (in millions of dollars)  

E-Print Network [OSTI]

.19 Small business technology transfer .............................. 14 program advances plasma science, fusion science, and fusion technology in order to establish the knowledge, an international burning plasma physics experiment being built in France in collaboration with the European Union

324

Measurement of MTF Target Plasma Temperature Using Filtered Silicon Photodiodes  

E-Print Network [OSTI]

Measurement of MTF Target Plasma Temperature Using Filtered Silicon Photodiodes Presented at the 40 Plasma Temperature Using Filtered Silicon Photodiodes Magnetized Target Fusion (MTF) is an approach photodiodes, and a plasma-density interferometer. The data obtained from the array of seven filtered silicon

325

E-Print Network 3.0 - absorbing column densities Sample Search...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

John - National Radio Astronomy Observatory Collection: Physics 3 Characteristics and energy balance of a plasma column sustained by a surface wave Summary: density distribution...

326

Dielectric covered hairpin probe for its application in reactive plasmas  

SciTech Connect (OSTI)

The hairpin probe is a well known technique for measuring local electron density in low temperature plasmas. In reactive plasmas, the probe characteristics are affected by surface sputtering, contamination, and secondary electron emission. At higher densities, the plasma absorbs the entire electromagnetic energy of hairpin and hence limits the density measurements. These issues can be resolved by covering the hairpin surface with a thin layer of dielectric. In this letter, the dielectric contribution to the probe characteristics is incorporated in a theory which is experimentally verified. The dielectric covering improves the performance of probe and also allows the hairpin tip to survive in reactive plasma where classical electrical probes are easily damaged.

Gogna, G. S.; Gaman, C.; Turner, M. M. [NCPST, School of Physical Sciences, Dublin City University, Dublin 9 (Ireland); Karkari, S. K. [Institute for Plasma Research Center, Bhat Gandhinagar, Gujarat 382428 (India)

2012-07-23T23:59:59.000Z

327

PISCES Program: Plasma-materials interactions and edge-plasma physics research  

SciTech Connect (OSTI)

This program investigates and characterizes the behavior of materials under plasma bombordment, in divertor regions. The PISCES facility is used to study divertor and plasma edge management concepts (in particular gas target divertors), as well as edge plasma turbulence and transport. The plasma source consists of a hot LaB[sub 6] cathode with an annular, water-cooled anode and attached drift tube. This cross sectional area of the plasma can be adjusted between 3 and 10 cm. A fast scanning diagnostic probe system was used for mapping plasma density profiles during biased limiter and divertor simulation experiments. Some experimental data are given on: (1) materials and surface physics, (2) edge plasma physics, and (3) a theoretical analysis of edge plasma modelling.

Conn, R.W.; Hirooka, Y.

1992-07-01T23:59:59.000Z

328

Plasma properties downstream of a low-power Hall thruster  

SciTech Connect (OSTI)

Triple Langmuir probes and emissive probes were used to measure the electron number density, electron temperature, and plasma potential downstream of a low-power Hall thruster. The results show a polytropic relation between electron temperature and electron number density throughout the sampled region. Over a large fraction of the plume, the plasma potential obeys the predictions of ambipolar expansion. Near the thruster centerline, however, observations show larger gradients of plasma potential than can be accounted for by this means. Radial profiles of plasma potential in the very-near-field plume are shown to contain large gradients that correspond in location to the boundaries of a visually intense plasma region.

Beal, Brian E.; Gallimore, Alec D.; Hargus, William A. Jr. [Plasmadynamics and Electric Propulsion Laboratory, Department of Aerospace Engineering, University of Michigan, College of Engineering, Ann Arbor, Michigan 48109 (United States); Air Force Research Laboratories, Edwards Air Force Base, Edwards, California 93524 (United States)

2005-12-15T23:59:59.000Z

329

Application of Plasma Waveguides to High Energy Accelerators  

SciTech Connect (OSTI)

The eventual success of laser-plasma based acceleration schemes for high-energy particle physics will require the focusing and stable guiding of short intense laser pulses in reproducible plasma channels. For this goal to be realized, many scientific issues need to be addressed. These issues include an understanding of the basic physics of, and an exploration of various schemes for, plasma channel formation. In addition, the coupling of intense laser pulses to these channels and the stable propagation of pulses in the channels require study. Finally, new theoretical and computational tools need to be developed to aid in the design and analysis of experiments and future accelerators. Here we propose a 3-year renewal of our combined theoretical and experimental program on the applications of plasma waveguides to high-energy accelerators. During the past grant period we have made a number of significant advances in the science of laser-plasma based acceleration. We pioneered the development of clustered gases as a new highly efficient medium for plasma channel formation. Our contributions here include theoretical and experimental studies of the physics of cluster ionization, heating, explosion, and channel formation. We have demonstrated for the first time the generation of and guiding in a corrugated plasma waveguide. The fine structure demonstrated in these guides is only possible with cluster jet heating by lasers. The corrugated guide is a slow wave structure operable at arbitrarily high laser intensities, allowing direct laser acceleration, a process we have explored in detail with simulations. The development of these guides opens the possibility of direct laser acceleration, a true miniature analogue of the SLAC RF-based accelerator. Our theoretical studies during this period have also contributed to the further development of the simulation codes, Wake and QuickPIC, which can be used for both laser driven and beam driven plasma based acceleration schemes. We will continue our development of advanced simulation tools by modifying the QuickPIC algorithm to allow for the simulation of plasma particle pick-up by the wake fields. We have also performed extensive simulations of plasma slow wave structures for efficient THz generation by guided laser beams or accelerated electron beams. We will pursue experimental studies of direct laser acceleration, and THz generation by two methods, ponderomotive-induced THz polarization, and THz radiation by laser accelerated electron beams. We also plan to study both conventional and corrugated plasma channels using our new 30 TW in our new lab facilities. We will investigate production of very long hydrogen plasma waveguides (5 cm). We will study guiding at increasing power levels through the onset of laser-induced cavitation (bubble regime) to assess the role played by the preformed channel. Experiments in direct acceleration will be performed, using laser plasma wakefields as the electron injector. Finally, we will use 2-colour ionization of gases as a high frequency THz source (<60 THz) in order for femtosecond measurements of low plasma densities in waveguides and beams.

Milchberg, Howard M

2013-03-30T23:59:59.000Z

330

INSTITUTE OF PHYSICS PUBLISHING PLASMA PHYSICS AND CONTROLLED FUSION Plasma Phys. Control. Fusion 46 (2004) 471487 PII: S0741-3335(04)69034-8  

E-Print Network [OSTI]

INSTITUTE OF PHYSICS PUBLISHING PLASMA PHYSICS AND CONTROLLED FUSION Plasma Phys. Control. Fusion the cold plasma dispersion relation, the ion­ion hybrid cutoff frequency is uniquely determined and tritium density equilibrium (nD nT), maximizing fusion reactions in a burning plasma experiment. A number

Heidbrink, William W.

331

The Heavy Ion Fusion Science Virtual National Laboratory  

E-Print Network [OSTI]

Final Focus Solenoid and Target Chamber ­ Cathodic Arc Plasma Source (CAPS) Developed by André AndersThe Heavy Ion Fusion Science Virtual National Laboratory Plasma Sources for Drivers and NDCX-II 19 P. Gilson Princeton Plasma Physics Laboratory #12;The Heavy Ion Fusion Science Virtual National

Gilson, Erik

332

Method of accelerating photons by a relativistic plasma wave  

DOE Patents [OSTI]

Photons of a laser pulse have their group velocity accelerated in a plasma as they are placed on a downward density gradient of a plasma wave of which the phase velocity nearly matches the group velocity of the photons. This acceleration results in a frequency upshift. If the unperturbed plasma has a slight density gradient in the direction of propagation, the photon frequencies can be continuously upshifted to significantly greater values.

Dawson, John M. (Pacific Palisades, CA); Wilks, Scott C. (Santa Monica, CA)

1990-01-01T23:59:59.000Z

333

Effect of plasma inhomogeneity on plasma wakefield acceleration driven by long bunches  

SciTech Connect (OSTI)

Effects of plasma inhomogeneity on self-modulating proton bunches and accelerated electrons were studied numerically. The main effect is the change of the wakefield wavelength which results in phase shifts and loss of accelerated particles. This effect imposes severe constraints on density uniformity in plasma wakefield accelerators driven by long particle bunches. The transverse two stream instability that transforms the long bunch into a train of micro-bunches is less sensitive to density inhomogeneity than are the accelerated particles. The bunch freely passes through increased density regions and interacts with reduced density regions.

Lotov, K. V. [Budker Institute of Nuclear Physics SB RAS, 630090 Novosibirsk, Russia and Novosibirsk State University, 630090 Novosibirsk (Russian Federation); Pukhov, A. [Institut fuer Theoretische Physik I, Heinrich-Heine-Universitaet Duesseldorf, 40225 Duesseldorf (Germany); Caldwell, A. [Max-Planck-Institut fuer Physik, 80805 Muenchen (Germany)

2013-01-15T23:59:59.000Z

334

Nonlocal fluxes at a plasma sheath  

SciTech Connect (OSTI)

The particle and energy fluxes of electrons at the boundary of a plasma in contact with a perfectly absorbing plate are considered. In general, the fluxes are shown not to be determined by the plasma temperature and density at the plate but rather by a convolution of the plasma profiles in the vicinity of the plate. A simple empirical expression is proposed for the nonlocal fluxes, which approximately reproduces the results of a full kinetic calculation. The implications of this, to divertor plasmas near the neutralizer plate, are discussed.

Marchand, R.; Abou-Assaleh, Z.; Matte, J.P. (INRS-Energie, C. P. 1020, Varennes, Quebec, J3X 1S2, Canada (CA))

1990-06-01T23:59:59.000Z

335

NSTX Plasma Response to Lithium Coated Divertor  

SciTech Connect (OSTI)

NSTX experiments have explored lithium evaporated on a graphite divertor and other plasma facing components in both L- and H- mode confinement regimes heated by high-power neutral beams. Improvements in plasma performance have followed these lithium depositions, including a reduction and eventual elimination of the HeGDC time between discharges, reduced edge neutral density, reduced plasma density, particularly in the edge and the SOL, increased pedestal electron and ion temperature, improved energy confinement and the suppression of ELMs in the H-mode. However, with improvements in confinement and suppression of ELMs, there was a significant secular increase in the effective ion charge Zeff and the radiated power in H-mode plasmas as a result of increases in the carbon and medium-Z metallic impurities. Lithium itself remained at a very low level in the plasma core, <0.1%. Initial results are reported from operation with a Liquid Lithium Divertor (LLD) recently installed.

H.W. Kugel, M.G. Bell, J.P. Allain, R.E. Bell, S. Ding, S.P. Gerhardt, M.A. Jaworski, R. Kaita, J. Kallman, S.M. Kaye, B.P. LeBlanc, R. Maingi, R. Majeski, R. Maqueda, D.K. Mansfield, D. Mueller, R. Nygren, S.F. Paul, R. Raman, A.L. Roquemore, S.A. Sabbagh, H. Schneider, C.H. Skinner, V.A. Soukhanovskii, C.N. Taylor, J.R. Timberlak, W.R. Wampler, L.E. Zakharov, S.J. Zweben, and the NSTX Research Team

2011-01-21T23:59:59.000Z

336

Solitary and shock waves in magnetized electron-positron plasma  

SciTech Connect (OSTI)

An Ohm's law for electron-positron (EP) plasma is obtained. In the framework of EP magnetohydrodynamics, we investigate nonrelativistic nonlinear waves' solutions in a magnetized EP plasma. In the collisionless limit, quasistationary propagating solitary wave structures for the magnetic field and the plasma density are obtained. It is found that the wave amplitude increases with the Mach number and the Alfvén speed. However, the dependence on the plasma temperature is just the opposite. Moreover, for a cold EP plasma, the existence range of the solitary waves depends only on the Alfvén speed. For a hot EP plasma, the existence range depends on the Alfvén speed as well as the plasma temperature. In the presence of collision, the electromagnetic fields and the plasma density can appear as oscillatory shock structures because of the dissipation caused by the collisions. As the collision frequency increases, the oscillatory shock structure becomes more and more monotonic.

Lu, Ding; Li, Zi-Liang; Abdukerim, Nuriman; Xie, Bai-Song, E-mail: bsxie@bnu.edu.cn [Key Laboratory of Beam Technology and Materials Modification of the Ministry of Education, and College of Nuclear Science and Technology, Beijing Normal University, Beijing 100875 (China)] [Key Laboratory of Beam Technology and Materials Modification of the Ministry of Education, and College of Nuclear Science and Technology, Beijing Normal University, Beijing 100875 (China)

2014-02-15T23:59:59.000Z

337

NON-INTRUSIVE TEMPERATURE DIAGNOSTIC FOR A NON-NEUTRAL PLASMA  

E-Print Network [OSTI]

NON-INTRUSIVE TEMPERATURE DIAGNOSTIC FOR A NON-NEUTRAL PLASMA by Michael Takeshi Nakata A thesis DIAGNOSTIC FOR A NON-NEUTRAL PLASMA M. Takeshi Nakata Department of Physics and Astronomy Master of Science A simple, non-destructive diagnostic for the temperature of a non-neutral plasma is desirable as plasma

Hart, Gus

338

Runaway electrons in a fully and partially ionized nonideal plasma  

SciTech Connect (OSTI)

This paper reports on a study of electron runaway for a nonideal plasma in an external electric field. Based on pseudopotential models of nonideal fully and partially ionized plasmas, the friction force was derived as a function of electron velocities. Dependences of the electron free path on plasma density and nonideality parameters were obtained. The impact of the relative number of runaway electrons on their velocity and temperature was considered for classical and semiclassical models of a nonideal plasma. It has been shown that for the defined intervals of the coupled plasma parameter, the difference between the relative numbers of runaway electron values is essential for various plasma models.

Ramazanov, T.S.; Turekhanova, K.M. [Al Farabi Kazakh National University, IETP, Tole bi 96a, Almaty 050012 (Kazakhstan)

2005-10-01T23:59:59.000Z

339

FUSION ENERGY SCIENCES SUMMER STUDY 2002 Gerald Navratil  

E-Print Network [OSTI]

-2003, and to the review of burning plasma science by the National Academy of Sciences called for by FESAC and EnergyPLANS FOR FUSION ENERGY SCIENCES SUMMER STUDY 2002 Gerald Navratil Columbia University American Physical Society - Division of Plasma Physics 2001 Annual Meeting, Long Beach, CA 29 October - 2 November

340

Multi-GeV Energy Gain in a Plasma-Wakefield Accelerator M. J. Hogan,1  

E-Print Network [OSTI]

m at the entrance of a 10 cm long column of lithium vapor with density 2:8 1017 atoms=cm3. The electron bunch fully ionizes the lithium vapor to create a plasma and then expels the plasma electrons-plasma interactions have demonstrated focusing gradients of MT=m [1] while laser plasma interactions have demonstrated

Jalali. Bahram

Note: This page contains sample records for the topic "density plasma science" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


341

Progress on Plasma Lens Experiment at the Final Focus Test Beam *  

E-Print Network [OSTI]

Progress on Plasma Lens Experiment at the Final Focus Test Beam * S. Chattopadhyay 1 , P. Chen 2 Collaboration proposed and has been approved to perform the Plasma Lens Experiment at the Final Focus Test Beam of the experiment are to study plasma focusing of high energy, high density particle beams; to investigate plasma

342

ORIGINAL PAPER BambooFiber Filled High Density Polyethylene Composites  

E-Print Network [OSTI]

ORIGINAL PAPER Bamboo­Fiber Filled High Density Polyethylene Composites: Effect of Coupling Springer Science+Business Media, LLC 2008 Abstract High density polyethylene (HDPE)/bamboo composites in the future study. Keywords Bamboo Á High density polyethylene Á Coupling treatment Á Nanoclay Introduction

343

1 Density Functional Theory for Emergents Robert O. Jones  

E-Print Network [OSTI]

1 Density Functional Theory for Emergents Robert O. Jones Peter-Gr¨unberg-Institut PGI-1 and German the widespread use of density functional (DF) theory in materials science and chemistry and the physical insight as basic variable 3 3 An "approximate practical method" 5 4 Density functional formalism 7 4.1 Single

344

E-Print Network 3.0 - atmospheric plasma-treated 3d Sample Search...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

OF MATERIALS SCIENCE LETTERS 17 (1998) 20832086 Effect of oxygen plasma treatment on SiO2 aerogel lms Summary: , microstructure, and electrical proper- ties of the oxygen plasma...

345

Ac#vi#es of the US Burning Plasma Organiza#on  

E-Print Network [OSTI]

=ons · USBPO ­ Coordinates US burning plasma research, to advance scien=fic understanding USBPO organizes the US Fusion Energy Science community to support burning plasma research 5 Charles Greenfield (Director) Amanda Hubbard (Deputy Director) Nermin

346

Effect of argon addition on plasma parameters and dust charging in hydrogen plasma  

SciTech Connect (OSTI)

Experimental results on effect of adding argon gas to hydrogen plasma in a multi-cusp dusty plasma device are reported. Addition of argon modifies plasma density, electron temperature, degree of hydrogen dissociation, dust current as well as dust charge. From the dust charging profile, it is observed that the dust current and dust charge decrease significantly up to 40% addition of argon flow rate in hydrogen plasma. But beyond 40% of argon flow rate, the changes in dust current and dust charge are insignificant. Results show that the addition of argon to hydrogen plasma in a dusty plasma device can be used as a tool to control the dust charging in a low pressure dusty plasma.

Kakati, B., E-mail: bharatkakati15@gmail.com; Kausik, S. S.; Saikia, B. K. [Centre of Plasma Physics-Institute for Plasma Research, Nazirakhat, Sonapur, Kamrup 782402, Assam (India); Bandyopadhyay, M.; Saxena, Y. C. [Institute for Plasma Research, Bhat, Gandhinagar 382 428 (India)

2014-10-28T23:59:59.000Z

347

SCIENCE CHINA Technological Sciences  

E-Print Network [OSTI]

SCIENCE CHINA Technological Sciences © Science China Press and Springer-Verlag Berlin Heidelberg and Nanosystems, Chinese Academy of Sciences, Beijing 100083, China; 2 Institute of Theoretical Physics, Lanzhou University, Lanzhou 730000, China; 3 School of Material Science and Engineering, Georgia Institute

Wang, Zhong L.

348

A large volume uniform plasma generator for the experiments of electromagnetic wave propagation in plasma  

SciTech Connect (OSTI)

A large volume uniform plasma generator is proposed for the experiments of electromagnetic (EM) wave propagation in plasma, to reproduce a 'black out' phenomenon with long duration in an environment of the ordinary laboratory. The plasma generator achieves a controllable approximate uniform plasma in volume of 260 mm Multiplication-Sign 260 mm Multiplication-Sign 180 mm without the magnetic confinement. The plasma is produced by the glow discharge, and the special discharge structure is built to bring a steady approximate uniform plasma environment in the electromagnetic wave propagation path without any other barriers. In addition, the electron density and luminosity distributions of plasma under different discharge conditions were diagnosed and experimentally investigated. Both the electron density and the plasma uniformity are directly proportional to the input power and in roughly reverse proportion to the gas pressure in the chamber. Furthermore, the experiments of electromagnetic wave propagation in plasma are conducted in this plasma generator. Blackout phenomena at GPS signal are observed under this system and the measured attenuation curve is of reasonable agreement with the theoretical one, which suggests the effectiveness of the proposed method.

Yang Min; Li Xiaoping; Xie Kai; Liu Donglin [School of Electronical and Mechanical Engineering, Xidian University, Xi'an Shaanxi 710071 (China); Liu Yanming [School of Telecommunications Engineering, Xidian University, Xi'an Shaanxi 710071 (China)

2013-01-15T23:59:59.000Z

349

A restoration model of distorted electron density in wave-cutoff probe measurement  

SciTech Connect (OSTI)

This study investigates the problem of electron density distortion and how the density can be restored in a wave-cutoff probe. Despite recent plasma diagnostics research using a wave-cutoff probe, the problem of electron density distortion caused by plasma conditions has not been resolved. Experimental results indicate that electron density measured using the wave-cutoff method is highly susceptible to variations in the probe tip gap. This electron density distortion is caused by the bulk plasma disturbance between probe tips, and it must be removed for calculating the absolute electron density. To do this, a detailed analytic model was developed using the power balance equation near probe tips. This model demonstrates the characteristics of plasma distortion in wave-cutoff probe measurement and successfully restored the absolute value of electron density with varying probe tip gaps.

Jun, Hyun-Su, E-mail: mtsconst@kaist.ac.kr; Lee, Yun-Seong [Department of Physics, Korea Advanced Institute of Science and Technology, Daejeon 305-701 (Korea, Republic of)] [Department of Physics, Korea Advanced Institute of Science and Technology, Daejeon 305-701 (Korea, Republic of)

2014-02-15T23:59:59.000Z

350

Plasma ignition and steady state simulations of the Linac4 H$^{-}$ ion source  

E-Print Network [OSTI]

The RF heating of the plasma in the Linac4 H- ion source has been simulated using an Particle-in-Cell Monte Carlo Collision method (PIC-MCC). This model is applied to investigate the plasma formation starting from an initial low electron density of 1012 m-3 and its stabilization at 1018 m-3. The plasma discharge at low electron density is driven by the capacitive coupling with the electric field generated by the antenna, and as the electron density increases the capacitive electric field is shielded by the plasma and induction drives the plasma heating process. Plasma properties such as e-/ion densities and energies, sheath formation and shielding effect are presented and provide insight to the plasma properties of the hydrogen plasma.

Mattei, S; Yasumoto, M; Hatayama, A; Lettry, J; Grudiev, A

2013-01-01T23:59:59.000Z

351

Electron velocity distribution instability in magnetized plasma wakes and artificial electron mass  

E-Print Network [OSTI]

The wake behind a large object (such as the moon) moving rapidly through a plasma (such as the solar wind) contains a region of depleted density, into which the plasma expands along the magnetic field, transverse to the ...

Hutchinson, Ian H.

352

An experimental study and modeling of Transformer-Coupled Toroidal Plasma processing of materials  

E-Print Network [OSTI]

The Transformer Coupled Toroidal Plasma (TCTP) source uses a high power density plasma formed in a toroidal-shaped chamber by transformer coupling using a magnetic core. The objectives of the thesis are (1) to characterize ...

Bai, Bo, Ph. D. Massachusetts Institute of Technology

2006-01-01T23:59:59.000Z

353

Electronically swept millimetre-wave interferometer for spatially resolved measurement of plasma electron  

E-Print Network [OSTI]

electron density John Howard and David Oliver Plasma Research Laboratory, Research School of Physical, located in the Plasma Research Laboratory at the Australian National University, is a flexible, medium

Howard, John

354

E-Print Network 3.0 - anodic arc plasma Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

SCIENCE, VOL. 33, NO. 1, FEBRUARY 2005 Gliding Arc Discharges... for their application to plasma-chemical processes. Diagnostics of gliding arc discharge: electron temperature,...

355

E-Print Network 3.0 - ambipolar plasma flow Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

will await consideration of individual charged particle Source: Howard, John - Plasma Research Laboratory, Research School of Physical Sciences and Engineering, Australian...

356

E-Print Network 3.0 - approximation plasma polarization Sample...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

detectors... ) are superimposed and launched into the ... Source: Howard, John - Plasma Research Laboratory, Research School of Physical Sciences and Engineering, Australian...

357

affordable near-term burning-plasma: Topics by E-print Network  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Physics and Fusion Websites Summary: ons USBPO - Coordinates US burning plasma research, to advance scienfic understanding USBPO organizes the US Fusion Energy Science...

358

Burning Plasma Support Research Program  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth (AOD)ProductssondeadjustsondeadjustAboutScienceCareersEnergy,ServicesBurning Plasma Support Research Program

359

Effect of Lithium PFC Coatings on NSTX Density Control  

SciTech Connect (OSTI)

Lithium coatings on the graphite plasma facing components (PFCs) in NSTX are being investigated as a tool for density profile control and reducing the recycling of hydrogen isotopes. Repeated lithium pellet injection into Center Stack Limited and Lower Single Null Ohmic Helium Discharges were used to coat graphite surfaces that had been pre-conditioned with Ohmic Helium Discharges of the same shape to reduce their contribution to hydrogen isotope recycling. The following deuterium NBI reference discharges exhibited a reduction in density by a factor of about 3 for limited and 2 for diverted plasmas respectively, and peaked density profiles. Recently, a lithium evaporator has been used to apply thin coatings on conditioned and unconditioned PFCs. Effects on the plasma density and the impurities were obtained by pre-conditioning the PFCs with ohmic helium discharges, and performing the first deuterium NBI discharge as soon as possible after applying the lithium coating.

Kugel, H W; Bell, M G; Bush, C; Gates, D; Gray, T; Kaita, R; Leblanc, B; Maingi, R; Majeski, R; Mansfield, D; Mueller, D; Raman, R; Roquemore, A L; Sabbagh, S; Skinner, C H; Soukhanovskii, V; Stevenson, T; Zakharov, L

2006-08-21T23:59:59.000Z

360

Direct measurements of the ionization profile in krypton helicon plasmas  

SciTech Connect (OSTI)

Helicons are efficient plasma sources, capable of producing plasma densities of 10{sup 19} m{sup -3} with only 100 s W of input rf power. There are often steep density gradients in both the neutral density and plasma density, resulting in a fully ionized core a few cm wide surrounded by a weakly ionized plasma. The ionization profile is usually not well known because the neutral density is typically inferred from indirect spectroscopic measurements or from edge pressure gauge measurements. We have developed a two photon absorption laser induced fluorescence (TALIF) diagnostic capable of directly measuring the neutral density profile. We use TALIF in conjunction with a Langmuir probe to measure the ionization fraction profile as a function of driving frequency, magnetic field, and input power. It is found that when the frequency of the driving wave is greater than a critical frequency, f{sub c} Almost-Equal-To 3f{sub lh}, where f{sub lh} is the lower hybrid frequency at the antenna, the ionization fraction is small (0.1%) and the plasma density low (10{sup 17} m{sup -3}). As the axial magnetic field is increased, or, equivalently, the driving frequency decreased, a transition is observed. The plasma density increases by a factor of 10 or more, the plasma density profile becomes strongly peaked, the neutral density profile becomes strongly hollow, and the ionization fraction in the core approaches 100%. Neutral depletion in the core can be caused by a number of mechanisms. We find that in these experiments the depletion is due primarily to plasma pressure and neutral pumping.

Magee, R. M.; Galante, M. E.; McCarren, D. W.; Scime, E. E. [Department of Physics, West Virginia University, Morgantown, West Virginia 26506 (United States); Gulbrandsen, N. [Department of Physics and Technology, Faculty of Science, University of Tromso, N-9037 Tromso (Norway)

2012-12-15T23:59:59.000Z

Note: This page contains sample records for the topic "density plasma science" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


361

Office of Science-President's FY 2006 Budget Program and Financing (in millions of dollars)  

E-Print Network [OSTI]

............................. 103 ................... ................... 00.19 Small business technology transfer of the science and technology of energy producing plasmas, as a partner in an international effort. The budget science, fusion science, and fusion technology. The program emphasizes the underlying basic research

362

Shock compression of low-density foams  

SciTech Connect (OSTI)

Shock compression of very low density micro-cellular materials allows entirely new regimes of hot fluid states to be investigated experimentally. Using a two-stage light-gas gun to generate strong shocks, temperatures of several eV are readily achieved at densities of roughly 0.5--1 g/cm{sup 3} in large, uniform volumes. The conditions in these hot, expanded fluids are readily found using the Hugoniot jump conditions. We will briefly describe the basic methodology for sample preparation and experimental measurement of shock velocities. We present data for several materials over a range of initial densities. This paper will explore the applications of these methods for investigations of equations of state and phase diagrams, spectroscopy, and plasma physics. Finally, we discus the need for future work on these and related low-density materials.

Holmes, N.C.

1993-07-01T23:59:59.000Z

363

Computer Science Computer Science?  

E-Print Network [OSTI]

Michigan Autonomous Aerial Vehicles, UM::Autonomy, U-M Programming, U-M Solar Car, Hybrid RacingComputer Science @ Michigan Life as a CS Student What is Computer Science? Computer science is shaping the future. A degree in computer science can help shape yours. Michigan CS students have

Eustice, Ryan

364

Spectroscopic Determination of the Magnetic Fields in Exploding Wire and X-pinch Plasmas  

SciTech Connect (OSTI)

In this report, we summarize the progress that was made toward developing a new magnetic field diagnostic known as Zeeman Broadening for current carrying high energy density plasmas.

Hammer, David A.

2013-12-19T23:59:59.000Z

365

Pair densities in density functional theory  

E-Print Network [OSTI]

The exact interaction energy of a many-electron system is determined by the electron pair density, which is not well-approximated in standard Kohn-Sham density functional models. Here we study the (complicated but well-defined) exact universal map from density to pair density. We show that many common functionals, including the most basic version of the LDA (Dirac exchange with no correlation contribution), arise from particular approximations of this map. We develop an algorithm to compute the map numerically, and apply it to one-parameter families {a*rho(a*x)} of one-dimensional homogeneous and inhomogeneous single-particle densities. We observe that the pair density develops remarkable multiscale patterns which strongly depend on both the particle number and the "width" 1/a of the single-particle density. The simulation results are confirmed by rigorous asymptotic results in the limiting regimes a>>1 and a<<1. For one-dimensional homogeneous systems, we show that the whole spectrum of patterns is rep...

Chen, Huajie

2015-01-01T23:59:59.000Z

366

Multi-scale investigation of sheared flows in magnetized plasmas  

SciTech Connect (OSTI)

Flows parallel and perpendicular to magnetic fields in a plasma are important phenomena in many areas of plasma science research. The presence of these spatially inhomogeneous flows is often associated with the stability of the plasma. In fusion plasmas, these sheared flows can be stabilizing while in space plasmas, these sheared flows can be destabilizing. Because of this, there is broad interest in understanding the coupling between plasma stability and plasma flows. This research project has engaged in a study of the plasma response to spatially inhomogeneous plasma flows using three different experimental devices: the Auburn Linear Experiment for Instability Studies (ALEXIS) and the Compact Toroidal Hybrid (CTH) stellarator devices at Auburn University, and the Space Plasma Simulation Chamber (SPSC) at the Naval Research Laboratory. This work has shown that there is a commonality of the plasma response to sheared flows across a wide range of plasma parameters and magnetic field geometries. The goal of this multi-device, multi-scale project is to understand how sheared flows established by the same underlying physical mechanisms lead to different plasma responses in fusion, laboratory, and space plasmas.

Thomas, Jr., Dr. Edward

2014-09-19T23:59:59.000Z

367

Landau Diamagnetism of Degenerate Collisional Plasma  

E-Print Network [OSTI]

For the first time the kinetic description of Landau diamagnetism for degenerate collisional plasma is given. The correct expression for transverse electric conductivity of the quantum plasma, found by authors (see arXiv:1002.1017 [math-ph] 4 Feb 2010) is used. In work S. Dattagupta, A.M. Jayannavar and N. Kumar [Current science, V. 80, No. 7, 10 April, 2001] was discussed the important problem of dissipation (collisions) influence on Landau diamagnetism. The analysis of this problem is given with the use of exact expression for transverse conductivity of quantum plasma.

A. V. Latyshev; A. A. Yushkanov

2010-07-05T23:59:59.000Z

368

Oblique interactions of dust density waves  

SciTech Connect (OSTI)

Self-excited dust density waves (DDWs) are studied in a striped electrode device. In addition to the usual perpendicularly (with respect to the electrode) propagating DDWs, which have been frequently observed in dusty plasma experiments on the ground, a low-frequency oblique mode is also observed. This low-frequency oblique DDW has a frequency much lower than the dust plasma frequency and its spontaneous excitation is observed even with a very low dust density. It is found that the low-frequency oblique mode can exist either separately or together with the usual perpendicular mode. In the latter case, a new mode arises as a result of the interactions between the perpendicular and the oblique modes. The experiments show that these three modes satisfy the wave coupling conditions in both the frequencies and the wave-vectors.

Wang, Zhelchui [Los Alamos National Laboratory; Li, Yang - Fang [MAX-PLANCK INSTITUTE; Hou, Lujing [MAX-PLANCK INSTITUTE; Jiang, Ke [MAX-PLANCK INSTITUTE; Wu, De - Jin [CHINA; Thomas, Hubertus M [MAX-PLANCK INSTITUTE; Morfill, Gregor E [MAX-PLANCK INSTITUTE

2010-01-01T23:59:59.000Z

369

Plasma wake field XUV radiation source  

DOE Patents [OSTI]

A XUV radiation source uses an interaction of electron beam pulses with a gas to create a plasma radiator. A flowing gas system (10) defines a circulation loop (12) with a device (14), such as a high pressure pump or the like, for circulating the gas. A nozzle or jet (16) produces a sonic atmospheric pressure flow and increases the density of the gas for interacting with an electron beam. An electron beam is formed by a conventional radio frequency (rf) accelerator (26) and electron pulses are conventionally formed by a beam buncher (28). The rf energy is thus converted to electron beam energy, the beam energy is used to create and then thermalize an atmospheric density flowing gas to a fully ionized plasma by interaction of beam pulses with the plasma wake field, and the energetic plasma then loses energy by line radiation at XUV wavelengths Collection and focusing optics (18) are used to collect XUV radiation emitted as line radiation when the high energy density plasma loses energy that was transferred from the electron beam pulses to the plasma.

Prono, Daniel S. (Los Alamos, NM); Jones, Michael E. (Los Alamos, NM)

1997-01-01T23:59:59.000Z

370

Optimized ECR plasma apparatus with varied microwave window thickness  

DOE Patents [OSTI]

The present invention describes a technique to control the radial profile of microwave power in an ECR plasma discharge. In order to provide for a uniform plasma density to a specimen, uniform energy absorption by the plasma is desired. By controlling the radial profile of the microwave power transmitted through the microwave window of a reactor, the profile of the transmitted energy to the plasma can be controlled in order to have uniform energy absorption by the plasma. An advantage of controlling the profile using the window transmission characteristics is that variations to the radial profile of microwave power can be made without changing the microwave coupler or reactor design. 9 figs.

Berry, L.A.

1995-11-14T23:59:59.000Z

371

ECR apparatus with magnetic coil for plasma refractive index control  

DOE Patents [OSTI]

The present invention describes a technique to control the radial profile of microwave power in an ECR plasma discharge. In order to provide for a uniform plasma density to a specimen, uniform energy absorption by the plasma is desired. By controlling the radial profile of the microwave power transmitted through the microwave window of a reactor, the profile of the transmitted energy to the plasma can be controlled in order to have uniform energy absorption by the plasma. An advantage of controlling the profile using the window transmission characteristics is that variations to the radial profile of microwave power can be made without changing the microwave coupler or reactor design. 9 figures.

Berry, L.A.

1994-04-26T23:59:59.000Z

372

Self-consistent quasiparticle model for quark-gluon plasma  

E-Print Network [OSTI]

Here we present a self-consistent quasi-particle model for quark-gluon plasma and apply it to explain the non-ideal behaviour seen in lattice simulations. The basic idea, borrowed from electrodynamic plasma, is that the gluons acquire mass as it propagates through plasma due to collective effects and is approximately equal to the plasma frequency. The statistical mechanics and thermodynamics of such a system is studied by treating it as an ideal gas of massive gluons. Since mass or plasma frequency depends on density, which itself is a thermodynamic quantity, the whole problem need to be solved self-consistently.

Vishnu M. Bannur

2006-09-19T23:59:59.000Z

373

Quantum plasma effects in the classical regime  

E-Print Network [OSTI]

For quantum effects to be significant in plasmas it is often assumed that the temperature over density ratio must be small. In this paper we challenge this assumption by considering the contribution to the dynamics from the electron spin properties. As a starting point we consider a multicomponent plasma model, where electrons with spin up and spin down are regarded as different fluids. By studying the propagation of Alfv\\'{e}n wave solitons we demonstrate that quantum effects can survive in a relatively high-temperature plasma. The consequences of our results are discussed.

G. Brodin; M. Marklund; G. Manfredi

2008-02-01T23:59:59.000Z

374

Langmuir Probe Measurements in Plasma Shadows  

SciTech Connect (OSTI)

When immersing a target into a plasma streaming along magnetic field lines, a distinct shadow region extending over large distances is observed by the naked eye downstream of the target.In this work we present an experimental study of the effect applying Langmuir probes. In contrast to expectations, there are only marginal changes in the profiles of temperature and density behind masks that cut away about 50% of the plasma cross-section. On the other hand, the mean density is drastically reduced by an order of magnitude. First attempts to simulate the observations by solving the classical 2D diffusion equation were not successful.

Waldmann, O. [Max-Planck-Institut fuer Plasmaphysik, TI Greifswald, Wendelsteinstr. 1, 17491 Greifswald, EURATOM Association (Germany); Koch, B.; Fussmann, G. [Max-Planck-Institut fuer Plasmaphysik, TI Greifswald, Wendelsteinstr. 1, 17491 Greifswald, EURATOM Association (Germany); Humboldt-Universitaet zu Berlin, Institut fuer Physik, PLA, Newtonstr. 15, 12489 Berlin (Germany)

2006-01-15T23:59:59.000Z

375

Dissipative phenomena in quark-gluon plasmas  

SciTech Connect (OSTI)

Transport coefficients of small-chemical-potential quark-gluon plasmas are estimated and dissipative corrections to the scaling hydrodynamic equations for ultrarelativistic nuclear collisions are studied. The absence of heat-conduction phenomena is clarified. Lower and upper bounds on the shear-viscosity coefficient are derived. QCD phenomenology is used to estimate effects of color-electric and -magnetic shielding, and nonperturbative antiscreening. Bulk viscosity associated with the plasma-to-hadron transition is estimated within the relaxation-time approximation. Finally, effects of dissipative phenomena on the relation between initial energy density and final rapidity density are estimated.

Danielewicz, P.; Gyulassy, M.

1985-01-01T23:59:59.000Z

376

Plasma Physics  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May Jun Jul(Summary)morphinanInformation Desert Southwest RegionatSearch Welcome to theNews & Blog »Physics PhysicsWeekPlasma

377

Tritium plasma experiment: Parameters and potentials for fusion plasma-wall interaction studies  

SciTech Connect (OSTI)

The tritium plasma experiment (TPE) is a unique facility devoted to experiments on the behavior of deuterium/tritium in toxic (e.g., beryllium) and radioactive materials for fusion plasma-wall interaction studies. A Langmuir probe was added to the system to characterize the plasma conditions in TPE. With this new diagnostic, we found the achievable electron temperature ranged from 5.0 to 10.0 eV, the electron density varied from 5.0 x 10{sup 16} to 2.5 x 10{sup 18} m{sup -3}, and the ion flux density varied between 5.0 x 10{sup 20} to 2.5 x 10{sup 22} m{sup -2} s{sup -1} along the centerline of the plasma. A comparison of these plasma parameters with the conditions expected for the plasma facing components (PFCs) in ITER shows that TPE is capable of achieving most ({approx}800 m{sup 2} of 850 m{sup 2} total PFCs area) of the expected ion flux density and electron density conditions.

Shimada, Masashi; Sharpe, J. Phillip [Fusion Safety Program, Idaho National Laboratory, Idaho Falls, Idaho 83415 (United States); Kolasinski, Robert D.; Causey, Rion A. [Hydrogen and Metallurgical Science Department, Sandia National Laboratories, Livermore, California 94551 (United States)

2011-08-15T23:59:59.000Z

378

Magneto-inertial Fusion: An Emerging Concept for Inertial Fusion and Dense Plasmas in Ultrahigh Magnetic Fields  

SciTech Connect (OSTI)

An overview of the U.S. program in magneto-inertial fusion (MIF) is given in terms of its technical rationale, scientific goals, vision, research plans, needs, and the research facilities currently available in support of the program. Magneto-inertial fusion is an emerging concept for inertial fusion and a pathway to the study of dense plasmas in ultrahigh magnetic fields (magnetic fields in excess of 500 T). The presence of magnetic field in an inertial fusion target suppresses cross-field thermal transport and potentially could enable more attractive inertial fusion energy systems. A vigorous program in magnetized high energy density laboratory plasmas (HED-LP) addressing the scientific basis of magneto-inertial fusion has been initiated by the Office of Fusion Energy Sciences of the U.S. Department of Energy involving a number of universities, government laboratories and private institutions.

Thio, Francis Y.C.

2008-01-01T23:59:59.000Z

379

PISCES Program: Plasma-materials interactions and edge-plasma physics research. Progress report, 1991--1992  

SciTech Connect (OSTI)

This program investigates and characterizes the behavior of materials under plasma bombordment, in divertor regions. The PISCES facility is used to study divertor and plasma edge management concepts (in particular gas target divertors), as well as edge plasma turbulence and transport. The plasma source consists of a hot LaB{sub 6} cathode with an annular, water-cooled anode and attached drift tube. This cross sectional area of the plasma can be adjusted between 3 and 10 cm. A fast scanning diagnostic probe system was used for mapping plasma density profiles during biased limiter and divertor simulation experiments. Some experimental data are given on: (1) materials and surface physics, (2) edge plasma physics, and (3) a theoretical analysis of edge plasma modelling.

Conn, R.W.; Hirooka, Y.

1992-07-01T23:59:59.000Z

380

Equation for liquid density  

SciTech Connect (OSTI)

Saturated liquid densities for organic chemicals are given as functions of temperature using a modified Rackett equation.

Yaws, C.L.; Yang, H.C.; Hopper, J.R.; Cawley, W.A. (Lamar Univ., Beaumont, TX (US))

1991-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "density plasma science" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


381

SUPPRESSION OF DIELECTRONIC RECOMBINATION DUE TO FINITE DENSITY EFFECTS  

SciTech Connect (OSTI)

We have developed a general model for determining density-dependent effective dielectronic recombination (DR) rate coefficients in order to explore finite-density effects on the ionization balance of plasmas. Our model consists of multiplying by a suppression factor those highly-accurate total zero-density DR rate coefficients which have been produced from state-of-the-art theoretical calculations and which have been benchmarked by experiment. The suppression factor is based upon earlier detailed collision-radiative calculations which were made for a wide range of ions at various densities and temperatures, but used a simplified treatment of DR. A general suppression formula is then developed as a function of isoelectronic sequence, charge, density, and temperature. These density-dependent effective DR rate coefficients are then used in the plasma simulation code Cloudy to compute ionization balance curves for both collisionally ionized and photoionized plasmas at very low (n{sub e} = 1 cm{sup -3}) and finite (n{sub e} = 10{sup 10} cm{sup -3}) densities. We find that the denser case is significantly more ionized due to suppression of DR, warranting further studies of density effects on DR by detailed collisional-radiative calculations which utilize state-of-the-art partial DR rate coefficients. This is expected to impact the predictions of the ionization balance in denser cosmic gases such as those found in nova and supernova shells, accretion disks, and the broad emission line regions in active galactic nuclei.

Nikolic, D.; Gorczyca, T. W.; Korista, K. T. [Western Michigan University, Kalamazoo, MI (United States); Ferland, G. J. [University of Kentucky, Lexington, KY (United States); Badnell, N. R. [University of Strathclyde, Glasgow (United Kingdom)

2013-05-01T23:59:59.000Z

382

Drift-/ Kinetic Alfven Eigenmodes in High Performance Tokamak Plasmas  

E-Print Network [OSTI]

Stockholm, Sweden 2) Plasma Science Fusion Centre, MIT, Cambridge MA 02139, USA 3) CRPP-EPFL, 1015 Lausanne to the kinetic Alfv´en wave. This stimulated the development of models such as continuum damping, complex-kinetic description for the bulk plasma. Such a model is required to calculate the power transfer between global fluid

Jaun, André

383

Analytical and Numerical Studies of the Complex Interaction of a Fast Ion Beam Pulse with a Background Plasma  

E-Print Network [OSTI]

]. In this paper, we focus on the nonlinear case where the plasma density has an arbitrary value compared with a Background Plasma Igor D. Kaganovich1 , Edward A. Startsev1 and Ronald C. Davidson1 1 Plasma Physics Laboratory, Princeton University, Princeton, New Jersey 08543, USA Received September 8, 2003 Abstract Plasma

Kaganovich, Igor

384

Ultra-High Intensity Magnetic Field Generation in Dense Plasma  

SciTech Connect (OSTI)

I. Grant Objective The main objective of this grant proposal was to explore the efficient generation of intense currents. Whereasthefficient generation of electric current in low-­?energy-­? density plasma has occupied the attention of the magnetic fusion community for several decades, scant attention has been paid to carrying over to high-­?energy-­? density plasma the ideas for steady-­?state current drive developed for low-­?energy-­? density plasma, or, for that matter, to inventing new methodologies for generating electric current in high-­?energy-­?density plasma. What we proposed to do was to identify new mechanisms to accomplish current generation, and to assess the operation, physics, and engineering basis of new forms of current drive in regimes appropriate for new fusion concepts.

Fisch, Nathaniel J

2014-01-08T23:59:59.000Z

385

Observation of pressure gradient and related flow rate effect on the plasma parameters in plasma processing reactor  

SciTech Connect (OSTI)

In industrial plasma processes, flow rate has been known to a key to control plasma processing results and has been discussed with reactive radical density, gas residence time, and surface reaction. In this study, it was observed that the increase in the flow rate can also change plasma parameters (electron temperature and plasma density) and electron energy distribution function in plasma processing reactor. Based on the measurement of gas pressure between the discharge region and the pumping port region, the considerable differences in the gas pressure between the two regions were found with increasing flow rate. It was also observed that even in the discharge region, the pressure gradient occurs at the high gas flow rate. This result shows that increasing the flow rate results in the pressure gradient and causes the changes in the plasma parameters.

Lee, Hyo-Chang; Kim, Aram; Chung, Chin-Wook [Department of Electrical Engineering, Hanyang University, 17 Haengdang-dong, Seongdong-gu, Seoul 133-791 (Korea, Republic of); Moon, Se Youn [Solar Energy Group, LG Electronics Advanced Research Institute, 16 Woomyeon-Dong, Seocho-Gu, Seoul 137-724 (Korea, Republic of)

2011-02-15T23:59:59.000Z

386

Interparticle interaction and transport processes in dense semiclassical plasmas  

SciTech Connect (OSTI)

On the basis of the density response formalism an expression for the pseudopotential of dense semiclassical plasma, which takes account of quantum-mechanical effects, local field corrections, and electronic screening effects is obtained. The static structure factors taking into account both local fields and quantum-mechanical effects are calculated. An electrical conductivity, thermal conductivity, and viscosity of dense semiclassical plasma are studied.

Baimbetov, F.B.; Giniyatova, Sh.G. [Department of Physics, Kazakh National University, Tole Bi 96, Almaty 480012 (Kazakhstan)

2005-04-15T23:59:59.000Z

387

Optical Spectroscopic Diagnostics Of Dusty Plasma In RF Discharge  

SciTech Connect (OSTI)

The parameters of the buffer plasma containing dust particles were measured by means of spectroscopic methods. The change in the emission spectrum of the buffer plasma with addition of dust was observed. It seems to relate to changing in temperature and number density of electrons due to the influence of dusts.

Orazbayev, S. A.; Jumagulov, M. N.; Dosbolayev, M. K.; Silamiya, M.; Ramazanov, T. S. [IETP, Al Farabi Kazakh National University, 96a, Tole bi, Almaty, 050012 (Kazakhstan); Boufendi, L. [Universite d'Orleans, 14 Rue d'Issoudun, B.P. 6744-45067 Orleans Cedex 2 (France)

2011-11-29T23:59:59.000Z

388

COMPRESSION OF A PLASMA COLUMN OF INFINITE ELECTROCONDUCTIVITY SITUATED  

E-Print Network [OSTI]

45 COMPRESSION OF A PLASMA COLUMN OF INFINITE ELECTROCONDUCTIVITY SITUATED IN AN EXTERNAL AXIAL velocity, ion temperature, electron temperature and plasma density is analysed. The experimental results [1. Amongst the dissipative processes we are primarily concerned here with the electron heat conductivity

Boyer, Edmond

389

SCIENCE CHINA Technological Sciences  

E-Print Network [OSTI]

SCIENCE CHINA Technological Sciences © Science China Press and Springer-Verlag Berlin Heidelberg HU HongChang, TIAN FuQiang* & HU HePing Department of Hydraulic Engineering, State Key Laboratory as a key soil physical parameter and has been widely used to predict soil hydraulic and other related

Ahmad, Sajjad

390

Observation and numerical analysis of plasma parameters in a capillary discharge-produced plasma channel waveguide  

SciTech Connect (OSTI)

We observed the parameters of the discharge-produced plasma in cylindrical capillary. Plasma parameters of the waveguide were investigated by use of both a Normarski laser interferometer and a hydrogen plasma line spectrum. A space-averaged maximum temperature of 3.3 eV with electron densities of the order of 10{sup 17} cm{sup -3} was observed at a discharge time of 150 ns and a maximum discharge current of 200 A. One-dimensional dissipative magnetohydrodynamic (MHD) code was used to analyze the discharge dynamics in the gas-filled capillary discharge waveguide for high-intensity laser pulses. Simulations were performed for the conditions of the experiment. We compared the temporal behavior of the electron temperature and the radial electron density profiles, measured in the experiment with the results of the numerical simulations. They occurred to be in a good agreement. An ultrashort, intense laser pulse was guided by use of this plasma channel.

Terauchi, Hiromitsu [Department of Advanced Interdisciplinary Sciences, and Center for Optical Research and Education (CORE) Utsunomiya University, Yoto 7-1-2, Utsunomiya, Tochigi 321-8585 (Japan); Bobrova, Nadezhda; Sasorov, Pavel [Institute for Theoretical and Experimental Physics, B. Cheremushkinskaya str. 25, 117259 Moscow (Russian Federation); Kikuchi, Takashi; Sasaki, Toru [Department of Electrical Engineering, Nagaoka University of Technology, Kami-tomiokamachi 1603-1, Nagaoka, Niigata 940-2188 Japan (Japan); Higashiguchi, Takeshi; Yugami, Noboru [Department of Advanced Interdisciplinary Sciences, and Center for Optical Research and Education (CORE) Utsunomiya University, Yoto 7-1-2, Utsunomiya, Tochigi 321-8585 (Japan); Japan Science and Technology Agency, CREST, 4-1-8 Honcho, Kanagawa, Saitama 332-0012 (Japan); Kodama, Ryosuke [Japan Science and Technology Agency, CREST, 4-1-8 Honcho, Kanagawa, Saitama 332-0012 (Japan); Graduate School of Engineering, Osaka University, 2-6 Yamada-oka, Suita, Osaka 565-0871 (Japan)

2011-03-01T23:59:59.000Z

391

Measurements of an expanding surface flashover plasma  

SciTech Connect (OSTI)

A better understanding of vacuum surface flashover and the plasma produced by it is of importance for electron and ion sources, as well as advanced accelerators and other vacuum electronic devices. This article describes time-of-flight and biased-probe measurements made on the expanding plasma generated from a vacuum surface flashover discharge. The plasma expanded at velocities of 1.2–6.5?cm/?s, and had typical densities of 10{sup 10}–10{sup 12}?cm{sup ?3}. The expansion velocity of the plasma leading edge often exhibited a sharp increase at distances of about 50?mm from the discharge site. Comparison with biased-probe data suggests that, under most conditions, the plasma leading edge was dominated by negative ions, with the apparent increase in velocity being due to fast H{sup ?} overtaking slower, heavier ions. In some cases, biased-probe data also showed abrupt discontinuities in the plasma energy distribution co-located with large changes in the intercepted plasma current, suggesting the presence of a shock in the leading edge of the expanding plasma.

Harris, J. R., E-mail: john.harris@colostate.edu [Department of Electrical and Computer Engineering, Colorado State University, Fort Collins, Colorado 80523 (United States)

2014-05-21T23:59:59.000Z

392

Laboratory Dipole Plasma Physics Columbia University  

E-Print Network [OSTI]

years of magnetospheric research: earth, Jupiter... · Dipole is simplest confinement field · Naturally occurring high- plasma ( ~ 2 in Jupiter) · p and ne strongly peaked · Relevant to space science & fusion strong inward particle pinch (radiation belts) #12;Magnetic topology determines equilibrium and stability

393

Plasma parameters and electron energy distribution functions in a magnetically focused plasma  

SciTech Connect (OSTI)

Spatially resolved measurements of ion density, electron temperature, floating potential, and the electron energy distribution function (EEDF) are presented for a magnetically focused plasma. The measurements identify a central plasma column displaying Maxwellian EEDFs at an electron temperature of about 5 eV indicating the presence of a significant fraction of electrons in the inelastic energy range (energies above 15 eV). It is observed that the EEDF remains Maxwellian along the axis of the discharge with an increase in density, at constant electron temperature, observed in the region of highest magnetic field strength. Both electron density and temperature decrease at the plasma radial edge. Electron temperature isotherms measured in the downstream region are found to coincide with the magnetic field lines.

Samuell, C. M.; Blackwell, B. D.; Howard, J.; Corr, C. S. [Plasma Research Laboratory, Research School of Physics and Engineering, Australian National University, Canberra (Australia)

2013-03-15T23:59:59.000Z

394

Princeton University Plasma Physics Laboratory, Princeton, New Jersey. Annual report, October 1, 1990--September 30, 1991  

SciTech Connect (OSTI)

This report discusses the following topics: Principal parameters of experimental devices; Tokamak Fusion Test Reactor; Burning Plasma Experiment; Princeton Beta Experiment-Modification; Current Drive Experiment-Upgrade; International Thermonuclear Experimental Reactor; International Collaboration; X-Ray Laser Studies; Hyperthermal Atomic Beam Source; Pure Electron Plasma Experiments; Plasma Processing: Deposition and Etching of Thin Films; Theoretical Studies; Tokamak Modeling; Engineering Department; Environment, Safety, and Health and Quality Assurance; Technology Transfer; Office of Human Resources and Administration; PPPL Patent Invention Disclosures; Office of Resource Management; Graduate Education: Plasma Physics; Graduate Education: Program in Plasma Science and Technology; and Science Education Program.

Not Available

1991-12-31T23:59:59.000Z

395

2012 Science Bowls | Princeton Plasma Physics Lab  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsrucLasDelivered‰PNGExperience hands-onASTROPHYSICS H. I. Park, L.2State of Matter

396

Submitted IEEE Trans. Plasma Science Shvets Fisch  

E-Print Network [OSTI]

/injector charged particle bunches. Since phase equiva- lently, ####) enhanced wake be controlled the detuning initially moves with v v acceler- ated velocity larger laser group velocity. The intensity threshold becomes

397

IEEE TRANSACTIONS ON PLASMA SCIENCE, VOL.  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth7-1D: Vegetation ProposedUsingFun withconfinementEtching. | EMSL Bubblesstructure link to facebook link to8

398

IEEE TRANSACTIONS ON PLASMA SCIENCE, VOL.  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth7-1D: Vegetation ProposedUsingFun withconfinementEtching. | EMSL Bubblesstructure link to facebook link

399

MIT Plasma Science & Fusion Center  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsrucLas Conchas recovery challenge fund Las ConchasTrail of aMEEM Energy Before

400

MIT Plasma Science & Fusion Center  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

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Note: This page contains sample records for the topic "density plasma science" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


401

Science Undergraduate Laboratory Internship (SULI) | Princeton Plasma  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsrucLas ConchasPassiveSubmitted forHighlights Nuclear Physics (NP) NP HomeHasan ResearchPhysics

402

Princeton Plasma Physics Lab - Science literacy  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear Security Administration the1 - SeptemberMicroneedles for4-16 FOR Primary Authorstem The acronym for the study

403

Princeton Plasma Physics Lab - Surface science  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear Security Administration the1 - SeptemberMicroneedles for4-16 FOR Primary Authorstem The acronym for

404

Surface science | Princeton Plasma Physics Lab  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsrucLas ConchasPassiveSubmittedStatus TomAbout »Lab (NewportSuccessSupply Center for

405

Tunable Laser Plasma Accelerator based on Longitudinal Density Tailoring  

E-Print Network [OSTI]

dot line), which increases to ? 3.5 compared with the vacuum focal value of ? 1.5, producing a bubble

Gonsalves, Anthony

2012-01-01T23:59:59.000Z

406

Magnetohydrodynamics in Tokamak Reactors and its Effect on Plasma Density  

E-Print Network [OSTI]

The world’s energy consumption is at a crossroads. While petroleum coffers continuously yield enough petroleum to meet the current state of energy consumption, increases in energy consumption and advancements in technology bear significant weight...

Morelli, Franco

2011-12-01T23:59:59.000Z

407

High Energy Density Laboratory Plasmas Program | National Nuclear Security  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsruc DocumentationP-SeriesFlickr FlickrGuidedCH2M HILL

408

High Energy Density Laboratory Plasmas | National Nuclear Security  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsruc DocumentationP-SeriesFlickr FlickrGuidedCH2M HILLAdministration | National Nuclear Security

409

Using Radio Waves to Control Fusion Plasma Density  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsrucLasDelivered energy consumption by sectorlongUpdates byUser GuideHadoop UsingUsingPFTP

410

Passive Spectroscopic Diagnostics for Magnetically-confined Fusion Plasmas  

SciTech Connect (OSTI)

Spectroscopy of radiation emitted by impurities and hydrogen isotopes plays an important role in the study of magnetically-confined fusion plasmas, both in determining the effects of impurities on plasma behavior and in measurements of plasma parameters such as electron and ion temperatures and densities, particle transport, and particle influx rates. This paper reviews spectroscopic diagnostics of plasma radiation that are excited by collisional processes in the plasma, which are termed 'passive' spectroscopic diagnostics to distinguish them from 'active' spectroscopic diagnostics involving injected particle and laser beams. A brief overview of the ionization balance in hot plasmas and the relevant line and continuum radiation excitation mechanisms is given. Instrumentation in the soft X-ray, vacuum ultraviolet, ultraviolet, visible, and near-infrared regions of the spectrum is described and examples of measurements are given. Paths for further development of these measurements and issues for their implementation in a burning plasma environment are discussed.

B.C. Stratton, M. Bitter, K.W. Hill, D.L. Hillis, and J.T. Hogan

2007-07-18T23:59:59.000Z

411

Explore Science  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Science Explore Science Explore Explore these Topics Activities Videos Cool Links Favorite Q&A invisible utility element Science is thinking in an organized way about things...

412

Detection Science  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Chemistry for Measurement and Detection Science Chemistry for Measurement and Detection Science Project Description Chemistry used in measurement and detection science plays a...

413

Three regimes of relativistic beam - plasma interaction  

SciTech Connect (OSTI)

Three regimes of relativistic beam - plasma interaction can in principle be reached at the ATF depending on the relative transverse and longitudinal size of the electron bunch when compared to the cold plasma collisionless skin depth c?{omega}{sub pe}: the plasma wakefield accelerator (PWFA), the self-modulation instability (SMI), and the current filamentation instability (CFI) regime. In addition, by choosing the bunch density, the linear, quasi-nonlinear and non linear regime of the PWFA can be reached. In the case of the two instabilities, the bunch density determines the growth rate and therefore the occurrence or not of the instability. We briefly describe these three regimes and outline results demonstrating that all these regime have or will be reached experimentally. We also outline planned and possible follow-on experiments.

Muggli, P.; Allen, B.; Fang, Y.; Yakimenko, V.; Babzien, M.; Kusche, K.; Fedurin, M.; Vieira, J.; Martins, J.; Silva, L. [Max Planck Institute for Physics, 80805 Munich (Germany) and University of Southern California, Los Angeles, CA 90089 (United States); University of Southern California, Los Angeles, CA 90089 (United States); Brookhaven National Laboratory, Upton, NY 11973 (United States); GoLP/Instituto de Plasmas e Fusao Nuclear - Laboratorio Associado Instituto Superior Tecnico (IST), Technical University of Lisbon, Lisboa (Portugal)

2012-12-21T23:59:59.000Z

414

How to model quantum plasmas  

E-Print Network [OSTI]

Traditional plasma physics has mainly focused on regimes characterized by high temperatures and low densities, for which quantum-mechanical effects have virtually no impact. However, recent technological advances (particularly on miniaturized semiconductor devices and nanoscale objects) have made it possible to envisage practical applications of plasma physics where the quantum nature of the particles plays a crucial role. Here, I shall review different approaches to the modeling of quantum effects in electrostatic collisionless plasmas. The full kinetic model is provided by the Wigner equation, which is the quantum analog of the Vlasov equation. The Wigner formalism is particularly attractive, as it recasts quantum mechanics in the familiar classical phase space, although this comes at the cost of dealing with negative distribution functions. Equivalently, the Wigner model can be expressed in terms of $N$ one-particle Schr{\\"o}dinger equations, coupled by Poisson's equation: this is the Hartree formalism, which is related to the `multi-stream' approach of classical plasma physics. In order to reduce the complexity of the above approaches, it is possible to develop a quantum fluid model by taking velocity-space moments of the Wigner equation. Finally, certain regimes at large excitation energies can be described by semiclassical kinetic models (Vlasov-Poisson), provided that the initial ground-state equilibrium is treated quantum-mechanically. The above models are validated and compared both in the linear and nonlinear regimes.

G. Manfredi

2005-05-01T23:59:59.000Z

415

Heating peculiarities of a plasma containing multiply charged ions in a Z-pinch  

SciTech Connect (OSTI)

Starting from the assumption of compression of the plasma column to the size of the Larmor radius, which is described by an ion in the self-magnetic field of the discharge, and the Bennet relations, expressions are obtained for the temperature and linear density of the plasma. It is shown that the plasma heating results from the excitation of ion-acoustic turbulence.

Bykovskii, Y.A.; Lagoda, V.B.; Sheroziya, G.A.

1980-03-05T23:59:59.000Z

416

Note: On the measurement of plasma potential fluctuations using emissive probes  

SciTech Connect (OSTI)

In this Note, it is pointed out that emissive probes cannot be used to directly and reliably measure plasma potential fluctuations. An experimentally validated model demonstrates indeed that the floating potential fluctuations of an emissive probe which floats at the mean plasma potential depend not only on the plasma potential fluctuations but also on electron density and temperature fluctuations.

Bousselin, G., E-mail: guillaume.bousselin@ens-lyon.fr; Lemoine, N.; Cavalier, J.; Heuraux, S.; Bonhomme, G. [IJL, Université de Lorraine, CNRS (UMR 7198), 54506 Vandoeuvre (France)] [IJL, Université de Lorraine, CNRS (UMR 7198), 54506 Vandoeuvre (France)

2014-05-15T23:59:59.000Z

417

TitleA Spectroscopy Diagnostic of Plasma Gradients in ICF Imploded Cores  

E-Print Network [OSTI]

TitleA Spectroscopy Diagnostic of Plasma Gradients in ICF Imploded Cores I. Golovkin, R. Mancini, S to be a powerful diagnostic of spatially-averaged temperature and density plasma conditions at the collapse of ICF-broadened line shapes. The next step in the spectroscopy of imploded cores is the bracketing of core plasma

Louis, Sushil J.

418

Bow shocks formed by plasma collisions in laser irradiated semi-cylindrical cavities  

E-Print Network [OSTI]

the axis to form a dense bright plasma focus. Later in time a long lasting bow shock is observed to develop a location near the cavity axis, where it collides forming a bright high density plasma focusBow shocks formed by plasma collisions in laser irradiated semi-cylindrical cavities Jorge Filevich

Rocca, Jorge J.

419

LITHIUM PLASMA SOURCES FOR ACCELERATION AND FOCUSING OF ULTRA-RELATIVISTIC ELECTRON BEAMSi  

E-Print Network [OSTI]

LITHIUM PLASMA SOURCES FOR ACCELERATION AND FOCUSING OF ULTRA-RELATIVISTIC ELECTRON BEAMSi P beam focusing (plasma lens). The Li vapor with a density in the 2Ã?1015 cm-3 range is produced in a heat to a focusing strength in excess of 6Ã?105 G/cm. A shorter section of plasma (L25 cm) can be used as an effective

420

Simulations of the SLAC Plasma Lens Shinichi Masuda \\Lambda and Pisin Chen y  

E-Print Network [OSTI]

between n p =n b = 0:1 and 100. The original bunch size is 3 and 5 ¯m in radius. Due to plasma focusing return current renders the plasma focusing effect suppressed when the plasma density further increases

Note: This page contains sample records for the topic "density plasma science" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


421

Plasma Sources Sci. Technol. 5 (1996) 173180. Printed in the UK Downstream physics of the helicon  

E-Print Network [OSTI]

Plasma Sources Sci. Technol. 5 (1996) 173­180. Printed in the UK Downstream physics of the helicon and that a dense, cool (Te downstream region. The density n and electron densities, it plays little role in the downstream evolution of the plasma. These results indicate

Chen, Francis F.

1996-01-01T23:59:59.000Z

422

Electron acceleration by a circularly polarized laser pulse in a plasma K. P. Singha)  

E-Print Network [OSTI]

of Physics, Indian Institute of Technology, New Delhi-110016, India Received 12 January 2004; accepted 4 May fields, and the electrons gain much higher energies. The resonance is stronger at higher values and plasma density, and initial electron energy. At higher plasma density, the group velocity of the laser

Roy, Subrata

423

Analytic model of electromagnetic fields around a plasma bubble in the blow-out regime  

SciTech Connect (OSTI)

An analytic model of the electric and magnetic fields surrounding the nonlinear plasma 'bubble' formed around the high-current electron bunch in a plasma wakefield accelerator is developed. The model, justified by the results of particle-in-cell simulations, accurately captures the thin high-density plasma sheath and extended return current layer surrounding the bubble. The resulting global fields inside and outside the bubble are used to investigate electron self-injection in a plasma with a smooth density gradient. It is shown that accurate description of the current/density sheaths is crucial for quantitative description of self-injection.

Yi, S. A.; Khudik, V.; Siemon, C.; Shvets, G. [Department of Physics and Institute for Fusion Studies, University of Texas, Austin, Texas 78712 (United States)

2013-01-15T23:59:59.000Z

424

131Cognitive Science COGNITIVE SCIENCE  

E-Print Network [OSTI]

131Cognitive Science COGNITIVE SCIENCE PROFESSOR ELMES* MAJOR A major in cognitive science leading courses: Cognitive Science 110, 395, 403, 473; Computer Science 111, 211; Philosophy 106, 313; Psychology Science: Com- puter Science 295 (LISP, PROLOG or C), 313, 315; Psychology 207 b. Philosophical Foundations

Marsh, David

425

Communication through plasma sheaths  

SciTech Connect (OSTI)

We wish to transmit messages to and from a hypersonic vehicle around which a plasma sheath has formed. For long distance transmission, the signal carrying these messages must be necessarily low frequency, typically 2 GHz, to which the plasma sheath is opaque. The idea is to use the plasma properties to make the plasma sheath appear transparent.

Korotkevich, A. O.; Newell, A. C.; Zakharov, V. E. [Landau Institute for Theoretical Physics RAS, 2, Kosygin Str., Moscow, 119334 (Russian Federation); Department of Mathematics, University of Arizona, 617 N. Santa Rita Ave., Tucson, Arizona 85721 (United States); Department of Mathematics, University of Arizona, 617 N. Santa Rita Ave., Tucson, Arizona 85721 (United States); Lebedev Physical Institute RAS, 53, Leninsky Prosp., GSP-1 Moscow, 119991 (Russian Federation); Landau Institute for Theoretical Physics RAS, 2, Kosygin Str., Moscow, 119334 (Russian Federation) and Waves and Solitons LLC, 918 W. Windsong Dr., Phoenix, Arizona 85045 (United States)

2007-10-15T23:59:59.000Z

426

Ion holes in the hydrodynamic regime in ultracold neutral plasmas  

SciTech Connect (OSTI)

We describe the creation of localized density perturbations, or ion holes, in an ultracold neutral plasma in the hydrodynamic regime, and show that the holes propagate at the local ion acoustic wave speed. We also observe the process of hole splitting, which results from the formation of a density depletion initially at rest in the plasma. One-dimensional, two-fluid hydrodynamic simulations describe the results well. Measurements of the ion velocity distribution also show the effects of the ion hole and confirm the hydrodynamic conditions in the plasma.

McQuillen, P.; Castro, J.; Strickler, T.; Bradshaw, S. J.; Killian, T. C. [Department of Physics and Astronomy, Rice University, Houston, Texas 77005 (United States)

2013-04-15T23:59:59.000Z

427

Plasma sweeper. [Patents  

DOE Patents [OSTI]

A device is described for coupling RF power (a plasma sweeper) from RF power introducing means to a plasma having a magnetic field associated therewith comprises at least one electrode positioned near the plasma and near the RF power introducing means. Means are described for generating a static electric field at the electrode directed into the plasma and having a component substantially perpendicular to the plasma magnetic field such that a non-zero vector cross-product of the electric and magnetic fields exerts a force on the plasma causing the plasma to drift.

Motley, R.W.; Glanz, J.

1982-10-25T23:59:59.000Z

428

Response of the plasma to the size of an anode electrode biased near the plasma potential  

SciTech Connect (OSTI)

As the size of a positively biased electrode increases, the nature of the interface formed between the electrode and the host plasma undergoes a transition from an electron-rich structure (electron sheath) to an intermediate structure containing both ion and electron rich regions (double layer) and ultimately forms an electron-depleted structure (ion sheath). In this study, measurements are performed to further test how the size of an electron-collecting electrode impacts the plasma discharge the electrode is immersed in. This is accomplished using a segmented disk electrode in which individual segments are individually biased to change the effective surface area of the anode. Measurements of bulk plasma parameters such as the collected current density, plasma potential, electron density, electron temperature and optical emission are made as both the size and the bias placed on the electrode are varied. Abrupt transitions in the plasma parameters resulting from changing the electrode surface area are identified in both argon and helium discharges and are compared to the interface transitions predicted by global current balance [S. D. Baalrud, N. Hershkowitz, and B. Longmier, Phys. Plasmas 14, 042109 (2007)]. While the size-dependent transitions in argon agree, the size-dependent transitions observed in helium systematically occur at lower electrode sizes than those nominally derived from prediction. The discrepancy in helium is anticipated to be caused by the finite size of the interface that increases the effective area offered to the plasma for electron loss to the electrode.

Barnat, E. V.; Laity, G. R. [Sandia National Laboratories, Albuquerque, New Mexico 87185 (United States); Baalrud, S. D. [Department of Physics and Astronomy, University of Iowa, Iowa City, Iowa 52242 (United States)

2014-10-15T23:59:59.000Z

429

Study on the effect of target on plasma parameters of magnetron sputtering discharge plasma  

SciTech Connect (OSTI)

In this study, the effect of magnetron target on different plasma parameters of Argon/Hydrogen (Ar - H{sub 2}) direct current (DC) magnetron discharge is examined. Here, Copper (Cu) and Chromium (Cr) are used as magnetron targets. The value of plasma parameters such as electron temperature (kT{sub e}), electron density (N{sub e}), ion density (N{sub i}), degree of ionization of Ar, and degree of dissociation of H{sub 2} for both the target are studied as a function of input power and hydrogen content in the discharge. The plasma parameters are determined by using Langmuir probe and Optical emission spectroscopy. On the basis of the different reactions in the gas phase, the variation of plasma parameters and sputtering rate are explained. The obtained results show that electron and ion density decline with gradual addition of Hydrogen in the discharge and increase with rising input power. It brings significant changes on the degree of ionization of Ar and dissociation of H{sub 2}. The enhanced value of electron density (N{sub e}), ion density (N{sub i}), degree of Ionization of Ar, and degree of dissociation of H{sub 2} for Cr compared to Cu target is explained on the basis of it's higher Ion Induced Secondary Electron Emission Coefficient (ISEE) value.

Saikia, P.; Kakati, B.; Saikia, B. K. [Centre of Plasma Physics, Institute for Plasma Research, Nazirakhat, Sonapur-782 402, Kamrup, Assam (India)] [Centre of Plasma Physics, Institute for Plasma Research, Nazirakhat, Sonapur-782 402, Kamrup, Assam (India)

2013-10-15T23:59:59.000Z

430

Density-dependent covariant energy density functionals  

SciTech Connect (OSTI)

Relativistic nuclear energy density functionals are applied to the description of a variety of nuclear structure phenomena at and away fromstability line. Isoscalar monopole, isovector dipole and isoscalar quadrupole giant resonances are calculated using fully self-consistent relativistic quasiparticle randomphase approximation, based on the relativistic Hartree-Bogoliubovmodel. The impact of pairing correlations on the fission barriers in heavy and superheavy nuclei is examined. The role of pion in constructing desnity functionals is also investigated.

Lalazissis, G. A. [Physics Department, Aristotle University of Thessaloniki, GR-54124 (Greece)

2012-10-20T23:59:59.000Z

431

Characterization of plasma expansion dynamics in a high power diode with a carbon-fiber-aluminum cathode  

SciTech Connect (OSTI)

Thermal plasma expansion is characterised during the operation of a high power diode with an explosive emission carbon-fiber-aluminum cathode driven by a 250?kV, 150?ns accelerating pulse. It is found that a quasi-stationary state of plasma expansion is obtained during the main part of the accelerating pulse and the whole plasma expansion exhibits an “U”-shape velocity evolution. A theoretical model describing the dynamics of plasma expansion is developed, which indicates that the plasma expansion velocity is determined by equilibrium between the diode current density and plasma thermal electron current density.

Ju, J.-C., E-mail: jujinchuan@126.com [College of Optoelectronic Science and Engineering, National University of Defense Technology, Changsha 410073 (China); Laboratoire de Physique des Gaz et des Plasmas, CNRS-Université Paris-Sud, Orsay 91405 (France); Liu, L.; Cai, D. [College of Optoelectronic Science and Engineering, National University of Defense Technology, Changsha 410073 (China)

2014-06-09T23:59:59.000Z

432

Dust-Plasma Sheath in an Oblique Magnetic Field  

SciTech Connect (OSTI)

Using numerical simulations of the multi fluid equations the structure of the magnetized sheath near a plasma boundary is studied in the presence of charged dust particles. The dependence of the electron, ion, and dust densities as well as the electrostatic potential, dust charge, and ion normal velocity, on the magnetic field strength and the edge dust number density is investigated.

Foroutan, G.; Mehdipour, H. [Physics Department, Faculty of Science, Sahand University of Technology, Tabriz (Iran, Islamic Republic of)

2008-09-07T23:59:59.000Z

433

Stable plateau formation and Brillouin suppression in laser plasma  

SciTech Connect (OSTI)

Among the variety of ponderomotively induced density structures in laser produced plasmas in one dimension, it is shown by particle-in-cell simulations that the stable plateau formation at critical, subcritical, and above critical density is possible. Stimulated Brillouin backscattering is suppressed with increasing laser intensity.

Mulser, P. [Theoretical Quantum Electronics (TQE), Technische Universitaet Darmstadt, D-64289 Darmstadt (Germany); Weng, S. M. [Theoretical Quantum Electronics (TQE), Technische Universitaet Darmstadt, D-64289 Darmstadt (Germany); Department of Physics, Ludwig-Maximilians-Universitaet Muenchen, D-80333 Munich (Germany)

2010-10-15T23:59:59.000Z

434

Cold atmospheric plasma in cancer therapy  

SciTech Connect (OSTI)

Recent progress in atmospheric plasmas has led to the creation of cold plasmas with ion temperature close to room temperature. This paper outlines recent progress in understanding of cold plasma physics as well as application of cold atmospheric plasma (CAP) in cancer therapy. Varieties of novel plasma diagnostic techniques were developed recently in a quest to understand physics of CAP. It was established that the streamer head charge is about 10{sup 8} electrons, the electrical field in the head vicinity is about 10{sup 7} V/m, and the electron density of the streamer column is about 10{sup 19} m{sup ?3}. Both in-vitro and in-vivo studies of CAP action on cancer were performed. It was shown that the cold plasma application selectively eradicates cancer cells in-vitro without damaging normal cells and significantly reduces tumor size in-vivo. Studies indicate that the mechanism of action of cold plasma on cancer cells is related to generation of reactive oxygen species with possible induction of the apoptosis pathway. It is also shown that the cancer cells are more susceptible to the effects of CAP because a greater percentage of cells are in the S phase of the cell cycle.

Keidar, Michael; Shashurin, Alex; Volotskova, Olga [Mechanical and Aerospace Engineering, George Washington University, Washington DC 20052 (United States)] [Mechanical and Aerospace Engineering, George Washington University, Washington DC 20052 (United States); Ann Stepp, Mary [Medical School, George Washington University, Washington DC 20052 (United States)] [Medical School, George Washington University, Washington DC 20052 (United States); Srinivasan, Priya; Sandler, Anthony [Childrens National Medical Center, Washington DC 20010 (United States)] [Childrens National Medical Center, Washington DC 20010 (United States); Trink, Barry [Head and Neck Cancer Research Division, Department of Otolaryngology, School of Medicine, Johns Hopkins University, Baltimore, Maryland 21205 (United States)] [Head and Neck Cancer Research Division, Department of Otolaryngology, School of Medicine, Johns Hopkins University, Baltimore, Maryland 21205 (United States)

2013-05-15T23:59:59.000Z

435

Large area atmospheric-pressure plasma jet  

DOE Patents [OSTI]

Large area atmospheric-pressure plasma jet. A plasma discharge that can be operated at atmospheric pressure and near room temperature using 13.56 MHz rf power is described. Unlike plasma torches, the discharge produces a gas-phase effluent no hotter than 250.degree. C. at an applied power of about 300 W, and shows distinct non-thermal characteristics. In the simplest design, two planar, parallel electrodes are employed to generate a plasma in the volume therebetween. A "jet" of long-lived metastable and reactive species that are capable of rapidly cleaning or etching metals and other materials is generated which extends up to 8 in. beyond the open end of the electrodes. Films and coatings may also be removed by these species. Arcing is prevented in the apparatus by using gas mixtures containing He, which limits ionization, by using high flow velocities, and by properly spacing the rf-powered electrode. Because of the atmospheric pressure operation, there is a negligible density of ions surviving for a sufficiently long distance beyond the active plasma discharge to bombard a workpiece, unlike the situation for low-pressure plasma sources and conventional plasma processing methods.

Selwyn, Gary S. (Los Alamos, NM); Henins, Ivars (Los Alamos, NM); Babayan, Steve E. (Huntington Beach, CA); Hicks, Robert F. (Los Angeles, CA)

2001-01-01T23:59:59.000Z

436

Science Mathematics Engineering  

E-Print Network [OSTI]

Science Mathematics Engineering . ­ p.1 #12;Science Mathematics Engineering Science, Computer `Science', . ­ p.1 #12;Science Mathematics Engineering Science, Computer `Science', Mathematics, . ­ p.1 #12;Science Mathematics Engineering Science, Computer `Science', Mathematics, and Software Development

Hamlet, Richard

437

Positron plasma control techniques for the production of cold antihydrogen  

SciTech Connect (OSTI)

An observation of a clear dependence of antihydrogen production on positron plasma shapes is reported. For this purpose a plasma control method has been developed combining the plasma rotating-wall technique with a mode diagnostic system. With the help of real-time and nondestructive observations, the rotating-wall parameters have been optimized. The positron plasma can be manipulated into a wide range of shapes (aspect ratio 6.5{<=}{alpha} < or approx. 80) and densities (1.5x10{sup 8}{<=}n < or approx. 7x10{sup 9} cm{sup -3}) within a short duration (25 s) compatible with the ATHENA antihydrogen production cycle.

Funakoshi, R.; Hayano, R. S. [Department of Physics, University of Tokyo, Tokyo 113-0033 (Japan); Amoretti, M.; Macri, M.; Testera, G.; Variola, A. [Istituto Nazionale di Fisica Nucleare, Sezione di Genova, 16146 Genova (Italy); Bonomi, G. [Dipartimento di Ingegneria Meccanica, Universita di Brescia, 25123 Brescia (Italy); Dipartimento di Fisica Nucleare e Teorica, Universita di Pavia, 27100 Pavia (Italy); Bowe, P. D.; Hangst, J. S.; Madsen, N. [Department of Physics and Astronomy, University of Aarhus, 8000 Aarhus C (Denmark); Canali, C.; Carraro, C.; Lagomarsino, V.; Manuzio, G. [Istituto Nazionale di Fisica Nucleare, Sezione di Genova, 16146 Genova (Italy); Dipartimento di Fisica, Universita di Genova, 16146 Genova (Italy); Cesar, C. L. [Instituto de Fisica, Universidade do Brasil, Cx Postal 68528, Rio de Janeiro 21941-972 (Brazil); Charlton, M.; Joergensen, L. V.; Mitchard, D.; Werf, D. P. van der [Department of Physics, University of Wales Swansea, Swansea SA2 8PP (United Kingdom); Doser, M. [PH Department, CERN, 1211 Geneva 23 (Switzerland)] (and others)

2007-07-15T23:59:59.000Z

438

Rayleigh-Taylor instability in quantum magnetized viscous plasma  

SciTech Connect (OSTI)

Quantum effects on Rayleigh-Taylor instability of stratified viscous plasmas layer under the influence of vertical magnetic field are investigated. By linearly solving the viscous QMHD equations into normal mode, a forth-order ordinary differential equation is obtained to describe the velocity perturbation. Then the growth rate is derived for the case where a plasma with exponential density distribution is confined between two rigid planes. The results show that, the presence of vertical magnetic field beside the quantum effect will bring about more stability on the growth rate of unstable configuration for viscous plasma, which is greater than that of inviscous plasma.

Hoshoudy, G. A., E-mail: g_hoshoudy@yahoo.com [South Valley University, Department of Applied Mathematics, Faculty of Science (Egypt)

2011-09-15T23:59:59.000Z

439

Influence of electron injection into 27 cm audio plasma cell on the plasma diagnostics  

SciTech Connect (OSTI)

In this article, the plasma is created in a Pyrex tube (L = 27 cm, ?= 4 cm) as a single cell, by a capacitive audio frequency (AF) discharge (f = 10–100 kHz), at a definite pressure of ?0.2 Torr. A couple of tube linear and deviating arrangements show plasma characteristic conformity. The applied AF plasma and the injection of electrons into two gas mediums Ar and N{sub 2} revealed the increase of electron density at distinct tube regions by one order to attain 10{sup 13}/cm{sup 3}. The electrons temperature and density strengths are in contrast to each other. While their distributions differ along the plasma tube length, they show a decaying sinusoidal shape where their peaks position varies by the gas type. The electrons injection moderates electron temperature and expands their density. The later highest peak holds for the N{sub 2} gas, at electrons injection it changes to hold for the Ar. The sinusoidal decaying density behavior generates electric fields depending on the gas used and independent of tube geometry. The effect of the injected electrons performs a responsive impact on electrons density not attributed to the gas discharge. Analytical tools investigate the interaction of the plasma, the discharge current, and the gas used on the electrodes. It points to the emigration of atoms from each one but for greater majority they behave to a preferred direction. Meanwhile, only in the linear regime, small percentage of atoms still moves in reverse direction. Traces of gas atoms revealed on both electrodes due to sheath regions denote lack of their participation in the discharge current. In addition, atoms travel from one electrode to the other by overcoming the sheaths regions occurring transportation of particles agglomeration from one electrode to the other. The electrons injection has contributed to increase the plasma electron density peaks. These electrons populations have raised the generated electrostatic fields assisting the elemental ions emigration to a preferred electrode direction. Regardless of plasma electrodes positions and plasma shape, ions can be departed from one electrode to deposit on the other one. In consequence, as an application the AF plasma type can enhance the metal deposition from one electrode to the other.

Haleem, N. A.; Ragheb, M. S.; Zakhary, S. G. [Accelerators Department, Nuclear Research Center, AEA, Cairo 13759 (Egypt)] [Accelerators Department, Nuclear Research Center, AEA, Cairo 13759 (Egypt); El Fiki, S. A.; Nouh, S. A. [Faculty of Science, Ain Shams University, Cairo 11566 (Egypt)] [Faculty of Science, Ain Shams University, Cairo 11566 (Egypt); El Disoki, T. M. [Faculty of Girls, Ain Shams University, Cairo 11566 (Egypt)] [Faculty of Girls, Ain Shams University, Cairo 11566 (Egypt)

2013-08-15T23:59:59.000Z

440

?Linear Gas Jet with Tailored Density Profile"  

SciTech Connect (OSTI)

Supersonic, highly collimated gas jets and gas-filled capillary discharge waveguides are two primary targets of choice for Laser Plasma Accelerators (LPA) . Present gas jets have lengths of only 2-4 mm at densities of 1-4E19 cm-3, sufficient for self trapping and electron acceleration to energies up to ~150 MeV. Capillary structures 3 cm long have been used to accelerate beams up to 1 GeV. Capillary discharges used in LPAs serve to guide the pump laser and optimize the energy gain. A wall-stabilized capillary discharge provides a transverse profile across the channel that helps guide the laser and combat diffraction. Gas injection via a fast nozzle at one end provides some longitudinal density control, to improve the coupling. Gas jets with uniform or controlled density profiles may be used to control electron bunch injection and are being integrated into capillary experiments to add tuning of density. The gas jet for electron injection has not yet been optimized. Our Ph-I results have provided the LPA community with an alternative path to realizing a 2-3GeV electron bunch using just a gas jet. For example, our slit/blade combination gives a 15-20mm long acceleration path with tunable density profile, serving as an alternative to a 20-mm long capillary discharge with gas injection at one end. In Ph-II, we will extend these results to longer nozzles, to see whether we can synthesize 30 or 40-mm long plasma channels for LPAs.

KRISHNAN, Mahadevan

2012-12-10T23:59:59.000Z

Note: This page contains sample records for the topic "density plasma science" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


441

Landau Damping in Relativistic Plasmas  

E-Print Network [OSTI]

We examine the phenomenon of Landau Damping in relativistic plasmas via a study of the relativistic Vlasov-Poisson system (rVP) on the torus for initial data sufficiently close to a spatially uniform steady state. We find that if the steady state is regular enough (essentially in a Gevrey class of degree in a specified range) and that the deviation of the initial data from this steady state is small enough in a certain norm, the evolution of the system is such that its spatial density approaches a uniform constant value sub-exponentially fast (i.e. like $\\exp(-C|t|^{\\overline{\

Brent Young

2014-10-10T23:59:59.000Z

442

Holographic plasma and anyonic fluids  

E-Print Network [OSTI]

We use alternative quantisation of the $D3/D5$ system to explore properties of a strongly coupled charged plasma and strongly coupled anyonic fluids. The $S$-transform of the $D3/D5$ system is used as a model for charged matter interacting with a U(1) gauge field in the large coupling regime, and we compute the dispersion relationship of the propagating electromagnetic modes as the density and temperature are changed. A more general $SL(2,\\mathbb{Z})$ transformation gives a strongly interacting anyonic fluid, and we study its transport properties as we change the statistics of the anyons and the background magnetic field.

Daniel K. Brattan; Gilad Lifschytz

2013-10-20T23:59:59.000Z

443

Science Fairs for Science Literacy  

E-Print Network [OSTI]

is supported by a National Science Foundation PostdoctoralT.  Culbertson is a middle school science and math teacher.for the Advancement of Science (AAAS) (1990), Science for

Mackey, Katherine; Culbertson, Timothy

2014-01-01T23:59:59.000Z

444

Wood and Fiber Science, 36(1), 2004, pp. 1725 2004 by the Society of Wood Science and Technology  

E-Print Network [OSTI]

Wood and Fiber Science, 36(1), 2004, pp. 17­25 2004 by the Society of Wood Science and Technology FUNDAMENTALS OF VERTICAL DENSITY PROFILE FORMATION IN WOOD COMPOSITES. PART III. MDF DENSITY FORMATION DURING of Wood Science and Forest Products 210 Cheatham Hall, Virginia Tech Blacksburg, VA 24061-0323 and Timothy

Wang, Siqun

445

Wood and Fiber Science, 35(4), 2003, pp. 482498 2003 by the Society of Wood Science and Technology  

E-Print Network [OSTI]

Wood and Fiber Science, 35(4), 2003, pp. 482­498 2003 by the Society of Wood Science and Technology. INTRODUCTION Strength properties of wood-based compos- ites are related to mean panel density and the density of the average panel density (Kruse et al. 2000). Modeling for the spatial structure of wood composites

446

Theoretical & Computational Plasma Physicist | Princeton Plasma...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Research Requisition Number: 1400777 PPPLTheory Department has an opening at the rank of Research Physicist in theoretical and computational plasma physics in the area of...

447

Wine Science Wine Sciencee Science  

E-Print Network [OSTI]

Wine Science Wine Sciencee Science Thomas Henick-Kling Professor of Enology Director of Viticulture & Enology Program #12;Wine Science Wine Science Growth of Washington Wine Industry #12;Wine Science Wine Science Wine Grapes utilized 2007 2008 2009 2010 WA 127,000 145,000 156,000 160,000 NY 24,000 26,000 30

448

1 Biomedical Sciences BIOMEDICAL SCIENCES  

E-Print Network [OSTI]

1 Biomedical Sciences BIOMEDICAL SCIENCES The interdisciplinary doctoral programs in the biomedical sciences are organized within the Institute for Biomedical Sciences. The first full year of study toward are admitted directly into the Institute for Biomedical Sciences through Columbian College of Arts and Sciences

Vertes, Akos

449

Plasma Response to Lithium-Coated Plasma-Facing Components in the National Spherical Torus Experiment  

SciTech Connect (OSTI)

Experiments in the National Spherical Torus Experiment (NSTX) have shown beneficial effects on the performance of divertor plasmas as a result of applying lithium coatings on the graphite and carbonfiber- composite plasma-facing components. These coatings have mostly been applied by a pair of lithium evaporators mounted at the top of the vacuum vessel which inject collimated streams of lithium vapor towards the lower divertor. In NBI-heated, deuterium H-mode plasmas run immediately after the application of lithium, performance modifications included decreases in the plasma density, particularly in the edge, and inductive flux consumption, and increases in the electron and ion temperatures and the energy confinement time. Reductions in the number and amplitude of ELMs were observed, including complete ELM suppression for periods up to 1.2 s, apparently as a result of altering the stability of the edge. However, in the plasmas where ELMs were suppressed, there was a significant secular increase in the effective ion charge Zeff and the radiated power as a result of increases in the carbon and medium-Z metallic impurities, although not of lithium itself which remained at a very low level in the plasma core, <0.1%. The impurity buildup could be inhibited by repetitively triggering ELMs with the application of brief pulses of an n = 3 radial field perturbation. The reduction in the edge density by lithium also inhibited parasitic losses through the scrape-off layer of ICRF power coupled to the plasma, enabling the waves to heat electrons in the core of H-mode plasmas produced by NBI. Lithium has also been introduced by injecting a stream of chemically stabilized, fine lithium powder directly into the scrape-off layer of NBI-heated plasmas. The lithium was ionized in the SOL and appeared to flow along the magnetic field to the divertor plates. This method of coating produced similar effects to the evaporated lithium but at lower amounts.

M.G. Bell, H.W. Kugel, R. Kaita, L.E. Zakharov, H. Schneider, B.P. LeBlanc, D. Mansfield, R.E. Bell, R. Maingi, S. Ding, S.M. Kaye, S.F. Paul, S.P. Gerhardt, J.M. Canik, J.C. Hosea, G. Taylor and the NSTX Research Team

2009-08-20T23:59:59.000Z

450

Fusion Nuclear Science Facility (FNSF)  

E-Print Network [OSTI]

Fusion Nuclear Science Facility (FNSF) ­ Motivation, Role, Required Capabilities YK Martin Peng;1 Managed by UT-Battelle for the Department of Energy Example: fusion nuclear-nonnuclear coupling effects-composites; Nano-structure alloy; PFC designs, etc. · Nuclear-nonnuclear coupling in PFC: - Plasma ion flux induces

451

Terahertz radiation from a laser plasma filament  

SciTech Connect (OSTI)

By the use of two-dimensional particle-in-cell simulations, we clarify the terahertz (THz) radiation mechanism from a plasma filament formed by an intense femtosecond laser pulse. The nonuniform plasma density of the filament leads to a net radiating current for THz radiation. This current is mainly located within the pulse and the first cycle of the wakefield. As the laser pulse propagates, a single-cycle and radially polarized THz pulse is constructively built up forward. The single-cycle shape is mainly due to radiation damping effect.

Wu, H.-C.; Meyer-ter-Vehn, J. [Max-Planck-Institut fuer Quantenoptik, D-85748 Garching (Germany); Ruhl, H. [Department fuer Physik der Ludwig-Maximillians-Universitaet, Theresienstrasse 37A, D-80333 Muenchen (Germany); Sheng, Z.-M. [Institute of Plasma Studies, Department of Physics, Shanghai Jiaotong University, Shanghai 200240 (China); Beijing National Laboratory of Condensed Matter Physics, Institute of Physics, CAS, Beijing 100190 (China)

2011-03-15T23:59:59.000Z

452

Global coherence of dust density waves  

SciTech Connect (OSTI)

The coherence of self-excited three-dimensional dust density waves has been experimentally investigated by comparing global and local wave properties. For that purpose, three-dimensional dust clouds have been confined in a radio frequency plasma with thermophoretic levitation. Global wave properties have been measured from the line-of-sight integrated dust density obtained from homogenous light extinction measurements. Local wave properties have been obtained from thin, two-dimensional illuminated laser slices of the cloud. By correlating the simultaneous global and local wave properties, the spatial coherence of the waves has been determined. We find that linear waves with small amplitudes tend to be fragmented, featuring an incoherent wave field. Strongly non-linear waves with large amplitudes, however, feature a strong spatial coherence throughout the dust cloud, indicating a high level of synchronization.

Killer, Carsten; Melzer, André [Institut für Physik, Ernst-Moritz-Arndt-Universität Greifswald, 17489 Greifswald (Germany)

2014-06-15T23:59:59.000Z

453

Oscillating plasma bubbles. III. Internal electron sources and sinks  

SciTech Connect (OSTI)

An internal electron source has been used to neutralize ions injected from an ambient plasma into a spherical grid. The resultant plasma is termed a plasma 'bubble.' When the electron supply from the filament is reduced, the sheath inside the bubble becomes unstable. The plasma potential of the bubble oscillates near but below the ion plasma frequency. Different modes of oscillations have been observed as well as a subharmonic and multiple harmonics. The frequency increases with ion density and decreases with electron density. The peak amplitude occurs for an optimum current and the instability is quenched at large electron densities. The frequency also increases if Langmuir probes inside the bubble draw electrons. Allowing electrons from the ambient plasma to enter, the bubble changes the frequency dependence on grid voltage. It is concluded that the net space charge density in the sheath determines the oscillation frequency. It is suggested that the sheath instability is caused by ion inertia in an oscillating sheath electric field which is created by ion bunching.

Stenzel, R. L.; Urrutia, J. M. [Department of Physics and Astronomy, University of California, Los Angeles, California 90095-1547 (United States)

2012-08-15T23:59:59.000Z

454

Is sustainability science really a science?  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Is sustainability science really a science? Is sustainability science really a science? The team's work shows that although sustainability science has been growing explosively...

455

The effect of laser wavelength on laser-induced carbon plasma  

SciTech Connect (OSTI)

The effect of laser wavelength on parameters of laser-ablated carbon plume is studied. A theoretical model is applied, which describes the target heating and formation of the plasma and its expansion, and calculations are made for the fundamental and third harmonic of a Nd:YAG laser. The calculated distributions of plasma temperature and electron density in the early phase of expansion show that plasma temperatures are higher in the case of 1064 nm but the electron densities are higher in the case of 355 nm, which is in agreement with experimental findings. It has been shown that while a higher plasma temperature in the case of 1064 nm is the result of stronger plasma absorption, the greater ablation rate in the case of 355 nm results in larger mass density of the ablated plume and hence, in higher electron densities. An additional consequence of a higher ablation rate is slower expansion and smaller dimensions of the plume.

Moscicki, T.; Hoffman, J.; Szymanski, Z. [Institute of Fundamental Technological Research, Pawinskiego 5B, 02-106 Warsaw (Poland)] [Institute of Fundamental Technological Research, Pawinskiego 5B, 02-106 Warsaw (Poland)

2013-08-28T23:59:59.000Z

456

Simulations of heating and electron energy distributions in optical field ionized plasmas Imperial College of Science, Technology and Medicine, Prince Consort Road, London SW7 2BZ, United Kingdom  

E-Print Network [OSTI]

Simulations of heating and electron energy distributions in optical field ionized plasmas T is important. The consequences that the calculated energy distributions have on three-body recombination rates extent 7­9 . In calculating the magnitude of the collisional heating the electron energy distribution

Ditmire, Todd

457

Dynamic polarizability of an atomic ion within a dense plasma  

SciTech Connect (OSTI)

We analyze the influence of plasma electron density on frequency-dependent linear field-response behavior of an atomic ion embedded in a dense plasma medium. The frequency-dependent atomic response, characterized by the dynamic dipole polarizability {alpha}{sub d}({omega}) as a function of the angular frequency {omega} of the time-dependent field, is estimated here up to the first pole of {alpha}{sub d}({omega}) on the {omega} axis (corresponding to the lowest resonance transition 1s{sup 2} {sup 1}S{yields}1s2p {sup 1}P) for the ground state 1s{sup 2} {sup 1}S of a two-electron atomic ion Ne{sup 8+} (Z = 10) at different plasma electron densities, as a typical example, employing the time-dependent coupled Hartree-Fock scheme within the framework of the ion-sphere model. It is observed that, owing to plasma density-induced enhancement of {alpha}{sub d}({omega}) at every {omega}, the pole position of {alpha}{sub d}({omega}) on the {omega} axis retracts toward the origin. This indicates a density-induced lowering (redshift) of the corresponding transition energy that conforms to experimentally observed trends. The polarizability calculation suggests a density-induced drop in the 1s{sup 2} {sup 1}S{yields}1s2p {sup 1}P absorption oscillator strength in the atomic ion within dense plasmas.

Basu, Joyee; Ray, Debasis [Department of Physics, Bengal Engineering and Science University, Shibpur, Howrah 711 103, West Bengal (India)

2011-01-15T23:59:59.000Z

458

Beam loading in a laser-plasma accelerator using a near-hollow plasma channel  

SciTech Connect (OSTI)

Beam loading in laser-plasma accelerators using a near-hollow plasma channel is examined in the linear wake regime. It is shown that, by properly shaping and phasing the witness particle beam, high-gradient acceleration can be achieved with high-efficiency, and without induced energy spread or emittance growth. Both electron and positron beams can be accelerated in this plasma channel geometry. Matched propagation of electron beams can be achieved by the focusing force provided by the channel density. For positron beams, matched propagation can be achieved in a hollow plasma channel with external focusing. The efficiency of energy transfer from the wake to a witness beam is calculated for single ultra-short bunches and bunch trains.

Schroeder, C. B.; Benedetti, C.; Esarey, E.; Leemans, W. P. [Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States)] [Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States)

2013-12-15T23:59:59.000Z

459

Princeton Plasma Physics Laboratory. Annual report, October 1, 1989--September 30, 1990  

SciTech Connect (OSTI)

This report discusses the following topics: principal parameters achieved in experimental devices fiscal year 1990; tokamak fusion test reactor; compact ignition tokamak; Princeton beta experiment- modification; current drive experiment-upgrade; international collaboration; x-ray laser studies; spacecraft glow experiment; plasma processing: deposition and etching of thin films; theoretical studies; tokamak modeling; international thermonuclear experimental reactor; engineering department; project planning and safety office; quality assurance and reliability; technology transfer; administrative operations; PPPL patent invention disclosures for fiscal year 1990; graduate education; plasma physics; graduate education: plasma science and technology; science education program; and Princeton Plasma Physics Laboratory reports fiscal year 1990.

Not Available

1990-12-31T23:59:59.000Z

460

Density Matrix Topological Insulators  

E-Print Network [OSTI]

Thermal noise can destroy topological insulators (TI). However we demonstrate how TIs can be made stable in dissipative systems. To that aim, we introduce the notion of band Liouvillian as the dissipative counterpart of band Hamiltonian, and show a method to evaluate the topological order of its steady state. This is based on a generalization of the Chern number valid for general mixed states (referred to as density matrix Chern value), which witnesses topological order in a system coupled to external noise. Additionally, we study its relation with the electrical conductivity at finite temperature, which is not a topological property. Nonetheless, the density matrix Chern value represents the part of the conductivity which is topological due to the presence of quantum mixed edge states at finite temperature. To make our formalism concrete, we apply these concepts to the two-dimensional Haldane model in the presence of thermal dissipation, but our results hold for arbitrary dimensions and density matrices.

A. Rivas; O. Viyuela; M. A. Martin-Delgado

2013-10-31T23:59:59.000Z

Note: This page contains sample records for the topic "density plasma science" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


461

Page 1 A E Costley, BPS Workshop II, General Atomics, 1 3 May 2001 DIAGNOSTICS FOR BURNING PLASMA EXPERIMENTS  

E-Print Network [OSTI]

ITER Page 1 A E Costley, BPS Workshop II, General Atomics, 1 Ð 3 May 2001 DIAGNOSTICS FOR BURNING PLASMA EXPERIMENTS A E Costley ITER Joint Central Team, Naka, Japan Burning Plasma Science Workshop II, 1 Ð 3 May 2001 OUTLINE Requirements for Plasma and First Wall Measurements on a BPX Environment

462

On the Floquet formulation of time-dependent density functional theory  

E-Print Network [OSTI]

On the Floquet formulation of time-dependent density functional theory Neepa T. Maitra *, Kieron by Elsevier Science B.V. Ground-state density functional theory (DFT) [1] has been tremendously successful generalized ground-state density functional theory to time-dependent problems (TDDFT) [4]. TDDFT has become

463

Tungsten spectroscopy relevant to the diagnostics development of ITER divertor plasmas  

SciTech Connect (OSTI)

The ITER tokamak will have tungsten divertor tiles and, consequently, the divertor plasmas are expected to contain tungsten ions. The spectral emission from these ions can serve to diagnose the divertor for plasma parameters such as tungsten concentrations, densities, ion and electron temperatures, and flow velocities. The ITER divertor plasmas will likely have densities around 10{sup 14-15} cm{sup -3} and temperatures below 150 eV. These conditions are similar to the plasmas at the Sustained Spheromak Physics Experiment (SSPX) in Livermore. To simulate ITER divertor plasmas, a tungsten impurity was introduced into the SSPX spheromak by prefilling it with tungsten hexacarbonyl prior to the usual hydrogen gas injection and initiation of the plasma discharge. The possibility of using the emission from low charge state tungsten ions to diagnose tokamak divertor plasmas has been investigated using a high-resolution extreme ultraviolet spectrometer.

Clementson, J; Beiersdorfer, P; Magee, E W; McLean, H S; Wood, R D

2009-12-01T23:59:59.000Z

464

Earth Sciences Environmental Earth Sciences,  

E-Print Network [OSTI]

94 Earth Sciences­ Environmental Earth Sciences, Geology Degree options MGeol (Single Honours Degrees) Earth Sciences BSc (Single Honours Degrees) Environmental Earth Sciences Geology BSc (Joint placement. * The Geology and Environmental Earth Sciences degrees are accredited by the Geological Society

Brierley, Andrew

465

1 Political Science POLITICAL SCIENCE  

E-Print Network [OSTI]

1 Political Science POLITICAL SCIENCE With Capitol Hill nearby and the White House just blocks away, GW is the ideal place to study political science. Students in the program benefit from rigorous study and behavioral sciences discipline in the Columbian College of Arts and Sciences, the program examines politics

Vertes, Akos

466

1 Forensic Sciences FORENSIC SCIENCES  

E-Print Network [OSTI]

1 Forensic Sciences FORENSIC SCIENCES As part of the Columbian College of Arts and Sciences' natural, mathematical and biomedical sciences programs, the forensic sciences program provides an understanding of the integration of forensic disciplines with the investigation of criminal activity, along

Vertes, Akos

467

FORENSIC SCIENCE About Forensic Science  

E-Print Network [OSTI]

Fact Sheet FORENSIC SCIENCE About Forensic Science: The Forensic Science program at SJSU offers: The SJSU Forensic Science program delivers coursework and training to · Empowergraduatestobecomeagentsofchangetorecognize, document and report errors and injustices in the practice of forensic science and crime scene

Su, Xiao

468

Density Functional Theory for Superconductors  

E-Print Network [OSTI]

Density Functional Theory for Superconductors LATHIOTAKIS, A. MARQUES, 1,2,3 LU DERS, L. FAST, 2004 words: theory superconductors; density functional theory; critical temperature; exchange matter physics theoretical chemistry is density functional theory (DFT). foundations were established mid

Gross, E.K.U.

469

Effect of strongly coupled plasma on photoionization cross section  

SciTech Connect (OSTI)

The effect of strongly coupled plasma on the ground state photoionization cross section is studied. In the non relativistic dipole approximation, cross section is evaluated from bound-free transition matrix element. The bound and free state wave functions are obtained by solving the radial Schrodinger equation with appropriate plasma potential. We have used ion sphere potential (ISP) to incorporate the plasma effects in atomic structure calculation. This potential includes the effect of static plasma screening on nuclear charge as well as the effect of confinement due to the neighbouring ions. With ISP, the radial equation is solved using Shooting method approach for hydrogen like ions (Li{sup +2}, C{sup +5}, Al{sup +12}) and lithium like ions (C{sup +3}, O{sup +5}). The effect of strong screening and confinement is manifested as confinement resonances near the ionization threshold for both kinds of ions. The confinement resonances are very much dependent on the edge of the confining potential and die out as the plasma density is increased. Plasma effect also results in appearance of Cooper minimum in lithium like ions, which was not present in case of free lithium like ions. With increasing density the position of Cooper minimum shifts towards higher photoelectron energy. The same behaviour is also true for weakly coupled plasma where plasma effect is modelled by Debye-Huckel potential.

Das, Madhusmita, E-mail: msdas@barc.gov.in [Department of Physics, Indian Institute of Technology, Powai, Mumbai 400076, India and Theoretical Physics Division, Bhabha Atomic Research Center, Mumbai 400085 (India)] [Department of Physics, Indian Institute of Technology, Powai, Mumbai 400076, India and Theoretical Physics Division, Bhabha Atomic Research Center, Mumbai 400085 (India)

2014-01-15T23:59:59.000Z

470

Coupled Langmuir oscillations in 2-dimensional quantum plasmas  

SciTech Connect (OSTI)

In this work, we present a hydrodynamic model to study the coupled quantum electron plasma oscillations (QEPO) for two dimensional (2D) degenerate plasmas, which incorporates all the essential quantum ingredients such as the statistical degeneracy pressure, electron-exchange, and electron quantum diffraction effect. Effects of diverse physical aspects like the electronic band-dispersion effect, the electron exchange-correlations and the quantum Bohm-potential as well as other important plasma parameters such as the coupling parameter (plasma separation) and the plasma electron number-densities on the linear response of the coupled system are investigated. By studying three different 2D plasma coupling types, namely, graphene-graphene, graphene-metalfilm, and metalfilm-metalfilm coupling configurations, it is remarked that the collective quantum effects can influence the coupled modes quite differently, depending on the type of the plasma configuration. It is also found that the slow and fast QEPO frequency modes respond very differently to the change in plasma parameters. Current findings can help in understanding of the coupled density oscillations in multilayer graphene, graphene-based heterojunctions, or nanofabricated integrated circuits.

Akbari-Moghanjoughi, M. [Department of Physics, Faculty of Sciences, Azarbaijan Shahid Madani University, 51745-406 Tabriz, Iran and International Centre for Advanced Studies in Physical Sciences and Institute for Theoretical Physics, Ruhr University Bochum, D-44780 Bochum (Germany)] [Department of Physics, Faculty of Sciences, Azarbaijan Shahid Madani University, 51745-406 Tabriz, Iran and International Centre for Advanced Studies in Physical Sciences and Institute for Theoretical Physics, Ruhr University Bochum, D-44780 Bochum (Germany)

2014-03-15T23:59:59.000Z

471

Science/Fusion Energy Sciences FY 2012 Congressional Budget Fusion Energy Sciences  

E-Print Network [OSTI]

. This is accomplished by studying plasma and its interactions with its surroundings across wide ranges of temperature and density, developing advanced diagnostics to make detailed measurements of its properties and dynamics and from plentiful supplies of lithium in the earth, whose resulting radioactivity is modest, and which

472

Upper Atmospheric Density Profiles  

E-Print Network [OSTI]

· Uncertainties in aerodynamics, problems with signals from shaking solar panel, rotation of instrument about · Change in latitude per unit change in longitude along profile set by orbit inclination and latitude (not engineering) instrument, very high sensitivity, unseen part of 11-yr solar cycle · Current science

Withers, Paul

473

Computational Science  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Computational Science and Engineering Petascale Initiative at LBNL Progress Report PI: Alice Koniges June 28, 2010 Computational Science and Engineering Petascale Initiative PI,...

474

Science & Engineering  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

and Technology Delivering basic and applied science discoveries and innovating engineering R&D is the hallmark of the Science and Engineering division in support of INL's...

475

356 OPTICS LETTERS / Vol. 25, No. 5 / March 1, 2000 Dense plasma diagnostics with an amplitude-division  

E-Print Network [OSTI]

356 OPTICS LETTERS / Vol. 25, No. 5 / March 1, 2000 Dense plasma diagnostics with an amplitude-created plasma. 2000 Optical Society of America OCIS codes: 340.7450, 140.7240. Interferometry with visible density in a large variety of dense plasmas.1,2 However, free­free absorption and refraction of the probe

Rocca, Jorge J.

476

Electron properties and air mixing in radio frequency driven argon plasma jets at atmospheric pressure  

SciTech Connect (OSTI)

A time modulated radio frequency (RF) plasma jet operated with an Ar mixture is investigated by measuring the electron density and electron temperature using Thomson scattering. The measurements have been performed spatially resolved for two different electrode configurations and as a function of the plasma dissipated power and air concentration admixed to the Ar. Time resolved measurements of electron densities and temperatures during the RF cycle and after plasma power switch-off are presented. Furthermore, the influence of the plasma on the air entrainment into the effluent is studied using Raman scattering.

Gessel, Bram van; Bruggeman, Peter [Department of Applied Physics, Eindhoven University of Technology, PO Box 513, 5600 MB Eindhoven (Netherlands)] [Department of Applied Physics, Eindhoven University of Technology, PO Box 513, 5600 MB Eindhoven (Netherlands); Brandenburg, Ronny [Department of Applied Physics, Eindhoven University of Technology, PO Box 513, 5600 MB Eindhoven (Netherlands) [Department of Applied Physics, Eindhoven University of Technology, PO Box 513, 5600 MB Eindhoven (Netherlands); Leibniz Institute for Plasma Science and Technology (INP Greifswald), Felix-Hausdorff-Str. 2, D-17489 Greifswald (Germany)

2013-08-05T23:59:59.000Z

477

Characteristics of a tapered capillary plasma waveguide for laser wakefield acceleration  

SciTech Connect (OSTI)

We developed a gas-filled capillary with a tapered density for laser wakefield acceleration, of which the tapering was realized by employing gas feed-lines with different cross-sections. Plasma diagnostics show that the capillary plasma has a significant longitudinal density tapering and a transverse parabolic profile. By using the tapered capillary plasma, high transmission (over 90%) of laser beams, meaning good optical guiding, was observed. These results demonstrate the potential of the tapered plasma source for high-energy laser wakefield acceleration, where the dephasing problem is minimized.

Kim, M. S.; Jang, D. G.; Lee, T. H.; Nam, I. H. [Department of Physics and Photon Science, Gwangju Institute of Science and Technology (GIST), Cheomdan-gwagiro, Buk-gu, Gwangju 500-712 (Korea, Republic of)] [Department of Physics and Photon Science, Gwangju Institute of Science and Technology (GIST), Cheomdan-gwagiro, Buk-gu, Gwangju 500-712 (Korea, Republic of); Lee, I. W.; Suk, H. [Department of Physics and Photon Science, Gwangju Institute of Science and Technology (GIST), Cheomdan-gwagiro, Buk-gu, Gwangju 500-712 (Korea, Republic of) [Department of Physics and Photon Science, Gwangju Institute of Science and Technology (GIST), Cheomdan-gwagiro, Buk-gu, Gwangju 500-712 (Korea, Republic of); APRI, Gwangju Institute of Science and Technology (GIST), Cheomdan-gwagiro, Buk-gu, Gwangju 500-712 (Korea, Republic of)

2013-05-20T23:59:59.000Z

478

Precise energy eigenvalues of hydrogen-like ion moving in quantum plasmas  

E-Print Network [OSTI]

The analytic form of the electrostatic potential felt by a slowly moving test charge in quantum plasma is being derived. It has been shown that the potential composed of two parts: Debye-Huckel screening term and near-field wake potential which depends on the velocity of the test charge and the number density of the plasma electrons. Rayleigh-Ritz variational calculation has been done to estimate precise energy eigenvalues of hydrogen-like ion under such plasma environment. A detailed analysis shows that the energy levels are gradually moves to the continuum with increasing plasma electron density while level crossing phenomenon have been observed with the variation of ion velocity.

Dutta, S; Mukherjee, T K

2014-01-01T23:59:59.000Z

479

Multiple density layered insulator  

DOE Patents [OSTI]

A multiple density layered insulator for use with a laser is disclosed which provides at least two different insulation materials for a laser discharge tube, where the two insulation materials have different thermoconductivities. The multiple layer insulation materials provide for improved thermoconductivity capability for improved laser operation. 4 figs.

Alger, T.W.

1994-09-06T23:59:59.000Z

480

Multiple density layered insulator  

DOE Patents [OSTI]

A multiple density layered insulator for use with a laser is disclosed wh provides at least two different insulation materials for a laser discharge tube, where the two insulation materials have different thermoconductivities. The multiple layer insulation materials provide for improved thermoconductivity capability for improved laser operation.

Alger, Terry W. (Tracy, CA)

1994-01-01T23:59:59.000Z

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