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1

Amplifying Magnetic Fields in High Energy Density Plasmas | U...  

Office of Science (SC) Website

Amplifying Magnetic Fields in High Energy Density Plasmas Fusion Energy Sciences (FES) FES Home About Research Facilities Science Highlights Benefits of FES Funding Opportunities...

2

Inner magnetosphere plasma densities  

E-Print Network (OSTI)

The radio plasma imager (RPI) on the IMAGE satellite performs radio sounding in the magnetosphere, transmitting coded signals stepping through the frequency range of interest and receiving the returned echoes. The measurements provide the echo amplitude as a function of frequency and echo delay time on a so-called plasmagram. A newly developed algorithm inverts THE echo traces on a plasmagram to electron density spatial distributions. Based on these observed density distributions, an empirical model is constructed to describe the two-dimensional density distribution in the inner magnetosphere.

Reinisch, B W

2002-01-01T23:59:59.000Z

3

High-Energy-Density Plasmas, Fluids  

NLE Websites -- All DOE Office Websites (Extended Search)

High-Energy-Density Plasmas, Fluids High-Energy-Density Plasmas, Fluids /science-innovation/_assets/images/icon-science.jpg High-Energy-Density Plasmas, Fluids National security depends on science and technology. The United States relies on Los Alamos National Laboratory for the best of both. No place on Earth pursues a broader array of world-class scientific endeavors. TRIDENT target chamber Sasi Palaniyappan, right, and Rahul Shah left inside a target chamber where the TRIDENT short pulse laser is aimed at a very thin diamond- foil target, a fraction of a micrometer thick. The laser delivers a power on target of 150 Terawatts focused into a 7 micrometer spot, yielding laser brilliance over 100 times more intense than needed to make the target electrons fully relativistic. These experiments test novel methods of producing intense

4

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

5

Michigan Institute for Plasma Science  

E-Print Network (OSTI)

of the Program in Plasma Physics and Professor of Astrophysical Sciences at Princeton University. He also serves as Associate Director for Academic Affairs at the Princeton Plasma Physics Laboratory. DrMichigan Institute for Plasma Science and Engineering Seminar Compressing Waves in Plasma

Shyy, Wei

6

High Energy Density Science with High Peak Power Light Sources  

Science Journals Connector (OSTI)

High energy density (HED) science is a growing sub-field of plasma and condensed matter physics. I will examine how recent technological developments in high peak power, petawatt-class...

Ditmire, Todd

7

Plasma probe characteristics in low density hydrogen pulsed plasmas  

E-Print Network (OSTI)

Probe theories are only applicable in the regime where the probe's perturbation of the plasma can be neglected. However, it is not always possible to know, a priori, that a particular probe theory can be successfully applied, especially in low density plasmas. This is especially difficult in the case of transient, low density plasmas. Here, we applied probe diagnostics in combination with a 2D particle-in-cell model, to an experiment with a pulsed low density hydrogen plasma. The calculations took into account the full chamber geometry, including the plasma probe as an electrode in the chamber. It was found that the simulations reproduce the time evolution of the probe IV characteristics with good accuracy. The disagreement between the simulated and probe measured plasma density is attributed to the limited applicability of probe theory to measurements of low density pulsed plasmas. Indeed, in the case studied here, probe measurements would lead to a large overestimate of the plasma density. In contrast, the ...

Astakhov, D I; Lee, C J; Ivanov, V V; Krivtsun, V M; Zotovich, A I; Zyryanov, S M; Lopaev, D V; Bijkerk, F

2014-01-01T23:59:59.000Z

8

Plasma Physics PART Al: INTRODUCTION TO PLASMA SCIENCE  

E-Print Network (OSTI)

Plasma Physics PART Al: INTRODUCTION TO PLASMA SCIENCE I. What is a plasma? 1 II. Plasma fundamentals 3 1. Quasineutrality and Debye length 2. Plasma frequency and acoustic velocity 3. Larmor radius; magnetic buckets Cross section data 21 PART A3: PLASMA SOURCES I IV. Introduction to plasma sources 25 1

Chen, Francis F.

9

N.P. Basse1 Plasma Science and Fusion Center  

E-Print Network (OSTI)

of multiscale density fluctuations Work supported by US DoE Office of Fusion Energy Sciences #12;Introduction 33rd IEEE International Conference on Plasma Science, Traverse City, Michigan, USA (2006) A study are presented. The comparative study is carried out between fusion plasma measurements and cosmological data1

Basse, Nils Plesner

10

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...

11

Science Education Lab | Princeton Plasma Physics Lab  

NLE Websites -- All DOE Office Websites (Extended Search)

Lab Lab Science Education Laboratory Overview Gallery: (Photo by Remote Control Glow Discharge) (Photo by DC Glow Discharges for Undergraduate Laboratories) (Photo by Atmospheric Plasma Laboratory) (Photo by 3D Printing Laboratory) (Photo by Remote Control Glow Discharge) (Photo by Plasma Speaker with 200 Hz input) (Photo by Dusty Plasma Laboratory) The Science Education Laboratory is a fusion (pun intended) of research between education and plasma science. This unique facility includes a teaching laboratory/classroom, two research labs, and student offices/storage/prep room. The research performed in the Science Education Laboratory is currently centered upon dusty plasmas, plasma speakers, remote control of plasmas for educational purposes, atmospheric plasmas and

12

3300 IEEE TRANSACTIONS ON PLASMA SCIENCE, VOL. 39, NO. 12, DECEMBER 2011 Direct-Coupled Plasma-Assisted Combustion  

E-Print Network (OSTI)

by coupling an atmospheric plasma dis- charge to a premixed methane/air flame. The absorbed microwave power3300 IEEE TRANSACTIONS ON PLASMA SCIENCE, VOL. 39, NO. 12, DECEMBER 2011 Direct-Coupled Plasma were observed as power increased. In the plasma-coupled pre- mixed flame, OH number densities, which

Lee, Tonghun

13

Science Education Programs | Princeton Plasma Physics Lab  

NLE Websites -- All DOE Office Websites (Extended Search)

Programs Programs Science Education Student Programs Undergraduates Community College Internship (CCI) National Undergraduate Fellowship Program (NUF) Science Undergraduate Laboratory Internship (SULI) Visiting Faculty Program (VFP) High School High School Internship New Jersey Regional Science Bowl PathSci Young Women's Conference in Science, Technology, Engineering & Mathematics K-8 New Jersey Regional Science Bowl Young Women's Conference in Science, Technology, Engineering & Mathematics Science Education Educator Programs Teacher Professional Development CLOuDS: Classroom Leadership: Operating in µ-gravity while Discovering Science Plasma Camp Science Education Outreach Programs Requests Classroom Visits Seminar Series Science on Saturday Lecture Series Community

14

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.

15

DENSITY LIMITS IN TOROIDAL PLASMAS MARTIN GREENWALD  

E-Print Network (OSTI)

(RFP) ---- Spheromaks and FRCs · Physics basis for density limit ---- Neutrals ---- Radiation models as fast terminations · Spheromak and FRC don't have density limit data operation at "optimized" density

Greenwald, Martin

16

Science literacy | Princeton Plasma Physics Lab  

NLE Websites -- All DOE Office Websites (Extended Search)

Science literacy Science literacy Subscribe to RSS - Science literacy Having the knowledge and understanding of scientific concepts and processes necessary to make informed decisions on scientific issues. Science on Saturday starts Jan. 11 Science fans of all ages can explore a rich variety of science and technology topics at the popular Science on Saturday lecture series hosted by the U.S. Department of Energy's Princeton Plasma Physics Laboratory. The series marks its 30-year anniversary when it begins on Saturday, Jan. 11. Science on Saturday offers free lectures about current topics from "The physics of cancer," to "What art can tell us about the brain," that are aimed at the general public from high school age and up. Read more about Science on Saturday starts Jan. 11

17

Princeton Plasma Physics Lab - Science literacy  

NLE Websites -- All DOE Office Websites (Extended Search)

science-literacy Having the knowledge science-literacy Having the knowledge and understanding of scientific concepts and processes necessary to make informed decisions on scientific issues. en Science on Saturday starts Jan. 11 http://www.pppl.gov/news/2014/01/science-saturday-starts-jan-11

Science fans of all ages can explore a rich variety of science and technology topics at the popular Science on Saturday lecture series hosted by the U.S. Department of Energy's Princeton Plasma Physics Laboratory. The series marks its 30-year anniversary when it begins on Saturday, Jan. 11.Science on Saturday offers free lectures about current

18

Measurement of Plasma Density in a Gas-Filled Ionizing Laser Focus.  

E-Print Network (OSTI)

??We use an interferometric method for measuring the plasma density in a laser-induced plasma as a function of time. Any changes in the density within (more)

Heilmann, Nathan Edward

2012-01-01T23:59:59.000Z

19

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

SciTech Connect

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

20

High Energy Density Laboratory Plasmas Program | National Nuclear Security  

National Nuclear Security Administration (NNSA)

Program | National Nuclear Security Program | National Nuclear Security Administration Our Mission Managing the Stockpile Preventing Proliferation Powering the Nuclear Navy Emergency Response Recapitalizing Our Infrastructure Continuing Management Reform Countering Nuclear Terrorism About Us Our Programs Our History Who We Are Our Leadership Our Locations Budget Our Operations Media Room Congressional Testimony Fact Sheets Newsletters Press Releases Speeches Events Social Media Video Gallery Photo Gallery NNSA Archive Federal Employment Apply for Our Jobs Our Jobs Working at NNSA Blog High Energy Density Laboratory Plasmas Program Home > High Energy Density Laboratory Plasmas Program High Energy Density Laboratory Plasmas Program Steady advances in increasing the energy, power, and brightness of lasers and particle beams and advances in pulsed power systems have made possible

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

High Energy Density Laboratory Plasmas | National Nuclear Security  

National Nuclear Security Administration (NNSA)

| National Nuclear Security | National Nuclear Security Administration Our Mission Managing the Stockpile Preventing Proliferation Powering the Nuclear Navy Emergency Response Recapitalizing Our Infrastructure Continuing Management Reform Countering Nuclear Terrorism About Us Our Programs Our History Who We Are Our Leadership Our Locations Budget Our Operations Media Room Congressional Testimony Fact Sheets Newsletters Press Releases Speeches Events Social Media Video Gallery Photo Gallery NNSA Archive Federal Employment Apply for Our Jobs Our Jobs Working at NNSA Blog HEDLP High Energy Density Laboratory Plasmas Home > About Us > Our Programs > Defense Programs > Office of Research, Development, Test, and Evaluation > University Partnerships / Academic Alliances > High Energy Density Laboratory Plasmas

22

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

23

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

NLE Websites -- All DOE Office Websites (Extended Search)

Publications & News Meetings & Seminars Contact Information Physics Research High-Energy- Density Physics Waves & Beams Fusion Technology & Engineering Plasma Technology...

24

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

NLE Websites -- All DOE Office Websites (Extended Search)

Publications & News Meetings & Seminars Contact Information Physics Research High-Energy- Density Physics Waves & Beams Fusion Technology & Engineering Plasma Technology...

25

Causal Link of Longitudinal Plasma Density Structure to Vertical Plasma Drift and Atmospheric Tides A Review  

Science Journals Connector (OSTI)

This chapter reviews recent advances in our understanding of the characteristics and driving mechanisms of the longitudinal plasma density structure in the low-latitude F...region. Various ionospheric observation...

Hyosub Kil; Larry J. Paxton

2011-01-01T23:59:59.000Z

26

Human Plasma Very Low Density Lipoprotein Carries Indian Hedgehog  

Science Journals Connector (OSTI)

Human Plasma Very Low Density Lipoprotein Carries Indian Hedgehog ... At each time point, the viability of the cells was evaluated by MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide), reduction assay,(20) and cell counting with trypan blue. ...

Karla C. S. Queiroz; Ren A. Tio; Clark J. Zeebregts; Maarten F. Bijlsma; Felix Zijlstra; Bahram Badlou; Marcel de Vries; Carmen V. Ferreira; C. Arnold Spek; Maikel P. Peppelenbosch; Farhad Rezaee

2010-09-14T23:59:59.000Z

27

Activities of the High Energy Density Laboratory Plasmas  

E-Print Network (OSTI)

Activities of the High Energy Density Laboratory Plasmas FESAC Panel R. Betti FPA Meeting December #12;F. Beg (UCSD) B. Remington (LLNL) R. Betti (UR) (chair) R. Davidson (Princeton) P. Drake (U. Betti (UR) D. Hammer (Cornell) G. Logan (LBNL) D. Meyerhofer (UR) J. Sethian (NRL) R. Siemon (UNR) IFE

28

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

E-Print Network (OSTI)

of these efforts have been focused on the sheath region of the plasma, but here we will focus on the main plasmaDusty plasma diagnostics methods for charge, electron temperature, and ion density Bin Liu,1 J Q and two plasma parameters, electron temperature Te, and ion density ni, in the main plasma region

Goree, John

29

IEEE TRANSACTIONS ON PLASMA SCIENCE, VOL. 35, NO. 3, JUNE 2007 693 Atmospheric Plasma Actuators for  

E-Print Network (OSTI)

IEEE TRANSACTIONS ON PLASMA SCIENCE, VOL. 35, NO. 3, JUNE 2007 693 Atmospheric Plasma Actuators- charges, flow control. I. INTRODUCTION PLASMA, operating in atmospheric pressure air conditions, holds atmospheric plasma that mainly consists of nitrogen/oxygen plasma components, which are coupled to an electric

Huang, Xun

30

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

E-Print Network (OSTI)

are with the Princeton Plasma Physics Laboratory, Princeton University, Princeton, NJ 08543 USA (e-mail: yraitses2034 IEEE TRANSACTIONS ON PLASMA SCIENCE, VOL. 36, NO. 5, OCTOBER 2008 Simulations, respectively. n, n0, ne, and ni Plasma, reference, electron, and ion densities, respectively. N Neutral gas

31

OH number densities and plasma jet behavior in atmospheric microwave plasma jets operating with different plasma gases (Ar, Ar/N2, and Ar/O2)  

Science Journals Connector (OSTI)

OH radical number density in multiple atmospheric pressure microwave plasma jets is measured using UV cavity ringdown ... 00) band at 308nm. The plasma cavity was excited by a 2.45GHz microwave plasma source a...

C. Wang; N. Srivastava

2010-12-01T23:59:59.000Z

32

Microwave interferometer for plasma-density measurement on TMX Upgrade  

SciTech Connect

A four-channel microwave interferometer operating at 140 GHz has been designed for installation on the upgrade to the Tandem Mirror Experiment (TMX Upgrade). The instrument can be used to measure plasma density simultaneously at four locations: by reconnecting the waveguide runs, density can be measured at other locations of interest. The design is an outgrowth of a system used on TMX, but includes some newly developed hardware. An over-mode circular waveguide system is used to transport the signals over long distances with only moderate losses. Several precautions have been taken to limit the effect of possible interference from the electron cyclotron resonant heating (ECRH) system used to heat the plasma. A high-resolution linear phase comparator has been designed that will operate over the wide range of signals expected. A CAMAC-based data-acquisition system provides for automatic data sampling and archival after each shot.

Coffield, F.E.; Stever, R.D.; Lund, N.P.

1981-09-25T23:59:59.000Z

33

MIT's Plasma Science Fusion Center: Tokamak Experiments Come...  

NLE Websites -- All DOE Office Websites (Extended Search)

Tokamak Experiments Come Clean about Impurity Transport American Fusion News Category: Massachusetts Institute of Technology (MIT) Link: MIT's Plasma Science Fusion Center: Tokamak...

34

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

35

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

SciTech Connect

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

36

Formation of a High?Density Deuterium Plasma Focus  

Science Journals Connector (OSTI)

During the early investigation of the high?energy low?pressure mode of a coaxial hydromagnetic gun a second mode of action was established for large gas fillings. This particular mode previously reported was found to lead to a high?density plasma focus situated at a distance ?11.5 cm beyond the face of the center electrode. The plasma focus has the following properties; particle density ? ? 23 1019/cm3 temperature T ? 13 keV time duration t ? 0.20.3 ?sec and volume ?15 mm3. Neutron yields >1010/burst and soft x rays are observed. These results are remarkably similar to those reported by Petrov et al. and Filippov et al. of the USSR using a metal wall pinch tube apparatus. The average velocity vz of the current sheath in the gun proper is found to depend on the fourth root of the applied voltage squares divided by the mass density according to the simple ``snowplow'' ``M'' theory. The current sheath is found to be nonplanar and mass pickup by the advancing sheath is nonlinear with radius. The sudden collapse of the radial current sheath toward the axis at the center electrode end is most likely caused by the rapid conversion of stored magnetic energy into radial sheath motion (v? r ? 3.5 107 cm/sec) forming in essence a super dense pinch effect.

J. W. Mather

1965-01-01T23:59:59.000Z

37

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

E-Print Network (OSTI)

Studies of electron heating on a 6.4 GHz ECR ion source 3.114 GHz Advanced Electron Cyclotron Source-Upgraded (AECR-U).spectra in electron cyclotron resonance ion source plasmas,

Noland, Jonathan David

2011-01-01T23:59:59.000Z

38

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.

39

IEEE TRANSACTIONS ON PLASMA SCIENCE, VOL.  

NLE Websites -- All DOE Office Websites (Extended Search)

of phenomena both in laboratory plasmas, like those magnetically confined in thermonuclear fusion exper- iments 1, and in several natural plasma systems, like for example...

40

HIGHLY COMPRESSED ION BEAMS FOR HIGH ENERGY DENSITY SCIENCE  

E-Print Network (OSTI)

HIGHLY COMPRESSED ION BEAMS FOR HIGH ENERGY DENSITY SCIENCE A. Friedman1,2 , J.J.Barnard1,2 , R Energy Density regimes required for Inertial Fu- sion Energy and other applications. An interim goal we are pursuing, low to medium mass ions with energies just above the Bragg peak are directed onto

Wurtele, Jonathan

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

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

42

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

SciTech Connect

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

43

A US Strategy to Explore the Science and Technology of Energy-Producing Plasmas  

E-Print Network (OSTI)

the fusion process. The specific objectives of the fusion program are to: (1) advance plasma science

44

Electron Acceleration Experiments by Using a Density-tapered Capillary Plasma Source  

Science Journals Connector (OSTI)

We have developed a density-tapered capillary plasma source for high energy electron generation by using the laser wakefield acceleration, where the dephasing problem will be...

Suk, Hyyong; Nam, Inhyuk; Kim, Minseok; Lee, Seungwoo; Lee, Taehee

45

COLLOQUIUM: The NASA Planetary Science Program | Princeton Plasma...  

NLE Websites -- All DOE Office Websites (Extended Search)

February 25, 2015, 4:00pm to 6:30pm Colloquia MBG Auditorium COLLOQUIUM: The NASA Planetary Science Program Dr. James Green NASA Colloquium Committee: The Princeton Plasma Physics...

46

ISRAELI PLASMA SCIENCE AND TECHNOLOGY ASSOCIATION  

E-Print Network (OSTI)

and applied aspects of plasmas. Many processes in technologies that involve plasmas occur naturally in space are directed to understanding the processes occurring in nature on an astronomical scale, and realizing, plasma processing, fusion research, sources of radiation and particle beams, pulsed power, or other basic

47

Relaxation of potential, flows, and density in the edge plasma of CASTOR tokamak  

E-Print Network (OSTI)

Relaxation of potential, flows, and density in the edge plasma of CASTOR tokamak M. Hron1 , V on the CASTOR tokamak. A biased electrode has been used to polarize the edge plasma. The edge plasma potential time in the range of 10 - 30 µs when the electrode biasing is turn off in the CASTOR tokamak

Boyer, Edmond

48

RIS-M-2594 ELECTRON CYCLOTRON RESONANCE HEATING OF A HIGH-DENSITY PLASMA  

E-Print Network (OSTI)

RIS?-M-2594 ELECTRON CYCLOTRON RESONANCE HEATING OF A HIGH-DENSITY PLASMA Flemming Ramskov Hansen Abstract. Various schemes for electron cyclotron resonance heat- ing of tokamak plasmas with the ratio of electron plasma frequen- cy to electron cyclotron frequency, "»pe/^ce* larger than 1 on axis

49

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

SciTech Connect

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

50

Experimental investigation of ultraviolet laser induced plasma density and temperature evolution in air  

E-Print Network (OSTI)

and collisional cascade processes for pressures ranging from 40 Torr to 5 atm. A laser shadowgraphy diagnosticExperimental investigation of ultraviolet laser induced plasma density and temperature evolution July 2008 We present measurements and analysis of laser induced plasma neutral densities

Scharer, John E.

51

IEEE TRANSACTIONS ON PLASMA SCIENCE, VOL. 39, NO. 12, DECEMBER 2011 3307 Microwave-Plasma-Coupled Re-Ignition of  

E-Print Network (OSTI)

-ignition phenomenon is observed when fuel/ oxidizer is re-introduced into an atmospheric-pressure plasma dischargeIEEE TRANSACTIONS ON PLASMA SCIENCE, VOL. 39, NO. 12, DECEMBER 2011 3307 Microwave-Plasma generated by cutting off the gas flow in a re-entrant microwave-plasma applicator system used for plasma

Lee, Tonghun

52

Dispersion relation and Landau damping of waves in high-energy density plasmas  

Science Journals Connector (OSTI)

We present a theoretical investigation on the propagation of electromagnetic waves and electron plasma waves in high energy density plasmas using the covariant Wigner function approach. Based on the covariant Wigner function and Dirac equation, a relativistic quantum kinetic model is established to describe the physical processes in high-energy density plasmas. With the zero-temperature FermiDirac distribution, the dispersion relation and Landau damping of waves containing the relativistic quantum corrected terms are derived. The relativistic quantum corrections to the dispersion relation and Landau damping are analyzed by comparing our results with those obtained in classical and non-relativistic quantum plasmas. We provide a detailed discussion on the Landau damping obtained in classical plasmas, non-relativistic Fermi plasmas and relativistic Fermi plasmas. The contributions of the Bohm potential, the Fermi statistics pressure and relativistic effects to the dispersion relation and Landau damping of waves are quantitatively calculated with real plasma parameters.

Jun Zhu; Peiyong Ji

2012-01-01T23:59:59.000Z

53

SAND2011-6616A Page 1 Session 2: High Energy Density, Plasmas, Magnetic Fields  

National Nuclear Security Administration (NNSA)

616A 616A Page 1 Session 2: High Energy Density, Plasmas, Magnetic Fields Dynamical Materials Experiments on Sandia's Z Machine: Obtaining Data with High Precision at HED Conditions Thomas R. Mattsson and Seth Root Sandia National Laboratories, Albuquerque, NM USA Summary: The Z machine at Sandia National Laboratories has successfully been used to study a wide range of materials under extreme conditions. In this paper, we will discuss the methodology resulting in high-pressure measurements at multi-Mbar pressures as well as present experimental data for shock compression of poly methyl-pentene, a hydrocarbon plastic. Introduction During the last few years, there has been a notable increase in the interest of high-pressure science. The increase in interest has been driven by the remarkable capabilities of new and improved platforms like

54

Science Education | Princeton Plasma Physics Lab  

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Efforts Graduate Programs Off Site University Research (OSUR) Organization Contact Us Science Education About Blog Programs Galleries Upcoming Events Lab Outreach Efforts Graduate...

55

Energetic particle production, cavition formation, and nonlinear development at a plasma density maximum  

SciTech Connect

We have investigated several phenomena of importance to laser-plasma interactions. In our studies, these are modeled by microwave and rf-plasma interactions. Our focus has been on resonant absorption of intense electromagnetic radiation at the plasma critical layer. Electron plasma wave (EPW) growth and caviton formation have been shown to be most efficient for shallow density gradients at the critical layer, where EPW convection losses are minimized. EPW electric field energies of 5000 times the plasma thermal energy, and energetic electron tails out to 5000T{sub e}, have been observed at the top of an inverse parabolic density profile. Ions receive delta-function-like impulses from localized electron plasma waves and wave-breaking electron ejection; the disruption of the ion fluid can only partially be described by the ponderomotive force. Our attempt is to test and illuminate some of the fundamental concepts of strong turbulence and EM wave-plasma interaction. 7 refs.

Wong, A.Y.; Bauer, B.S. (California Univ., Los Angeles, CA (USA). Dept. of Physics)

1990-09-04T23:59:59.000Z

56

SciTech Connect: "plasma science"  

Office of Scientific and Technical Information (OSTI)

plasma science" Find plasma science" Find How should I search Scitech Connect ... Basic or Advanced? Basic Search Advanced × Advanced Search Options Full Text: Bibliographic Data: Creator / Author: Name Name ORCID Title: Subject: Identifier Numbers: Research Org.: Sponsoring Org.: Site: All Alaska Power Administration, Juneau, Alaska (United States) Albany Research Center (ARC), Albany, OR (United States) Albuquerque Complex - NNSA Albuquerque Operations Office, Albuquerque, NM (United States) Amarillo National Resource Center for Plutonium, Amarillo, TX (United States) Ames Laboratory (AMES), Ames, IA (United States) Argonne National Laboratory (ANL), Argonne, IL (United States) Argonne National Laboratory-Advanced Photon Source (United States) Atlanta Regional Office, Atlanta, GA (United States) Atmospheric Radiation Measurement (ARM)

57

Surface science | Princeton Plasma Physics Lab  

NLE Websites -- All DOE Office Websites (Extended Search)

Surface science Surface science Subscribe to RSS - Surface science The study of the chemical and physical processes that occur in the interface between two phases of matter, such as solid to liquid or liquid to gas. Bruce E Koel Bruce Koel is professor of chemical and biological engineering at Princeton University. He is associated faculty in chemistry at the Princeton Institute for the Science and Technology of Materials (PRISM); associated faculty in the Princeton Department of Mechanical and Aerospace Engineering, and a collaborator on the National Spherical Torus Experiment at PPPL. Koel is a Fellow of the American Association for the Advancement of Science, the American Physical Society and the American Vacuum Society, and a member of the governing board of the Council for Chemical Research.

58

Two-dimensional laser-induced fluorescence imaging of metastable density in low-pressure radio frequency argon plasmas with added O2, Cl2,  

E-Print Network (OSTI)

frequency argon plasmas with added O2, Cl2, and CF4 Brian K. McMillina) and M. R. Zachariah Chemical Science, and CF4 on the argon metastable relative density and spatial distribution in low-pressure, radio at the powered electrode. In contrast, the addition of either Cl2 or CF4 was found to significantly modify

Zachariah, Michael R.

59

Two-dimensional imaging of CF2 density by laser-induced fluorescence in CF4 etching plasmas in the gaseous electronics conference  

E-Print Network (OSTI)

frequency argon plasmas with added O2, Cl2, and CF4 Brian K. McMillina) and M. R. Zachariah Chemical Science, and CF4 on the argon metastable relative density and spatial distribution in low-pressure, radio at the powered electrode. In contrast, the addition of either Cl2 or CF4 was found to significantly modify

Zachariah, Michael R.

60

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

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.
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61

1012 IEEE TRANSACTIONS ON PLASMA SCIENCE, VOL. 36, NO. 4, AUGUST 2008 Plasma Emission Modifications and Instabilities  

E-Print Network (OSTI)

tails or planetary atmospheres. In artificial plasmas, these dust particles are fatal for processes a polymer layer exposed to a low-pressure radio- frequency (13.56 MHz) argon plasma. The capacitively1012 IEEE TRANSACTIONS ON PLASMA SCIENCE, VOL. 36, NO. 4, AUGUST 2008 Plasma Emission Modifications

Paris-Sud XI, Université de

62

1998 IEEE TRANSACTIONS ON PLASMA SCIENCE, VOL. 36, NO. 5, OCTOBER 2008 Controlling the Plasma Flow in the  

E-Print Network (OSTI)

. Fisch are with the Princeton Plasma Physics Laboratory, Princeton, NJ 08540 USA (e-mail: yraitses1998 IEEE TRANSACTIONS ON PLASMA SCIENCE, VOL. 36, NO. 5, OCTOBER 2008 Controlling the Plasma Flow electron emis- sion. The thruster operation in this mode greatly expands the range of the plasma

63

1204 IEEE TRANSACTIONS ON PLASMA SCIENCE, VOL. 36, NO. 4, AUGUST 2008 Plasma Plume of Annular and  

E-Print Network (OSTI)

are with the Princeton Plasma Physics Laboratory, Princeton University, Princeton, NJ 08543-0451 USA (e-mail: fisch1204 IEEE TRANSACTIONS ON PLASMA SCIENCE, VOL. 36, NO. 4, AUGUST 2008 Plasma Plume of Annular potential induced within the plasma. Annular-geometry Hall thrusters tend to have narrower plumes. However

64

Using Radio Waves to Control Fusion Plasma Density  

NLE Websites -- All DOE Office Websites (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...

65

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

SciTech Connect

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

66

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

67

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

68

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

SciTech Connect

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

69

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

70

Using Radio Waves to Control Fusion Plasma Density  

NLE Websites -- All DOE Office Websites (Extended Search)

simulation shows turbulent density fluctuations in the core of the Alcator C-Mod tokamak during strong electron heating. Image: Darin Ernst, MIT Recent fusion experiments on...

71

MIT Plasma Science & Fusion Center  

NLE Websites -- All DOE Office Websites (Extended Search)

Fusion Technology & Engineering Fusion Technology & Engineering Plasma Technology Useful Links Alcator C-Mod 5 Year Program Plan Review, May 13 - 14, 2003, PSFC NW17-218 Agenda Tuesday, May 13, 2003 8:00 Executive Session 8:30 Welcome M. Porkolab 8:40 Introduction I. Hutchinson 8:50 Charge J. Willis/R. Dagazian 9:00 Program Overview E. Marmar 10:15 Break 10:30 Advanced Tokamak Program A. Hubbard 11:20 Burning Plasma Support Program S. Wolfe 12:10 Lunch (on-site) 1:00 Facility Tour 1:30 Transport A. Hubbard 2:15 RF S. Wukitch 3:00 Break 3:15 Divertor and Edge Physics B. Lipschultz 4:00 MHD and Stability Research R. Granetz 4:30 Executive Session Wednesday, May 14, 2003 8:00 Executive Session 8:30 PPPL Collaboration G. Schilling 9:00 Operations and Facilities J. Irby

72

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

SciTech Connect

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

73

Density-dependent response of an ultracold plasma to few-cycle radio-frequency pulses  

Science Journals Connector (OSTI)

Ultracold neutral plasmas exhibit a density-dependent resonant response to applied radio-frequency (rf) fields in the frequency range of several to hundreds of megahertz for achievable densities. We have conducted measurements where short bursts of an rf fieldwere applied to these plasmas, with pulse durations as short as two cycles. We still observed a density-dependent resonant response to these short pulses, but the time scale of the response is too short to be consistent with local heating of electrons in the plasma from collisions under a range of experimental parameters. Instead, our results are consistent with rapid energy transfer to individual electrons from electric fields resulting from an overall displacement of the electron cloud from the ions during the collective motion of the electrons. This collective motion was also observed by applying two sharp electric field pulses separated in time to the plasma. These measurements demonstrate the importance of collective motion in the energy transport in these systems.

Truman M. Wilson; Wei-Ting Chen; Jacob L. Roberts

2013-01-14T23:59:59.000Z

74

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

75

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

SciTech Connect

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

76

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

SciTech Connect

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

77

DERIVING PLASMA DENSITIES AND ELEMENTAL ABUNDANCES FROM SERTS DIFFERENTIAL EMISSION MEASURE ANALYSIS  

SciTech Connect

We use high-resolution spectral emission line data obtained by the SERTS instrument during three rocket flights to demonstrate a new approach for constraining electron densities of solar active region plasma. We apply differential emission measure (DEM) forward-fitting techniques to characterize the multithermal solar plasma producing the observed EUV spectra, with constraints on the high-temperature plasma from the Yohkoh Soft X-ray Telescope. In this iterative process, we compare line intensities predicted by an input source distribution to observed line intensities for multiple iron ion species, and search a broad range of densities to optimize {chi}{sup 2} simultaneously for the many available density-sensitive lines. This produces a density weighted by the DEM, which appears to be useful for characterizing the bulk of the emitting plasma over a significant range of temperature. This 'DEM-weighted density' technique is complementary to the use of density-sensitive line ratios and less affected by uncertainties in atomic data and ionization fraction for any specific line. Once the DEM shape and the DEM-weighted density have been established from the iron lines, the relative elemental abundances can be determined for other lines in the spectrum. We have also identified spectral lines in the SERTS wavelength range that may be problematic.

Schmelz, J. T.; Kimble, J. A. [Physics Department, University of Memphis, Memphis, TN 38152 (United States); Saba, J. L. R., E-mail: jschmelz@memphis.edu [Astronomy Department, University of Maryland, College Park, MD 20742 (United States)

2012-09-20T23:59:59.000Z

78

IEEE TRANSACTIONS ON PLASMA SCIENCE, VOL. 39, NO. 11, NOVEMBER 2011 3103 Helicon Plasma Discharge in a Toroidal  

E-Print Network (OSTI)

that are perpendicular to the toroidal magnetic field and driven by a 13.56-MHz radio-frequency (RF) source at a powerIEEE TRANSACTIONS ON PLASMA SCIENCE, VOL. 39, NO. 11, NOVEMBER 2011 3103 Helicon Plasma Discharge. Ge, X. M. Wu, H. T. Ji, and J. G. Li Abstract--A helicon wave plasma (HWP) discharge in an exper

Ji, Hantao

79

Application of high?resolution interferometry to plasma density measurements on TEXT?Upgrade  

Science Journals Connector (OSTI)

High?resolution interferometry using far?infrared laser radiation is employed on TEXT?Upgrade to measure the spatial and temporal evolution of the electron density profile as well as small?scale perturbations. Perturbations to the electron density induced by naturally occurring sawtooth oscillations or externally imposed gas modulations can be used to ascertain the local particle flux and transport coefficients in the plasma interior. Density islands associated with Mirnov activity can also be resolved providing detailed information on the density profile at island X and O points. Implementation of a second orthogonal view will allow accurate determination of the density profile in the various asymmetric plasma configurations of TEXT?Upgrade.

D. L. Brower; Y. Jiang; W. A. Peebles; S. Burns; N. C. Luhmann Jr.

1992-01-01T23:59:59.000Z

80

Highly Compressed Ion Beam for High Energy Density Science  

E-Print Network (OSTI)

L . the improvement in focus when plasma was present; an ex-focus, which must be accommodated. Possible approaches include use of a strong solenoid, a plasma

2005-01-01T23:59:59.000Z

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.


81

Plasma devices to guide and collimate a high density of MeV electrons  

Science Journals Connector (OSTI)

... energetic beams will revolutionize their applications. Here we report high-conductivity devices consisting of transient plasmas that increase the energy density of MeV electrons generated in lasermatter interactions by more ... MeV electrons generated in lasermatter interactions by more than one order of magnitude. A plasma fibre created on a hollow-cone target guides and collimates electrons in a manner akin ...

R. Kodama; Y. Sentoku; Z. L. Chen; G. R. Kumar; S. P. Hatchett; Y. Toyama; T. E. Cowan; R. R Freeman; J. Fuchs; Y. Izawa; M. H. Key; Y. Kitagawa; K. Kondo; T. Matsuoka; H. Nakamura; M. Nakatsutsumi; P. A. Norreys; T. Norimatsu; R. A. Snavely; R. B. Stephens; M. Tampo; K. A. Tanaka; T. Yabuuchi

2004-12-23T23:59:59.000Z

82

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

SciTech Connect

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

83

Control of ion density distribution by magnetic traps for plasma electrons  

SciTech Connect

The effect of a magnetic field of two magnetic coils on the ion current density distribution in the setup for low-temperature plasma deposition is investigated. The substrate of 400 mm diameter is placed at a distance of 325 mm from the plasma duct exit, with the two magnetic coils mounted symmetrically under the substrate at a distance of 140 mm relative to the substrate centre. A planar probe is used to measure the ion current density distribution along the plasma flux cross-sections at distances of 150, 230, and 325 mm from the plasma duct exit. It is shown that the magnetic field strongly affects the ion current density distribution. Transparent plastic films are used to investigate qualitatively the ion density distribution profiles and the effect of the magnetic field. A theoretical model is developed to describe the interaction of the ion fluxes with the negative space charge regions associated with the magnetic trapping of the plasma electrons. Theoretical results are compared with the experimental measurements, and a reasonable agreement is demonstrated.

Baranov, Oleg; Romanov, Maxim [Plasma Laboratory, National Aerospace University 'KhAI,' Kharkov 61070 (Ukraine); Fang Jinghua [Plasma Nanoscience Centre Australia (PNCA), CSIRO Materials Science and Engineering, P.O. Box 218, Lindfield, New South Wales 2070 (Australia); School of Physics, University of Melbourne, Parkville, VIC 3010 (Australia); Cvelbar, Uros [Jozef Stefan Institute, Jamova cesta 39, SI-1000 Ljubljana (Slovenia); Ostrikov, Kostya [Plasma Nanoscience Centre Australia (PNCA), CSIRO Materials Science and Engineering, P.O. Box 218, Lindfield, New South Wales 2070 (Australia); University of Sydney, Sydney, NSW 2006 (Australia)

2012-10-01T23:59:59.000Z

84

Stable relativistic/charge-displacement channels in ultrahigh power density (?1021 W/cm3) plasmas  

Science Journals Connector (OSTI)

...the contemporary production of vigorous thermonuclear environments, the achievable power density...acceleration, and the fast ignition of fusion targets. The key to the...Rhodes C K ( 1995 ) Plasma Phys Control Fusion 37 : 569 597 . 2 Borisov A B Borovskiy...

A. B. Borisov; J. W. Longworth; K. Boyer; C. K. Rhodes

1998-01-01T23:59:59.000Z

85

Absolute atomic oxygen density profiles in the discharge core of a microscale atmospheric pressure plasma jet  

Science Journals Connector (OSTI)

The micro atmospheric pressure plasma jet is an rf driven (13.56 MHz ? 20 ? W ) capacitively coupled discharge producing a homogeneous plasma at ambient pressure when fed with a gas flow of helium (1.4 slm) containing small admixtures of oxygen ( ? 0.5 % ) . The design provides excellent optical access to the plasma core. Ground state atomic oxygen densities up to 3 10 16 ? cm ? 3 are measured spatially resolved in the discharge core by absolutely calibrated two-photon absorption laser-induced fluorescence spectroscopy. The atomic oxygen density builds up over the first 8 mm of the discharge channel before saturating at a maximum level. The absolute value increases linearly with applied power.

Nikolas Knake; Kari Niemi; Stephan Reuter; Volker Schulz-von der Gathen; Jrg Winter

2008-01-01T23:59:59.000Z

86

Observations of small-scale plasma density depletions in arecibo HF heating experiments  

SciTech Connect

Observations of incoherent scattering of electromagnetic waves at UHF from Langmuir waves by a new scheme involving linear frequency modulation (chirping) of a UHF transmitter and the demodulation (dechirping) of the received signals have been applied during HF heating experiments. These observations show that the high power HF wave used for ionospheric modification creates small-scale plasma depletions instantly on a time scale of 5 ms. For a plasma frequency of 5.1 MHz, plasma frequency gradient of the order of 50 kHz/km, and power density input of the HF heater wave of 8.0 x 10/sup -5/ W/m/sup 2/ the depletion ranged from 3 to 5%. This appears to provide direct evidence that the HF-induced modifications involve Langmuir waves trapped in density cavities. copyrightAmerican Geophysical Union 1987

Isham, B.; Birkmayer, W.; Hagfors, T.; Kofman, W.

1987-05-01T23:59:59.000Z

87

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

SciTech Connect

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

88

Magnetic topology and current channels in plasmas with toroidal current density inversions  

SciTech Connect

The equilibrium magnetic field inside axisymmetric plasmas with inversions on the toroidal current density is considered. Previous works have shown that internal regions with negative current density lead to non-nested magnetic surfaces inside the plasma. Following these results, we derive a general expression relating the positive and negative currents inside the non-nested surfaces. This is done in terms of an anisotropy parameter that is model-independent and is based in very general properties of the magnetic field. We demonstrate that the positive currents in axisymmetric islands screen the negative one in the plasma center by reaching about twice its magnitude. Further, we illustrate these results by developing a family of analytical local solutions for the poloidal magnetic field in a region of interest that contains the inverted current. These local solutions exhibit non-nested magnetic surfaces with a combined current of at least twice the magnitude of the negative one, as prescribed from the topological arguments, and allow to study topological transitions driven by geometrical changes in the current profile. To conclude, we discuss the signatures of internal current density inversions in a confinement device and show that magnetic pitch measurements may be inappropriate to differentiate current reversals and small current holes in plasmas.

Ciro, D.; Caldas, I. L. [Departamento de Fsica Aplicada, Universidade de So Paulo, 05508-090 So Paulo (Brazil)] [Departamento de Fsica Aplicada, Universidade de So Paulo, 05508-090 So Paulo (Brazil)

2013-10-15T23:59:59.000Z

89

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

SciTech Connect

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

90

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

SciTech Connect

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

91

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

Science Journals Connector (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.

Ariel Mrquez; Jos Gonzlez; Ariel Tarifeo-Saldivia; Cristian Pavez; Leopoldo Soto; Alejandro Clausse

2012-01-01T23:59:59.000Z

92

Density profile in shock wave fronts of partially ionized xenon plasmas  

Science Journals Connector (OSTI)

Results for the reflection coefficient of shock-compressed dense xenon plasmas at pressures of 1.620 GPa and temperatures around 30 000 K are interpreted. In addition to former experiments using laser beams with ? = 1.06 m, measurements at ? = 0.694 m have been performed recently. Reflectivities typical for metallic systems are found at high densities. Besides free carriers, the theoretical description also takes into account the influence of the neutral component of the plasma on the reflectivity. A consistent description of the measured reflectivities is achieved only if a finite width of the shock wave front is considered.

H Reinholz; G Rpke; I Morozov; V Mintsev; Yu Zaparoghets; V Fortov; A Wierling

2003-01-01T23:59:59.000Z

93

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

94

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

95

Current initiation in low-density foam z-pinch plasmas  

Science Journals Connector (OSTI)

Low density agar and aerogel foams were tested as z-pinch loads on the Saturn accelerator to study current flow initiation. In these first experiments we studied the initial plasma conditions by measuring the visible emission at early times with a framing camera and a streaked one-dimensional imaging system. Later near the stagnation when the plasma is hotter x-ray imaging and spectraldiagnostics were used to characterize the plasma.Filamentation and arcing at the current contacts were observed. Bright implosion features were also observed. Increasing the early time conductivity by coating the target with a high-z layer and by providing a low-current prepulse is the most important factor in obtaining good coupling to the machine. None of the pinches were uniform along the z axis. The prime causes of these problems are believed to be the electrode contacts and the current return configuration. Solutions are discussed.

M. S. Derzon; T. J. Nash; G. O. Allshouse; A. J. Antolak; M. Hurst; J. S. McGurn; D. J. Muron; J. F. Seaman; J. MacFarlane; T. Demiris; L. Hrubesh; H. Lewis; D. Ryutov; T. Barber; T. Gilliland; D. Jobe; S. Lazier

1997-01-01T23:59:59.000Z

96

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

SciTech Connect

The electron-atom neutral bremsstrahlung continuum radiation emitted from weakly ionized plasmas is investigated for electron density and temperature diagnostics. The continuum spectrum in 4501000?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 280450?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

97

Controlling Plasmas for a Cleaner World | U.S. DOE Office of Science (SC)  

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Controlling Plasmas for a Cleaner World Controlling Plasmas for a Cleaner World Fusion Energy Sciences (FES) FES Home About Research Facilities Science Highlights Benefits of FES Funding Opportunities Fusion Energy Sciences Advisory Committee (FESAC) News & Resources Contact Information Fusion Energy Sciences U.S. Department of Energy SC-24/Germantown Building 1000 Independence Ave., SW Washington, DC 20585 P: (301) 903-4941 F: (301) 903-8584 E: sc.fes@science.doe.gov More Information » October 2012 Controlling Plasmas for a Cleaner World New findings indicate that ionized plasmas like those in neon lights and plasma TVs can be used to sterilize water, making it antimicrobial for as long as a week after treatment. Print Text Size: A A A Subscribe FeedbackShare Page Click to enlarge photo. Enlarge Photo

98

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

99

Effect of low density H-mode operation on edge and divertor plasma parameters  

SciTech Connect

We present a study of the impact of H-mode operation at low density on divertor plasma parameters on the DIII-D tokamak. The line-average density in H-mode was scanned by variation of the particle exhaust rate, using the recently installed divertor cryo-condensation pump. The maximum decrease (50%) in line-average electron density was accompanied by a factor of 2 increase in the edge electron temperature, and 10% and 20% reductions in the measured core and divertor radiated power, respectively. The measured total power to the inboard divertor target increased by a factor of 3, with the major contribution coming from a factor of 5 increase in the peak heat flux very close to the inner strike point. The measured increase in power at the inboard divertor target was approximately equal to the measured decrease in core and divertor radiation.

Maingi, R. [Oak Ridge Associated Universities, Inc., TN (United States); Mioduszewski, P.K. [Oak Ridge National Lab., TN (United States); Cuthbertson, J.W. [Sandia National Labs., Albuquerque, NM (United States)] [and others

1994-07-01T23:59:59.000Z

100

Analysis of pulsed high-density HBr and Cl{sub 2} plasmas: Impact of the pulsing parameters on the radical densities  

SciTech Connect

The dynamic of charged particles in pulsed plasma is relatively well known since the 1990s. In contrast, works reporting on the impact of the plasma modulation frequency and duty cycle on the radicals' densities are scarce. In this work, we analyze the impact of these modulation parameters on the radicals' composition in Cl{sub 2} and HBr plasmas. The radicals' densities are measured by broad-band UV and vacuum-ultraviolet (VUV) absorption spectroscopy and modulated-beam mass spectrometry. We show that pulsing the rf power allows controlling the plasma chemistry and gives access to the plasma conditions that cannot be reached in continuous wave plasmas. In particular, we show that above 500 Hz, the pulsing frequency has no influence on the plasma chemistry, whereas in contrast the duty cycle is an excellent knob to control the fragmentation of the parent gas, thus the chemical reactivity of the discharge. At low duty cycle, a reduced gas fragmentation combined with a large ion flux leads to new etching conditions, compared to cw plasmas and the expected consequences on pulsed-etching processes are discussed.

Bodart, P.; Brihoum, M.; Cunge, G.; Joubert, O.; Sadeghi, N. [Laboratoire des Technologies de la Microelectronique, CNRS-LTM, 17 rue des Martyrs, Grenoble 38054 (France)

2011-12-01T23:59:59.000Z

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.
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101

INSTITUTE OF PHYSICS PUBLISHING PLASMA SOURCES SCIENCE AND TECHNOLOGY Plasma Sources Sci. Technol. 13 (2004) 309314 PII: S0963-0252(04)78552-7  

E-Print Network (OSTI)

pressure the removal rate decreases [1]. Atmospheric microwave-induced plasma sources have been studiedINSTITUTE OF PHYSICS PUBLISHING PLASMA SOURCES SCIENCE AND TECHNOLOGY Plasma Sources Sci. Technol of microwave-induced reactive low-power plasma jets Thomas Arnold1 , Sergey Grabovski2 , Axel Schindler1

Greifswald, Ernst-Moritz-Arndt-Universität

102

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)

and Nathaniel J Fisch Princeton Plasma Physics Laboratory, Princeton University, Princeton, New Jersey, 08543Plasma Sources Science and Technology Plasma Sources Sci. Technol. 23 (2014) 044005 (6pp) doi:10.1088/0963-0252/23/4/044005 Cross-field plasma lens for focusing of the Hall thruster plume Martin E Griswold, Yevgeny Raitses

103

Application of maximum likelihood methods to laser Thomson scattering measurements of low density plasmas  

SciTech Connect

Laser Thomson scattering (LTS) is an established plasma diagnostic technique that has seen recent application to low density plasmas. It is difficult to perform LTS measurements when the scattered signal is weak as a result of low electron number density, poor optical access to the plasma, or both. Photon counting methods are often implemented in order to perform measurements in these low signal conditions. However, photon counting measurements performed with photo-multiplier tubes are time consuming and multi-photon arrivals are incorrectly recorded. In order to overcome these shortcomings a new data analysis method based on maximum likelihood estimation was developed. The key feature of this new data processing method is the inclusion of non-arrival events in determining the scattered Thomson signal. Maximum likelihood estimation and its application to Thomson scattering at low signal levels is presented and application of the new processing method to LTS measurements performed in the plume of a 2-kW Hall-effect thruster is discussed.

Washeleski, Robert L.; Meyer, Edmond J. IV; King, Lyon B. [Michigan Technological University, Houghton, Michigan 49931 (United States)] [Michigan Technological University, Houghton, Michigan 49931 (United States)

2013-10-15T23:59:59.000Z

104

The National Ignition Facility: A New Era in High Energy Density Science  

SciTech Connect

The National Ignition Facility, the world's most energetic laser system, is now operational. This talk will describe NIF, the ignition campaign, and new opportunities in fusion energy and high energy density science enabled by NIF.

Moses, E

2009-06-10T23:59:59.000Z

105

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

106

The Physics of Ultrahigh-Density Magnetic Recording Series in Surface Sciences, 41)  

E-Print Network (OSTI)

1 The Physics of Ultrahigh-Density Magnetic Recording (Springer Series in Surface Sciences, 41. #550, Pittsburgh, PA 15203 + Materials Science and Engineering Department and Data Storage Systems an overview of the effects of various microstructural features on the resulting magnetic properties

Laughlin, David E.

107

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

SciTech Connect

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

108

Spectroscopic study of a long high-electron-density argon plasma column generated at atmospheric pressure  

SciTech Connect

A stable plasma column is generated in a quartz tube using a pair of hollow electrodes driven by a sinusoidal power supply of 45 kHz at atmospheric pressure in argon. Two distinct operating modes (low-current and high-current modes) are identified through observing its discharge phenomena, measuring its electrical characteristics, and determining the gas temperatures by spectroscopic diagnosis of Q branch of UV OH spectrum. The electron density in the high-current mode is diagnosed by Stark broadening and is found to be two orders higher than that in low-current mode.

Li Shouzhe; Huang Wentong; Wang Dezhen [Key Laboratory of Materials Modification by Laser, Ion and Electron Beams (Dalian University of Technology), Ministry of Education, and School of Physics and Optoelectronic Technology, Dalian University of Technology, Dalian 116023 (China)

2010-02-15T23:59:59.000Z

109

Study of magnetic configuration effects on plasma boundary and measurement of edge electron density in the spherical tokamak compact plasma wall interaction experimental device using Li sheet beam  

SciTech Connect

Two-dimensional lithium beam imaging technique has been applied in the spherical tokamak CPD (compact plasma wall interaction experimental device) to study the effects of magnetic field configurations on rf plasma boundary in the absence of any plasma current, and also for the measurement of a two-dimensional edge electron density profile. With the present working condition of the diagnostics, the minimum measured electron density can be {approx}1.0x10{sup 16} m{sup -3}; this is considered to be the definition for the plasma boundary. The performance of the lithium sheet beam is absolutely calibrated using a quartz crystal monitor. Experimental results reveal that magnetic field configuration, either mirror or so-called null, critically affects the rf plasma boundary. A sharp lower boundary is found to exist in magnetic null configuration, which is quite different from that in the weak mirror configuration. Theoretical calculations of particle drift orbit and magnetic connection length (wall-to-wall) suggest that only mirror trapped particles are confined within a region where the magnetic connection length is {approx}4.0 m or more. A two-dimensional edge electron density profile is obtained from the observed Li I intensity profile. Overdense plasma formation is discussed from the viewpoint of mode conversion of rf wave into electron Bernstein wave and its dependence on the electron density profile.

Bhattacharyay, R.; Inada, Y.; Kikukawa, T.; Watanabe, S.; Sasaki, K.; Ryoukai, T. [Interdisciplinary Graduate School of Engineering Science, Kyushu University, Kasuga, Fukuoka 816 8580 (Japan); Zushi, H.; Hasegawa, M.; Hanada, K.; Sato, K. N.; Nakamura, K.; Sakamoto, M.; Idei, H.; Yoshinaga, T.; Kawasaki, S.; Nakashima, H.; Higashijima, A. [Research Institute of Applied Mechanics, Kyushu University, Kasuga, Fukuoka 816 8580 (Japan); Morisaki, T. [National Institute for Fusion Science, Toki 509 5292 (Japan)

2008-02-15T23:59:59.000Z

110

Study of magnetic configuration effects on plasma boundary and measurement of edge electron density in the spherical tokamak compact plasma wall interaction experimental device using Li sheet beam  

Science Journals Connector (OSTI)

Two-dimensional lithium beam imaging technique has been applied in the spherical tokamak CPD (compact plasma wall interaction experimental device) to study the effects of magnetic field configurations on rf plasma boundary in the absence of any plasma current and also for the measurement of a two-dimensional edge electron density profile. With the present working condition of the diagnostics the minimum measured electron density can be ? 1.0 10 16 m ? 3 ; this is considered to be the definition for the plasma boundary. The performance of the lithium sheet beam is absolutely calibrated using a quartz crystal monitor. Experimental results reveal that magnetic field configuration either mirror or so-called null critically affects the rf plasma boundary. A sharp lower boundary is found to exist in magnetic null configuration which is quite different from that in the weak mirror configuration. Theoretical calculations of particle drift orbit and magnetic connection length (wall-to-wall) suggest that only mirror trapped particles are confined within a region where the magnetic connection length is ? 4.0 m or more. A two-dimensional edge electron density profile is obtained from the observed Li I intensity profile. Overdense plasma formation is discussed from the viewpoint of mode conversion of rf wave into electron Bernstein wave and its dependence on the electron density profile.

R. Bhattacharyay; H. Zushi; T. Morisaki; Y. Inada; T. Kikukawa; S. Watanabe; K. Sasaki; T. Ryoukai; M. Hasegawa; K. Hanada; K. N. Sato; K. Nakamura; M. Sakamoto; H. Idei; T. Yoshinaga; S. Kawasaki; H. Nakashima; A. Higashijima

2008-01-01T23:59:59.000Z

111

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

NLE Websites -- All DOE Office Websites (Extended Search)

Department of Energy's Plasma Science Center holds third annual meeting at PPPL By John Greenwald May 22, 2012 Tweet Widget Google Plus One Share on Facebook Jeff Walker, a...

112

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

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I-Mode Powers Up on Alcator C-Mod Tokamak American Fusion News Category: Massachusetts Institute of Technology (MIT) Link: MIT's Plasma Science Fusion Center: I-Mode Powers Up on...

113

MIT Plasma Science & Fusion Center: research, alcator, publications...  

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Reversal and Energy Confinement Saturation in Alcator C-Mod (APS 2011) Getting a Fusion Plasma to Take Out the Trash (APS 2011) Hot and Dense Plasmas with Low Power Loads on...

114

Fast oscillatory behavior of the excited xenon density in the discharge cells of a plasma display panel  

SciTech Connect

Fast oscillation of the excited xenon density occurs universally after an electrical discharge in the cells of a plasma display panel. A theoretical model based on ion plasma oscillation simulates this oscillatory behavior of the excited xenon density reasonably well. The magnitude and lifetime of the excited xenon density in a metastable state depend highly on the electrode configuration. Particularly, T-type electrodes provide better generation and confinement of excited xenon atoms for an abundant emission of 173 nm ultraviolet light at a high level of efficiency.

Uhm, Han S. [Department of Molecular Science and Technology, Ajou University, Suwon 443-749 (Korea, Republic of); Choi, Eun H. [Department of Electrophysics, PDP Research Center, Kwangwoon University, Seoul 139-701 (Korea, Republic of)

2009-03-15T23:59:59.000Z

115

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

SciTech Connect

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

116

Sheath model for radio-frequency-biased, high-density plasmas valid for all ?/?i  

Science Journals Connector (OSTI)

A model is proposed for sheaths in high-density discharges, with radio-frequency (rf) bias applied at frequencies ? comparable to ?i, the ion plasma frequency at the edge of the sheath. The model treats ion dynamics using fluid equations, including all time-dependent terms. Model predictions for current, impedance, and power were compared to measurements performed in high-density discharges in argon at 1.33 Pa (10 mTorr) at rf bias frequencies from 0.1 to 10 MHz (?/?i from 0.006 to 1.8) and rf bias voltages from 1 to 200 V. Model predictions were in good agreement with measurements, much better than that obtained by models that neglect time-dependent ion dynamics. In particular, differences of as much as 4050 % between power measurements and the power predicted by previous models are now explained and eliminated. The model also explains why methods of extracting plasma parameters from electrical measurements using previous sheath models may fail, and it suggests more accurate methods of extracting these parameters.

Mark A. Sobolewski

2000-12-01T23:59:59.000Z

117

Experimental test of models of high-plasma-density, radio-frequency sheaths  

Science Journals Connector (OSTI)

Measurements of the rf-bias current and voltage applied to the substrate electrode of a high-density plasma reactor, combined with dc measurements of the ion current at the electrode and capacitive probe measurements of the plasma potential, enabled a rigorous, quantitative test of models of the electrical properties of the sheath adjacent to the electrode. The measurements were performed for argon discharges at 1.33 Pa (10 mTorr), ion current densities of 1.313 mA/cm2, rf-bias frequencies of 0.110 MHz, and rf-bias voltages from less than 1 to more than 100 V. From the measurements, the current, voltage, impedance, and power of the sheath adjacent to the electrode were determined and were compared to model predictions. The properties of the opposing sheath, adjacent to grounded surfaces, were also determined. The behavior of the two sheaths ranged from nearly symmetric to very asymmetric. Changes in the symmetry are explained by models of the sheath impedance.

Mark A. Sobolewski

1999-01-01T23:59:59.000Z

118

EVIDENCE FOR GENTLY SLOPING PLASMA DENSITY PROFILES IN THE DEEP CORONA: TYPE III OBSERVATIONS  

SciTech Connect

Type III radio bursts are produced near the local electron plasma frequency f{sub p} and near its harmonic 2f{sub p} by fast electrons ejected from the solar active regions and moving through the corona and solar wind. The coronal bursts have dynamic spectra with frequency rapidly falling with time, the typical duration being about 1-3 s. In the present paper, 37 well-defined coronal type III radio bursts (25-450 MHz) are analyzed. The results obtained substantiate an earlier statement that the dependence of the central frequency of the emission on time can be fitted to a power-law model, f(t) {proportional_to} (t - t{sub 0}){sup -{alpha}}, where {alpha} can be as low as 1. In the case of negligible plasma acceleration and conical flow, it means that the electron number density within about 1 solar radius above the photosphere will decrease as r {sup -2}, like in the solar wind. For the data set chosen, the index {alpha} varies in the range from 0.2 to 7 or bigger, with mean and median values of 1.2 and 0.5, respectively. A surprisingly large fraction of events, 84%, have {alpha} {<=} 1.2. These results provide strong evidence that in the type III source regions the electron number density scales as n(r) {proportional_to} (r - r{sub 0}){sup -{beta}}, with minimum, mean, and median {beta} = 2{alpha} of 0.4, 2.4, and 1.0, respectively. Hence, the typical density profiles are more gently sloping than those given by existing empirical coronal models. Several events are found with a wind-like dependence of burst frequency on time. Smaller power-law indices could result from the effects of non-conical geometry of the plasma flow tubes, deceleration of coronal plasma, and/or the curvature of the magnetic field lines. The last effect is shown to be too weak to explain such low power-law indices. A strong tendency is found for bursts from the same group to have similar power-law indices, thereby favoring the hypothesis that they are usually produced by the same source region.

Lobzin, V. V.; Cairns, I. H.; Robinson, P. A. [School of Physics, University of Sydney, NSW 2006 (Australia); Warmuth, A.; Mann, G. [Astrophysikalisches Institut Potsdam, D 14482 Potsdam (Germany); Gorgutsa, R. V.; Fomichev, V. V. [Pushkov Institute of Terrestrial Magnetism, Ionosphere and Radiowave Propagation, 142190, Troitsk, Moscow Region (Russian Federation)

2010-12-01T23:59:59.000Z

119

Science On Saturday Archive | Princeton Plasma Physics Lab  

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Upcoming Events Events Calendar Colloquia Archive Science On Saturday Archive Research Education Organization Contact Us Upcoming Events Events Calendar Colloquia Archive Science...

120

Science on Saturday Archive | Princeton Plasma Physics Lab  

NLE Websites -- All DOE Office Websites (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...

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.


121

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

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

122

INSTITUTE OF PHYSICS PUBLISHING PLASMA SOURCES SCIENCE AND TECHNOLOGY Plasma Sources Sci. Technol. 15 (2006) 817 doi:10.1088/0963-0252/15/1/002  

E-Print Network (OSTI)

and driven by ac voltage of frequency 10 kHz. The discharge gap was 2.2 mm and 5 mm, respectively at atmospheric pressure. Usually the DBD plasma consists of many tiny microdischarges (or filamentsINSTITUTE OF PHYSICS PUBLISHING PLASMA SOURCES SCIENCE AND TECHNOLOGY Plasma Sources Sci. Technol

Greifswald, Ernst-Moritz-Arndt-Universität

123

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

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of larger Directory of Plasma Conferences list with some additions (see also the Nuclear Fusion calendar). ITPA meetings schedule Fusion meetings calendars Conference, Workshop,...

124

MIT Plasma Science & Fusion Center: research, alcator, publications...  

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of Plasma Physics, Denver, CO - 2013 Alcator Introduction Facility Information Tokamak Data & Real-Time Information Computer & Data Systems Research Program Information...

125

MIT Plasma Science & Fusion Center: research, alcator, publications...  

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of Plasma Physics, Providence, RI - 2012 Alcator Introduction Facility Information Tokamak Data & Real-Time Information Computer & Data Systems Research Program Information...

126

MIT Plasma Science & Fusion Center: research, alcator, publications...  

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of Plasma Physics, new orleans, la - 2014 Alcator Introduction Facility Information Tokamak Data & Real-Time Information Computer & Data Systems Research Program Information...

127

MIT Plasma Science & Fusion Center: research  

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Journal Articles Presentations at Scientific Meetings APSIAEA Abstracts and Posters EPS 2004 TTF 2003 International Conference on Numerical Simulation of Plasmas 2003...

128

National Science Bowl bound! | Princeton Plasma Physics Lab  

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National Science Bowl bound! National Science Bowl bound! April 28, 2013 Congratulations to Princeton High School, of Princeton, NJ for ranking 14th place in the top 16 High School teams at the National Science Bowl from April 26-30, 2012. Gallery: Out of 69 high school teams from all 50 states, Puerto Rico and the U.S. Virgin Islands, the Princeton High School Science Team placed 14th in the top 16 High School teams at the National Science bowl!! Thanks to their efforts Princeton High School will receive $1000 towards the purchase of supplies for their Science Department! Kudos to Thomas Grover Middle School for making it to and for participating at finals... They competed like champs!!! See you next year!! You can learn more about the National Science Bowl here. To learn more about the NJ Regional Science Bowl competition visit our website.

129

NJ Regional Middle School Science Bowl | Princeton Plasma Physics Lab  

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February 22, 2013, 8:00am February 22, 2013, 8:00am Science Education Lab-wide Event NJ Regional Middle School Science Bowl Teams of students are invited to participate in the Department of Energy's National Science Bowl Competition. Each year PPPL hosts the New Jersey Regional Science Bowl which decides which teams from the local area can continue onto the national competition in Washington, D.C. The Science Bowl is a double elimination contest with oral question and answer rounds in the fields of chemistry, biology, physics, astronomy and mathematics plus general and earth sciences. Questions are given in a toss-up with a bonus format. For more information, visit our Science Bowl website! Contact Information Website: NJ Regional Middle School Science Bowl Coordinator(s): Deedee Ortiz

130

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

131

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

132

Origin of protons accelerated by an intense laser and the dependence of their energy on the plasma density  

Science Journals Connector (OSTI)

We study the high-energy (14 MeV) proton production from a slab plasma irradiated by a ultrashort high-power laser. In our 2.5-dimensional particle-in-cell simulations, a p-polarized laser beam of 1.61019 W/cm2, 300 fs, ?L=1.053 ?m, illuminates a slab plasma normally; the slab plasma consists of a hydrogen plasma, and the target plasma thickness and the laser spot size are 2.5?L and 5?L, respectively. The simulation results show that an emitted proton energy depends on the slab plasma density, and three kinds of high-energy proton beams are generated at the target plasma surfaces: one kind of the proton beams is produced at the laser-illuminated target surface and accelerated to the same laser-incident side. The second is generated at the target surface opposite to the laser-illuminated target surface and is accelerated outward on the same side. The third is generated at the laser-illuminated target surface and accelerated to the opposite side while passing through the target plasma. The simulations also show a mechanism of proton accelerations. In an overdense plasma, laser energy goes to energies of hot electrons and magnetic fields in part; the electrons oscillate around the slab plasma so that a static electric field is generated and consequently protons are extracted. The magnetic field generated in the slab plasma exists longer and heats up the plasma electrons to sustain the static electric field even after the laser termination.

Takashi Nakamura and Shigeo Kawata

2003-02-06T23:59:59.000Z

133

MIT Plasma Science & Fusion Center: research> alcator> computers...  

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Publications & News Meetings & Seminars Contact Information Physics Research High-Energy- Density Physics Waves & Beams Fusion Technology & Engineering Francis Bitter...

134

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

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Publications & News Meetings & Seminars Contact Information Physics Research High-Energy- Density Physics Waves & Beams Technology & Engineering Francis Bitter Magnet...

135

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

136

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

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J. Terry Comparisons of EdgeSOL Turbulence in L- and H-mode Plasmas of Alcator C-Mod Posters Baumgaertel Marginal stability studies of microturbulence near ITB onset on Alcator...

137

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

138

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

E-Print Network (OSTI)

and Aerospace Engineering and the Center for Energy Research, University of California San Diego, 9500 Gilman significantly reduce laser energy absorbed in the solid plasma. The ionization of the density jump was confirmed , extreme ultraviolet lithography (EUVL) source 3 , and inertial fusion energy (IFE) 4 . During

Tillack, Mark

139

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

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Real-Time Information Computer & Data Systems Research Program Information Publications & News Meetings & Seminars Contact Information Physics Research High-Energy- Density...

140

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

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Energy Density Physics Waves & Beams Technology & Engineering Useful Links Program Advisory Committee Meeting Agenda, February 23 - 25, 2004 Monday, February 23, 2004 1:00 pm...

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141

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

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Publications & News Meetings & Seminars Contact Information Physics Research High-Energy- Density Physics Waves & Beams Fusion Technology & Engineering Francis Bitter Magnet...

142

New Jersey Regional Science Bowl | Princeton Plasma Physics Lab  

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New Jersey Regional Science Bowl New Jersey Regional Science Bowl Competition Overview: Each year PPPL hosts the New Jersey Regional Science Bowl which decides which teams from the local area can continue onto the national competition in Washington, D.C.! The Science Bowl is a double elimination contest with question and answer rounds in the fields of chemistry, biology, physics, astronomy, mathematics and general and earth sciences. Middle School: Teams of a coach and five middle school students (four members and an alternate) in grades 6-8 from middle schools and home schools are invited to enter. High School: Teams of a coach and five high school students (four members and an alternate) in grades 9-12 from high schools and home schools are invited to enter. The NJ Regional Competition is open to all of NJ and surrounding areas that

143

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

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

144

The effect of the driving frequency on the confinement of beam electrons and plasma density in low pressure capacitive discharges  

E-Print Network (OSTI)

The effect of changing the driving frequency on the plasma density and the electron dynamics in a capacitive radio-frequency argon plasma operated at low pressures of a few Pa is investigated by Particle in Cell/Monte Carlo Collisions simulations and analytical modeling. In contrast to previous assumptions the plasma density does not follow a quadratic dependence on the driving frequency in this non-local collisionless regime. Instead, a step-like increase at a distinct driving frequency is observed. Based on the analytical power balance model, in combination with a detailed analysis of the electron kinetics, the density jump is found to be caused by an electron heating mode transition from the classical $\\alpha$-mode into a low density resonant heating mode characterized by the generation of two energetic electron beams at each electrode per sheath expansion phase. These electron beams propagate through the bulk without collisions and interact with the opposing sheath. In the low density mode, the second bea...

Wilczek, S; Schulze, J; Schuengel, E; Brinkmann, R P; Derzsi, A; Korolov, I; Donk, Z; Mussenbrock, T

2014-01-01T23:59:59.000Z

145

High repetition rate plasma mirror device for attosecond science  

SciTech Connect

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 1kHz. 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 Applique, ENSTA-ParisTech, CNRS, Ecole Polytechnique, UMR 7639, 91761 Palaiseau (France)] [Laboratoire d'Optique Applique, 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

146

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

SciTech Connect

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 130.0132.0?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, FriedrichAlexander University at Erlangen-Nrnberg, 91058 Erlangen (Germany)

2014-03-28T23:59:59.000Z

147

IEEE TRANSACTIONS ON PLASMA SCIENCE, VOL. 28, NO. 6, DECEMBER 2000 1931 High Performance Computer Methods Applied to  

E-Print Network (OSTI)

solution-adaptive techniques, and recent fundamental advances in basic numerical methods we have develIEEE TRANSACTIONS ON PLASMA SCIENCE, VOL. 28, NO. 6, DECEMBER 2000 1931 High Performance Computer complex natural system involving many different interacting elements. Today, the science of space plasma

Stout, Quentin F.

148

Viscosity and dilepton production of a chemically equilibrating quark-gluon plasma at finite baryon density  

E-Print Network (OSTI)

By considering the effect of shear viscosity we have investigated the evolution of a chemically equilibrating quark-gluon plasma at finite baryon density. Based on the evolution of the system we have performed a complete calculation for the dilepton production from the following processes: $q\\bar{q}{\\to}l\\bar{l}$, $q\\bar{q}{\\to}gl\\bar{l}$, Compton-like scattering ($qg{\\to}ql\\bar{l}$, $\\bar{q}g{\\to}{\\bar{q}}l\\bar{l}$), gluon fusion $g\\bar{g}{\\to}c\\bar{c}$, annihilation $q\\bar{q}{\\to}c\\bar{c}$ as well as the multiple scattering of quarks. We have found that quark-antiquark annihilation, Compton-like scatterring, gluon fusion, and multiple scattering of quarks give important contributions. Moreover, we have also found that the dilepton yield is an increasing function of the initial quark chemical potential, and the increase of the quark phase lifetime because of the viscosity also obviously raises the dilepton yield.

N. N. Guan; Z. J. He; J. L. Long; X. Z. Cai; Y. G. Ma; J. W. Li; W. Q. Shen

2009-09-02T23:59:59.000Z

149

The Effects of the Scattering by Edge Plasma Density Fluctuations on Lower Hyybrid Wave Propagation  

SciTech Connect

Scattering effects induced by edge density fluctuations on lower hybrid (LH) wave propagation are investigated. The scattering model used here is based on the work of Bonoli and Ott [Phys. Fluids 25 (1982) 361]. It utilizes an electromagnetic wave kinetic equation solved by a Monte Carlo technique. This scattering model has been implemented in GENRAY , a ray tracing code which explicitly simulates wave propagation, as well as collisionless and collisional damping processes, over the entire plasma discharge, including the scrape-off layer (SOL) that extends from the separatrix to the vessel wall. A numerical analysis of the LH wave trajectories and the power deposition profile with and without scattering is presented for Alcator CMod discharges. Comparisons between the measured hard x-ray emission on Alcator C-Mod and simulations of the data obtained from the synthetic diagnostic included in the GENRAY/CQL3D package are shown, with and without the combination of scattering and collisional damping. Implications of these results on LH current drive are discussed.

Bertelli, N; Bonoli, P T; Harvey, R W; Smirnov, A P; Baek, S G; Parker, R R; Phillips, C K; Valeo, E J; Wilson, J R

2012-08-27T23:59:59.000Z

150

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

151

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

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Primary tabs View(active tab) High Resolution News Science on Saturday starts Jan. 11 By Jeanne Jackson DeVoe January 10, 2014 Tweet Widget Google Plus One Share on Facebook Joshua...

152

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

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Science on Saturday starts Jan. 11 By Jeanne Jackson DeVoe January 10, 2014 Tweet Widget Google Plus One Share on Facebook Joshua E. G. Peek, a Hubble Fellow at Columbia...

153

2012 USA Science & Engineering Festival | Princeton Plasma Physics...  

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USA Science & Engineering Festival View larger image IMG 0658 View larger image IMG 0659 View larger image IMG 0664 View larger image IMG 0667 View larger image IMG 0682 View...

154

MIT Research using High-Energy Density Plasmas at OMEGA and the NIF  

E-Print Network (OSTI)

HEDP division at MIT performs cutting-edge research using laser-generated plasmas · Recent research

155

Nanometer scale linewidth control during etching of polysilicon gates in high-density plasmas  

Science Journals Connector (OSTI)

We address some of the plasma issues encountered for ultimate silicon gate patterning that should be fixed in order to establish the long term viability of plasma processes in integrated circuits manufacturing. For sub-100-nm gate dimensions, one of ... Keywords: CMOS scaling, critical dimension control, gate patterning, plasma etching

O. Joubert; E. Pargon; J. Foucher; X. Detter; G. Cunge; L. Vallier

2003-09-01T23:59:59.000Z

156

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

SciTech Connect

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

157

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

158

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

159

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

160

Fusion and Plasmas | U.S. DOE Office of Science (SC)  

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Fusion and Fusion and Plasmas Fusion Energy Sciences (FES) FES Home About Staff Organization Chart .pdf file (104KB) FES Budget FES Committees of Visitors Directions Jobs Fusion and Plasmas Research Facilities Science Highlights Benefits of FES Funding Opportunities Fusion Energy Sciences Advisory Committee (FESAC) News & Resources Contact Information Fusion Energy Sciences U.S. Department of Energy SC-24/Germantown Building 1000 Independence Ave., SW Washington, DC 20585 P: (301) 903-4941 F: (301) 903-8584 E: sc.fes@science.doe.gov More Information » About Fusion and Plasmas Print Text Size: A A A RSS Feeds FeedbackShare Page WHAT IS FUSION? a Fusion the process that powers the sun and the stars. In one type of this reaction, two atoms of hydrogen combine together, or , to form an atom of helium. In the process some of the mass of the hydrogen is converted into energy. The easiest fusion reaction to make happen combines (or "heavy hydrogen") with (or "heavy-heavy hydrogen") to make and a . Deuterium is plentifully available in ordinary water. Tritium can be produced by combining the fusion neutron with the abundant light metal . Thus fusion has the potential to be an inexhaustible source of energy.

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,
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to obtain the most current and comprehensive results.


161

Experiments in Plasma Physics and Fusion Science on the Alcator C-Mod Tokamak J.L. Terry for the Alcator C-Mod Team1  

E-Print Network (OSTI)

the left (red) panel below.) However, such heating is not always observed - (see the right (green) panel Temperature Central Electron Density Central Electron Density Plasma Stored Energy Plasma Stored Energy 6 #12 of energy and result in high confinement

Terry, Jim

162

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

SciTech Connect

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

163

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

SciTech Connect

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

164

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

E-Print Network (OSTI)

CA, 94551, USA Princeton Plasma Physics Laboratory,Laboratory, and Princeton Plasma Physics Laboratory (theEng-48, and by the Princeton Plasma Physics Laboratory under

Logan, B.G.

2007-01-01T23:59:59.000Z

165

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

SciTech Connect

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.

Cortzar, 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); Mega-Macas, A.; Vizcano-de-Julin, 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

166

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

SciTech Connect

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.; Dppner, 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 fr Schwerionenforschung, 64291 Darmstadt (Germany); Redmer, R. [Institut fr Physik, Universitt Rostock, 18051 Rostock (Germany); and others

2014-08-15T23:59:59.000Z

167

Plasma jets and plasma bullets  

Science Journals Connector (OSTI)

Plasma plumes, or plasma jets, belong to a large family of gas discharges whereby the discharge plasma is extended beyond the plasma generation region into the surrounding ambience, either by a field (e.g. electromagnetic, convective gas flow, or shock wave) or a gradient of a directionless physical quantity (e.g. particle density, pressure, or temperature). This physical extension of a plasma plume gives rise to a strong interaction with its surrounding environment, and the interaction alters the properties of both the plasma and the environment, often in a nonlinear and dynamic fashion. The plasma is therefore not confined by defined physical walls, thus extending opportunities for material treatment applications as well as bringing in new challenges in science and technology associated with complex open-boundary problems. Some of the most common examples may be found in dense plasmas with very high dissipation of externally supplied energy (e.g. in electrical, optical or thermal forms) and often in or close to thermal equilibrium. For these dense plasmas, their characteristics are determined predominantly by strong physical forces of different fields, such as electrical, magnetic, thermal, shock wave, and their nonlinear interactions [1]. Common to these dense plasma plumes are significant macroscopic plasma movement and considerable decomposition of solid materials (e.g. vaporization). Their applications are numerous and include detection of elemental traces, synthesis of high-temperature materials and welding, laser--plasma interactions, and relativistic jets in particle accelerators and in space [2][4]. Scientific challenges in the understanding of plasma jets are exciting and multidisciplinary, involving interweaving transitions of all four states of matter, and their technological applications are wide-ranging and growing rapidly. Using the Web of Science database, a search for journal papers on non-fusion plasma jets reveals that a long initial phase up to 1990 with only 31 papers per year on average, and a total of some 1300 papers, precedes a considerable growth of some 3550% in research activity every five years, over the last 20 years or so. As shown in the table, the annual dissemination of the field is more than 1600 papers and the total number of papers is in excess of 20000. This upwards trajectory is typical of a strong and growing subject area in physical science, with considerable capacity in both fundamental science and applications. PeriodNumber of papersPapers per annum 19481990130031 199119952279456 199620003447689 200120054571914 2006201066401328 2011 1658 In many of the dense plasma jets discussed above, strong physical forces generated by the plasma are often desired and this favours plasma generation at elevated gas pressure, including atmospheric pressure, which favours a high level of gas ionization. Historically it has been challenging to reduce and control the strong physical forces in high-pressure plasmas for applications where these are unwanted, for example, surface modification of polymeric sheets [5]. Indeed, there is a real need for a vast range of material processing applications at temperatures below 100oC (or below 400 K) and this favours atmospheric-pressure plasma jets sustained far from thermal equilibrium with the dissipated electrical energy largely used not in heat generation but in unleashing non-equilibrium chemical reactions. The long-standing difficulty of effectively controlling the level of gas ionization at atmospheric pressure was overcome by the technological breakthrough of achieving atmospheric-pressure glow discharges in the late 1980s [6]. A related challenge stemming from high collisionality of atmospheric-pressure plasmas (v >> ?0) means that large-area plasmas sustained between parallel-plate electrodes are very susceptible to strong plasma instabilities when molecular gases are introduced for processing applications. This led to an effective technological solution in the early to late 1990s of confining atmospheric plasmas in a small v

M G Kong; B N Ganguly; R F Hicks

2012-01-01T23:59:59.000Z

168

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.

169

IEEE TRANSACTIONS ON PLASMA SCIENCE, VOL. 34, NO. 4, AUGUST 2006 1317 Killing of S. mutans Bacteria Using a Plasma  

E-Print Network (OSTI)

Using a Plasma Needle at Atmospheric Pressure J. Goree, Member, IEEE, Bin Liu, David Drake, and Eva-size atmospheric-pressure glow- discharge plasma or plasma needle. The plasma was applied to a culture of S. mutans plasma, plasma applica- tions, sterilization. I. INTRODUCTION ATMOSPHERIC-PRESSURE glow discharges show

Goree, John

170

Plasma density ramp for relativistic self-focusing of an intense laser  

Science Journals Connector (OSTI)

It is known that a high-power laser propagating through an underdense plasma can acquire a minimum spot size due to relativistic self-focusing. Beyond the focus, the nonlinear...

Gupta, Devki N; Hur, Min S; Hwang, Ilmoon; Suk, Hyyong; Sharma, Ashok K

2007-01-01T23:59:59.000Z

171

National Security Science  

NLE Websites -- All DOE Office Websites (Extended Search)

NSS cover - april NSS cover - april Read the April 2013 issue: web | interactive| pdf Skip to Content Skip to Search Skip to Utility Navigation Skip to Top Navigation Skip to Content Navigation Los Alamos National Laboratory submit About | Mission | Business | Newsroom | Phonebook Los Alamos National Laboratory links to site home page Science & Innovation Collaboration Careers, Jobs Community, Environment Science & Innovation Home » Science & Engineering Capabilities Accelerators, Electrodynamics Bioscience, Biosecurity, Health Chemical Science Earth, Space Sciences Energy Engineering High Energy Density Plasmas, Fluids Information Science, Computing, Applied Math Materials Science National Security, Weapons Science Nuclear & Particle Physics, Astrophysics, Cosmology

172

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.

173

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

NLE Websites -- All DOE Office Websites (Extended Search)

Science on Saturday attracts science fans of all ages Science on Saturday attracts science fans of all ages By Jeanne Jackson DeVoe January 28, 2013 Tweet Widget Facebook Like Google Plus One Joshua E. G. Peek, a Hubble Fellow at Columbia University's Department of Astronomy and son of PPPL physicist and former director Robert Goldston, discusses "Outer Space!" (Photo by Elle Starkman/PPPL Office of Communications) Joshua E. G. Peek, a Hubble Fellow at Columbia University's Department of Astronomy and son of PPPL physicist and former director Robert Goldston, discusses "Outer Space!" Gallery: High school senior Varuni Bewtra comes to the lectures to learn about possible careers in science. (Photo by Photo by Jeanne Jackson DeVoe/PPPL Office of Communications) High school senior Varuni Bewtra comes to the lectures to learn about

174

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

SciTech Connect

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 beams current, while the filaments radius is shown to be smaller than the collisionless skin depth in the plasma and primarily determined by the beams initial size. The model also accurately predicts the repartitioning ratio of the initial energy of the beams 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 beams 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 beams 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

175

MIT Plasma Science & Fusion Center: research, alcator, publications & news,  

NLE Websites -- All DOE Office Websites (Extended Search)

8th Annual Meeting of the APS Division of Plasma Physics, Philadelphia, 2006 8th Annual Meeting of the APS Division of Plasma Physics, Philadelphia, 2006 Invited Orals A. Hubbard H-mode pedestal and threshold studies over an expanded operating space on Alcator C-Mod R. Parker Lower Hybrid Current Drive Experiments in Alcator C-Mod J. Terry Investigation of Edge Localized Modes on Alcator C-Mod (talk | poster) Contributed Orals M. Bakhtiari Using Mixed Gases for Massive Gas Injection Disruption Mitigation on Alcator C-Mod I. Cziegler Structure and Characteristics of the Quasi-Coherent Mode in EDA H-mode Plasmas M. Greenwald Density peaking at low collisionality on Alcator C-Mod (pdf | powerpoint) V. Izzo Simulations of gas jet disruption mitigation B. Labombard Critical edge gradients and flows with reversed magnetic field in Alcator C-Mod

176

Quasi-monoenergetic Electron Beams from Laser-plasma Acceleration by Ionization-induced Injection in Low- density Pure Nitrogen  

E-Print Network (OSTI)

We report a laser wakefield acceleration of electron beams up to 130 MeV from laser-driven 4-mm long nitrogen gas jet. By using a moderate laser intensity (3.5*10^18 W.cm^(-2) ) and relatively low plasma densities (0.8*10^18 cm^(-3) to 2.7*10^18 cm^(-3)) we have achieved a stable regime for laser propagation and consequently a stable generation of electron beams. We experimentally studied the dependence of the drive laser energy on the laser-plasma channel and electron beam parameters. The quality of the generated electron beams is discussed within the framework of the ionization-induced injection mechanism.

Tao, Mengze; Li, Song; Mirzaie, Mohammad; Chen, Liming; He, Fei; Cheng, Ya; Zhang, Jie

2014-01-01T23:59:59.000Z

177

Observation of magnetic fluctuations and rapid density decay of magnetospheric plasma in Ring Trap 1  

SciTech Connect

The Ring Trap 1 device, a magnetospheric configuration generated by a levitated dipole field magnet, has created high-{beta} (local {beta} {approx} 70%) plasma by using electron cyclotron resonance heating (ECH). When a large population of energetic electrons is generated at low neutral gas pressure operation, high frequency magnetic fluctuations are observed. When the fluctuations are strongly excited, rapid loss of plasma was simultaneously observed especially in a quiet decay phase after the ECH microwave power is turned off. Although the plasma is confined in a strongly inhomogeneous dipole field configuration, the frequency spectra of the fluctuations have sharp frequency peaks, implying spatially localized sources of the fluctuations. The fluctuations are stabilized by decreasing the hot electron component below approximately 40%, realizing stable high-{beta} confinement.

Saitoh, H.; Yoshida, Z.; Morikawa, J.; Yano, Y.; Mikami, H.; Kasaoka, N.; Sakamoto, W. [Graduate School of Frontier Sciences, University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8561 (Japan)

2012-06-15T23:59:59.000Z

178

Secondary instability as cause of minor disruptions in density limit tokamak plasmas  

SciTech Connect

Experimental evidence was found in JET plasmas of a new instability at the onset of minor disruptions. This instability is observed during the growth of the well known m/n = 2/1 magnetic island and is localized close to it, behaving as a secondary instability to the island. The large heat fluxes towards the plasma edge, characteristic of minor disruptions, occur during the low rotation phase of the magnetic island at a time the amplitude of the secondary instability suffers a large increase. No poloidal or toroidal mode numbers could be assigned to the secondary instability.

Salzedas, F. [JET EFDA, Culham Science Centre, Abingdon, OX14 3DB (United Kingdom); Eng. Phys. Department, Faculdade de Engenharia da Universidade do Porto, Rua Roberto Frias s/n, 4200-465 Porto (Portugal); Instituto de Plasmas e Fusao Nuclear, Association Euratom-IST, Av. Rovisco Pais, 1049-001 Lisboa (Portugal); Collaboration: JET EFDA Contributors

2011-10-15T23:59:59.000Z

179

Amyloid protein SAA is an apoprotein of mouse plasma high density lipoprotein  

Science Journals Connector (OSTI)

...less cumbersome and more rapid method of thermal denaturation, which has been used to...6 M urea buffer were subjected to this thermal denaturation. Antigen solutions in the...migration (anode at bot- tom); stain, Sudan black B. plasma is illustrated in Fig...

E P Benditt; N Eriksen; R H Hanson

1979-01-01T23:59:59.000Z

180

Computational Support for Alternative Confinement Concepts Basic Plasma Science  

SciTech Connect

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

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181

Direct photoetching of polymers using radiation of high energy density from a table-top extreme ultraviolet plasma source  

Science Journals Connector (OSTI)

In order to perform material interaction studies with intense extreme ultraviolet(EUV)radiation a Schwarzschild mirror objective coated with Mo/Si multilayers was adapted to a compact laser-driven EUV plasma source utilizing a solid Au target. By 10 demagnified imaging of the plasma a maximum pulse energy density of ? 0.73 ? J / cm 2 at a wavelength of 13.5 nm can be achieved in the image plane of the objective at a pulse duration of 8.8 ns. In this paper we present EUV photoetching rates measured for polymethyl methacrylate polycarbonate and polytetrafluoroethylene at various fluence levels. A linear dependence between etch depth and applied EUV pulse number could be observed without the necessity for any incubation pulses. By evaluating the slope of these data etch rates were determined revealing also a linear behavior for low fluences. A threshold energy density could not be observed. The slope of the linear etch regime as well as deviations from the linear trend at higher energy densities are discussed and compared to data known from deep UV laser ablation. Furthermore the surface roughness of the structuredpolymers was measured by atomic force microscopy and compared to the nonirradiated polymer surface indicating a rather smooth etch process (roughness increase of 20%30%). The different shapes of the etch craters observed for the three polymers at high energy densities can be explained by the measured fluence dependence of the etch rates having consequences for the proper use of polymerablation for beam profiling of focused EUVradiation.

Frank Barkusky; Armin Bayer; Christian Peth; Klaus Mann

2009-01-01T23:59:59.000Z

182

Direct photoetching of polymers using radiation of high energy density from a table-top extreme ultraviolet plasma source  

SciTech Connect

In order to perform material interaction studies with intense extreme ultraviolet (EUV) radiation, a Schwarzschild mirror objective coated with Mo/Si multilayers was adapted to a compact laser-driven EUV plasma source utilizing a solid Au target. By 10x demagnified imaging of the plasma a maximum pulse energy density of {approx}0.73 J/cm{sup 2} at a wavelength of 13.5 nm can be achieved in the image plane of the objective at a pulse duration of 8.8 ns. In this paper we present EUV photoetching rates measured for polymethyl methacrylate, polycarbonate, and polytetrafluoroethylene at various fluence levels. A linear dependence between etch depth and applied EUV pulse number could be observed without the necessity for any incubation pulses. By evaluating the slope of these data, etch rates were determined, revealing also a linear behavior for low fluences. A threshold energy density could not be observed. The slope of the linear etch regime as well as deviations from the linear trend at higher energy densities are discussed and compared to data known from deep UV laser ablation. Furthermore, the surface roughness of the structured polymers was measured by atomic force microscopy and compared to the nonirradiated polymer surface, indicating a rather smooth etch process (roughness increase of 20%-30%). The different shapes of the etch craters observed for the three polymers at high energy densities can be explained by the measured fluence dependence of the etch rates, having consequences for the proper use of polymer ablation for beam profiling of focused EUV radiation.

Barkusky, Frank; Bayer, Armin; Peth, Christian; Mann, Klaus [Laser-Laboratorium-Goettingen e.V., Hans-Adolf-Krebs-Weg 1, D-37077 Goettingen (Germany)

2009-01-01T23:59:59.000Z

183

Investigating the Dynamics and Density Evolution of Returning Plasma Blobs from the 2011 June 7 Eruption  

E-Print Network (OSTI)

This work examines infalling matter following an enormous Coronal Mass Ejection (CME) on 2011 June 7. The material formed discrete concentrations, or blobs, in the corona and fell back to the surface, appearing as dark clouds against the bright corona. In this work we examined the density and dynamic evolution of these blobs in order to formally assess the intriguing morphology displayed throughout their descent. The blobs were studied in five wavelengths (94, 131, 171, 193 and 211 \\AA) using the Solar Dynamics Observatory Atmospheric Imaging Assembly (SDO/AIA), comparing background emission to attenuated emission as a function of wavelength to calculate column densities across the descent of four separate blobs. We found the material to have a column density of hydrogen of approximately 2 $\\times$ 10$^{19}$ cm$^{-2}$, which is comparable with typical pre-eruption filament column densities. Repeated splitting of the returning material is seen in a manner consistent with the Rayleigh-Taylor instability. Furthe...

Carlyle, Jack; van Driel-Gesztelyi, Lidia; Innes, Davina; Hillier, Andrew; Matthews, Sarah

2014-01-01T23:59:59.000Z

184

Electron density measurements of atmospheric-pressure non-thermal N2 plasma jet by Stark broadening and irradiance intensity methods  

Science Journals Connector (OSTI)

An atmospheric-pressure non-thermal plasma jet excited by high frequency alternating current using nitrogen is developed and the electron density in the active region of this plasma jet is investigated by two different methods using optical emission spectroscopy Stark broadening and irradiance intensity method. The irradiance intensity method shows that the average electron density is about 1020/m3 which is slightly smaller than that by the Stark broadening method. However the trend of the change in the electron density with input power obtained by these two methods is consistent.

2014-01-01T23:59:59.000Z

185

Radial excitation temperatures and electron number densities in a 9, 27 and 50 \\{MHz\\} inductively-coupled argon plasma  

Science Journals Connector (OSTI)

This work is the result of experiments performed on a 9, 27 and 50 \\{MHz\\} atmospheric pressure argon ICP uing the same thermometric species and instrumentation. Radiation originating from plasma volume with 0.25 mm2 projected areas were measured. The lateral observed spatially integrated radiances were transformed to radial functions by using Abel integral equations. Variations of radiances from Ca atom and ion transitions as function of observation height were studied. Two ion transitions of Ca with sufficient excitation energy difference were chosen for two-line temperature determinations, while substitution of atom to ion radiance ratios into the Saha equation were used in calculating values for the electron number density. The cooling effect of the central penetrating nebulizer gas on the plasma centres was clearly observed through a decrease in the excitation temperatures at the lowest observation heights above the r.f. coils. Experimental evidence indicates a general decrease in excitation temperature with increasing generator frequency. The same tendency was observed for the electron number density. These phenomena are probably due to the variation in skin depth at the different frequencies.

W.H. Gunter; K. Visser; P.B. Zeeman

1983-01-01T23:59:59.000Z

186

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

SciTech Connect

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 3.55.0?. 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

187

Hard TiCx/SiC/a-C:H nanocomposite thin films using pulsed high energy density plasma focus device  

Science Journals Connector (OSTI)

Abstract Thin films of TiCx/SiC/a-C:H were synthesized on Si substrates using a complex mix of high energy density plasmas and instability accelerated energetic ions of filling gas species, emanated from hot and dense pinched plasma column, in dense plasma focus device. The conventional hollow copper anode of Mather type plasma focus device was replaced by solid titanium anode for synthesis of TiCx/SiC/a-C:H nanocomposite thin films using CH4:Ar admixture of (1:9, 3:7 and 5:5) for fixed 20 focus shots as well as with different number of focus shots with fixed CH4:Ar admixture ratio 3:7. XRD results showed the formation of crystalline TiCx/SiC phases for thin film synthesized using different number of focus shots with CH4:Ar admixture ratio fixed at 3:7. SEM results showed that the synthesized thin films consist of nanoparticle agglomerates and the size of agglomerates depended on the CH4:Ar admixture ratio as well as on the number of focus shots. Raman analysis showed the formation of polycrystalline/amorphous Si, SiC and a-C for different CH4:Ar ratio as well as for different number of focus shots. The XPS analysis confirmed the formation of TiCx/SiC/a-C:H composite thin film. Nanoindentation results showed that the hardness and elastic modulus values of composite thin films increased with increasing number of focus shots. Maximum values of hardness and elastic modulus at the surface of the composite thin film were found to be about 22 and 305GPa, respectively for 30 focus shots confirming the successful synthesis of hard composite TiCx/SiC/a-C:H coatings.

Z.A. Umar; R.S. Rawat; K.S. Tan; A.K. Kumar; R. Ahmad; T. Hussain; C. Kloc; Z. Chen; L. Shen; Z. Zhang

2013-01-01T23:59:59.000Z

188

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

189

Stable relativistic/charge-displacement channels in ultrahigh power density (?1021 W/cm3) plasmas  

Science Journals Connector (OSTI)

...mankind with an origin that predates the Stone Age. From the use of a wooden club to the contemporary production of vigorous thermonuclear environments, the achievable power density (W/cm 3 ) has been advanced by approximately a factor of 20 orders of magnitude...

A. B. Borisov; J. W. Longworth; K. Boyer; C. K. Rhodes

1998-01-01T23:59:59.000Z

190

MIT Plasma Science & Fusion Center: research, alcator, publications & news,  

NLE Websites -- All DOE Office Websites (Extended Search)

Long Beach, 2001 Long Beach, 2001 Review Talk M. Greenwald Density Limits in Toroidal Plasmas Review_PDF Invited Orals A. Mazurenko An Experimental Study of ICRF Wave propagation and Mode Conversion to IBW by Phase Contrast Imaging in Alcator C-Mod Invited_PDF S.J. Wukitch Double Transport Barrier Experiments onAlcator C-Mod Invited_PDF S.J. Zweben Edge Turbulence Imaging in Alcator C-Mod Invited_PDF Contributed Orals P.T. Bonoli Analysis of ICRF Heated Internal Transport Barrier Modes in Alcator C-Mod Oral_PDF C. Boswell Inner wall Da emission on Alcator C-Mod Oral_PDF C.L. Fiore Transport Properties in Alcator C-Mod ITB Plasmas Oral_PDF J. Hughes Structure and Scalings of the H-Mode Pedestal on Alcator C-Mod Oral_PDF J. Irby Recent Results from the Alcator C-Mod Tokamak Oral_PDF

191

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

SciTech Connect

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

192

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

193

Resonant and Nonresonant Electron Cyclotron Heating at Densities above the Plasma Cutoff by O-X-B Mode Conversion at the W7-As Stellarator  

Science Journals Connector (OSTI)

The extension of the experimentally accessible plasma densities with electron cyclotron heating beyond the plasma cutoff density and the removal of the restriction to a resonant magnetic field, both via mode conversion heating from an O-wave to an X-wave and, finally, to an electron Bernstein (O-X-B) wave, was investigated and successfully demonstrated at the W7-AS stellarator. In addition to the heating effect, clear evidence for both mode conversion steps was detected for the first time.

H. P. Laqua; V. Erckmann; H. J. Hartfu; H. Laqua; W7-AS Team ECRH Group

1997-05-05T23:59:59.000Z

194

High Core Electron Confinement Regimes in FTU Plasmas with Low- or Reversed-Magnetic Shear and High Power Density Electron-Cyclotron-Resonance Heating  

Science Journals Connector (OSTI)

Electron temperatures in excess of 8 keV have been obtained by electron-cyclotron-resonance heating on FTU plasmas at peak densities up to 81019 m -3. The magnetic shear in the plasma core is low or negative, and the electron heat diffusivity remains at, or below, the Ohmic level (0.2 m 2/s), in spite of the very large heating power density (1020 MW/m 3) which produces extremely high temperature gradients (up to 120 keV/m). The ion heat transport remains at the neoclassical level.

P. Buratti et al.

1999-01-18T23:59:59.000Z

195

DIRECT RADIO PROBING AND INTERPRETATION OF THE SUN'S PLASMA DENSITY PROFILE  

SciTech Connect

The Sun's electron number density profile n{sub e} (r) is vital for solar physics but not well measured or understood within a few solar radii R{sub S} . Here, a new technique extracts n{sub e} (r) directly from coronal type III radio bursts for 40 <= f <= 180 MHz. Unexpectedly, wind-like regions with n{sub e} propor to (r - R{sub S} ){sup -2} are quite common below 2R{sub S} , and coronal type IIIs often have closely linear 1/f - t spectra. The profile n{sub e} propor to (r - R{sub S} ){sup -2} is consistent with the radio data and simulations and is interpreted in terms of conical flow from localized sources (e.g., UV funnels) close to the photosphere. It is consistent with solar wind acceleration occurring for 2 <= r/R{sub S} <= 10.

Cairns, I. H.; Lobzin, V. V.; Li, B.; Robinson, P. A. [School of Physics, University of Sydney, NSW 2006 (Australia); Warmuth, A.; Mann, G. [Astrophysikalisches Institut Potsdam, D 14482 Potsdam (Germany)

2009-12-01T23:59:59.000Z

196

Photoresist Trimming in Oxygen-Based High-Density Plasmas:? Effect of HBr and Cl2 Addition to CF4/O2 Mixtures  

Science Journals Connector (OSTI)

Cl2/CF4/O2c ... using NF3, CF4, SiF4, Cl2, HBr, and He/O2. ... Resist trimming in high-density CF4/O2 plasmas for sub-0.1 ?m device fabrication ...

Chian-Yuh Sin; Bing-Hung Chen; W. L. Loh; J. Yu; P. Yelehanka; A. See; L. Chan

2003-10-23T23:59:59.000Z

197

IEEE TRANSACTIONS ON PLASMA SCIENCE, VOL. XX, NO. Y, MONTH 1999 1 Global Particle Simulation for a Space  

E-Print Network (OSTI)

intensity in the near future. Keywords 3-D electromagnetic particle simulation, solar windIEEE TRANSACTIONS ON PLASMA SCIENCE, VOL. XX, NO. Y, MONTH 1999 1 Global Particle Simulation report progress in the long-term effort to represent the interaction of the solar wind with the Earth

Nishikawa, Ken-Ichi

198

2452 IEEE TRANSACTIONS ON PLASMA SCIENCE, VOL. 39, NO. 11, NOVEMBER 2011 Permanent-Magnet Helicon Discharge Array  

E-Print Network (OSTI)

) which are powered by radio-frequency generators. Helicon-wave sources have been found to create higher, which consists of an array of eight tubes driven in parallel by a 3.2-kW RF supply at 13.56 MHz. Between2452 IEEE TRANSACTIONS ON PLASMA SCIENCE, VOL. 39, NO. 11, NOVEMBER 2011 Permanent-Magnet Helicon

Chen, Francis F.

199

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

SciTech Connect

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

200

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

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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

Behaviour and stability of Trivelpiece-Gould modes in non-neutral plasma containing small density fraction of background gas ions  

SciTech Connect

It is shown that the frequencies of Trivelpiece-Gould (TG) modes in non-neutral plasma can get into the low-frequency range due to the Doppler shift caused by plasma rotation in crossed fields. TG modes interact with the ion modes that leads to plasma instability. In paper the frequency spectrum of 'cold' electron plasma completely filling a waveguide and containing small density fraction of ions of background gas is determined numerically. For ions the kinetic description is used. Oscillations having azimuthal number m= 2 are considered. In this case both low- and upper-hybrid TG modes get into the low-frequency range. The spectrum consists of families of 'modified' ion cyclotron (MIC) modes and electron TG modes with the frequencies equal to hybrid frequencies with the Doppler shift. The growth rates of upper-hybrid modes are much faster than the growth rates of low-hybrid and MIC modes.

Yeliseyev, Y. N. [Institute of Plasma Physics, National Science Center Kharkov Institute of Physics and Technology, Akademicheskaya St., 1, 61108 Kharkov (Ukraine)

2013-03-19T23:59:59.000Z

202

MIT Plasma Science & Fusion Center: research>alcator>  

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Physics Research Physics Research High-Energy- Density Physics Waves & Beams Technology & Engineering Useful Links earl marmar head of alcator reviewing data Dr. Earl Marmar, leader of the Alcator Project, studies C-Mod data. Today, we are closer than ever to realizing the dream of harnessing the nuclear process that powers our sun. This stellar process, called fusion, produces minimal waste and offers the hope of an almost limitless supply of safe, dependable energy. Among fusion research groups, MIT's Alcator C-Mod project is unique in its dedication to compact size and high performance. It is the world's highest magnetic field tokamak plasma confinement experiment. As a result, Alcator experiments have performed at levels rivaling the largest fusion experiments in the world.

203

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

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& Program Information & Program Information Publications & News Meetings & Seminars Contact Information Physics Research High-Energy- Density Physics Waves & Beams Fusion Technology & Engineering Plasma Technology Useful Links Collaborations at Alcator C-Mod Collaborations form an integral and important part of the Alcator C-Mod research effort. Among the major facilities, C-Mod has a relatively small scientific staff, and collaborations provide a high leverage avenue to increase our productivity. Opportunities for collaboration can be found across the entire spectrum of our research activities. Education is a primary mission of MIT, and we particularly welcome and encourage student participation in our program. The Alcator program is centered around the overall theme of: Compact

204

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

NLE Websites -- All DOE Office Websites (Extended Search)

Energy- Energy- Density Physics Waves & Beams Technology & Engineering Useful Links Program Advisory Committee Meeting Agenda, February 20-21, 2003 Thursday, February 20, 2003 8:15 Executive Session 8:30 Welcome/Introduction M. Porkolab 8:35 Introduction/Charge to PACsp; Hutchinson 8:45 Program Overview E. Marmar 9:45 Break 10:00 Advanced Tokamak Program A. Hubbard 10:50 Burning Plasma Support Program S. Wolfe 11:30 Transport Program M. Greenwald 12:10 Lunch 1:15 RF S. Wukitch 1:45 Divertor and Edge Physics Program B. Lipschultz 2:30 MHD Stability Research Program R. Granetz 3:00 Break 3:15 Executive Session 5:15 Feedback/Questions from PAC 7:00 Dinner (off-site) Friday, 21 February 2003 8:15 Executive Session 9:00 PPPL Collaboration G. Schilling

205

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

SciTech Connect

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 (23) 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

206

MIT Plasma Science & Fusion Center: research, alcator, publications & news,  

NLE Websites -- All DOE Office Websites (Extended Search)

Quebec City, 2000 Quebec City, 2000 Invited Talks Fiore, C.L. - Core Internal Transport Barriers in Alcator C-Mod Plasmas Invited PDF (0.5MB) LaBombard, B. - Particle Transport in the Scrape-Off Layer of Alcator C-Mod Invited PDF (0.7MB) Hubbard, A.E. - Pedestal Profiles and Fluctuations in C-Mod Enhanced D-alpha H-modes Invited PDF (1.0MB) Oral Presentations Boivin, R.L. - Recent Results from the Alcator C-Mod Tokamak Oral PDF (1.7MB) Rice, J.E. - Central Toroidal Rotation Reversal with ITB Formation in Alcator C-Mod Plasmas IAEA Paper PDF (0.6MB) Snipes, J.A. - Peaked Density Profiles in H-mode in Alcator C-Mod Oral PDF (0.2MB) Oral PDF (0.3MB) Greenwald, M. - Studies of EDA H-mode and Its Relation to the Micro-Stability of the Pedestal Oral PDF (0.3MB) Zweben, S.J. - Two Dimensional Imaging of Edge Turbulence in Alcator C-Mod, PPPL

207

Density sensitivity of intrinsic rotation profiles in ion cyclotron range of frequency-heated L-mode plasmas  

E-Print Network (OSTI)

The physical mechanisms that cause tokamak plasmas to rotate toroidally without external momentum input are of considerable interest to the plasma physics community. This paper documents a substantial change in both the ...

Reinke, Matthew Logan

208

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

209

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

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

210

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

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

211

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

212

LA-UR-98-3007 Submitted to IEEE Trans on Plasma Science, special issue on Images of Plasmas Plasma Tails: Comets Hale-Bopp and Hyakutake  

E-Print Network (OSTI)

the course of six months in 1996-1997. Because the dust responds to gravity and light pressure, but plasmas Alamos, NM 87544. I. M. Gladstone Jr. is an amateur astronomer and medical doctor in Eugene, Oregon

213

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

SciTech Connect

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

214

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

215

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

216

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

217

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

Office of Scientific and Technical Information (OSTI)

DOE Plasma Research DOE Plasma Research Image credit: NASA Plasma, the electrified gas that surrounds and illuminates our world, is the fourth state of matter. The behavior, nature, and complexity of plasma allows DOE scientists, research institutions and international partners to research a diverse number of applications that are significant to our world. DOE plasma theorists are developing the fundamental plasma theory and computational base needed to understand plasma. Hall thrusters are being studied that satellites and space probes use for propulsion. Research on beam dynamics is yielding applications from particle accelerators to the creation of fusion. Plasma-based systems are being developed to manufacture a radioactive element vital to medical exams. Nanomaterials are being

218

Science  

NLE Websites -- All DOE Office Websites (Extended Search)

Science newsroomassetsimagesscience-icon.png Science Cutting edge, multidisciplinary national-security science. Health Space Computing Energy Earth Materials Science...

219

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

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

220

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

E-Print Network (OSTI)

-reaching and is poised for a transformation Ambition: Fusion contributes to energy and climate solutions by mid- century 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

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

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

222

3-D particle-in-cell simulations for quasi-phase matched direct laser electron acceleration in density-modulated plasma waveguides  

E-Print Network (OSTI)

Quasi-phase matched direct laser acceleration (DLA) of electrons can be realized with guided, radially polarized laser pulses in density-modulated plasma waveguides. A 3-D particle-in-cell model has been developed to describe the interactions among the laser field, injected electrons, and the background plasma in the DLA process. Simulations have been conducted to study the scheme in which seed electron bunches with moderate energies are injected into a plasma waveguide and the DLA is performed by use of relatively low-power (0.5-2 TW) laser pulses. Selected bunch injection delays with respect to the laser pulse, bunch lengths, and bunch transverse sizes have been studied in a series of simulations of DLA in a plasma waveguide. The results show that the injection delay is important for controlling the final transverse properties of short electron bunches, but it also affects the final energy gain. With a long injected bunch length, the enhanced ion-focusing force helps to collimate the electrons and a relativ...

Lin, M -W; Chen, S -H; Jovanovic, I

2014-01-01T23:59:59.000Z

223

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

224

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

Office of Science (SC) Website

Princeton Plasma Physics Laboratory Laboratory Policy (LP) LP Home About Laboratory Appraisal Process FY 2013 Report Cards FY 2012 Report Cards FY 2011 Report Cards Report Card...

225

Particle beam dynamics | Princeton Plasma Physics Lab  

NLE Websites -- All DOE Office Websites (Extended Search)

Particle beam dynamics Particle beam dynamics Subscribe to RSS - Particle beam dynamics The study of the physics of charged particle beams and the accelerators that produce them. This cross-disciplinary area intersects with fields such as plasma physics, high-energy density science, and ultra-fast lasers. Premiere issue of "Quest" magazine details PPPL's strides toward fusion energy and advances in plasma science Quest Magazine Summer 2013 Welcome to the premiere issue of Quest, the annual magazine of the U.S. Department of Energy's Princeton Plasma Physics Laboratory (PPPL). Read more about Premiere issue of "Quest" magazine details PPPL's strides toward fusion energy and advances in plasma science Ronald C Davidson Ronald Davidson heads PPPL research on charged particle beam dynamics and

226

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.

227

MIT Plasma Science & Fusion Center: research, alcator, publications & news,  

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1st Annual Meeting of the APS Division of Plasma Physics, Atlanta, 2009 1st Annual Meeting of the APS Division of Plasma Physics, Atlanta, 2009 Invited Orals I. Cziegler Structures and Velocities of the Edge Turbulence in Alcator C-Mod M. Greenwald Verification and Validation for Magnetic Fusion: Moving Toward Predictive Capability J. Hughes Edge Pedestal and Confinement Regulation on Alcator C-Mod L. Lin Comparison of Experimental Measurements and Gyrokinetic Turbulent Electron Transport Models in Alcator C-Mod Plasmas M. Porkolab Taming Magnetically Confined Plasmas with RF Waves: a Historical Perspective S. Shiraiwa Plasma Wave Simulation Based on a Versatile FEM Solver on Alcator C-Mod D. Whyte Runaway Electron Transport & Disruption Mitigation Optimization on Alcator C-Mod Contributed Orals B. Bose Studies of Filament Formation during Lithium Pellet Injection in Alcator C-Mod

228

Calculation of the Electron Velocity Distribution Function in a Plasma Slab with Large Temperature and Density Gradients  

Science Journals Connector (OSTI)

...velocity. The distribution function for the...calculate the distribution function as a...region of the quiet Sun using several data-sets for temperature and density gradients...high-velocity tail of the distribution function. The...

1990-01-01T23:59:59.000Z

229

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

SciTech Connect

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

230

Michigan Institute for Plasma Science and Engineering Fall 2011 Seminar Series  

E-Print Network (OSTI)

Assisted Combustion Wednesday 21 September 4:00 ­ 5:00 pm 1005 EECS Special Seminar opening the MIPSE EECS Dr. Joe Borovsky AOSS and Los Alamos National Laboratory The Solar Wind Plasma Wednesday

Shyy, Wei

231

IEEE TRANSACTIONS ON PLASMA SCIENCE, VOL. 40, NO. 5, MAY 2012 1265 Guest Editorial: Special Issue on Plenary and  

E-Print Network (OSTI)

, and medical plasma applications; 6) plasma diagnostics; and 7) pulsed-power and other plasma applications energy, coherent light sources, flat-panel displays, coatings, surface modification, microscopic

Harilal, S. S.

232

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

SciTech Connect

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

233

MIT Plasma Science & Fusion Center: research, alcator, publications & news,  

NLE Websites -- All DOE Office Websites (Extended Search)

2nd Annual Meeting of the APS Division of Plasma Physics, Chicago, 2010 2nd Annual Meeting of the APS Division of Plasma Physics, Chicago, 2010 Invited Orals A. Hubbard I-mode regime with an edge energy transport barrier but no particle barrier in Alcator C-Mod B. LaBombard Scaling of the power exhaust channel in Alcator C-Mod A. Loarte High confinement/high radiated power H-mode experiments in Alcator C-Mod and consequences for ITER Qdt=10 operation A. Schmidt Investigation of LH physics through power modulation experiments on Alcator C-Mod Contributed Orals A. Bader Investigating highly energetic ions in the Alcator C-Mod tokamak D. Ernst Using modulated on-axis ICRH to control fluctuations in an internal transport barrier C. Fiore The role of rotation in C-Mod internal transport barriers R. Granetz Effect of plasma configuration on disruption runaway electrons

234

Fusion through the eyes of a veteran science journalist | Princeton Plasma  

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Fusion through the eyes of a veteran science journalist Fusion through the eyes of a veteran science journalist July 15, 2013 Tweet Widget Facebook Like Google Plus One Daniel Clery (Photo by Sadie Windscheffel-Clarke) Daniel Clery Gallery: Author Daniel Clery recently published "A Piece of the Sun," a 320-page narrative of the history of fusion research and the personalities who have devoted their careers to it. Clery is a United Kingdom-based reporter for Science magazine who holds a bachelor's degree in theoretical physics from York University and has covered fusion for more than a decade. While hardly an uncritical flag-waver for fusion, he recognizes its vast potential. He discussed his new book and the future of fusion with PPPL Science Writer John Greenwald. How did you gather your detailed information from labs like PPPL?

235

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

236

Interdisciplinary plasma theory workshop | Princeton Plasma Physics...  

NLE Websites -- All DOE Office Websites (Extended Search)

Science sponsored the week-long event with additional support from the Max Planck-Princeton Center for Plasma Physics, whose members include PPPL and the Princeton...

237

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

NLE Websites -- All DOE Office Websites (Extended Search)

Fusion Technology Fusion Technology & Engineering Plasma Technology Useful Links Program Advisory Committee Meeting Agenda, March 2-4, 211 Wednesday, March 2, 2011 8:30 Executive Session R. Hawryluk 9:00 Welcome and Charge M. Porkolab 9:10 Program Introduction E. Marmar 9:40 Facilities and Upgrades J. Irby 10:40 Break 10:55 Transport M. Greenwald 11:35 Pedestal J. Hughes 12:05 Lunch 13:05 Plasma Boundary B. Lipschultz 13:55 Macrostability R. Granetz 14:15 DNB R. Granetz 14:25 LHRF: Status G. Wallace 14:45 LHRF: Plans R. Parker 15:05 ITER Baseline Scenarios S. Wolfe 15:45 Executive Session R. Hawryluk 17:45 Feedback and Questions to C-Mod Staff R. Hawryluk 18:15 Adjourn 19:00 Dinner - Sidney's Grille at Le Meridien Thursday, March 3, 2011 8:30 Executive Session R. Hawryluk

238

Education | Princeton Plasma Physics Lab  

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Education Science Education Welcome to the Science Education Department at the Princeton Plasma Physics Laboratory (PPPL), where we combine the lab's core research activities with...

239

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

NLE Websites -- All DOE Office Websites (Extended Search)

Fusion Technology Fusion Technology & Engineering Plasma Technology Useful Links Program Advisory Committee Meeting Agenda, February 6-8, 2008 Wednesday, February 6, 2008 8:30 am Executive Session Chuck Kessel 9:00 am Welcome & Charge Miklos Porkolab 9:10 am Comments from DoE Rostom Dagazian 9:15 am Program Overview Earl Marmar 10:05 am Transport Martin Greenwald 10:45 am Break 11:00 am ICRF Steve Wukitch 11:30 am LHRF Ron Parker 12:00 pm Lunch (on-site) 1:00 pm Macro-Stability Bob Granetz 1:30 pm Pedestal Physics Jerry Hughes 2:00 pm Plasma-Boundary Bruce Lipschultz 2:45 pm Break 3:00 pm Int. Scen.: ITER H-Mode Baseline Steve Wolfe 3:30 pm Int. Scen.: Advanced Scenarios Amanda Hubbard 4:00 pm Theory and Modeling Paul Bonoli 4:40 pm Executive Session 5:30 pm Adjourn

240

MIT Plasma Science & Fusion Center: research>alcator>Conference Room  

NLE Websites -- All DOE Office Websites (Extended Search)

Density Physics Density Physics Waves & Beams Technology & Engineering Useful Links Conference Rooms The PSFC is using google apps for education to support calendars for shared resources. There are currently two calendars implemented. One for the Alcator C-Mod Run Schedule, and one to schedule the NW17-132 conference room. These links will display read only views of the calendars. In order to schedule the conference room visit your personal psfc calendar as described below. In order to view these calendars you must be signed in to the g-apps.psfc.mit.edu domain. When prompted by https://sso.psfc.mit.edu/ for a username and password, enter your PSFC login credentials. After you authenticate for the first time, you get a screen which asks you to accept new account. Note that: THIS IS DIFFERENT AND SEPARATE FROM YOUR OTHER GOOGLE

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

Advances in compact proton spectrometers for inertial-confinement fusion and plasma nuclear science  

SciTech Connect

Compact wedge-range-filter proton spectrometers cover proton energies {approx}3-20 MeV. They have been used at the OMEGA laser facility for more than a decade for measuring spectra of primary D{sup 3}He protons in D{sup 3}He implosions, secondary D{sup 3}He protons in DD implosions, and ablator protons in DT implosions; they are now being used also at the National Ignition Facility. The spectra are used to determine proton yields, shell areal density at shock-bang time and compression-bang time, fuel areal density, and implosion symmetry. There have been changes in fabrication and in analysis algorithms, resulting in a wider energy range, better accuracy and precision, and better robustness for survivability with indirect-drive inertial-confinement-fusion experiments.

Seguin, F. H.; Sinenian, N.; Rosenberg, M.; Zylstra, A.; Manuel, M. J.-E.; Sio, H.; Waugh, C.; Rinderknecht, H. G.; Johnson, M. Gatu; Frenje, J.; Li, C. K.; Petrasso, R. [Plasma Science and Fusion Center, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States); Sangster, T. C.; Roberts, S. [Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623 (United States)

2012-10-15T23:59:59.000Z

242

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

NLE Websites -- All DOE Office Websites (Extended Search)

Program Program Information Publications & News Meetings & Seminars Contact Information Physics Research Fusion Technology & Engineering Plasma Technology Waves & Beams Useful Links Quarterly Review, Thursday, July 14, 2005 10:00 Steve Wolfe: Status of the run campaign, and research operations weeks JOULE target 10:15 Yijun Lin: Status of "all metal wall" JOULE target 10:30 Ron Parker: Lower Hybrid status 10:45 Jim Irby: Cryopump status 10:55 Bob Granetz: DNB status 11:05 Bob Granetz: Disruption mitigation by massive gas puff -- experiments and plans 11:15 Brian LaBombard: Rotation and H-mode scrape-off layer flows, the role of the X-point and connections to the L-H power threshold in Alcator C-Mod 77 Massachusetts Avenue, NW16, Cambridge, MA 02139, info@psfc.mit.edu

243

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

244

Measurement of electron densities by a microwave cavity method in 13.56-MHz RF plasmas of Ar, CF4, C2F6, and CHF3  

Science Journals Connector (OSTI)

Electron densit ies have been determined /or RF plasmas that were generated within a microwave resonant cavity by measuring the difference of the resonance frequencies with and without plasma. Since that metho...

M. Haverlag; G. M. W. Kroesen; T. H. J. Bisschops

1991-09-01T23:59:59.000Z

245

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

SciTech Connect

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.; Dpp, A.; Cros, B. [Laboratoire de Physique des Gaz et des Plasmas, CNRS-Universit Paris-Sud, 91405 Orsay (France)] [Laboratoire de Physique des Gaz et des Plasmas, CNRS-Universit Paris-Sud, 91405 Orsay (France); Svensson, K.; Genoud, G.; Wojda, F.; Burza, M.; Persson, A.; Lundh, O.; Wahlstrm, 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 Cientficas y Tcnicas (CONICET) and CNEA-CAB (Argentina)] [Consejo Nacional de Investigaciones Cientficas y Tcnicas (CONICET) and CNEA-CAB (Argentina)

2013-08-15T23:59:59.000Z

246

Research | Princeton Plasma Physics Lab  

NLE Websites -- All DOE Office Websites (Extended Search)

Overview Experimental Fusion Research Theoretical Fusion Research Basic Plasma Science Plasma Astrophysics Other Physics and Engineering Research PPPL Technical Reports Education Organization Contact Us Overview Experimental Fusion Research Theoretical Fusion Research Basic Plasma Science Plasma Astrophysics Other Physics and Engineering Research PPPL Technical Reports Research The U.S. Department of Energy's Princeton Plasma Physics Laboratory is dedicated to developing fusion as a clean and abundant source of energy and to advancing the frontiers of plasma science. The Laboratory pursues these goals through experiments and computer simulations of the behavior of plasma, the hot electrically charged gas that fuels fusion reactions and has a wide range of practical applications.

247

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

NLE Websites -- All DOE Office Websites (Extended Search)

February 4-6, 2009 February 4-6, 2009 Wednesday, February 4, 2009 8:30 am Executive Session R. Hawryluk 9:00 am Welcome & Charge M. Porkolab 9:10 am Comments from DoE R. Dagazian 9:15 am Program Overview E. Marmar 10:15 am Break 10:30 am Facilities and Upgrade J. Irby 11:10 am Alternator Status R. Granetz 11:30 am Lower Hybrid RF R. Parker 12:00 pm Lunch (on-site) 1:00 pm ICRF S. Wukitch 1:30 pm Plasma Boundary B. Lipschultz 2:20 pm Pedestal J. Hughes 2:40 pm Break 2:55 pm Transport J. Hughes 3:25 pm Macrostability R. Granetz 3:45 pm Executive Session R. Hawryluk 5:30 pm Feedback and Questions to C-Mod Staff R. Hawryluk 5:45 pm Adjourn 6:30 pm Working Dinner Off-Site (if desired) Thursday, February 5, 2009 8:30 am Executive Session R. Hawryluk 9:00 am

248

MIT Plasma Science & Fusion Center: research>alcator>facility info  

NLE Websites -- All DOE Office Websites (Extended Search)

Density Physics Waves & Beams Technology & Engineering Useful Links Alcator C-Mod Criteria for Design of Vacuum Components This document is meant to be a guideline for design and construction of components that interface with the CMOD vacuum system. It does not intend to cover all situations but instead is designed to start one thinking about the problems encountered in constructing a successful device that will operate in the Alcator vacuum environment without causing any unwanted effect on the quality of that vacuum. Material Selection The Alcator vacuum vessel is made from 304L SS, as are most of the support devices and diagnostic assemblies in the vacuum. Other than Molybdenum on the limiters and in the divertor, this is the predominate material used in

249

MIT Plasma Science & Fusion Center: research> alcator>tokamak data &  

NLE Websites -- All DOE Office Websites (Extended Search)

ALCATOR C-Mod ALCATOR C-Mod Alcator Introduction Facility Information Tokamak Data & Real-Time Information Computer & Data Systems Research Program Information Publications & News Meetings & Seminars Contact Information Physics Research High-Energy- Density Physics Waves & Beams Technology & Engineering Useful Links Tokamak Data & Real-time Information Shot cycle display Web cameras Live video and audio from the control room - coming soon Network AC Power Switches (Authorized access only) Compact PCI Acquisition Hardware status (Local access only) Data from latest shot Logbook (Authorized access only) Engineering status Cryo Report Heat Report Torvac Report RGA Report Glow Discharge Report Engineering Reports Signals table lookup Descriptions of the signals stored in the C-Mod data set. Names, Units,

250

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

SciTech Connect

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

251

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.

252

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

253

High-Fidelity Simulation of Tokamak Edge Plasma Transport | Argonne...  

NLE Websites -- All DOE Office Websites (Extended Search)

Plasma density fluctuation from large amplitude nonlinear turbulence in the tokamak edge region, obtained from the gyrokinetic code XGC1 Plasma density fluctuation from large...

254

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

E-Print Network (OSTI)

with an external antenna carrying a radio-frequency (RF) current, usually at the industrial frequency of 13.56 MHz, radio-frequency plasma, transport barrier. I. INTRODUCTION ATHOUGH plasmas were first studied in weakly Transport in RF Plasmas Francis F. Chen, Life Fellow, IEEE Abstract--Three examples are given of experiments

Kaganovich, Igor

255

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

256

Thermionic energy conversion plasmas  

SciTech Connect

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

257

Frontiers for Discovery in High Energy Density Physics  

SciTech Connect

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

258

Science  

Science Journals Connector (OSTI)

As a self-confessed purveyor of ``frequently outrageous views,'' Steve Fuller can be relied on for a spirited and provocative text - and so this proves. Jerry Ravetz's gushing endorsement on the back cover claims that the public's understanding of science ``will never be the same again'' and that the book proves Steve Fuller to be ``actually science's best friend.'' But those of an orthodox scientific persuasion (though perhaps not his intended audience) are likely to be provoked into dyspeptic displeasure by the first few sideswipes at what they hold most dear. This short text comprises one volume of the series `` Concepts in Social Science,'' in publishing order sandwiched between Rights and Liberalism. Its expressed aim is that the reader come away thinking ``that the idea and institution of `science' go to the very heart of what the social sciences are about.'' In a style that is always inspired but for all save the cognoscenti can sometimes verge on the abstruse, Fuller argues that social and scientific realities are inextricably intertwined. Science's implausible knowledge claims of detachment and objectivity succeed only in perpetuating self-delusion, sowing the seeds for science's own demise. For those familiar with the sociology of scientific knowledge (SSK) debates, the overall message will not be entirely new - and indeed the book is in part a reworking of some of Fuller's previously-published journal articles - but the liveliness of this contentious prose and its immodest, sweeping polemical style present a critical case against science that is often uncomfortably near the bone. What is impressive is Fuller's intellectual boldness in weaving together a wealth of sociological, philosophical and historical arguments that aim to reveal for public scrutiny the true nature of science. The picture of science created is of its frailty and everydayness - qualities that Fuller claims have been disguised by an unattractive mix of intellectual cunning and social naivet from scientists. Fuller portrays a lay public that combines insight and innocence. Sometimes the public can see through science's ploys for extravagant research proposals, thereby ``displaying a fundamentally sound instinctive response to science.'' At other times, the public is foolish enough to regard scientific knowledge as distinct and authoritative - ``reliable'' lay beliefs about science he says are sadly rare. Thus, in Fuller's eyes, misunderstandings of science abound. Whereas some critics see the yearly panjandrum that constitutes Science Weeks as a clumsy and politically naive stab at ``public relations,'' Fuller sees darker forces of ignorance at work - ``evidence of the scientific community misunderstanding something significant about the social conditions that enable its existence.'' Tackling the public understanding of science (PUS) debate in such a spirit in Chapter 1 sets the tone for the protracted dissection of science that follows. But Fuller's aim is more to do with the revelation of sociological phenomena than with ridicule of science. For example, in Chapter 2 the idiosyncrasies of particular scientific disciplines are picked apart (in the best sociological tradition, physics comes in for a good deal of epistemological stick). Fuller succeeds in portraying the various branches of science as fundamentally different, with distinct working practices shaped by different histories and presumptions. Why, the author then muses, are interdisciplinary wars within science rare, in contrast to social science? With such questions to crack, science is rich pickings for sociological inquiry. In Chapter 3, Fuller's concern is the many-layered meanings of the terms science, scientific and scientists. Here the author takes us through the sociological and philosophical twists and turns of meaning with ideological ease, neatly contrasting today's science with that of the past. For example, long gone is science's unquestioned claim always to serve the best interest of the state; now science is self-serving. Much missed too is science's ability to stab

Jeff Thomas, Centre for Science Education, The Open

1998-01-01T23:59:59.000Z

259

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 capacitively coupled CF4/H2 plasmas (CCP) with rf (13.56 MHz) powers up to 200 W. Rotational of the feed gas (e.g. CF4 or C4F8) but also play an important role in the etching and deposition process

Greifswald, Ernst-Moritz-Arndt-Universität

260

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

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

PathSci | Princeton Plasma Physics Lab  

NLE Websites -- All DOE Office Websites (Extended Search)

PathSci The Princeton Plasma Physics Laboratory's Pathways to Science program is now partnering with ARISE (Advanced Research and Innovation in Science Education) and the...

262

SCIENCE  

Science Journals Connector (OSTI)

SCIENCE ... Sedoheptulose phosphate may be an important intermediate in carbohydrate metabolism in animals as well as in plants, the NIH scientists observe. ... NOL Makes Magnetic Material ...

1952-06-23T23:59:59.000Z

263

Large Scale Computing and Storage Requirements for Fusion Energy Sciences Research  

E-Print Network (OSTI)

General Plasma Science Magnetic Fusion Energy Magneticfor Fusion Energy Sciences Magnetic Fusion Plasma from the crosscutting science of magnetic reconnection and

Gerber, Richard

2012-01-01T23:59:59.000Z

264

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

265

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

266

44 IEEE TRANSACTIONS ON PLASMA SCIENCE, VOL. 27, NO. 1, FEBRUARY 1999 Ultraviolet Imaging of the Anode Attachment  

E-Print Network (OSTI)

of the Anode Attachment in Transferred-Arc Plasma Cutting Byron L. Bemis and Gary S. Settles Abstract-- The anode phenomena occurring at the location of current transfer from the plasma jet to the plate affects imaging technique was used to visualize the anode attachment spot under various cut- ting conditions

Settles, Gary S.

267

1134 IEEE TRANSACTIONS ON PLASMA SCIENCE, VOL. 36, NO. 4, AUGUST 2008 Soft X-Ray Laser Interferometry of Colliding  

E-Print Network (OSTI)

) accelerates plasma toward the axis of the cavity where plasma interactions can range from stagnation received November 30, 2007. This work was supported by the National Nuclear Security Administration under by a vacuum spatial filter, and it was shaped into a 310-m-wide 1.5-mm-FWHM-long line focus by a pair

Rocca, Jorge J.

268

PPPL Open House | Princeton Plasma Physics Lab  

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June 1, 2013, 9:00am to 4:00pm Open House at Princeton Plasma Physics Laboratory PPPL Open House Hot Plasma, Cool Science: Princeton Plasma Physics Lab Open House on June 1 Mark...

269

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

SciTech Connect

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

270

Working Principle of the Hollow-Anode Plasma Source Hollow-Anode Plasma  

NLE Websites -- All DOE Office Websites (Extended Search)

36240 36240 Plasma Sources Science and Technology 4 (1995) 571-575. Working Principle of the Hollow-Anode Plasma Source André Anders and Simone Anders Lawrence Berkeley National Laboratory, University of California, Berkeley, CA 94720 ABSTRACT The hollow-anode discharge is a special form of glow discharge. It is shown that a drastically reduced anode area is responsible for a positive anode voltage drop of 30-40 V and an increased anode sheath thickness. This leads to an ignition of a relatively dense plasma in front of the anode hole. Langmuir probe measurements inside a specially designed hollow anode plasma source give an electron density and temperature of n e = 10 9 -10 11 cm -3 and T e = 1 - 3 eV, respectively (nitrogen, current 100 mA, flow rate 5-50 scc/min). Driven by a pressure gradient, the "anode" plasma is blown through the anode hole and forms a bright plasma jet streaming with supersonic velocity (Mach number 1.2). The plasma stream can be used, for instance, in plasma-assisted deposition of thin films

271

Princeton Plasma Physics Lab - Particle beam dynamics  

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particle-beam-dynamics The study of particle-beam-dynamics The study of the physics of charged particle beams and the accelerators that produce them. This cross-disciplinary area intersects with fields such as plasma physics, high-energy density science, and ultra-fast lasers. en Premiere issue of "Quest" magazine details PPPL's strides toward fusion energy and advances in plasma science http://www.pppl.gov/news/2013/09/premiere-issue-quest-magazine-details-pppls-strides-toward-fusion-energy-and-advances-0

272

518 IEEE TRANSACTIONS ON PLASMA SCIENCE, VOL. 34, NO. 3, JUNE 2006 Operational Characteristics of a 14-W 140-GHz  

E-Print Network (OSTI)

002026. C. D. Joye, M. A. Shapiro, J. R. Sirigiri, R. J. Temkin, and P. P. Woskov are with the Plasma Rosay, Michael A. Shapiro, Member, IEEE, Jagadishwar R. Sirigiri, Member, IEEE, Richard J. Temkin

Griffin, Robert G.

273

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

274

SCIENCE  

Science Journals Connector (OSTI)

SCIENCE ... Neutral V-particles were first discovered in 1947 at the University of Manchester where researchers observed v-shaped tracks in a magnetic cloud chamber exposed to cosmic rays. ...

1953-08-17T23:59:59.000Z

275

2512 IEEE TRANSACTIONS ON PLASMA SCIENCE, VOL. 36, NO. 5, OCTOBER 2008 Experimental Investigation of 193-nm  

E-Print Network (OSTI)

-initiated electron cascading plasma process begins when a pulsed laser beam is focused down to a small spatial domain of 193-nm Laser Breakdown in Air Magesh Thiyagarajan, Member, IEEE, and John E. Scharer, Senior Member, IEEE Abstract--We present the measurements and analysis of laser- induced breakdown processes in dry

Scharer, John E.

276

ADVANCES IN APPLIED PLASMA SCIENCE, Vol.9, 2013 ISAPS '13, Istanbul Dynamic Simulation of Materials Modification and Deuterium  

E-Print Network (OSTI)

Hassanein Center for Materials Under eXtreme Environment, School of Nuclear Engineering Purdue University of Materials Modification and Deuterium Retention in Tokamak Fusion Environment Tatyana Sizyuk and Ahmed environment and plasma performance. In this regard, mixing and degradation of materials at the surface layers

Harilal, S. S.

277

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.

278

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

279

Fundamentals of Plasma Physics  

E-Print Network (OSTI)

Fundamentals of Plasma Physics James D. Callen University of Wisconsin, Madison June 28, 2006 #12;PREFACE Plasma physics is a relatively new branch of physics that became a mature science over the last half of the 20th century. It builds on the fundamental areas of classical physics: mechanics

Callen, James D.

280

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

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

Science  

NLE Websites -- All DOE Office Websites (Extended Search)

149802 149802 , 1291 (2007); 318 Science et al. L. Ozyuzer, Superconductors Emission of Coherent THz Radiation from www.sciencemag.org (this information is current as of November 29, 2007 ): The following resources related to this article are available online at http://www.sciencemag.org/cgi/content/full/318/5854/1291 version of this article at: including high-resolution figures, can be found in the online Updated information and services, http://www.sciencemag.org/cgi/content/full/318/5854/1291/DC1 can be found at: Supporting Online Material found at: can be related to this article A list of selected additional articles on the Science Web sites http://www.sciencemag.org/cgi/content/full/318/5854/1291#related-content http://www.sciencemag.org/cgi/content/full/318/5854/1291#otherarticles

282

SCience  

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all all SCience Chicago Office Environment, Safety and Health Functions, Responsibilities, and Authorities Manual December 2012 ~5 {?JI-- l L-H1- I Roxanne E. Purucker, Manager Date SC-CH FRAM Revision 7 Office of Science - Chicago Office SC-CH Revision History TITLE: SC-CH Functions, Responsibilities, and Authorities Manual POINT OF CONTACT: Karl Moro SCMS MANAGEMENT SYSTEM: Environment, Safety and Health (ES&H) TO BE UPDATED: December 31, 2013 Revision Date Reason/Driver Description 5 Oct 10 Annual review and revision of the SC-CH ES&H Functions, Responsibilities, and Authorities Manual Changes were primarily made to address administrative and organizational changes and general improvement of text and presentation. I 6 Nov 11 Annual review and revision of

283

2009 US-Japan Workshop on Advanced Simulation Methods in Plasma Physics Advanced Target Design for Fast Ignition  

E-Print Network (OSTI)

Institute for Fusion Science, Toki 509-5292, Japan Fast ignition is an attractive scheme in laser fusion [1]. In Fast Ignition, at first high- density fuel core plasma is assembled by implosion laser, and then, just target for Fast Ignition is a shell fitted with a reentrant gold cone to make a pass for heating laser

Ito, Atsushi

284

X-ray emission from the plasma is used as a proxy for the amount  

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X-ray emission from the plasma is used as a proxy for the amount X-ray emission from the plasma is used as a proxy for the amount of driven current. The solid line indicates the amount of x-ray emission predicted by a computer simulation if edge losses are not included, while the dashed line represents the computer simulation including edge losses. The colored points are experimental data from Alcator C-Mod. Contact: Gregory Wallace MIT Plasma Science and Fusion Center 175 Albany St. Cambridge, MA 02139 wallaceg@mit.edu Post deadline invited talk: Lower hybrid current drive at high density in the multi-pass regime A post-deadline invited talk explains how experiments on the Alcator C-Mod tokamak at the MIT Plasma Science and Fusion Center are making important steps towards learning how to keep future fusion power plants running 24/7.

285

AFRD - Fusion Energy Science  

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Heavy Ion Fusion Virtual National Laboratory Heavy Ion Fusion Virtual National Laboratory AFRD - Fusion Energy Sciences AFRD - Home Fusion - Home HIF-VNL Website Ion Beam Technology Group website Artist's conception of a heavy ion fusion power plant Artist's conception of an IFE powerplant We further inertial fusion energy as a future power source, primarily through R&D on heavy-ion induction accelerators. Our program is part of a "Virtual National Laboratory," headquartered in AFRD, that joins us with Lawrence Livermore National Laboratory and the Princeton Plasma Physics Laboratory in close collaboration on inertial fusion driven by beams of heavy ions. The related emergent science of high-energy-density physics (HEDP) has become a major focus. For further synergy, we have combined forces with the former Ion Beam

286

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

287

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

288

Perspective on the Role of Negative Ions and Ion-Ion Plasmas in Heavy Ion Fusion Science, Magnetic Fusion Energy, and Related Fields  

E-Print Network (OSTI)

1 and J. W. Kwan 2 Princeton Plasma Physics Laboratory, P.California 94720 and Princeton Plasma Physics Laboratory P.Department of Energy by Princeton Plasma Physics Laboratory

Kwan, J.W.

2008-01-01T23:59:59.000Z

289

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

290

Current Drive in Recombining Plasma  

SciTech Connect

The Langevin equations describing the average collisional dynamics of suprathermal particles in nonstationary plasma remarkably admit an exact analytical solution in the case of recombining plasma. The current density produced by arbitrary particle fluxes is derived including the effect of charge recombination. Since recombination has the effect of lowering the charge density of the plasma, thus reducing the charged particle collisional frequencies, the evolution of the current density can be modified substantially compared to plasma with fixed charge density. The current drive efficiency is derived and optimized for discrete and continuous pulses of current, leading to the discovery of a nonzero "residual" current density that persists indefinitely under certain conditions, a feature not present in stationary plasmas.

P.F. Schmit and N.J. Fisch

2012-05-15T23:59:59.000Z

291

Perspective on the Role of Negative Ions and Ion-Ion Plasmas in Heavy Ion Fusion Science, Magnetic Fusion Energy, and Related Fields  

E-Print Network (OSTI)

in Heavy Ion Fusion Science, Magnetic Fusion Energy, andin Heavy Ion Fusion Science, Magnetic Fusion Energy, and

Kwan, J.W.

2008-01-01T23:59:59.000Z

292

Plasma Chemistry and Plasma Processing, Vol. 12, No.4, 1992 Infrared Radiation from an Arc Plasma and Its  

E-Print Network (OSTI)

of an atmospheric-pressure arc plasma are described from the viewpoint of continuorts radiation tlieory of the atmospheric arc plasma column is very sensitive to the electron density in the near infrared frequency rangeB ) Plasma Chemistry and Plasma Processing, Vol. 12, No.4, 1992 Infrared Radiation from an Arc

Eagar, Thomas W.

293

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

SciTech Connect

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

294

Nonlinear Mixing of Electromagnetic Waves in Plasmas  

Science Journals Connector (OSTI)

...nc, where ne is the plasma density and n, is...regions X(3) ofa plasma can be orders of magnitude larger than those for other...Conclusions The beat-wave plasma interaction is an important...rapidly growing research area in plasma physics and...

V. STEFAN; B. I. COHEN; C. JOSHI

1989-01-27T23:59:59.000Z

295

Ultraprecision Finishing of Photomask Substrate by Utilizing Atmospheric Pressure Plasma  

Science Journals Connector (OSTI)

In the case of the atmospheric pressure plasma, localized high density plasma is generated around the electrode. Therefore, ... new ultra precision machining method which is named plasma chemical vaporization mac...

Kazuya Yamamura; Akihiro Fujiwara; Koji Ueno

2007-01-01T23:59:59.000Z

296

Better Fusion Plasma Operating Scenarios are Being Explored and...  

Office of Science (SC) Website

can be accessed at relatively low plasma density, and then maintained as both density and power to the plasma are increased, as is expected to be the approach on ITER. Summary...

297

Princeton Plasma Physics Lab - Inertial confinement fusion  

NLE Websites -- All DOE Office Websites (Extended Search)

inertial-confinement-fusion An inertial-confinement-fusion An experimental process that uses lasers to compress plasma to sufficiently high temperatures and densities for fusion to occur. Such experiments are carried out in places such as the National Ignition Facility at the Lawrence Livermore National Laboratory in Livermore, California. en Fusion through the eyes of a veteran science journalist http://www.pppl.gov/news/2013/07/fusion-through-eyes-veteran-science-journalist-1

Author Daniel Clery recently published "A Piece of the Sun," a 320-page narrative of the history of fusion research and the

298

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

SciTech Connect

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

299

E-Print Network 3.0 - angular momentum densities Sample Search...  

NLE Websites -- All DOE Office Websites (Extended Search)

required determine whether torque density will applied plasma determine... minority ion-cyclotron heating, even though ... Source: Princeton Plasma Physics Laboratory, Theory...

300

Graduate Programs | Princeton Plasma Physics Lab  

NLE Websites -- All DOE Office Websites (Extended Search)

Graduate Programs PPPL supports graduate education primarily through the Program in Plasma Physics in the Department of Astrophysical Sciences of Princeton University. Students are...

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

Theoretical Fusion Research | Princeton Plasma Physics Lab  

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Theory Department The fusion energy sciences mission of the Theory Department at the Princeton Plasma Physics Laboratory (PPPL) is to help provide the scientific foundations...

302

Allan H Reiman | Princeton Plasma Physics Lab  

NLE Websites -- All DOE Office Websites (Extended Search)

Cornell University and a staff position at the University of Maryland before joining the Princeton Plasma Physics Laboratory in 1981. He has been a consultant at Science...

303

Daren P Stotler | Princeton Plasma Physics Lab  

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Daren P Stotler Principal Research Physicist, Science Focus Group Head, Plasma-B Dr. Daren Stotler is a Principal Research Physicist in the Theory Department primarily interested...

304

First Plasma Wave Observations at Neptune  

Science Journals Connector (OSTI)

...revealed that Neptune has a large and complex magnetosphere...first observations of plasma waves and low-frequency...from lightning. Such large dispersions would require path lengths and plasma densities that are much larger than anything plausible...

D. A. Gurnett; W. S. Kurth; R. L. Poynter; L. J. Granroth; I. H. Cairns; W. M. Macek; S. L. Moses; F. V. Coroniti; C. F. Kennel; D. D. Barbosa

1989-12-15T23:59:59.000Z

305

Gun Injection into a Microwave Plasma J. C. Sprott  

E-Print Network (OSTI)

Gun Injection into a Microwave Plasma by J. C. Sprott May, 1970 Plasma Studies University high densities by rapid pulsed gun injection. TIlis no te describes measurements made -Cwo years ago in which a gun plasma was injected into a background microwave plasma of variable density in the toroidal

Sprott, Julien Clinton

306

Galleries | Princeton Plasma Physics Lab  

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Events Events Research Education Science Education About Blog Programs Galleries Upcoming Events Lab Outreach Efforts Graduate Programs Off Site University Research (OSUR) Organization Contact Us Science Education About Blog Programs Galleries Upcoming Events Lab Outreach Efforts Graduate Programs Off Site University Research (OSUR) Galleries Subscribe to RSS - Galleries 2013 Young Women's Conference 2013 Young Women's Conference63 images 2013 Plasma Camp 2013 Plasma Camp7 images 2013 Science on Saturday Lecture Series 2013 Science on Saturday Lecture Series7 images 2013 Summer's End Poster Session 2013 Summer's End Poster Session19 images 2013 Science Bowl 2013 Science Bowl12 images 2013 Pathways to Science Summit 2013 Pathways to Science Summit17 images 2012-2013 PathSci Kick-Off Event

307

National Spherical Torus Experiment (NSTX) | Princeton Plasma...  

NLE Websites -- All DOE Office Websites (Extended Search)

the physics principles of spherically shaped plasmas -- hot ionized gases in which nuclear fusion will occur under the appropriate conditions of temperature, density, and...

308

About | U.S. DOE Office of Science (SC)  

Office of Science (SC) Website

About About Fusion Energy Sciences (FES) FES Home About Staff Organization Chart .pdf file (104KB) FES Budget FES Committees of Visitors Directions Jobs Fusion and Plasmas Research Facilities Science Highlights Benefits of FES Funding Opportunities Fusion Energy Sciences Advisory Committee (FESAC) News & Resources Contact Information Fusion Energy Sciences U.S. Department of Energy SC-24/Germantown Building 1000 Independence Ave., SW Washington, DC 20585 P: (301) 903-4941 F: (301) 903-8584 E: sc.fes@science.doe.gov More Information » About Print Text Size: A A A RSS Feeds FeedbackShare Page Mission The FES program mission is to expand the fundamental understanding of matter at very high temperatures and densities and to build the scientific foundation needed to develop a fusion energy source. This is accomplished

309

Microsoft Word - Defense Science Quarterly 03-09.doc  

National Nuclear Security Administration (NNSA)

March 2009 March 2009 Defense Science Quarterly Inside This Issue 1 Message from the Director 2 Carnegie-DOE Alliance Center 3 Cornell Center for the Study of Pulsed Power Driven High Energy Density Plasmas 4 Center of Excellence for Radioactive Ion Beam Studies for Stewardship Science 5 The Texas Center for High Intensity Laser Science 6 The Institute for Shock Physics, Washington State University 7 The High Pressure Science and Engineering Center at the University of Nevada, Las Vegas 8 HEDP Research at the Nevada Terawatt Facility 9 Publication Highlights and Awards and Highlights Message from the Director Chris Deeney, Defense Science Division This quarterly newsletter was very therapeutic. We are embroiled in so much budget action that taking the time

310

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

311

Reflectivity of nonideal plasmas  

Science Journals Connector (OSTI)

New results on optical reflectance measurements of shock-compressed dense xenon plasma at wavelengths ? = 532 nm and ? = 694 nm are reported. The investigations have been performed for nonideal plasma (? = 0.872.0) at densities ? = 0.273.84 g cm?3 and pressures P = 1.617 GPa. The obtained high optical reflectance values are characteristic of a metallic fluid and are evidence for a conducting state in the shocked xenon. Reflectance measurements at different wavelengths provide information about the density profile of the shock wave front.

Yu Zaporoghets; V Mintsev; V Gryaznov; V Fortov; H Reinholz; T Raitza; G Rpke

2006-01-01T23:59:59.000Z

312

Plasma turbulence  

SciTech Connect

The origin of plasma turbulence from currents and spatial gradients in plasmas is described and shown to lead to the dominant transport mechanism in many plasma regimes. A wide variety of turbulent transport mechanism exists in plasmas. In this survey the authors summarize some of the universally observed plasma transport rates.

Horton, W. [Univ. of Texas, Austin, TX (United States). Inst. for Fusion Studies; Hu, G. [Globalstar LP, San Jose, CA (United States)

1998-07-01T23:59:59.000Z

313

Large-Volume, Helicon-Plasma Source for Simulation Experiments of Space Plasmas  

E-Print Network (OSTI)

; e.g., plasma processing, nuclear fusion, and basic fields including space plasmas. Recently is discussed, considering the power balance between input and loss. It has been found that the radial density

Boyer, Edmond

314

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 Center Massachusetts Institute of Technology Outline: Nuclear Power in the US and the World Limitations

315

News & Resources | U.S. DOE Office of Science (SC)  

NLE Websites -- All DOE Office Websites (Extended Search)

News & Resources News & Resources Fusion Energy Sciences (FES) FES Home About Research Facilities Science Highlights Benefits of FES Funding Opportunities Fusion Energy Sciences Advisory Committee (FESAC) News & Resources Workshop Reports FES Presentations FES Program Documents Contact Information Fusion Energy Sciences U.S. Department of Energy SC-24/Germantown Building 1000 Independence Ave., SW Washington, DC 20585 P: (301) 903-4941 F: (301) 903-8584 E: sc.fes@science.doe.gov More Information » News & Resources Print Text Size: A A A RSS Feeds FeedbackShare Page ITER news can be found here External link . Other recent fusion program news can be found below. News about the U.S. Burning Plasma Organization can be found here External link . Information/Subject Date/Link FY2013 Joint High Energy Density Laboratory Plasma Program: The Department of Energy's Office of Science and the National Nuclear Security Administration (NNSA) have awarded 10 new research grants totaling $4.7 million as part of the Joint High Energy Density Laboratory Plasmas (HEDLP) Program. November, 2013

316

Thermodynamics of a dusty plasma  

Science Journals Connector (OSTI)

In the present work, we develop the thermodynamics of a dusty plasma and give an equation of state for two cases: (a) when the dust forms a stationary background and the charge on the grain does not vary and (b) when the dust charge fluctuates either due to the fluctuations in the electron and ion number densities or due to the dust density variation. Application of the results to the various space plasma situations has been indicated.

B. P. Pandey

2004-02-27T23:59:59.000Z

317

Triton burnup in plasma focus plasmas  

Science Journals Connector (OSTI)

Pure deuterium plasma discharge from plasma focus breeds 1.01 MeV tritons via the D(d p)T fusion branch which has the same cross section as the D(d n)3He (E n =2.45 MeV) fusion branch. Tritons are trapped in and collide with the background deuterium plasma producing 14.1 MeV neutrons via the D(t n)4He reaction. The paper presents published in preliminary form as well as unpublished experimental data and theoretical studies of the neutron yield ratio R=Y n (14.1 MeV)/Y n (2.45 MeV). The experimental data were obtained from 1 MJ Frascati plasma focus operated at W=490 kJ with pure deuterium plasma (in the early 1980s). Neutrons were monitored using the nuclear activation method and nuclear emulsions. The present theoretical analysis of the experimental data is based on an exact adaptation of the binary encounter theory developed by Gryzinski. It is found that the experimentally defined value 1?10?3plasma domains of very high density (n?1021 cm?3) high temperature (kT?1 keV) and short trapping time (t 0?20 ns). These domains are known as efficient traps of MeV ions but are not the main source of D(d n)3He fusion.

Jan S. Brzosko; Jan R. Brzosko Jr.; Benjamin V. Robouch; Luigi Ingrosso

1995-01-01T23:59:59.000Z

318

Long-wavelength density turbulence in the TFTR tokamak  

Science Journals Connector (OSTI)

Long-wavelength (k??itokamak plasma with auxiliary heating. Density fluctuations of n?/n>0.5% exist for k?tokamaks.

R. J. Fonck; G. Cosby; R. D. Durst; S. F. Paul; N. Bretz; S. Scott; E. Synakowski; G. Taylor

1993-06-14T23:59:59.000Z

319

COHERENCE AND INTERMITTENCY OF ELECTRON DENSITY IN SMALL-SCALE  

NLE Websites -- All DOE Office Websites (Extended Search)

OF ELECTRON DENSITY IN SMALL-SCALE INTERSTELLAR TURBULENCE P. W. Terry and K. W. Smith Center for Magnetic Self-Organization in Laboratory and Astrophysical Plasmas and...

320

Plasma wakefields driven by an incoherent combination of laser pulses: a path towards high-average power laser-plasma accelerators  

E-Print Network (OSTI)

and W.P. Leemans, Phys. Plasmas 18, 083103 (2011). 34 C.IEEE Transactions on plasma science 36, 1790 (2008). 35 C.Plasma wakefields driven by an incoherent combination of

Benedetti, C

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.


321

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

SciTech Connect

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

322

NEWTON's Material Science Videos  

NLE Websites -- All DOE Office Websites (Extended Search)

Material Science Videos Material Science Videos Do you have a great material science video? Please click our Ideas page. Featured Videos: University of Maryland - Material Science University of Maryland - Material Science The Department of Materials Science and Engineering offers a set of videos about various topics in material science to help students understand what material science is. Learn about plasma, polymers, liquid crystals and much more. LearnersTV.com - Material Science LearnersTV.com - Material Science LearnersTV.com offers a series of educational material science lectures that are available to the public for free. Learn about topics like polymers, non-crystalline solids, crystal geometry, phase diagrams, phase transformations and more. NanoWerk - Nanotechnology Videos NanoWerk - Nanotechnology Videos

323

First Sustained Burning Plasma. Starts in 2019.  

E-Print Network (OSTI)

-T fusion power density is approximated by: Plasma pressure in atmospheres We need >1MWm-3 for an economic system -- need a few Atmospheres of plasma pressure. Can we hold it with a magnetic field? MagneticITER JET (to scale) JET (to scale) First Sustained Burning Plasma. Starts in 2019. BASIC PARAMETERS

324

MIT Plasma Science & Fusion Center  

NLE Websites -- All DOE Office Websites (Extended Search)

Facility Information Tokamak Data & Real-Time Information Computer & Data Systems Research Program Information Publications & News Meetings & Seminars Contact Information Physics...

325

Meter scale plasma source for plasma wakefield experiments  

SciTech Connect

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

326

Neutral depletion and the helicon density limit  

SciTech Connect

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

327

Plasma-beam interaction in a wiggler  

Science Journals Connector (OSTI)

The possibility of obtaining self-bunching of the beam, emission of coherent radiation and strong electrostatic fields in a plasma loaded free electron laser, is studied by means of a set of nonlinear self-consistent equations deduced from the Maxwell equations, the fluid plasma model, and the relativistic equations of motion for the electrons of the beam in the limit of plasma density much larger than the beam density.

V. Petrillo; A. Serbeto; C. Maroli; R. Parrella; R. Bonifacio

1995-06-01T23:59:59.000Z

328

June 21, 2014 1 Fusion Energy Sciences: Workforce Development Needs  

E-Print Network (OSTI)

represent a vibrant component of plasma science research and likely will remain so in the foreseeable future

329

Nonlocal collisionless phenomena in Plasmas PPPL, Princeton 2005  

E-Print Network (OSTI)

1 Nonlocal collisionless phenomena in Plasmas PPPL, Princeton 2005 A. Dunaevsky Measurements. of Astrophysical Sciences Princeton University, Princeton, NJ 08543 #12;2 Diagnostics in expanding plasmas" by A. Dunaevsky Princeton 2005 #12;3 Kinetics of expanding plasmaKinetics of expanding plasma Kinetics

Kaganovich, Igor

330

Plasma Simulation Program  

SciTech Connect

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

331

Trapping of Gun-Injected Plasma by a Tokamak  

Science Journals Connector (OSTI)

It is shown that a plasma produced by a Marshall gun can be injected into and trapped by a tokamak plasma. Gun injection raises the line-averaged density and peaks the density profile. Trapping of the gun-injected plasma is explainable in terms of a depolarization current mechanism.

A. W. Leonard; R. N. Dexter; J. C. Sprott

1986-07-21T23:59:59.000Z

332

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

SciTech Connect

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

333

Microinstabilities in weak density gradient tokamak systems  

SciTech Connect

A prominent characteristic of auxiliary-heated tokamak discharges which exhibit improved (''H-mode type'') confinement properties is that their density profiles tend to be much flatter over most of the plasma radius. Depsite this favorable trend, it is emphasized here that, even in the limit of zero density gradient, low-frequency microinstabilities can persist due to the nonzero temperature gradient.

Tang, W.M.; Rewoldt, G.; Chen, L.

1986-04-01T23:59:59.000Z

334

DEVELOPMENTS IN UPPER ATMOSPHERIC SCIENCE DURING THE IQSY  

Science Journals Connector (OSTI)

...and some evidence on plasma motions near the knee...0 -O NO + + N at thermal energy," Planet...seasonal variations in atmospheric densities obtained...Enhancement of plasma density fluctuations by non- thermal electrons," Phys...

Francis S. Johnson

1967-01-01T23:59:59.000Z

335

Density dependence of reactor performance with thermal confinement scalings  

SciTech Connect

Energy confinement scalings for the thermal component of the plasma published thus far have a different dependence on plasma density and input power than do scalings for the total plasma energy. With such thermal scalings, reactor performance (measured by Q, the ratio of the fusion power to the sum of the ohmic and auxiliary input powers) worsens with increasing density. This dependence is the opposite of that found using scalings based on the total plasma energy, indicating that reactor operation concepts may need to be altered if this density dependence is confirmed in future research.

Stotler, D.P.

1992-03-01T23:59:59.000Z

336

Attenuation of Electromagnetic Waves by a Plasma Layer at Atmospheric Pressure  

Science Journals Connector (OSTI)

Plasma layers at atmospheric pressure, are good broad band absorbers of ... have to be optimized. These are the plasma number density, and the thickness of the plasma layer. It is found that in order ... an effec...

Mounir Laroussi; William T. Anderson

1998-03-01T23:59:59.000Z

337

Characterization of the conduction phase of a plasma opening switch using a hydrogen plasma  

E-Print Network (OSTI)

densities greater than 1015 cm-3 , the penetration rate of the field into the plasma by Hall mechanisms of the magnetic field front and the heavier-ion plasma is penetrated by the field. Species-separation effects may to be characterized by fast magnetic field (current) penetration into the plasma.9­11 In recent experiments

338

Surface modification with a remote atmospheric pressure plasma  

Science Journals Connector (OSTI)

A remote atmospheric pressure DC glow discharge is used for the treatment of polymer foils. The envisaged plasma effect is an increase in the surface ... the distribution of the current density in the plasma. The...

E. Temmerman; C. Leys

2004-03-01T23:59:59.000Z

339

Properties of Ion Beams Generated by Nitrogen Plasma Focus  

Science Journals Connector (OSTI)

Numerical experiments have been systematically carried out using the modified Lee model code on various plasma focus devices operated with nitrogen gas. The ion ... flow density, and damage factor) of the plasma focus

M. Akel; S. Alsheikh Salo; S. H. Saw; S. Lee

2014-04-01T23:59:59.000Z

340

Furth Plasma Physics Libary  

NLE Websites -- All DOE Office Websites (Extended Search)

Contacts Hours Online Access Directions Contacts Hours Online Access Directions QuickFind Main Catalog Databases PPPL Publications & Reports/PPLcat Plasma Physics E-Journals clear Click arrows to scroll for more clear Plasma Physics Colloquia The Global Carbon Cycle and Earth's Climate - January 15, 2014 Addressing Big Data Challenges in Simulation-based Science - January 22, 2014 "The Usefulness of Useless Knowledge?: The History of the Institute for Advanced Study - January 29, 2014 PM-S-1 PDF PM-S-2 PDF PM-S-3 PDF PM-S-4 PDF PM-S-5 PDF PM-S-6 PDF See All Library History Intro 950 1960-1970 1980 1990 2000 Quick Order Article Express Borrow Direct Interlibrary Loan PPL Book Request More Resources and Services Search & Find Articles & Databases - Plasma Physics, Physics, Engineering & Technology,

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

Aerodynamic Focusing Of High-Density Aerosols  

SciTech Connect

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

342

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

343

FESAC Agenda - January 2009 | U.S. DOE Office of Science (SC)  

Office of Science (SC) Website

January 2009 January 2009 Fusion Energy Sciences Advisory Committee (FESAC) FESAC Home Meetings Members Charges/Reports Charter .pdf file (140KB) FES Committees of Visitors FES Home Meetings FESAC Agenda - January 2009 Print Text Size: A A A RSS Feeds FeedbackShare Page Fusion Energy Sciences Advisory Committee Meeting Gaithersburg Hilton 620 Perry Parkway 301-977-8900 January 13, 2009 Time Duration Topic Speaker 8:00 5 Meeting Agenda and Logistics Professor Riccardo Betti, University of Rochester, FESAC Vice-Chair 8:05 40 Office of Science Perspectives Dr. Patricia Dehmer, Deputy Director for Science Programs, DOE 8:45 45 OFES Perspectives Steve Eckstrand, Acting Associate Director for Fusion Energy Sciences, DOE 9:30 15 Break 9:45 90 Final Report: Panel on High Energy Density Laboratory Plasmas

344

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

E-Print Network (OSTI)

of the experiment are to study plasma focusing of high energy, high density particle beams; to investigate plasma colliders. INTRODUCTION Plasma focusing devices are compact, simple, and very strong focusing elements­of­principle experiments using low density particle beams have demonstrated plasma focusing (10­ 12). Our goal

345

FES Science Network Requirements - Report of the Fusion Energy Sciences Network Requirements Workshop Conducted March 13 and 14, 2008  

E-Print Network (OSTI)

the Office of Science started as the Magnetic Fusion EnergyRequirements and Science Process All U.S. magnetic fusionMagnetic Fusion Energy Program 11 MIT Plasma Science &

Dart, Eli

2008-01-01T23:59:59.000Z

346

Newsletters: July 2014 | Princeton Plasma Physics Lab  

NLE Websites -- All DOE Office Websites (Extended Search)

(PPPL). We are pleased to provide this news of our strides in advancing research into fusion energy and plasma science-two topics of vital interest to the United States and the...

347

Newsletters: September 2013 | Princeton Plasma Physics Lab  

NLE Websites -- All DOE Office Websites (Extended Search)

(PPPL). We are pleased to provide this news of our strides in advancing research into fusion energy and plasma science-two topics of vital interest to the United States and the...

348

Abstract P2-01-04: High-density lipoprotein cholesterol is associated with mammographic density in premenopausal women  

Science Journals Connector (OSTI)

...Registry of Norway, Oslo, Norway; Faculty of Health Sciences, University of Tromso, Tromso, Norway; Harvard University, Cambridge...University of Life Sciences, Aas, Norway Background: High-Density...years, participating in the Energy Balance and Breast cancer Aspects...

VG Flote; H Frydenberg; G Ursin; T Wilsgaard; A Iversen; PT Ellison; EA Wist; T Egeland; I Thune; and A-S Furberg

2013-12-15T23:59:59.000Z

349

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

350

Distribution of Radiation Density in a Homogeneous Cloudy Laye  

NLE Websites -- All DOE Office Websites (Extended Search)

A. M. Obukhov Institute of Atmospheric Physics Russian Academy of Sciences Moscow, Russia The program block (Monte-Carlo method) allowing calculating radiation density in...

351

Neutrino oscillations in a turbulent plasma  

SciTech Connect

A new model for the joint neutrino flavor and plasma oscillations is introduced, in terms of the dynamics of the neutrino flavor polarization vector in a plasma background. Fundamental solutions are found for both time-invariant and time-dependent media, considering slow and fast variations of the electron plasma density. The model is shown to be described by a generalized Hamiltonian formalism. In the case of a broad spectrum of electron plasma waves, a statistical approach indicates the shift of both equilibrium value and frequency oscillation of flavor coherence, due to the existence of a turbulent plasma background.

Mendona, J. T. [Instituto de Fsica, Universidade de So Paulo, So Paulo, SP, CEP 05508-090 Brazil and IPFN, Instituto Superior Tcnico, 1049-001 Lisboa (Portugal)] [Instituto de Fsica, Universidade de So Paulo, So Paulo, SP, CEP 05508-090 Brazil and IPFN, Instituto Superior Tcnico, 1049-001 Lisboa (Portugal); Haas, F. [Departamento de Fsica, Universidade Federal do Paran, Curitiba PR, CEP 81531-990 (Brazil)] [Departamento de Fsica, Universidade Federal do Paran, Curitiba PR, CEP 81531-990 (Brazil)

2013-07-15T23:59:59.000Z

352

Plasma Physics  

NLE Websites -- All DOE Office Websites (Extended Search)

of light years can emerge from the frenetic motion of plasmas. A team of Lawrence Livermore researchers has discovered that supersonic counter-streaming (directed at each...

353

Numerical Study of Radiation Emission from the Argon Plasma Focus  

Science Journals Connector (OSTI)

Ion populations and emitted spectrum of argon plasma have been calculated using the POPULATE and SPECTRA codes of the RATION suite at different conditions (electron temperatures, electron densities, ion densities...

M. Akel; S. Alsheikh Salo; C. S. Wong

2013-04-01T23:59:59.000Z

354

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

355

Sensitivity to Error Fields in NSTX High Beta Plasmas  

SciTech Connect

It was found that error field threshold decreases for high ? in NSTX, although the density correlation in conventional threshold scaling implies the threshold would increase since higher ? plasmas in our study have higher plasma density. This greater sensitivity to error field in higher ? plasmas is due to error field amplification by plasmas. When the effect of amplification is included with ideal plasma response calculations, the conventional density correlation can be restored and threshold scaling becomes more consistent with low ? plasmas. However, it was also found that the threshold can be significantly changed depending on plasma rotation. When plasma rotation was reduced by non-resonant magnetic braking, the further increase of sensitivity to error field was observed.

Jong-Kyu Park, Jonathan E. Menard, Stefan P. Gerhardt, Richard J. Buttery, Steve A. Sabbagh, Ronald E. Bell and Benoit P. LeBlanc

2011-11-07T23:59:59.000Z

356

Plasma-parameter measurements using neutral-particle-beam attenuation  

SciTech Connect

Intense and energetic neutral-particle-beam injection used for fueling or heating magnetically confined, controlled-fusion experimental plasmas can also provide diagnostic measurements of the plasmas. The attenuation of an atomic beam (mainly from charge-exchange and ionization interactions) when passing through a plasma gives the plasma line density. Orthogonal arrays of highly collimated detectors of the secondary-electron-emission type have been used in magnetic-mirror experiments to measure neutral-beam attenuation along chords through the plasma volume at different radial and axial positions. The radial array is used to infer the radial plasma-density profile; the axial array, to infer the axial plasma-density profile and the ion angular distribution at the plasma midplane.

Foote, J.H.; Molvik, A.W.; Turner, W.C.

1982-07-07T23:59:59.000Z

357

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

358

Plasma Radiation  

Science Journals Connector (OSTI)

... JUST over ten years ago the first book on plasma physics as a subject in its own right appeared; in a gradually swelling stream ... been surprisingly few monographs. One topic which has had scant coverage in any form is plasma radiation (except for spectral-line radiation which has been dealt with very fully in ...

T. J. M. BOYD

1967-07-01T23:59:59.000Z

359

Nonlinear dynamics and plasma transport  

SciTech Connect

This progress report details work done on a program in nonlinear dynamical aspects of plasma turbulence and transport funded by DOE since 1989. This program has been in cooperation with laboratories in theUSSR [now Russia and the Confederation of Independent States (CIS)]. The purpose of this program has been: To promote the utilization of recent pathbreaking developments in nonlinear science in plasma turbulence and transport. To promote cooperative scientific investigations between the US and CIS in the related areas of nonlinear science and plasma turbulence and transport. In the work reported in our progress report, we have studied simple models which are motivated by observation on actual fusion devices. The models focus on the important physical processes without incorporating the complexity of the geometry of real devices. This allows for a deeper analysis and understanding of the system both analytically and numerically.

Antonsen, T.M. Jr.; Drake, J.F.; Finn, J.M.; Guzdar, P.N.; Hassam, A.B.; Sageev, R.Z.

1993-01-01T23:59:59.000Z

360

Voyager 2 Plasma Wave Observations at Saturn  

Science Journals Connector (OSTI)

...on the basis of plasma probe data) and infer...the weak 3.25-kHz waves represent electro-magnetic...pitch-angle dif-fusion and atmospheric precipitation, but for this low plasma density and high magnetic...f = 0.8 to 1.3 kHz) and a structured...

F. L. SCARF; D. A. GURNETT; W. S. KURTH; R. L. POYNTER

1982-01-29T23:59:59.000Z

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

Electron Plasmas in a Magnetic Mirror  

E-Print Network (OSTI)

scale with the magnetic field strength; the electrostatic potential varies along the field lines to make this density variation possible. Further, the plasma profile does not follow the magnetic field lines proportional to magnetic field. · Potential varies along field lines. · Outer plasma radius necks down more

Wurtele, Jonathan

362

Princeton Plasma Physics Laboratory NSTX Experimental Proposal  

E-Print Network (OSTI)

the optimal sequencing of H-mode, heating, and current ramp rate to reliably access qmin >> 1 at the end/ empirical justification Rapid penetration of the current density during the current ramp phase of a tokamak operation. Such rapid current penetration can be caused by either high plasma resistivity or plasma

Princeton Plasma Physics Laboratory

363

Physics of Laser-driven plasma-based acceleration  

SciTech Connect

The physics of plasma-based accelerators driven by short-pulse lasers is reviewed. This includes the laser wake-field accelerator, the plasma beat wave accelerator, the self-modulated laser wake-field accelerator, and plasma waves driven by multiple laser pulses. The properties of linear and nonlinear plasma waves are discussed, as well as electron acceleration in plasma waves. Methods for injecting and trapping plasma electrons in plasma waves are also discussed. Limits to the electron energy gain are summarized, including laser pulse direction, electron dephasing, laser pulse energy depletion, as well as beam loading limitations. The basic physics of laser pulse evolution in underdense plasmas is also reviewed. This includes the propagation, self-focusing, and guiding of laser pulses in uniform plasmas and plasmas with preformed density channels. Instabilities relevant to intense short-pulse laser-plasma interactions, such as Raman, self-modulation, and hose instabilities, are discussed. Recent experimental results are summarized.

Esarey, Eric; Schroeder, Carl B.

2003-06-30T23:59:59.000Z

364

Magnetic Reconnection in Plasmas: a Celestial Phenomenon in the Laboratory  

E-Print Network (OSTI)

Magnetic Reconnection in Plasmas: a Celestial Phenomenon in the Laboratory Jan Egedal MIT Physics Lin, T Phan, M ?ieroset (Space Science Laboratory, UC Berkeley) #12;Magnetic Reconnection · A change in magnetic topology in the presence of a plasma Plasma carrying a current Magnetic fields j Consider a small

365

Science Showcase | OSTI, US Dept of Energy, Office of Scientific and  

Office of Scientific and Technical Information (OSTI)

Science Showcase Science Showcase 2013 2012 2011 2010 2009 December DOE Science Showcase - Light-emitting Diode (LED) Lighting Research November DOE Science Showcase - Gamma-Ray Bursts October DOE Science Showcase - Bayesian Inference September DOE Science Showcase - Understanding High-Temperature Superconductors August DOE Science Showcase - Exciting Higgs Boson Research July DOE Science Showcase - DOE's Smart Grid Research June DOE Science Showcase - DOE Plasma Research May DOE Science Showcase - Oil Shale Research April DOE Science Showcase - Fission Theory March DOE Science Showcase - Free-Electron Lasers February DOE Science Showcase - Heat Pump Research January DOE Science Showcase - Monte Carlo Methods December DOE Science Showcase - Quantum Computer Hardware November DOE Science Showcase - Metamaterials

366

Expert Topics | Princeton Plasma Physics Lab  

NLE Websites -- All DOE Office Websites (Extended Search)

AC power Education Emergency planning Engineering Fusion energy Fusion reactor design Fusion roadmapping ITER Inertial confinement fusion International collaborations Laser diagnostics Lithium Magnetic reconnection Nuclear energy Nuclear safety Particle beam dynamics Plasma astrophysics Plasma diagnostics Plasma physics Power system design Power systems Quality assurance STEM Science literacy Stellarators Surface science Sustainability Tokamaks Visiting PPPL History Fusion Basics DOE and Fusion Links Contract Documents Speakers Bureau Tours News Events Research Education Organization Contact Us Overview Learn More AC power Education Emergency planning Engineering Fusion energy Fusion reactor design Fusion roadmapping ITER Inertial confinement fusion International collaborations Laser diagnostics

367

Robert Kaita | Princeton Plasma Physics Lab  

NLE Websites -- All DOE Office Websites (Extended Search)

Kaita Kaita Principal Research Physicist, P.I., LTX Robert (Bob) Kaita is the head of plasma diagnostic operations and acting head of boundary physics operations for the National Spherical Torus Experiment (NSTX). Kaita is also a co-principal investigator of the Lithium Tokamak Experiment (LTX). He is a Fellow of the American Physical Society and a recipient of the Kaul Foundation Prize for Excellence in Plasma Physics Research. He has supervised the research of many students in the PPPL Program in Plasma Physics in the Department of Astrophysical Sciences at Princeton University. Interests Neutral beam and radiofrequency plasma heating Plasma diagnostics Plasma-surface interactions Solid and liquid plasma-facing components Contact Information Phone: 609-243-3275

368

Materials Science  

NLE Websites -- All DOE Office Websites (Extended Search)

Materials Science science-innovationassetsimagesicon-science.jpg Materials Science National security depends on science and technology. The United States relies on Los Alamos...

369

U S Burning Plasma Organization:U.S. Burning Plasma Organization: Supporting US Scientific Contributions to  

E-Print Network (OSTI)

Community (TTF,...) US Technology Community · USBPO mission is to coordinate US Burning Plasma related research to advance science USBPO Director, Jim Van Dam, also serves as US IPO Chief Scientist, assuring

370

What we've learned so far about the Stability of Plasma  

E-Print Network (OSTI)

of Technology About PSFC Research People Education News & Even The Plasma Science & Fusion Center (PSFC Philadelphia, PA October 30 through November 3, 2006 Plasma Science & Fusion Center Massachusetts Institue. This poster discusses these new results with the aim of understanding linear, nonlinear, and turbulent plasma

371

Princeton Plasma Physics Lab - Education  

NLE Websites -- All DOE Office Websites (Extended Search)

education The PPPL function that education The PPPL function that reaches out to students, teachers and the general public through programs ranging from student internships to weekly talks on scientific topics from January through April. en Science on Saturday starts Jan. 11 http://www.pppl.gov/news/2014/01/science-saturday-starts-jan-11

Science fans of all ages can explore a rich variety of science and technology topics at the popular Science on Saturday lecture series hosted by the U.S. Department of Energy's Princeton Plasma Physics Laboratory. The series marks its 30-year anniversary when it begins on Saturday, Jan.

372

Plasma catalytic reforming of methane  

Science Journals Connector (OSTI)

Thermal plasma technology can be efficiently used in the production of hydrogen and hydrogen-rich gases from methane and a variety of fuels. This article describes progress in plasma reforming experiments and calculations of high temperature conversion of methane using heterogeneous processes. The thermal plasma is a highly energetic state of matter that is characterized by extremely high temperatures (several thousand degrees Celsius), and a high degree of dissociation and a substantial degree of ionization. The high temperatures accelerate the reactions involved in the reforming process. Hydrogen-rich gas (40% H2, 17% CO2 and 33% N2, for partial oxidation/water shifting) can be efficiently made in compact plasma reformers. Experiments have been carried out in a small device (23 kW) and without the use of efficient heat regeneration. For partial oxidation/water shifting, it was determined that the specific energy consumption in the plasma reforming processes is 16 MJ/kg H2 with high conversion efficiencies. Larger plasmatrons, better reactor thermal insulation, efficient heat regeneration and improved plasma catalysis could also play a major role in specific energy consumption reduction and increasing the methane conversion. A system has been demonstrated for hydrogen production with low CO content (?1.5%) with power densities of ?30 kW (H2 HHV)/l of reactor, or ?10m3/h H2 per liter of reactor. Power density should further increase with increased power and improved design.

L Bromberg; D.R Cohn; A Rabinovich; N Alexeev

1999-01-01T23:59:59.000Z

373

Laser beat wave excitation of terahertz radiation in a plasma slab  

SciTech Connect

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

374

Origin of Tokamak Density Limit Scalings  

Science Journals Connector (OSTI)

The onset criterion for radiation driven islands [P.?H. Rebut and M. Hugon, Plasma Physics and Controlled Nuclear Fusion Research 1984: Proc. 10th Int. Conf. London, 1984, (IAEA, Vienna, 1985), Vol.2] in combination with a simple cylindrical model of tokamak current channel behavior is consistent with the empirical scaling of the tokamak density limit [M. Greenwald, Nucl. Fusion 28, 2199 (1988)]. Many other unexplained phenomena at the density limit are consistent with this novel physics mechanism.

D. A. Gates and L. Delgado-Aparicio

2012-04-20T23:59:59.000Z

375

Plasma temperatures in Saturn's ionosphere Luke Moore,1  

E-Print Network (OSTI)

Plasma temperatures in Saturn's ionosphere Luke Moore,1 Marina Galand,2 Ingo Mueller-Wodarg,2 Roger the height of peak electron density, while they can reach 500 K during the day at the topside. Plasma scale of Saturn have been used to estimate plasma temperature as a comparison. Such an estimate agrees well

Mendillo, Michael

376

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

377

Clustered gases as a medium for efficient plasma waveguide generation  

Science Journals Connector (OSTI)

...on-axis density of a plasma waveguide is determined...or Bessel beam) line focus breakdown of a gas using...heater of the cluster plasma despite the fact that...a Bessel-beam line focus breakdown in an elongated...axicon which heat the plasma and are transmitted through...

2006-01-01T23:59:59.000Z

378

Application of Plasma Waveguides to High Energy Accelerators  

SciTech Connect

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

379

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

SciTech Connect

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

Plasma properties downstream of a low-power Hall thruster  

SciTech Connect

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

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

Linear accelerator design study with direct plasma injection scheme for warm dense matter  

SciTech Connect

Warm Dense Matter (WDM) is a challenging science field, which is related to heavy ion inertial fusion and planetary science. It is difficult to expect the behavior because the state with high density and low temperature is completely different from ideal condition. The well-defined WDM generation is required to understand it. Moderate energy ion beams ({approx} MeV/u) slightly above Bragg peak is an advantageous method for WDM because of the uniform energy deposition. Direct Plasma Injection Scheme (DPIS) with a Interdigital H-mode (IH) accelerator has a potential for the beam parameter. We show feasible parameters of the IH accelerator for WDM. WDM physics is a challenging science and is strongly related to Heavy Ion Fusion science. WDM formation by Direct Plasma Injection Scheme (DPIS) with IH accelerator, which is a compact system, is proposed. Feasible parameters for IH accelerator are shown for WDM state. These represents that DPIS with IH accelerator can access a different parameter region of WDM.

Kondo, K.; Kanesue, T; Okamura, M.

2011-03-28T23:59:59.000Z

382

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.

383

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

NLE Websites -- All DOE Office Websites (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...

384

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.

385

Plasma Wakefield Acceleration  

NLE Websites -- All DOE Office Websites (Extended Search)

rpwa rpwa Sign In Launch the Developer Dashboard SLAC National Accelerator Laboratory DOE | Stanford | SLAC | SSRL | LCLS | AD | PPA | Photon Science | PULSE | SIMES FACET User Facility : FACET An Office of Science User Facility Search this site... Search Help (new window) Top Link Bar FACET User Facility FACET Home About FACET FACET Experimental Facilities FACET Users Research at FACET SAREC Expand SAREC FACET FAQs FACET User Facility Quick Launch FACET Users Home FACET Division ARD Home About FACET FACET News FACET Users FACET Experimental Facilities FACET Research Expand FACET Research FACET Images Expand FACET Images SAREC Expand SAREC FACET Project Site (restricted) FACET FAQs FACET Site TOC All Site Content Department of Energy Page Content Plasma Wakefield Acceleration

386

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

387

Science satellites seek Santa  

NLE Websites -- All DOE Office Websites (Extended Search)

Science satellites seek Santa Science satellites seek Santa Science satellites seek Santa Los Alamos scientists will use two advanced science satellites to mark the course taken by the elfin traveler. December 16, 2009 Los Alamos National Laboratory sits on top of a once-remote mesa in northern New Mexico with the Jemez mountains as a backdrop to research and innovation covering multi-disciplines from bioscience, sustainable energy sources, to plasma physics and new materials. Los Alamos National Laboratory sits on top of a once-remote mesa in northern New Mexico with the Jemez mountains as a backdrop to research and innovation covering multi-disciplines from bioscience, sustainable energy sources, to plasma physics and new materials. Contact Nancy Ambrosiano Communications Office

388

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

SciTech Connect

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

389

On the feasibility of electron cyclotron heating of overcritical plasma in a magnetic mirror trap  

SciTech Connect

The feasibility of matching electromagnetic radiation in the electron cyclotron frequency range to a dense plasma in an open magnetic trap by producing an inverted (with a minimum on the axis) plasma density profile is discussed. The use of such a profile shows promise for the implementation of efficient cyclotron heating at plasma densities above the critical density, at which the Langmuir frequency is equal to the heating radiation frequency. Examples of the magnetic field and plasma density distributions in a mirror trap are presented for which analysis of the beam trajectories shows the feasibility of efficient electron cyclotron absorption of microwave beams in overcritical plasma.

Vodopyanov, A. V.; Golubev, S. V.; Gospodchikov, E. D.; Smolyakova, O. B.; Suvorov, E. V. [Russian Academy of Sciences, Institute of Applied Physics (Russian Federation)

2012-06-15T23:59:59.000Z

390

Nonlocal fluxes at a plasma sheath  

SciTech Connect

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

391

Dense plasma properties from shock wave experiments  

Science Journals Connector (OSTI)

A review is presented of the novel experimental results of investigation of physical properties of the coupled dense plasmas generated as a result of shock compression up to megabar pressure range. High-energy plasma states were generated by single and multiple shock compression. The highly time-resolved diagnostics permit us to measure thermodynamical, electrophysical and optical properties of high pressure condensed plasmas in the broad phase diagram regionfrom the compressed condensed solid state up to the low density gas range, including strongly coupled plasma and metalinsulator transition regions.

V B Mintsev; V E Fortov

2006-01-01T23:59:59.000Z

392

Tonal Noise Excited by Plasma in Cylinder Wakes Using Closed-loop Control  

E-Print Network (OSTI)

atmosphere uniform glow discharge surface plasma," IEEE International Conference on Plasma Science, IEEETonal Noise Excited by Plasma in Cylinder Wakes Using Closed-loop Control Wenjun Yu , and Xun Huang controlled by a closed-loop plasma control system was demonstrated in this work. The flow around a cylinder

Huang, Xun

393

Solitary and shock waves in magnetized electron-positron plasma  

SciTech Connect

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 Alfvn 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 Alfvn speed. For a hot EP plasma, the existence range depends on the Alfvn 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

394

E-Print Network 3.0 - atomic vapor density Sample Search Results  

NLE Websites -- All DOE Office Websites (Extended Search)

T is temperature, Qris... F, is magnetic force, J is vapor plasma current density, c is speed of light, and B is magnetic flux... density. The induced magnetic force will act as...

395

Characteristics of plasma properties in an ablative pulsed plasma thruster  

SciTech Connect

Pulsed plasma thrusters are electric space propulsion devices which create a highly transient plasma bulk in a short-time arc discharge that is expelled to create thrust. The transitional character and the dependency on the discharge properties are yet to be elucidated. In this study, optical emission spectroscopy and Mach-Zehnder interferometry are applied to investigate the plasma properties in variation of time, space, and discharge energy. Electron temperature, electron density, and Knudsen numbers are derived for the plasma bulk and discussed. Temperatures were found to be in the order of 1.7 to 3.1 eV, whereas electron densities showed maximum values of more than 10{sup 17} cm{sup -3}. Both values showed strong dependency on the discharge voltage and were typically higher closer to the electrodes. Capacitance and time showed less influence. Knudsen numbers were derived to be in the order of 10{sup -3}-10{sup -2}, thus, indicating a continuum flow behavior in the main plasma bulk.

Schoenherr, Tony; Nees, Frank; Arakawa, Yoshihiro [Department of Aeronautics and Astronautics, University of Tokyo, Bunkyo, Tokyo 113-8656 (Japan); Komurasaki, Kimiya [Department of Advanced Energy, University of Tokyo, Kashiwa, Chiba 277-8561 (Japan); Herdrich, Georg [Institute of Space Systems (IRS), University of Stuttgart, 70569 Stuttgart, Baden-Wuerttemberg (Germany)

2013-03-15T23:59:59.000Z

396

Tokamak Equilibria with Reversed Current Density  

Science Journals Connector (OSTI)

Observations of nearly zero toroidal current in the central region of tokamaks (the current hole) raises the question of the existence of toroidal equilibria with very low or reversed current in the core. The solutions of the Grad-Shafranov equilibrium equation with hollow toroidal current density profile including negative current density in the plasma center are investigated. Solutions of the corresponding eigenvalue problem provide simple examples of such equilibrium configurations. More realistic equilibria with toroidal current density reversal are computed using a new equilibrium problem formulation and computational algorithm which do not assume nested magnetic surfaces.

A. A. Martynov; S. Yu. Medvedev; L. Villard

2003-08-21T23:59:59.000Z

397

NEWTON's Material Science Archive  

NLE Websites -- All DOE Office Websites (Extended Search)

Materials Science Archive: Materials Science Archive: Loading Most Recent Materials Science Questions: Hydrogen Compounds and Heat Conduction Weaving Carbon Nanotubes Metal as Electrical Conductor, Not Thermal Steel Changes with Age PETE, Ultraviolet Light, Benefits Strength of Yarn by Spinning Each Substance Unique Density Alloy versus Constituent Density Knowing When Material is Melted Crystalline Metal Versus Metallic Glass and Conduction Super Glue, Surgery, and Skin Silica Gel Teflon Non-Stick Property Salt Crystal Formation Lubricating Rubber Bands and Elasticity Materials for Venus Probe Crystalline Solids and Lowest Energy Sodium Polycarbonate and Salt Water Early Adhesives Surface Energy and Temperature Separating Polypropylene, Polyester, and Nylon Factors Effecting Polymer Flexibility

398

Interactions of Non-Thermal Atmospheric Pressure Plasma with Solid and Liquid Food Systems: A Review  

Science Journals Connector (OSTI)

Non-equilibrium atmospheric pressure plasma processes combine several advantages such as non- ... science and technology dealing with the application of plasma processes on solid and liquid foodstuff. Starting wi...

Bjrn Surowsky; Oliver Schlter; Dietrich Knorr

2014-07-01T23:59:59.000Z

399

Dynamical Plasma Response during Driven Magnetic Reconnection J Egedal,* A Fasoli,  

E-Print Network (OSTI)

Massachusetts Institute of Technology, Plasma Science and Fusion Center, Cambridge, Massachusetts 02139 in association with reconnection phenomena [1] both in space and laboratory plasmas, e.g., in solar flares [2

Egedal, Jan

400

Dynamical Plasma Response during Driven Magnetic Reconnection J Egedal, * A Fasoli, + and J Nazemi  

E-Print Network (OSTI)

Massachusetts Institute of Technology, Plasma Science and Fusion Center, Cambridge, Massachusetts 02139 in association with reconnection phenomena [1] both in space and laboratory plasmas, e.g., in solar flares [2

Egedal, Jan

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

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

402

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

403

Magnetic fluctuations of a large nonuniform plasma column J. E. Maggsa)  

E-Print Network (OSTI)

Magnetic fluctuations of a large nonuniform plasma column J. E. Maggsa) and G. J. Morales Physics of spontaneously generated magnetic fluctuations in a large linear device in which the plasma density has different as at an interior plasma­plasma interface, thus phenomena of interest to magnetic fusion research as well

California at Los Angles, University of

404

FES Budget | U.S. DOE Office of Science (SC)  

Office of Science (SC) Website

Budget Fusion Energy Sciences (FES) FES Home About Staff Organization Chart .pdf file (104KB) FES Budget FES Committees of Visitors Directions Jobs Fusion and Plasmas Research...

405

E-Print Network 3.0 - avec des plasmas Sample Search Results  

NLE Websites -- All DOE Office Websites (Extended Search)

Collection: Engineering ; Computer Technologies and Information Sciences 5 DCHARGES HF ENTRETENUES SOIT SUR UNE RSONANCE DE CAVIT, SOIT SUR UNE RSONANCE DE PLASMA Summary:...

406

Effect of viscosity on the plasma decay in a magnetic field  

SciTech Connect

The effect of viscosity on the evolution of an axisymmetric plasma column in a longitudinal magnetic field is considered. It is found that, under the action of viscosity, the plasma density profile tends to become Gaussian.

Timofeev, A. V.; Kuyanov, A. Yu. [Russian Research Centre Kurchatov Institute (Russian Federation)

2010-11-15T23:59:59.000Z

407

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.

408

Negative ion-containing plasma in parallel-plate radio-frequency discharge in oxygen  

Science Journals Connector (OSTI)

The properties of a plasma in a parallel-plate radio frequency (rf) symmetric discharge of 13.56 MHz in oxygen have been investigated. The plasma contains negative ions. The temperature and density ... .6 eV, dep...

H. Amemiva; N. Yasuda; M. Endou

1994-09-01T23:59:59.000Z

409

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

410

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 focus

Rocca, Jorge J.

411

Gasification of biomass in water/gas-stabilized plasma for syngas production  

Science Journals Connector (OSTI)

The experimental reactor PLASGAS for plasma pyrolysis and vitrification equipped with the hybrid gas-water stabilized torch was used in the experiments. The plasma torch is characterized by low density, high t...

M. Hrabovsky; M. Konrad; V. Kopecky; M. Hlina; T. Kavka

2006-10-01T23:59:59.000Z

412

Localized whistlers in magnetized spin quantum plasmas  

SciTech Connect

The nonlinear propagation of electromagnetic (EM) electron-cyclotron waves (whistlers) along an external magnetic field, and their modulation by electrostatic small but finite amplitude ion-acoustic density perturbations are investigated in a uniform quantum plasma with intrinsic spin of electrons. The effects of the quantum force associated with the Bohm potential and the combined effects of the classical as well as the spin-induced ponderomotive forces (CPF and SPF, respectively) are taken into consideration. The latter modify the local plasma density in a self-consistent manner. The coupled modes of wave propagation is shown to be governed by a modified set of nonlinear Schroedinger-Boussinesq-like equations which admit exact solutions in form of stationary localized envelopes. Numerical simulation reveals the existence of large-scale density fluctuations that are self-consistently created by the localized whistlers in a strongly magnetized high density plasma. The conditions for the modulational instability (MI) and the value of its growth rate are obtained. Possible applications of our results, e.g., in strongly magnetized dense plasmas and in the next generation laser-solid density plasma interaction experiments are discussed.

Misra, A. P.; Brodin, G.; Marklund, M. [Department of Physics, Umeaa University, SE-901 87 Umeaa (Sweden); Shukla, P. K. [Department of Physics, Umeaa University, SE-901 87 Umeaa (Sweden); RUB International Chair, International Centre for Advanced Studies in Physical Sciences, Faculty of Physics and Astronomy, Ruhr University Bochum, D-44780 Bochum (Germany)

2010-11-15T23:59:59.000Z

413

Collisional Processes at Low Densities in Magnetic Mirror Systems  

Science Journals Connector (OSTI)

The study of collisional processes in plasmas produced by neutral?atom injection into magnetic mirror fields is described. The emphasis is on the many collisional processes which occur as the plasma density increases. Experimental and theoretical results are given. The experimental results are discussed first in terms of a simple model which assumes a Maxwellian electron distribution and a monoenergetic ion component of much higher energy. Analytical solutions may be obtained for this model. Also presented is a more complete theory employing two time?dependent Fokker?Planck equations to describe the behavior of the electron and ion distribution functions. Both models are in good agreement with measured values of the electron temperature and plasma potential. The equilibrium values of these two quantities are found to vary as the 3 5 power of the ratio of the plasma density to the background?gas density.

A. H. Futch; C. C. Damm; J. H. Foote; A. L. Gardner; J. Killeen

1971-01-01T23:59:59.000Z

414

Labs at-a-Glance: Princeton Plasma Physics Laboratory | U.S. DOE Office of  

Office of Science (SC) Website

Princeton Plasma Princeton Plasma Physics Laboratory Laboratories Ames Laboratory Argonne National Laboratory Brookhaven National Laboratory Fermi National Accelerator Laboratory Lawrence Berkeley National Laboratory Oak Ridge National Laboratory Pacific Northwest National Laboratory Princeton Plasma Physics Laboratory SLAC National Accelerator Laboratory Thomas Jefferson National Accelerator Facility Laboratory Policy and Evaluation Safety, Security and Infrastructure Laboratory Science Highlights Contact Information Office of Science U.S. Department of Energy 1000 Independence Ave., SW Washington, DC 20585 P: (202) 586-5430 Labs at-a-Glance: Princeton Plasma Physics Laboratory Print Text Size: A A A RSS Feeds FeedbackShare Page Princeton Plasma Physics Laboratory Logo Visit the Princeton Plasma Physics

415

Measurement and modeling of Ar ? H 2 ? C H 4 arc jet discharge chemical vapor deposition reactors II: Modeling of the spatial dependence of expanded plasma parameters and species number densities  

Science Journals Connector (OSTI)

Detailed methodology and results are presented for a two-dimensional ( r z ) computer model applicable to dc arc jet reactors operating on argon/hydrogen/hydrocarbon gas mixtures and used for chemical vapor deposition of micro- and nanocrystalline diamond and diamondlike carbon films. The model incorporates gas activation expansion into the low pressure reactor chamber and the chemistry of the neutral and charged species. It predicts the spatial variation of temperature flow velocities and number densities of 25 neutral and 14 charged species and the dependence of these parameters on the operating conditions of the reactor such as flows of H 2 and C H 4 and input power. Selected outcomes of the model are compared with experimental data in the accompanying paper [C. J. Rennick et al. J. Appl. Phys.102 063309 (2007)]. Two-dimensional spatial maps of the number densities of key radical and molecular species in the reactor derived from the model provide a summary of the complicated chemical processing that occurs. In the vortex region beyond the plume the key transformations are C H 4 ? C H 3 ? C 2 H 2 ? large hydrocarbons; in the plume or the transition zone to the cooler regions the chemical processing involves C 2 H x ? ( C H y and C H z ) C 3 H x ? ( C H y and C 2 H z ) ( C 2 H y and C 2 H z ) ? C 4 H x ? ( C H y and C 3 H z ) . Depending on the local gas temperature T g and the H ? H 2 ratio the equilibria of H-shifting reactions favor C CH and C 2 species (in the hot H-rich axial region of the plume) or C H 2 C 2 H and C 2 H 2 species (at the outer boundary of the transition zone). Deductions are drawn about the most abundant C-containing radical species incident on the growing diamond surface (C atoms and CH radicals) within this reactor and the importance of chemistry involving charged species is discussed. Modifications to the boundary conditions and model reactor geometry allow its application to a lower power arc jet reactor operated and extensively studied by Jeffries and co-workers at SRI International and comparisons are drawn with the reported laser induced fluorescence data from these studies.

Yu. A. Mankelevich; M. N. R. Ashfold; A. J. Orr-Ewing

2007-01-01T23:59:59.000Z

416

Hunting the Quark Gluon Plasma ASSESSMENTS  

NLE Websites -- All DOE Office Websites (Extended Search)

Hunting the Quark Gluon Plasma Hunting the Quark Gluon Plasma ASSESSMENTS BY THE EXPERIMENTAL COLLABORATIONS Relativistic Heavy Ion Collider (RHIC) * Brookhaven National Laboratory, Upton, NY 11974-5000 RESULTS FROM THE FIRST 3 YEARS AT RHIC managed for the U.S. Department of Energy by Brookhaven Science Associates, a company founded by Stony Brook University and Battelle April 18, 2005 BNL -73847-2005 Formal Report

417

FESAC Agenda - July 2003 | U.S. DOE Office of Science (SC)  

Office of Science (SC) Website

3 3 Fusion Energy Sciences Advisory Committee (FESAC) FESAC Home Meetings Members Charges/Reports Charter .pdf file (140KB) FES Committees of Visitors FES Home Meetings FESAC Agenda - July 2003 Print Text Size: A A A RSS Feeds FeedbackShare Page Fusion Energy Sciences Advisory Committee Meeting Agenda July 31 - August 1, 2003 Gaitherburg, Maryland Date/Time Topic Speaker July 31 0900 Welcome/Logistics Richard Hazeltine 0905 OFES Perspective Anne Davies .pdf file (602KB) 945 Break 1000 Final Report from the Non-Electric Application Panel Kathy McCarthy .pdf file (1.6MB) 1100 Discussion FESAC 1200 Lunch 1300 Science Presentation on Inertial Fusion Energy, Fast Ignition, and High Energy Density Physics Mike Campbell 1400 Burning Plasma Physics Program Ned Sauthoff .pdf file (2.6MB)

418

The magnetospheric clock of SaturnA self-organized plasma dynamo  

SciTech Connect

The plasma in the inner magnetosphere of Saturn is characterized by large-amplitude azimuthal density variations in the equatorial plane, with approximately a sinusoidal dependence on the azimuthal angle [D. A. Gurnett et al., Science 316, 442 (2007)]. This structure rotates with close to the period of the planet itself and has been proposed to steer other nonaxisymmetric phenomena, e.g., the Saturn kilometric radiation SKR [W. S. Kurth et al., Geophys. Res. Lett. 34, L02201 (2007)], and inner-magnetosphere magnetic field perturbations [D. J. Southwood and M. G. Kivelson, J. Geophys. Res. 112(A12), A12222 (2007)]. There is today no consensus regarding the basic driving mechanism. We here propose it to be a plasma dynamo, located in the neutral gas torus of Enceladus but coupled both inwards, through electric currents along the magnetic field lines down to the planet, and outwards through the plasma flow pattern there. Such a dynamo mechanism is shown to self-regulate towards a state that, with realistic parameters, can reproduce the observed configuration of the magnetosphere. This state is characterized by three quantities: the Pedersen conductivity in the polar cap, the ionization time constant in the neutral gas torus, and a parameter characterizing the plasma flow pattern. A particularly interesting property of the dynamo is that regular (i.e., constant-amplitude, sinusoidal) variations in the last parameter can lead to complicated, non-periodic, oscillations around the steady-state configuration.

Olson, J.; Brenning, N. [Space and Plasma Physics, Royal Institute of Technology (KTH), SE-100 44 Stockholm (Sweden)] [Space and Plasma Physics, Royal Institute of Technology (KTH), SE-100 44 Stockholm (Sweden)

2013-08-15T23:59:59.000Z

419

Analysis of pedestal plasma transport  

Science Journals Connector (OSTI)

An H-mode edge pedestal plasma transport benchmarking exercise was undertaken for a single DIII-D pedestal. Transport modelling codes used include 1.5D interpretive (ONETWO, GTEDGE), 1.5D predictive (ASTRA) and 2D ones (SOLPS, UEDGE). The particular DIII-D discharge considered is 98889, which has a typical low density pedestal. Profiles for the edge plasma are obtained from Thomson and charge-exchange recombination data averaged over the last 20% of the average 33.53?ms repetition time between type I edge localized modes. The modelled density of recycled neutrals is largest in the divertor X-point region and causes the edge plasma source rate to vary by a factor ~102 on the separatrix. Modelled poloidal variations in the densities and temperatures on flux surfaces are small on all flux surfaces up to within about 2.6?mm (?N > 0.99) of the mid-plane separatrix. For the assumed Fick's-diffusion-type laws, the radial heat and density fluxes vary poloidally by factors of 23 in the pedestal region; they are largest on the outboard mid-plane where flux surfaces are compressed and local radial gradients are largest. Convective heat flows are found to be small fractions of the electron (10%) and ion (25%) heat flows in this pedestal. Appropriately averaging the transport fluxes yields interpretive 1.5D effective diffusivities that are smallest near the mid-point of the pedestal. Their 'transport barrier' minima are about 0.3 (electron heat), 0.15 (ion heat) and 0.035 (density) m2?s?1. Electron heat transport is found to be best characterized by electron-temperature-gradient-induced transport at the pedestal top and paleoclassical transport throughout the pedestal. The effective ion heat diffusivity in the pedestal has a different profile from the neoclassical prediction and may be smaller than it. The very small effective density diffusivity may be the result of an inward pinch flow nearly balancing a diffusive outward radial density flux. The inward ion pinch velocity and density diffusion coefficient are determined by a new interpretive analysis technique that uses information from the force balance (momentum conservation) equations; the paleoclassical transport model provides a plausible explanation of these new results. Finally, the measurements and additional modelling needed to facilitate better pedestal plasma transport modelling are discussed.

J.D. Callen; R.J. Groebner; T.H. Osborne; J.M. Canik; L.W. Owen.; A.Y. Pankin; T. Rafiq; T.D. Rognlien; W.M. Stacey

2010-01-01T23:59:59.000Z

420

Media Contacts  

NLE Websites -- All DOE Office Websites (Extended Search)

biosecurity, health Chemical science Earth, space sciences Energy, energy security Engineering High energy density plasmas, fluids Information science, supercomputing New...

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

Laboratory Density Functionals  

E-Print Network (OSTI)

We compare several definitions of the density of a self-bound system, such as a nucleus, in relation with its center-of-mass zero-point motion. A trivial deconvolution relates the internal density to the density defined in the laboratory frame. This result is useful for the practical definition of density functionals.

B. G. Giraud

2007-07-26T23:59:59.000Z

422

Transport coefficients for dense metal plasmas  

Science Journals Connector (OSTI)

Thermoelectric transport coefficients of metal plasmas are calculated within the linear response theory applied previously to determine the electrical conductivity of Al and Cu plasmas [R. Redmer, Phys. Rev. E 59, 1073 (1999)]. We consider temperatures of 13 eV and densities of 0.0011 g/cm3 as relevant in rapid wire evaporation experiments. The plasma composition is calculated considering higher ionization stages of atoms up to 5+, and solving the respective system of coupled mass action laws. Interactions between charged particles are treated on T matrix level. Results for the electrical conductivity of various metal plasmas are in reasonable agreement with experimental data. Thermal conductivity and thermopower are also given. In addition, we compare with experimental data for temperatures up to 25 eV and liquidlike densities.

Sandra Kuhlbrodt and Ronald Redmer

2000-11-01T23:59:59.000Z

423

Plasma catalytic reforming of methane  

SciTech Connect

Thermal plasma technology can be efficiently used in the production of hydrogen and hydrogen-rich gases from methane and a variety of fuels. This paper describes progress in plasma reforming experiments and calculations of high temperature conversion of methane using heterogeneous processes. The thermal plasma is a highly energetic state of matter that is characterized by extremely high temperatures (several thousand degrees Celsius) and high degree of dissociation and substantial degree of ionization. The high temperatures accelerate the reactions involved in the reforming process. Hydrogen-rich gas (50% H{sub 2}, 17% CO and 33% N{sub 2}, for partial oxidation/water shifting) can be efficiently made in compact plasma reformers. Experiments have been carried out in a small device (2--3 kW) and without the use of efficient heat regeneration. For partial oxidation/water shifting, it was determined that the specific energy consumption in the plasma reforming processes is 16 MJ/kg H{sub 2} with high conversion efficiencies. Larger plasmatrons, better reactor thermal insulation, efficient heat regeneration and improved plasma catalysis could also play a major role in specific energy consumption reduction and increasing the methane conversion. A system has been demonstrated for hydrogen production with low CO content ({approximately} 1.5%) with power densities of {approximately} 30 kW (H{sub 2} HHV)/liter of reactor, or {approximately} 10 m{sup 3}/hr H{sub 2} per liter of reactor. Power density should further increase with increased power and improved design.

Bromberg, L.; Cohn, D.R.; Rabinovich, A. [Massachusetts Inst. of Technology, Cambridge, MA (United States). Plasma Science and Fusion Center; Alexeev, N. [Russian Academy of Sciences, Moscow (Russian Federation). Baikov Inst. of Metallurgy

1998-08-01T23:59:59.000Z

424

Formation and Stability of Impurity "snakes" in Tokamak Plasmas  

SciTech Connect

New observations of the formation and dynamics of long-lived impurity-induced helical "snake" modes in tokamak plasmas have recently been carried-out on Alcator C-Mod. The snakes form as an asymmetry in the impurity ion density that undergoes a seamless transition from a small helically displaced density to a large crescent-shaped helical structure inside q < 1, with a regularly sawtoothing core. The observations show that the conditions for the formation and persistence of a snake cannot be explained by plasma pressure alone. Instead, many features arise naturally from nonlinear interactions in a 3D MHD model that separately evolves the plasma density and temperature

L. Delgado-Aparicio, et. al.

2013-01-28T23:59:59.000Z

425

Nuclear fusion in a dense plasma  

E-Print Network (OSTI)

The standard theory of nuclear fusion rates in a strongly interacting plasma can be (correctly) derived only when the energy release, Q, is large compared to other energies in the problem. We exhibit a result for rates that provides a basis for calculating the finite Q corrections. Crude estimates indicate a significant defect in the conventional results for some regions of high density and strong plasma coupling. We also lay some groundwork for a path integral calculation of the new effects.

R. F. Sawyer

2010-02-04T23:59:59.000Z

426

Volumetric plasma source development and characterization.  

SciTech Connect

The development of plasma sources with densities and temperatures in the 10{sup 15}-10{sup 17} cm{sup -3} and 1-10eV ranges which are slowly varying over several hundreds of nanoseconds within several cubic centimeter volumes is of interest for applications such as intense electron beam focusing as part of the x-ray radiography program. In particular, theoretical work [1,2] suggests that replacing neutral gas in electron beam focusing cells with highly conductive, pre-ionized plasma increases the time-averaged e-beam intensity on target, resulting in brighter x-ray sources. This LDRD project was an attempt to generate such a plasma source from fine metal wires. A high voltage (20-60kV), high current (12-45kA) capacitive discharge was sent through a 100 {micro}m diameter aluminum wire forming a plasma. The plasma's expansion was measured in time and space using spectroscopic techniques. Lineshapes and intensities from various plasma species were used to determine electron and ion densities and temperatures. Electron densities from the mid-10{sup 15} to mid-10{sup 16} cm{sup -3} were generated with corresponding electron temperatures of between 1 and 10eV. These parameters were measured at distances of up to 1.85 cm from the wire surface at times in excess of 1 {micro}s from the initial wire breakdown event. In addition, a hydrocarbon plasma from surface contaminants on the wire was also measured. Control of these contaminants by judicious choice of wire material, size, and/or surface coating allows for the ability to generate plasmas with similar density and temperature to those given above, but with lower atomic masses.

Crain, Marlon D. (National Security Technologies, LLC, Las Vegas, NV); Maron, Yitzhak (Weizmann Institute of Science, Rehovot, Israel); Oliver, Bryan Velten; Starbird, Robert L. (National Security Technologies, LLC, Las Vegas, NV); Johnston, Mark D.; Hahn, Kelly Denise; Mehlhorn, Thomas Alan; Droemer, Darryl W. (National Security Technologies, LLC, Las Vegas, NV); National Security Technologies, LLC, Las Vegas, NV

2008-09-01T23:59:59.000Z

427

5 - Surface Wave Plasma Sources  

Science Journals Connector (OSTI)

Publisher Summary This chapter summarizes the advantages of the surface wave (SW) plasma sources. It includes a summary of the wave and plasma properties of SW sustained plasma columns, review of the essential parts composing a SW plasma source; describes a family of efficient SW launchers for such plasma sources, dwells on three typical experimental arrangements and a brief summary recalling the advantages of SW plasma sources. Surface wave discharges have the advantage of the broadest operating conditions in terms of frequency, tube dimensions and shape, and gas pressure. For example they can be utilized over both the RF (radiofrequency) and microwave domains, which permits one to optimize given processes as a function of frequency (generally through changes in the electron energy distribution function). A further advantage of SW plasmas is that they are the best modeled HF plasmas. This provides insight into HF discharges in general since, to a first approximation, the local plasma properties of SW discharges are the same as in all RF and microwave discharges under given discharge conditions, and for a given HF power density deposited in the plasma. Compared to other RF and microwave plasma sources, SW discharges are undoubtedly the most flexible ones. They also are efficient discharges since very little HF power is lost in the impedance matching circuit. Finally, a major future avenue for these discharges is their operation as magnetized plasmas. As a first approach to presenting surface wave (SW) plasma sources, let us consider their distinctive features with respect to the other plasma sources described in the book:o1. The discharge can be sustained far away from the active zone of the field applicator. This is because the electric field supporting the discharge is provided by a wave that carries away the power from the applicator. It is an electromagnetic surface wave whose sole guiding structure is the plasma column that it sustains and the dielectric tube enclosing it [1][3]. This is, thus, a non-cumbersome method for producing long plasma columns; plasma columns up to 6 meters in length have been achieved in our laboratory while launching the wave with a field applicator that surrounded the discharge tube over a few centimeters in length only. [4][5] 2. The range of the applied field frequency f=?/2? is the broadest of all kinds of high frequency (HF) sustained plasma sources. We have succeeded in realizing HF power transfer to the discharge efficiently from approximately 10 \\{MHz\\} to 10 \\{GHz\\} [6] and, with impaired coupling efficiency, down to 200 kHz [7]. This frequency range includes radiofrequencies (RF) and the lower part of the microwave frequency spectrum; we use the term high frequencies to designate RF as well as microwave frequencies. An interesting aspect of this frequency flexibility is the possibility of acting on the electron energy distribution function (EEDF) to optimize a given plasma process [8]. 3. The gas pressure range is extremely large. On the one hand, one can operate SW discharges in the sub-mtorr range under electron cyclotron resonance (ECR) conditions, [9] while, on the other hand, it is possible to sustain a stable plasma of a few millimeters diameter at pressures at least a few times atmospheric pressure [10]. 4. The range of plasma, density, n, is very large. At reduced pressure and with f in the few \\{MHz\\} range, n, can be as low as 108 cm?3, [7] while at atmospheric pressure it can exceed 1015 cm?3[10] A related parameter is the degree of ionization ?i, i.e. the plasma density relative to the initial neutral atom concentration. Under ECR conditions, for example with f=2.45 \\{GHz\\} where n can reach up to a few 1012 cm?3, ?i ranges approximately from 0.110%, whereas in the above-mentioned atmospheric pressure case, it is smaller than 10?4. The higher n, the higher the rate of plasma processes depending on ions or on neutral particles (e.g., atoms, radicals) when the latter are obtained through electron collisions [8]. Large ?i values favor the existence of

Michel Moisan; Jolle Margot; Zenon Zakrzewski

1996-01-01T23:59:59.000Z

428

Quest Magazine Summer 2013 | Princeton Plasma Physics Lab  

NLE Websites -- All DOE Office Websites (Extended Search)

(PPPL). We are pleased to provide this news of our strides in advancing research into fusion energy and plasma science-two topics of vital interest to the United States and the...

429

Space-potential and density fluctuations in the ISX-B tokamak  

Science Journals Connector (OSTI)

The fluctuating plasma potential and electron density has been measured in Ohmic and neutral-beamheated tokamak discharges. Radial profiles are presented in the outer two-thirds of the plasma, and the EB transport calculated. The transport is found to be an order of magnitude larger for beam driven plasmas. Measurements indicate the linearized Boltzman equation is satisfied in the interior, but not at the plasma edge.

G. A. Hallock; A. J. Wootton; R. L. Hickok

1987-09-21T23:59:59.000Z

430

Structure of an exploding laser-produced plasma  

SciTech Connect

Currents and instabilities associated with an expanding dense plasma embedded in a magnetized background plasma are investigated by direct volumetric probe measurements of the magnetic field and floating potential. A diamagnetic cavity is formed and found to collapse rapidly compared to the expected magnetic diffusion time. The three-dimensional current density within the expanding plasma includes currents along the background magnetic field, in addition to the diamagnetic current. Correlation measurements reveal that flutelike structures at the plasma surface translate with the expanding plasma across the magnetic field and extend into the current system that sustains the diamagnetic cavity, possibly contributing to its collapse.

Collette, A. [Laboratory for Atmospheric and Space Physics, UCB 392, Boulder, Colorado 80309 (United States); Gekelman, W. [Department of Physics and Astronomy, University of California, Los Angeles, Los Angeles, California 90095 (United States)

2011-05-15T23:59:59.000Z

431

Anomalous High-Frequency Resistivity and Heating of a Plasma  

Science Journals Connector (OSTI)

Computer experiments have been carried out on the anomalous heating of a one-dimensional plasma by a large-amplitude long-wavelength electric field oscillating near the plasma frequency. Above a certain threshold the large driver field excites an instability in the plasma and drives up ion-density fluctuations as well as plasma oscillations. When the ion fluctuations reach a sufficiently large level, the plasma begins to heat very efficiently according to an anomalous resistivity. An effective collision frequency as high as 0.2?pe has been observed. A theoretical explanation of the observed results is given.

W. L. Kruer; P. K. Kaw; J. M. Dawson; C. Oberman

1970-05-04T23:59:59.000Z

432

Relativistic laser channeling in plasmas for fast ignition  

Science Journals Connector (OSTI)

We report an experimental observation suggesting plasma channel formation by focusing a relativistic laser pulse into a long-scale-length preformed plasma. The channel direction coincides with the laser axis. Laser light transmittance measurement indicates laser channeling into the high-density plasma with relativistic self-focusing. A three-dimensional particle-in-cell simulation reproduces the plasma channel and reveals that the collimated hot-electron beam is generated along the laser axis in the laser channeling. These findings hold the promising possibility of fast heating a dense fuel plasma with a relativistic laser pulse.

A. L. Lei, A. Pukhov, R. Kodama, T. Yabuuchi, K. Adumi, K. Endo, R. R. Freeman, H. Habara, Y. Kitagawa, K. Kondo, G. R. Kumar, T. Matsuoka, K. Mima, H. Nagatomo, T. Norimatsu, O. Shorokhov, R. Snavely, X. Q. Yang, J. Zheng, and K. A. Tanaka

2007-12-18T23:59:59.000Z

433

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

434

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

435

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

SciTech Connect

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

436

Dissipative phenomena in quark-gluon plasmas  

SciTech Connect

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

437

Dense plasma diagnostics by fast proton beams  

Science Journals Connector (OSTI)

Coulomb energy losses by 3-MeV protons in a capillary discharge channel are used as a diagnostics tool to measure the plasma density. By combining the proton energy loss data with the electron temperature measurements,we have been able to diagnose the free electron density nfe=6.41019cm-3 in a 3.3-eV CH2 plasma to an accuracy of 17%. A considerably better accuracy can be expected for higher values of the electron temperature.

A. Golubev, M. Basko, A. Fertman, A. Kozodaev, N. Mesheryakov, B. Sharkov, A. Vishnevskiy, V. Fortov, M. Kulish, V. Gryaznov, V. Mintsev, E. Golubev, A. Pukhov, V. Smirnov, U. Funk, S. Stoewe, M. Stetter, H.-P. Flierl, D. H. H. Hoffmann, J. Jacoby, and I. Iosilevski

1998-03-01T23:59:59.000Z

438

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

SciTech Connect

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

439

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

440

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

SciTech Connect

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

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

Intense plasma waves at and near the solar wind termination shock  

Science Journals Connector (OSTI)

... from the Sun. If the electric field spectral densities are normalized by dividing by the solar wind energy density and the frequencies are normalized by dividing by the electron plasma frequency, then ...

D. A. Gurnett; W. S. Kurth

2008-07-03T23:59:59.000Z

442

Photon Science  

NLE Websites -- All DOE Office Websites (Extended Search)

Photon Science Along with its primary missions-global security, energy security, basic science, and national competitiveness-the NIF & Photon Science Directorate also pursues...

443

Science Engagement  

NLE Websites -- All DOE Office Websites (Extended Search)

Science Engagement Science Engagement Move your data Programs & Workshops Science Requirements Reviews Case Studies Contact Us Technical Assistance: 1 800-33-ESnet (Inside US) 1...

444

Science Briefs  

NLE Websites -- All DOE Office Websites (Extended Search)

Science Briefs newsroomassetsimagesnewsroom-icon.jpg Science Briefs Read in detail about specific Los Alamos science achievements, and the honors our scientists are accruing....

445

Detection Science  

NLE Websites -- All DOE Office Websites (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...

446

2009 US-Japan Workshop on Advanced Simulation Methods in Plasma Physics Plasma Particle Simulation with Adaptive Mesh Refinement Technique  

E-Print Network (OSTI)

2009 US-Japan Workshop on Advanced Simulation Methods in Plasma Physics Plasma Particle Simulation-5292, Japan 2 Kobe University, Kobe 657-8501, Japan 3 Kyoto University, Uji 611-0011, Japan 4 Japan Aerospace Exploration Agency, Sagamihara 229-8510, Japan 5 Japan Science and Technology Agency, CREST, Kawaguchi 332

Ito, Atsushi

447

Symmetric Density Functionals  

E-Print Network (OSTI)

Variations in distinct restricted spaces of wave functions generate distinct density functionals. In particular, angular momentum projected Slater determinants define a new density functional, compatible simultaneously with angular momentum quantum number and mean field descriptions.

B. G. Giraud

2005-07-13T23:59:59.000Z

448

Density measurements Viscosity measurements  

E-Print Network (OSTI)

Density measurements Viscosity measurements Temperature measurements Pressure measurements Flow rate measurements Velocity measurements Sensors How to measure fluid flow properties ? Am´elie Danlos Ravelet Experimental methods for fluid flows: an introduction #12;Density measurements Viscosity

Ravelet, Florent

449

Radio frequency discharge with control of plasma potential distribution  

SciTech Connect

A RF discharge plasma generator with additional electrodes for independent control of plasma potential distribution is proposed. With positive biasing of this ring electrode relative end flanges and longitudinal magnetic field a confinement of fast electrons in the discharge will be improved for reliable triggering of pulsed RF discharge at low gas density and rate of ion generation will be enhanced. In the proposed discharge combination, the electron energy is enhanced by RF field and the fast electron confinement is improved by enhanced positive plasma potential which improves the efficiency of plasma generation significantly. This combination creates a synergetic effect with a significantly improving the plasma generation performance at low gas density. The discharge parameters can be optimized for enhance plasma generation with acceptable electrode sputtering.

Dudnikov, Vadim [Muons, Inc., Batavia, Illinois 60510 (United States); Dudnikov, A. [BINP, Novosibirsk 63090 (Russian Federation)

2012-02-15T23:59:59.000Z

450

Properties of Nonneutral Plasma  

Science Journals Connector (OSTI)

We describe an apparatus for producing a magnetized column of nonneutral electron plasma which is many Debye lengths in radius. The plasma exhibits the linear and nonlinear electron-wave effects observed in neutralized plasmas.

J. H. Malmberg and J. S. deGrassie

1975-09-01T23:59:59.000Z

451

Changes in compression dynamics for seeded plasma focus pinches  

Science Journals Connector (OSTI)

The effects of radiation emission on the dynamic development of a neon seeded dense plasma focus are observed. The radiative cooling of the discharge is found to be responsible for the >10 times the increase in density of the pinch.

F. Venneri; K. Boulais; G. Gerdin

1990-01-01T23:59:59.000Z

452

Ultra-High Intensity Magnetic Field Generation in Dense Plasma  

SciTech Connect

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

453

Contrib. Plasma Phys. 49, No. 1, 76 89 (2009) / DOI 10.1002/ctpp.200910011 Electric Microfield Distributions in Li+  

E-Print Network (OSTI)

widely applied in plasma diagnostics to evaluate plasma densities in stellar atmosphere or in laboratoryContrib. Plasma Phys. 49, No. 1, 76 ­ 89 (2009) / DOI 10.1002/ctpp.200910011 Electric Microfield Distributions in Li+ Plasma With Account of the Ion Structure S. Sadykova1 , W. Ebeling1 , I. Valuev2 , and I

Ebeling, Werner

454

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

455

Equilibrium and Stability Studies of Plasmas Confined in a Dipole Magnetic Field Using  

E-Print Network (OSTI)

Equilibrium and Stability Studies of Plasmas Confined in a Dipole Magnetic Field Using Magnetic Measurements by Ishtak Karim Submitted to the Department of Nuclear Science and Engineering in partial fulfillment of the requirements for the degree of Doctor of Science in Applied Plasma Physics

456

Thomson scattering measurements in atmospheric plasma jets  

Science Journals Connector (OSTI)

Electron temperature and electron density in a dc plasma jet at atmospheric pressure have been obtained using Thomson laser scattering. Measurements performed at various scattering angles have revealed effects that are not accounted for by the standard scattering theory. Differences between the predicted and experimental results suggest that higher order corrections to the theory may be required, and that corrections to the form of the spectral density function may play an important role.

G. Gregori; J. Schein; P. Schwendinger; U. Kortshagen; J. Heberlein; E. Pfender

1999-02-01T23:59:59.000Z

457

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

458

NREL: Energy Sciences - Materials Science  

NLE Websites -- All DOE Office Websites (Extended Search)

Materials Science Hydrogen Technology & Fuel Cells Process Technology & Advanced Concepts Research Staff Computational Science Printable Version Materials Science Learn about our...

459

High-Frequency Gas Discharge Plasma in Hydrogen  

Science Journals Connector (OSTI)

The high-frequency electric field required to maintain a hydrogen plasma has been measured as a function of pressure and plasma electron density. A theory of the plasma based on a solution of the Boltzmann transport equation has been developed to predict this field; it agrees satisfactorily with experiment. The theory has no adjustable parameters, and uses only the probabilities of collision, excitation, and ionization of the gas by electrons, and the ionic mobility.

David J. Rose and Sanborn C. Brown

1955-04-15T23:59:59.000Z

460

Magnetic Confinement Fusion Science Status and Challenges  

E-Print Network (OSTI)

Magnetic Confinement Fusion Science Status and Challenges S. Prager University of Wisconsin February, 2005 #12;Two approaches to fusion Inertial confinement extremely dense, short-lived Magnetic ·Control plasma disruptions ·Develop new magnetic configurations ·Control the plasma-wall interaction

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

Fusion roadmapping | Princeton Plasma Physics Lab  

NLE Websites -- All DOE Office Websites (Extended Search)

Fusion roadmapping Fusion roadmapping Subscribe to RSS - Fusion roadmapping The process of mapping a path to a commercial fusion reactor by planning a sequence of future machines. Premiere issue of "Quest" magazine details PPPL's strides toward fusion energy and advances in plasma science Quest Magazine Summer 2013 Welcome to the premiere issue of Quest, the annual magazine of the U.S. Department of Energy's Princeton Plasma Physics Laboratory (PPPL). Read more about Premiere issue of "Quest" magazine details PPPL's strides toward fusion energy and advances in plasma science PPPL and ITER: Lab teams support the world's largest fusion experiment with leading-edge ideas and design Read more about PPPL and ITER: Lab teams support the world's largest fusion experiment with leading-edge ideas and design

462

Plasma Wave Observations at Comet Giacobini-Zinner  

Science Journals Connector (OSTI)

...profile for the electron plasma frequency,fp, can be...over-lapping coverage down to 30 kHz andmany additional cha ls extendingup to 2 MHz. Mgeyr-Vernet et al...detailed profile of the plasma tem-prature and density...For instnce, the 100-kHz I8 APRIL 1986 ICE-To...

FREDERICK L. SCARF; FERDINAND V. CORONITI; CHARLES F. KENNEL; DONALD A. GURNETT; WING-HUEN IP; EDWARD J. SMITH

1986-04-18T23:59:59.000Z

463

Nonequilibrium Alfvnic Plasma Jets Associated with Spheromak Formation  

Science Journals Connector (OSTI)

Nonequilibrium Alfvnic flows have been observed in plasma jets during the helicity injection stage of the Caltech spheromak experiment. Density and time of flight measurements of these jets show that the flows convect dense plasma (??1) because of the axial gradient in the current channel profile. A simplified MHD theory is derived to model the flow.

Deepak Kumar and Paul M. Bellan

2009-09-04T23:59:59.000Z

464

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

465

The status and evolution of plasma wakefield particle accelerators  

Science Journals Connector (OSTI)

...respectively. This electric field will tend to focus the rest of the electron beam that resides...If the density length product of the plasma is large enough, the electron beam can focus within the plasma itself and indeed undergo multiple focusing...

2006-01-01T23:59:59.000Z

466

ccsd00001995, Plasma Production by Helicon Waves with Single  

E-Print Network (OSTI)

ccsd­00001995, version 1 ­ 20 Oct 2004 Plasma Production by Helicon Waves with Single Mode Number density (10 12 10 13 cm 3 ) is obtained with comparatively ease under a low gas pressure of a few hundreds commercially a disadvantage for operating helicon-wave plasma sources with the lower running cost

467

"Method for Controlling of Spatial and Temporal Variations of Plasma  

NLE Websites -- All DOE Office Websites (Extended Search)

Method for Controlling of Spatial and Temporal Variations of Plasma Method for Controlling of Spatial and Temporal Variations of Plasma Properties in Plasma Devices with Crossed Electric and Magnetic Fields" Inventors Yevgeny Raitses, Alexander Merzhevskiy A method of crafting spatial variations of the electron cross-field transport by means of localized current-conducting plasma structures such as rotating spoke, in order to control spatial variations of macroscopic plasma properties, including the electric field, electron temperature and plasma density in relevant E crossed B plasma devices such as Hall and helicon plasma thrusters, plasma-beam devices for material processing, magnetic filters for plasma sources, including negative and positive ion sources, and rotating plasma devices such as E cross B mass separation

468

Radio and Plasma Wave Observations at Saturn from Cassini's Approach and First Orbit  

Science Journals Connector (OSTI)

...Cassini Radio and Plasma Wave Science (RPWS...radio emissions and plasma waves across a broad...from 1 Hz to 16 MHz for electric fields and from 1 Hz to 12 kHz for magnetic fields...temperature of the local plasma. Our observations are...rotation of the upper atmosphere of Saturn, the period...

D. A. Gurnett; W. S. Kurth; G. B. Hospodarsky; A. M. Persoon; T. F. Averkamp; B. Cecconi; A. Lecacheux; P. Zarka; P. Canu; N. Cornilleau-Wehrlin; P. Galopeau; A. Roux; C. Harvey; P. Louarn; R. Bostrom; G. Gustafsson; J.-E. Wahlund; M. D. Desch; W. M. Farrell; M. L. Kaiser; K. Goetz; P. J. Kellogg; G. Fischer; H.-P. Ladreiter; H. Rucker; H. Alleyne; A. Pedersen

2005-02-25T23:59:59.000Z

469

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

SciTech Connect

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

470

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

SciTech Connect

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

471

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

472

Capabilities Strategy: Science Pillars  

NLE Websites -- All DOE Office Websites (Extended Search)

Innovation Capabilities Strategy: Science Pillars science-innovationassetsimagesicon-science.jpg Capabilities Strategy: Science Pillars The Lab's four Science Pillars...

473

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

474

BIOLOGICAL SCIENCES Contemporary biological science  

E-Print Network (OSTI)

BIOLOGICAL SCIENCES Contemporary biological science covers a range of diverse and overlapping in cellular and molecular biology. Wichita State University's Department of Biological Sciences offers courses in most aspects of contemporary biological science. Our required core courses will expose you

475

Production of 1-m size uniform plasma by modified magnetron-typed RF discharge with a subsidiary electrode for resonance  

Science Journals Connector (OSTI)

A large-diameter uniform plasma of 1 m in size is produced using a modified magnetron-typed (MMT) RF plasma source at the frequency of 13.56 MHz. The construction and operation of the MMT RF plasma source are very simple and we can place two substrates simultaneously. To achieve an efficient production of high density plasma, a parallel resonance circuit is connected to one of the substrates which acts as a subsidiary RF electrode controlling the plasma parameters. In the case of the resonance the plasma density increases to approximately three times as much as that in case of non-resonance. The plasma density reaches?11011/cm3 in Ar at 1 mtorr when the RF input power is 2.8 kW. The MMT RF plasma source provides a plasma with uniformity within several percent over 1 m in diameter in front of the substrate in the low gas pressure regime.

Yuji Urano; Yunlong Li; Keiichi Kanno; Satoru Iizuka; Noriyoshi Sato

1998-01-01T23:59:59.000Z

476

News Archive | Princeton Plasma Physics Lab  

NLE Websites -- All DOE Office Websites (Extended Search)

Press Releases Press Releases Publications Princeton Journal Watch Blog Events Research Education Organization Contact Us News Room News Archive American Fusion News Press Releases Publications Princeton Journal Watch Blog News Archive Subscribe to News Archive January 10, 2014 Science on Saturday starts Jan. 11 By Jeanne Jackson DeVoe Joshua E. G. Peek, a Hubble Fellow at Columbia University's Department of Astronomy and son of PPPL physicist and former director Robert Goldston, discussed "Outer Space!" at a Science on Saturday lecture in 2013. Science fans of all ages can explore a rich variety of science and technology topics at the popular Science on Saturday lecture series hosted by the U.S. Department of Energy's Princeton Plasma Physics Laboratory. The series marks its 30-year anniversary when it begins on Saturday, Jan.

477

This article has been accepted for inclusion in a future issue of this journal. Content is final as presented, with the exception of pagination. IEEE TRANSACTIONS ON PLASMA SCIENCE 1  

E-Print Network (OSTI)

of sterilization. Sterilization technology has broad applications, from medical devices to food preparation equipment. When plasma is generated, radicals are formed, such as ozone, along with heat, and UV light

Roy, Subrata

478

The Science of Science Foundation  

Science Journals Connector (OSTI)

... THE 'science of ... of science' is an awkward name but, as it describes accurately what is meant, it ...

MAURICE GOLDSMITH

1965-01-02T23:59:59.000Z

479

Science in science fiction  

Science Journals Connector (OSTI)

Science fiction, from Star Trek to Star Wars, is hugely popular and pupils will surely have encountered good and bad physics there, but do they really notice? Discussing the science implied in books and movies, such as in the use of transporters, can be a good way of getting students interested in physics.

Jonathan Allday

2003-01-01T23:59:59.000Z

480

Passive Spectroscopic Diagnostics for Magnetically-confined Fusion Plasmas  

SciTech Connect

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

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.


481

Three regimes of relativistic beam - plasma interaction  

SciTech Connect

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

482

Magnetohydrodynamics in Tokamak Reactors and its Effect on Plasma Density  

E-Print Network (OSTI)

The worlds 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

483

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

484

Nathaniel J Fisch | Princeton Plasma Physics Lab  

NLE Websites -- All DOE Office Websites (Extended Search)

His professional interests include: plasma physics with applications to nuclear fusion, astrophysics, plasma-based pulse compression, plasma thrusters, plasma...

485

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

486

Characterization of a spheromak plasma gun: The effect of refractory electrode coatings  

E-Print Network (OSTI)

Characterization of a spheromak plasma gun: The effect of refractory electrode coatings M. FL Brown, the center electrode of the spheromak plasma gun has been coated with a variety of metals (bare steel, copper in the gun breech was monitored for each of the coated electrodes. Plasma density and temperature

Brown, Michael R.

487

Formation of laser plasma channels in a stationary gas A. Dunaevsky  

E-Print Network (OSTI)

a high-current arc discharge leads to overdense plasma near the front pinhole and further refraction-current glow discharge initiated in the chamber improves the uniformity of the plasma channel slightly, while fluctuation of the plasma density is nez ne a0 p , 1 where a0=eE/mc is normalized electric field in the beam

488

Electrostatic plasma instabilities driven by neutral gas flows in the solar chromosphere  

Science Journals Connector (OSTI)

......investigate electrostatic plasma instabilities of Farley-Buneman...Typical length-scales of plasma density fluctuations...scintillations) by these plasma irregularities can serve...who suggested that the atmosphere of the sun is heated...high-frequency (10-50 mHz) acoustic waves was......

G. Gogoberidze; Y. Voitenko; S. Poedts; J. De Keyser

2014-01-01T23:59:59.000Z

489

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

490

Communication through plasma sheaths  

SciTech Connect

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

491

Shapes of Spectral Lines of Nonuniform Plasma of Electric Arc Discharge Between Copper Electrodes  

SciTech Connect

The radial profiles of the temperature and electron density in the plasma of the free burning electric arc between copper electrodes are studied by optical spectroscopy techniques. The electron density and the temperature in plasma as initial parameters were used in the calculation of the plasma composition in local thermodynamic equilibrium (LTE) assumption. We used the Saha's equation for copper, nitrogen and oxygen, dissociation equation for nitrogen and oxygen, the equation of plasma electrical neutrality and Dalton's law as well. So, it would be possible to determine the amounts of metal vapours in plasma.

Babich, Ida L.; Boretskij, Viacheslav F.; Veklich, Anatoly N. [Radiophysics Faculty, Taras Shevchenko Kyiv National University, 64, Volodymyrs'ka Str., Kyiv 01033 (Ukraine)

2007-09-28T23:59:59.000Z

492

Effect of dual frequency on the plasma characteristics in an internal linear inductively coupled plasma source  

SciTech Connect

An internal-type linear inductive antenna, referred to as a ''double comb-type antenna,'' was used as a large area plasma source with a substrate size of 880x660 mm{sup 2} (fourth generation glass size). The effects of the dual frequency (2 and 13.56 MHz) radio frequency (rf) power to the antenna as well as the power ratio on the plasma characteristics were investigated. High-density plasma on the order of 1.7x10{sup 11} cm{sup -3} could be obtained with a dual frequency power of 5 kW (13.56 MHz) and 1 kW (2 MHz) at a pressure of 15 mTorr Ar. This plasma density was lower than that obtained for the double comb-type antenna using a single frequency alone (5 kW, 13.56 MHz). However, the use of the dual frequency with a rf power ratio of approximately 1(2 MHz):5(13.56 MHz) showed better plasma uniformity than that obtained using the single frequency. Plasma uniformity of 6.1% could be obtained over the substrate area. Simulations using FL2L code confirmed the improvement in the plasma uniformity using the dual frequency to the double comb-type antenna.

Kim, K. N.; Lim, J. H.; Yeom, G. Y.; Lee, S. H.; Lee, J. K. [Department of Materials Science and Engineering, Sungkyunkwan University, Suwon, Kyunggi-do 440-746 (Korea, Republic of); Department of Electronic and Electrical Engineering, Pohang University of Science and Technology, Pohang 790-784 (Korea, Republic of)

2006-12-18T23:59:59.000Z

493

Anomalous radial transport in tokamak edge plasma  

E-Print Network (OSTI)

Transport in tokamak plasma . . . . . . . . . . . . . . .Numerical simulations of tokamak plasma . . . . . . . . .of blobs in tokamak edge plasmas . . . . . . . . . . . . . .

Bodi, Vasudeva Raghavendra Kowsik

2010-01-01T23:59:59.000Z

494

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

495

Lasers as a tool for plasma diagnostics  

SciTech Connect

Lasers can be used as non-perturbative probes to measure many plasma parameters. Plasma refractivity is primarily a function of electron density, and interferometric measurements of phase changes with either pulsed or CW lasers can determine this parameter with spatial or temporal resolution over several orders of magnitude sensitivity by using laser wavelengths from the near uv to the far infrared. Laser scattering from free electrons yields the most fundamental electron temperature measurements in the plasma parameter range where individual scattering events are uncorrelated in phase and ion temperature or plasma wave and turbulence structure in the opposite limit. Laser scattering from bound electrons can be many orders of magnitude larger if the laser is matched to appropriate resonance frequencies and can be used in specialized circumstances for measuring low-ionized impurity or dominant species neutral concentrations and velocities.

Jahoda, F.C.

1981-01-01T23:59:59.000Z

496

Characterization of plasma expansion dynamics in a high power diode with a carbon-fiber-aluminum cathode  

SciTech Connect

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-Universit 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

497

COUNTER PROPAGATION OF ELECTRON AND CO2 LASER BEAMS IN A PLASMA CHANNEL.  

SciTech Connect

A high-energy CO{sub 2} laser is channeled in a capillary discharge. Occurrence of guiding conditions at a relatively low plasma density (<10{sup 18} cm{sup -3}) is confirmed by MHD simulations. Divergence of relativistic electron beam changes depending on the plasma density. Counter-propagation of the electron and laser beams inside the plasma channel results in intense x-ray generation.

HIROSE,T.; POGORELSKY,I.V.; BEN ZVI,I.; YAKIMENKO,V.; KUSCHE,K.; SIDDONS,P.; KUMITA,T.; KAMIYA,Y.; ZIGLER,A.; GREENBERG,B.; ET AL

2002-11-12T23:59:59.000Z

498

Stable plateau formation and Brillouin suppression in laser plasma  

SciTech Connect

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

499

Cold atmospheric plasma in cancer therapy  

SciTech Connect

Recent progress in atmospheric plasmas has led to the creation of cold plasmas with ion temperatur