National Library of Energy BETA

Sample records for density plasma science

  1. COLLOQUIUM: Frontiers in Plasma Science: A High Energy Density...

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

    January 13, 2016, 4:15pm to 5:30pm Colloquia MBG AUDITORIUM COLLOQUIUM: Frontiers in Plasma Science: A High Energy Density Perspective Dr. Bruce A. Remington Lawrence Livermore ...

  2. High-Energy-Density Plasmas, Fluids

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

    Capabilities High-Energy-Density Plasmas, Fluids science-innovationassetsimagesicon-science.jpg High-Energy-Density Plasmas, Fluids National security depends on science and ...

  3. Science on Tap - Plasmas

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

    Science on Tap - Plasmas Science on Tap - Plasmas WHEN: Apr 21, 2016 5:30 PM - 7:00 PM WHERE: UnQuarked Wine Room 145 Central Park Square, Los Alamos, New Mexico 87544 USA CONTACT: Linda Anderman (505) 665-9196 CATEGORY: Bradbury INTERNAL: Calendar Login Science on tap Event Description Science On Tap happens every third Thursday of the month, featuring a new topic each week. It begins with an informal 15-minute talk and is followed by a lively group discussion. Observing the stuff of stars (and

  4. Plasma digital density determining device

    DOE Patents [OSTI]

    Sprott, Julien C.; Lovell, Thomas W.; Holly, Donald J.

    1976-01-01

    The density of a decaying plasma in an electrically conducting enclosure is determined by applying an excitation to the cavity formed by the enclosure and counting digitally the number of resonant frequencies traversed by the combination of the cavity and the decaying plasma.

  5. Basic Plasma Science | Princeton Plasma Physics Lab

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

    Russia, Japan, Korea and China. PPPL research has expanded knowledge of the science behind such systems and has led to new conceptual designs. The charged particles in plasma...

  6. High Energy Density Laboratory Plasmas | National Nuclear Security

    National Nuclear Security Administration (NNSA)

    Administration High Energy Density Laboratory Plasmas NNSA's Office of Inertial Confinement Fusion and DOE's Office of Science established a joint program in HEDLP in 2008. Initially, this program was a combination of work that was funded as part of the NNSA's Stewardship Science Academic Alliances Program in the research area of high energy density physics and the DOE Office of Science's HEDLP Program and Innovative Confinement Concepts Program. Steady advances in increasing the energy,

  7. Plasma density diagnostic for capillary-discharge based plasma...

    Office of Scientific and Technical Information (OSTI)

    Plasma density diagnostic for capillary-discharge based plasma channels Authors: Daniels, J. 1 Search SciTech Connect for author "Daniels, J." Search SciTech Connect for...

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

    National Nuclear Security Administration (NNSA)

    Jobs Apply for Our Jobs Our Jobs Working at NNSA Blog Home High Energy Density Laboratory Plasmas Program High Energy Density Laboratory Plasmas Program NNSA invests in next ...

  9. Science Education Lab | Princeton Plasma Physics Lab

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

    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

  10. High energy density Z-pinch plasmas using flow stabilization

    SciTech Connect (OSTI)

    Shumlak, U. Golingo, R. P. Nelson, B. A. Bowers, C. A. Doty, S. A. Forbes, E. G. Hughes, M. C. Kim, B. Knecht, S. D. Lambert, K. K. Lowrie, W. Ross, M. P. Weed, J. R.

    2014-12-15

    The ZaP Flow Z-Pinch research project[1] at the University of Washington investigates the effect of sheared flows on MHD instabilities. Axially flowing Z-pinch plasmas are produced that are 100 cm long with a 1 cm radius. The plasma remains quiescent for many radial Alfvn times and axial flow times. The quiescent periods are characterized by low magnetic mode activity measured at several locations along the plasma column and by stationary visible plasma emission. Plasma evolution is modeled with high-resolution simulation codes Mach2, WARPX, NIMROD, and HiFi. Plasma flow profiles are experimentally measured with a multi-chord ion Doppler spectrometer. A sheared flow profile is observed to be coincident with the quiescent period, and is consistent with classical plasma viscosity. Equilibrium is determined by diagnostic measurements: interferometry for density; spectroscopy for ion temperature, plasma flow, and density[2]; Thomson scattering for electron temperature; Zeeman splitting for internal magnetic field measurements[3]; and fast framing photography for global structure. Wall stabilization has been investigated computationally and experimentally by removing 70% of the surrounding conducting wall to demonstrate no change in stability behavior.[4] Experimental evidence suggests that the plasma lifetime is only limited by plasma supply and current waveform. The flow Z-pinch concept provides an approach to achieve high energy density plasmas,[5] which are large, easy to diagnose, and persist for extended durations. A new experiment, ZaP-HD, has been built to investigate this approach by separating the flow Z-pinch formation from the radial compression using a triaxial-electrode configuration. This innovation allows more detailed investigations of the sheared flow stabilizing effect, and it allows compression to much higher densities than previously achieved on ZaP by reducing the linear density and increasing the pinch current. Experimental results and scaling analyses will be presented. In addition to studying fundamental plasma science and high energy density physics, the ZaP and ZaP-HD experiments can be applied to laboratory astrophysics.

  11. Interferometer for the measurement of plasma density

    DOE Patents [OSTI]

    Jacobson, Abram R.

    1980-01-01

    An interferometer which combines the advantages of a coupled cavity interferometer requiring alignment of only one light beam, and a quadrature interferometer which has the ability to track multi-fringe phase excursions unambiguously. The device utilizes a Bragg cell for generating a signal which is electronically analyzed to unambiguously determine phase modulation which is proportional to the path integral of the plasma density.

  12. Extreme hydrogen plasma densities achieved in a linear plasma generator

    SciTech Connect (OSTI)

    Rooij, G. J. van; Veremiyenko, V. P.; Goedheer, W. J.; de Groot, B.; Kleyn, A. W.; Smeets, P. H. M.; Versloot, T. W.; Whyte, D. G.; Engeln, R.; Schram, D. C.; Cardozo, N. J. Lopes

    2007-03-19

    A magnetized hydrogen plasma beam was generated with a cascaded arc, expanding in a vacuum vessel at an axial magnetic field of up to 1.6 T. Its characteristics were measured at a distance of 4 cm from the nozzle: up to a 2 cm beam diameter, 7.5x10{sup 20} m{sup -3} electron density, {approx}2 eV electron and ion temperatures, and 3.5 km/s axial plasma velocity. This gives a 2.6x10{sup 24} H{sup +} m{sup -2} s{sup -1} peak ion flux density, which is unprecedented in linear plasma generators. The high efficiency of the source is obtained by the combined action of the magnetic field and an optimized nozzle geometry. This is interpreted as a cross-field return current that leads to power dissipation in the beam just outside the source.

  13. NSTX Diagnostics for Fusion Plasma Science Studies

    SciTech Connect (OSTI)

    R. Kaita; D. Johnson; L. Roquemore; M. Bitter; F. Levinton; F. Paoletti; D. Stutman; and the NSTX Team

    2001-07-05

    This paper will discuss how plasma science issues are addressed by the diagnostics for the National Spherical Torus Experiment (NSTX), the newest large-scale machine in the magnetic confinement fusion (MCF) program. The development of new schemes for plasma confinement involves the interplay of experimental results and theoretical interpretations. A fundamental requirement, for example, is a determination of the equilibria for these configurations. For MCF, this is well established in the solutions of the Grad-Shafranov equation. While it is simple to state its basis in the balance between the kinetic and magnetic pressures, what they are as functions of space and time are often not easy to obtain. Quantities like the plasma pressure and current density are not directly measurable. They are derived from data that are themselves complex products of more basic parameters. The same difficulties apply to the understanding of plasma instabilities. Not only are the needs for spatial and temporal resolution more stringent, but the wave parameters which characterize the instabilities are difficult to resolve. We will show how solutions to the problems of diagnostic design on NSTX, and the physics insight the data analysis provides, benefits both NSTX and the broader scientific community.

  14. Science Education | Princeton Plasma Physics Lab

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

    Events Research Education Organization Contact Us 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 science education programs to create a center of excellence for students, teachers and the general public. We contribute to the training of the next generation of scientists and engineers, collaborate with K-12 teachers on ways to improve science teaching using an inquiry-based

  15. Using Radio Waves to Control Fusion Plasma Density

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

    showed that beaming microwaves into the center of the plasma can be used to control the density in the center of the plasma, where a fusion reactor would produce most of its power. ...

  16. Internal field, density & temperature measurements in MTF plasmas...

    Office of Scientific and Technical Information (OSTI)

    Title: Internal field, density & temperature measurements in MTF plasmas using Pulsed Polarimetry final report Authors: Smith, Roger J. Publication Date: 2014-08-11 OSTI ...

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

    National Nuclear Security Administration (NNSA)

    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 ...

  18. Practicality of magnetic compression for plasma density control...

    Office of Scientific and Technical Information (OSTI)

    control Citation Details In-Document Search This content will become publicly available on March 16, 2017 Title: Practicality of magnetic compression for plasma density control ...

  19. Science Undergraduate Laboratory Internship (SULI) | Princeton Plasma

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

    Physics Lab Science Undergraduate Laboratory Internship (SULI) The Department of Energy's SULI Program enables undergraduates to join research groups at one of the state-of-the-art National Laboratories. The Science Undergraduate Laboratory Internship (SULI) program at PPPL is for undergraduates interested in performing plasma physics and fusion energy research. Students perform research, under the guidance of laboratory staff scientists or engineers, on projects supporting PPPL's research.

  20. Science literacy | Princeton Plasma Physics Lab

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

    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. Fun and inspiration for 575 young women at PPPL's Young Women's Conference Some 575 seventh- to tenth-grade girls from throughout New Jersey, as well as Pennsylvania and Maryland, found fun and inspiration doing myriad hands-on activities and meeting female scientists at The Princeton Plasma Physics

  1. Surface science | Princeton Plasma Physics Lab

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

    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. Physicist Tyler Abrams models lithium erosion in tokamaks The world of fusion energy is a world of extremes. For instance, the center of the ultrahot plasma contained within the walls of doughnut-shaped fusion machines known as tokamaks can reach temperatures well above the 15 million degrees

  2. Plasmas, Dielectrics and the Ultrafast: First Science and Operational...

    Office of Scientific and Technical Information (OSTI)

    Plasmas, Dielectrics and the Ultrafast: First Science and Operational Experience at FACET Citation Details In-Document Search Title: Plasmas, Dielectrics and the Ultrafast: First ...

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

    SciTech Connect (OSTI)

    Schroeder, C. B.; Esarey, E.; Leemans, W. P.

    2012-12-21

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

  4. IEEE TRANSACTIONS ON PLASMA SCIENCE, VOL.

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

    8 IEEE TRANSACTIONS ON PLASMA SCIENCE, VOL. 33, NO. 2, APRIL 2005 Imaging of a Double Helical Structure in the Reversed Field Pinch F. Bonomo, B. E. Chapman, P. Franz, L. Marrelli, P. Martin, P. Piovesan, I. Predebon, G. Spizzo, and R. B. White Abstract-X-ray tomography and Poincaré reconstructions with the ORBIT code allow imaging of coherent structures emerging in a magnetized fusion plasma when chaos in the magnetic field is reduced. Index Terms-Magnetohydrodynamic (MHD), Monte Carlo

  5. Internal field, density & temperature measurements in MTF plasmas using

    Office of Scientific and Technical Information (OSTI)

    Pulsed Polarimetry (Technical Report) | SciTech Connect Technical Report: Internal field, density & temperature measurements in MTF plasmas using Pulsed Polarimetry Citation Details In-Document Search Title: Internal field, density & temperature measurements in MTF plasmas using Pulsed Polarimetry final report Authors: Smith, Roger J. Publication Date: 2014-08-11 OSTI Identifier: 1149491 Report Number(s): 001 DOE Contract Number: SC0002396 Resource Type: Technical Report Research

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

    SciTech Connect (OSTI)

    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)

    2014-04-15

    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.

  7. Normal and abnormal evolution of argon metastable density in high-density plasmas

    SciTech Connect (OSTI)

    Seo, B. H.; Kim, J. H.; You, S. J.

    2015-05-15

    A controversial problem on the evolution of Ar metastable density as a function of electron density (increasing trend versus decreasing trend) was resolved by discovering the anomalous evolution of the argon metastable density with increasing electron density (discharge power), including both trends of the metastable density [Daltrini et al., Appl. Phys. Lett. 92, 061504 (2008)]. Later, by virtue of an adequate physical explanation based on a simple global model, both evolutions of the metastable density were comprehensively understood as part of the abnormal evolution occurring at low- and high-density regimes, respectively, and thus the physics behind the metastable evolution has seemed to be clearly disclosed. In this study, however, a remarkable result for the metastable density behavior with increasing electron density was observed: even in the same electron density regime, there are both normal and abnormal evolutions of metastable-state density with electron density depending on the measurement position: The metastable density increases with increasing electron density at a position far from the inductively coupled plasma antenna but decreases at a position close to the antenna. The effect of electron temperature, which is spatially nonuniform in the plasma, on the electron population and depopulation processes of Argon metastable atoms with increasing electron density is a clue to understanding the results. The calculated results of the global model, including multistep ionization for the argon metastable state and measured electron temperature, are in a good agreement with the experimental results.

  8. Stable laserplasma accelerators at low densities

    SciTech Connect (OSTI)

    Li, Song; Hafz, Nasr A. M. Mirzaie, Mohammad; Ge, Xulei; Sokollik, Thomas; Chen, Min; Sheng, Zhengming; Zhang, Jie

    2014-07-28

    We report stable laser wakefield acceleration using 1750 TW laser pulses interacting with 4?mm-long helium gas jet. The initial laser spot size was relatively large (28??m) and the plasma densities were 0.482.0??10{sup 19?}cm{sup ?3}. High-quality 100MeV electron beams were generated at the plasma density of 7.5??10{sup 18?}cm{sup ?3}, at which the beam parameters (pointing angle, energy spectrum, charge, and divergence angle) were measured and stabilized. At higher densities, filamentation instability of the laser-plasma interaction was observed and it has led to multiple wakefield accelerated electron beams. The experimental results are supported by 2D particle-in-cell simulations. The achievement presented here is an important step toward the use of laser-driven accelerators in real applications.

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

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

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

    National Nuclear Security Administration (NNSA)

    Administration 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 the exploration of matter at extremely high energy density in the laboratory. Exciting new experimental regimes are being realized by exploiting the scientific capabilities of existing ICF Office facilities, as well as the relevant Department of Defense (DoD) and university

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

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

    Contact Information Physics Research High-Energy- Density Physics Waves & Beams Fusion Technology & Engineering Plasma Technology Useful Links Collaborations at Alcator...

  12. Plasma ionization frequency, edge-to-axis density ratio, and density on axis of a cylindrical gas discharge

    SciTech Connect (OSTI)

    Palacio Mizrahi, J. H.

    2014-06-15

    A rigorous derivation of expressions, starting from the governing equations, for the ionization frequency, edge-to-axis ratio of plasma density, plasma density at the axis, and radially averaged plasma density in a cylindrical gas discharge has been obtained. The derived expressions are simple and involve the relevant parameters of the discharge: Cylinder radius, axial current, and neutral gas pressure. The found expressions account for ion inertia, ion temperature, and changes in plasma ion collisionality.

  13. On the density limit in the helicon plasma sources

    SciTech Connect (OSTI)

    Kotelnikov, Igor A.

    2014-12-15

    Existence of the density limit in the helicon plasma sources is revisited. The low- and high-frequency regimes of a helicon plasma source operation are distinguished. In the low-frequency regime with ω<√(ω{sub ci}ω{sub ce}), the density limit is deduced from the Golant-Stix criterion of the accessibility of the lower hybrid resonance. In the high-frequency case, ω>√(ω{sub ci}ω{sub ce}), an appropriate limit is given by the Shamrai-Taranov criterion. Both these criteria are closely related to the phenomenon of the coalescence of the helicon wave with the Trivelpiece-Gould mode. We draw a conclusion that the derived density limits are not currently achieved in existing devices, perhaps, because of high energy cost of gas ionization.

  14. Helicon Plasma Source Configuration Analysis by Means of Density Measurements

    SciTech Connect (OSTI)

    Angrilli, F.; Barber, G.C.; Carter, M.D.; Goulding, R.H.; Maggiora, R.; Pavarin, D.; Sparks, D.O.

    1999-11-13

    Initial results have been obtained from operation of a helicon plasma source built to conduct optimization studies for space propulsion applications. The source features an easily reconfigurable antenna to test different geometries. Operating with He as the source gas, peak densities >= 1.6X10{sup 19} m{sup -3} have been achieved. Radial and axial plasma profiles have been obtained using a microwave interferometer that can be scanned axially and a Langmuir probe. The source will be used to investigate operation at high magnetic field, frequency, and input power.

  15. Beam Matching to a Plasma Wakefield Accelerator Using a Ramped Density

    Office of Scientific and Technical Information (OSTI)

    Profile at the Plasma Boundary (Conference) | SciTech Connect Conference: Beam Matching to a Plasma Wakefield Accelerator Using a Ramped Density Profile at the Plasma Boundary Citation Details In-Document Search Title: Beam Matching to a Plasma Wakefield Accelerator Using a Ramped Density Profile at the Plasma Boundary An important aspect of plasma wake field accelerators (PWFA) is stable propagation of the drive beam. In the under dense plasma regime, the drive beam creates an ion channel

  16. Science Education Programs | Princeton Plasma Physics Lab

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

    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 Semester-Long Internship High School Summer 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,

  17. DOE New Jersey Regional Middle School Science Bowl | Princeton Plasma

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

    Physics Lab 0, 2015, 9:00am to 3:00pm Science Education Lab-wide DOE New Jersey Regional Middle School Science Bowl Contact Information Website: New Jersey Regional Science Bowl Coordinator(s): Deedee Ortiz-Arias, Science Education Department Program Administraor dortiz@pppl.gov PPPL Entrance Procedures Visitor Information, Directions, Security at PPPL As a federal facility, the Princeton Plasma Physics Laboratory is operating under heightened security measures because of the events of

  18. Science Education Group | Princeton Plasma Physics Lab

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

    Science Education Group View larger image Sci Ed Group 15 View larger image Group 21

  19. Effects of argon gas pressure on its metastable-state density in high-density plasmas

    SciTech Connect (OSTI)

    Seo, B. H.; Kim, J. H.; You, S. J.

    2015-05-15

    The effect of argon gas pressure on its metastable density in inductively coupled plasmas (ICPs) is investigated by using the laser-induced fluorescence method. Our results show that the metastable-state density of argon varies with the gas pressure depending on the measurement position; the density decreases with the pressure at a position far from the ICP antenna, whereas it increases with the pressure at a position near the antenna. This contrast in the metastable-state density trend with the pressure is explained by considering the electron temperature variations at the two measurement positions. The theoretical interpretation and calculation using a global model are also addressed in detail in this paper.

  20. 2012 APS-DPP Plasma Science Expo, Providence, RI | Princeton...

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

    APS-DPP Plasma Science Expo, Providence, RI View larger image IMG 1847 View larger image IMG 1598 View larger image IMG 1608 View larger image IMG 1609 View larger image IMG 1614...

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

    SciTech Connect (OSTI)

    Perego, M.; Gunzburger, M. D.; Howell, P. D.; Ockendon, J. R.; Allen, J. E.

    2013-05-15

    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.

  2. Plasmas, Dielectrics and the Ultrafast: First Science and Operational

    Office of Scientific and Technical Information (OSTI)

    Experience at FACET (Conference) | SciTech Connect Conference: Plasmas, Dielectrics and the Ultrafast: First Science and Operational Experience at FACET Citation Details In-Document Search Title: Plasmas, Dielectrics and the Ultrafast: First Science and Operational Experience at FACET FACET (Facility for Advanced Accelerator and Experimental Tests) is an accelerator R&D test facility that has been recently constructed at SLAC National Accelerator Laboratory. The facility provides 20 GeV,

  3. DOE's NJ HIGH SCHOOL SCIENCE BOWL® | Princeton Plasma Physics Lab

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

    5, 2012 (All day) Science Education MBG Auditorium DOE's NJ HIGH SCHOOL SCIENCE BOWL® DOE's NJ HIGH SCHOOL SCIENCE BOWL® PPPL Entrance Procedures Visitor Information, Directions, Security at PPPL As a federal facility, the Princeton Plasma Physics Laboratory is operating under heightened security measures because of the events of September 11, 2001. Upon arrival at PPPL, adult visitors must show a government-issued photo I.D. - for example, a passport or a driver's license. Non-U.S. citizens

  4. Science Education | Princeton Plasma Physics Lab

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

    Education Science Education Energy is a physical quantity that follows precise natural laws. Check out our NEW Energy Literacy Video Series, which highlights the 7 Essential Principles of Energy to help engage students in energy. | Energy Department Video. For kids of all ages, there is always something new to learn about science and technology. The Energy Department supports science education through educational online content, resources for parents and teachers, internships and student

  5. About Science Education | Princeton Plasma Physics Lab

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

    About Science Education Our Mission Using the human, scientific, and technological resources of PPPL, our mission is to: Provide opportunities for students and teachers to engage in scientific inquiry in ways that enhance their understanding of science concepts and scientific ways of thinking. Provide innovative opportunities for educators to work together and with scientists and engineers to enhance science teaching and learning. Reach out to all students and teachers, particularly those

  6. Science Education Upcoming Events | Princeton Plasma Physics...

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

    Upcoming Events January 9, 2016 January 9, 2016, 9:30am January 9, 2016: Science on Saturday: Dr. Alan Hirshfeld: Starlight Detectives: How Astronomers, Inventors, and Eccentrics...

  7. Princeton Plasma Physics Lab - Science literacy

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

    science-literacy Having the knowledge and understanding of scientific concepts and processes necessary to make informed decisions on scientific issues. en COLLOQUIUM: Chance,...

  8. Exploring Plasma Science Advances from Fusion Findings to Astrophysical

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

    Achievements | Princeton Plasma Physics Lab Exploring Plasma Science Advances from Fusion Findings to Astrophysical Achievements By John Greenwald December 4, 2012 Tweet Widget Google Plus One Share on Facebook The latest advances in plasma physics were the focus of more than 1,000 scientists from around the world who gathered in Providence, R.I., from Oct. 29 through Nov. 2 for the 54th Annual Meeting of the American Physical Society's Division of Plasma Physics (APS-DPP). Papers, posters

  9. IEEE TRANSACTIONS ON PLASMA SCIENCE, VOL.

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

    the average electronic thermal diffusivity in the region of the plasma where the pulse prop- agates. A model of diffusive heat propagation in a cylinder is under development and...

  10. Advances and Challenges in Computational Plasma Science

    SciTech Connect (OSTI)

    W.M. Tang; V.S. Chan

    2005-01-03

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

  11. The National Ignition Facility: Ushering in a new age for high energy density science

    SciTech Connect (OSTI)

    Moses, E. I.; Boyd, R. N.; Remington, B. A.; Keane, C. J.; Al-Ayat, R.

    2009-04-15

    The National Ignition Facility (NIF) [E. I. Moses, J. Phys.: Conf. Ser. 112, 012003 (2008); https://lasers.llnl.gov/], completed in March 2009, is the highest energy laser ever constructed. The high temperatures and densities achievable at NIF will enable a number of experiments in inertial confinement fusion and stockpile stewardship, as well as access to new regimes in a variety of experiments relevant to x-ray astronomy, laser-plasma interactions, hydrodynamic instabilities, nuclear astrophysics, and planetary science. The experiments will impact research on black holes and other accreting objects, the understanding of stellar evolution and explosions, nuclear reactions in dense plasmas relevant to stellar nucleosynthesis, properties of warm dense matter in planetary interiors, molecular cloud dynamics and star formation, and fusion energy generation.

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

    SciTech Connect (OSTI)

    Nishikawa, Takeshi

    2014-07-15

    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.

  13. Exploration of Plasma Jets Approach to High Energy Density Physics. Final report

    SciTech Connect (OSTI)

    Chen, Chiping

    2013-08-26

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

  14. Science on Saturday: Dealing With Iran's Nuclear Program | Princeton Plasma

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

    Physics Lab 30, 2016, 9:30am Science On Saturday PPPL, MBG Auditorium Science on Saturday: Dealing With Iran's Nuclear Program Professor Frank von Hippel Princeton University Science_on_Saturday30Jan2016_FvonHippel Contact Information Coordinator(s): Ms. Deedee Ortiz-Arias dortiz@pppl.gov Host(s): Dr. Andrew Zwicker azwicker@pppl.gov PPPL Entrance Procedures Visitor Information, Directions, Security at PPPL As a federal facility, the Princeton Plasma Physics Laboratory is operating under

  15. Science on Saturday: Plastic Electronics | Princeton Plasma Physics Lab

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

    February 6, 2016, 9:30am Science On Saturday MBG Auditorium, PPPL Science on Saturday: Plastic Electronics Professor Lynn Loo Princeton University Abstract: PDF icon 05 Loo.pdf Science_on_Saturday06Feb2016_LLoo Contact Information Coordinator(s): Ms. Deedee Ortiz-Arias dortiz@pppl.gov Host(s): Dr. Andrew Zwicker azwicker@pppl.gov PPPL Entrance Procedures Visitor Information, Directions, Security at PPPL As a federal facility, the Princeton Plasma Physics Laboratory is operating under heightened

  16. Science on Saturday: Taking the Universe's Baby Picture | Princeton Plasma

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

    Physics Lab March 12, 2016, 9:30am Science On Saturday MBG Auditorium at PPPL Science on Saturday: Taking the Universe's Baby Picture Professor David Spergel Princeton University Abstract: PDF icon D. Spergel.pdf Science_on_Saturday12Mar2016_DSpergel Contact Information Coordinator(s): Ms. Deedee Ortiz-Arias dortiz@pppl.gov Host(s): Dr. Andrew Zwicker azwicker@pppl.gov PPPL Entrance Procedures Visitor Information, Directions, Security at PPPL As a federal facility, the Princeton Plasma

  17. Science Education Staff | Princeton Plasma Physics Lab

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

    Staff Andrew Zwicker Head of Science Education Telephone: 609-243-2150 Email: azwicker@pppl.gov Read Andrew's blog Arturo Dominguez Senior Program Leader Telephone: 609-243-2197 Email: adomingu@pppl.gov Deedee Ortiz Program Administrator Telephone: 609-243-2785 Email: dortiz@pppl.gov Shannon Greco Program Leader Telephone: 609-243-2208 Email: sgreco@pppl.gov Larry Guttadora Technical Specialist Telephone: 609-243-3144 Email: lguttadora@pppl.gov Sophia Gershman Senior Program Advisor Telephone:

  18. 2012 Science Bowls | Princeton Plasma Physics Lab

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

    Energy, Office of Scientific and Technical Information STIP Account Login Is Required for this Page (If you're a human, don't change the following field) Enter your name: 374b9f8e43374b Your first name. Please enable Javascript to use this form. E-mail: * Password: * Log in Create new account Request new password

    Science Bowls View larger image IMG 0357 View larger image IMG 0358 View larger image IMG 0359 View larger image IMG 0360 View larger image IMG 0361 View larger image IMG 0362

  19. Stewardship Science Academic Alliances Annual

    National Nuclear Security Administration (NNSA)

    target at the critical density layer (green) by an ultra-intense laser pulse ... Stewardship Science Academic Alliances High Energy Density Laboratory Plasmas National ...

  20. Particle Gas Target for High Density Laser Produced Plasmas Charles H.

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

    Skinner, Nathaniel Fisch, and Ernest Valeo | Princeton Plasma Physics Lab Particle Gas Target for High Density Laser Produced Plasmas Charles H. Skinner, Nathaniel Fisch, and Ernest Valeo This invention is a novel "particle gas" cell for achieving plasma densities higher than accessible in conventional gas jets. The particle gas cell has a silicon nitride window and is partially filled with melamine spheres in the sub-micron to micron diameter range. The cell is acoustically

  1. Assessment of plasma impedance probe for measuring electron density and collision frequency in a plasma with spatial and temporal gradients

    SciTech Connect (OSTI)

    Hopkins, Mark A. King, Lyon B.

    2014-05-15

    Numerical simulations and experimental measurements were combined to determine the ability of a plasma impedance probe (PIP) to measure plasma density and electron collision frequency in a plasma containing spatial gradients as well as time-varying oscillations in the plasma density. A PIP is sensitive to collision frequency through the width of the parallel resonance in the Re[Z]-vs.-frequency characteristic, while also being sensitive to electron density through the zero-crossing of the Im[Z]-vs.-frequency characteristic at parallel resonance. Simulations of the probe characteristic in a linear plasma gradient indicated that the broadening of Re[Z] due to the spatial gradient obscured the broadening due to electron collision frequency, preventing a quantitative measurement of the absolute collision frequency for gradients considered in this study. Simulation results also showed that the PIP is sensitive to relative changes in electron collision frequency in a spatial density gradient, but a second broadening effect due to time-varying oscillations made collision frequency measurements impossible. The time-varying oscillations had the effect of causing multiple zero-crossings in Im[Z] at parallel resonance. Results of experiments and simulations indicated that the lowest-frequency zero-crossing represented the lowest plasma density in the oscillations and the highest-frequency zero-crossing represented the highest plasma density in the oscillations, thus the PIP probe was found to be an effective tool to measure both the average plasma density as well as the maximum and minimum densities due to temporal oscillations.

  2. Metrology Challenges for High Energy Density Science Target Manufacture

    SciTech Connect (OSTI)

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

    2009-02-19

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

  3. High-efficiency acceleration in the laser wakefield by a linearly increasing plasma density

    SciTech Connect (OSTI)

    Dong, Kegong; Wu, Yuchi; Zhu, Bin; Zhang, Zhimeng; Zhao, Zongqing; Zhou, Weimin; Hong, Wei; Cao, Leifeng; Gu, Yuqiu

    2014-12-15

    The acceleration length and the peak energy of the electron beam are limited by the dephasing effect in the laser wakefield acceleration with uniform plasma density. Based on 2D-3V particle in cell simulations, the effects of a linearly increasing plasma density on the electron acceleration are investigated broadly. Comparing with the uniform plasma density, because of the prolongation of the acceleration length and the gradually increasing accelerating field due to the increasing plasma density, the electron beam energy is twice higher in moderate nonlinear wakefield regime. Because of the lower plasma density, the linearly increasing plasma density can also avoid the dark current caused by additional injection. At the optimal acceleration length, the electron energy can be increased from 350 MeV (uniform) to 760 MeV (linearly increasing) with the energy spread of 1.8%, the beam duration is 5 fs and the beam waist is 1.25 μm. This linearly increasing plasma density distribution can be achieved by a capillary with special gas-filled structure, and is much more suitable for experiment.

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

    SciTech Connect (OSTI)

    Mega-Macas, A.; Vizcano-de-Julin, A.; Cortzar, O. D.

    2014-03-15

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

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

    DOE Patents [OSTI]

    Thode, L.E.

    A device and method for relativistic electron beam heating of a high density plasma in a small localized region are described. 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/.

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

    SciTech Connect (OSTI)

    Habibi, M.; Ghamari, F.

    2012-10-15

    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.

  7. Energy density dependence of hydrogen combustion efficiency in atmospheric pressure microwave plasma

    SciTech Connect (OSTI)

    Yoshida, T.; Ezumi, N.; Sawada, K.; Tanaka, Y.; Tanaka, M.; Nishimura, K.

    2015-03-15

    The recovery of tritium in nuclear fusion plants is a key issue for safety. So far, the oxidation procedure using an atmospheric pressure plasma is expected to be part of the recovery method. In this study, in order to clarify the mechanism of hydrogen oxidation by plasma chemistry, we have investigated the dependence of hydrogen combustion efficiency on gas flow rate and input power in the atmospheric pressure microwave plasma. It has been found that the combustion efficiency depends on energy density of absorbed microwave power. Hence, the energy density is considered as a key parameter for combustion processes. Also neutral gas temperatures inside and outside the plasma were measured by an optical emission spectroscopy method and thermocouple. The result shows that the neutral gas temperature in the plasma is much higher than the outside temperature of plasma. The high neutral gas temperature may affect the combustion reaction. (authors)

  8. Independent control of electron energy and density using a rotating magnetic field in inductively coupled plasmas

    SciTech Connect (OSTI)

    Kondo, Takahiro; Ohta, Masayuki; Ito, Tsuyohito; Okada, Shigefumi

    2013-09-21

    Effects of a rotating magnetic field (RMF) on the electron energy distribution function (EEDF) and on the electron density are investigated with the aim of controlling the radical composition of inductively coupled plasmas. By adjusting the RMF frequency and generation power, the desired electron density and electron energy shift are obtained. Consequently, the amount and fraction of high-energy electrons, which are mostly responsible for direct dissociation processes of raw molecules, will be controlled externally. This controllability, with no electrode exposed to plasma, will enable us to control radical components and their flux during plasma processing.

  9. Effect of secondary emission on the argon plasma afterglow with large dust density

    SciTech Connect (OSTI)

    Denysenko, I. B.; Azarenkov, N. A.; Burmaka, G. P.; Stefanovi?, I.

    2015-02-15

    A zero-dimensional, space-averaged model for argon plasma afterglow with large dust density is developed. In the model, three groups of electrons in the plasma afterglow are assumed: (i) thermal electrons with Maxwellian distribution, (ii) energetic electrons generated by metastable-metastable collisions (metastable pooling), and (iii) secondary electrons generated at collisions of ions with the electrodes, which have sufficiently large negative voltages in the afterglow. The model calculates the time-dependencies for electron densities in plasma afterglow based on experimental decay times for metastable density and electrode bias. The effect of secondary emission on electron density in the afterglow is estimated by varying secondary emission yields. It is found that this effect is less important than metastable pooling. The case of dust-free plasma afterglow is considered also, and it is found that in the afterglow the effect of secondary emission may be more important than metastable pooling. The secondary emission may increase thermal electron density n{sub e} in dust-free and dusty plasma afterglows on a few ten percentages. The calculated time dependencies for n{sub e} in dust-free and dusty plasma afterglows describe well the experimental results.

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

    DOE Patents [OSTI]

    Thode, Lester E.

    1981-01-01

    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.

  11. A new method for determining the plasma electron density using optical frequency comb interferometer

    SciTech Connect (OSTI)

    Arakawa, Hiroyuki Tojo, Hiroshi; Sasao, Hajime; Kawano, Yasunori; Itami, Kiyoshi

    2014-04-15

    A new method of plasma electron density measurement using interferometric phases (fractional fringes) of an optical frequency comb interferometer is proposed. Using the characteristics of the optical frequency comb laser, high density measurement can be achieved without fringe counting errors. Simulations show that the short wavelength and wide wavelength range of the laser source and low noise in interferometric phases measurements are effective to reduce ambiguity of measured density.

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

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

    Fusion and Plasmas Fusion Energy Sciences (FES) FES Home About Organization Chart .pdf file (78KB) Staff 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) Community 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)

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

    SciTech Connect (OSTI)

    Bulanov, Sergei V.; Esirkepov, Timur Zh.; Kando, Masaki; Koga, James K.; Pirozhkov, Alexander S.; Nakamura, Tatsufumi; Bulanov, Stepan S.; Schroeder, Carl B.; Esarey, Eric; Califano, Francesco; Pegoraro, Francesco

    2012-11-15

    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.

  14. The impact of Hall physics on magnetized high energy density plasma jets

    SciTech Connect (OSTI)

    Gourdain, P.-A.; Seyler, C. E.; Atoyan, L.; Greenly, J. B.; Hammer, D. A.; Kusse, B. R.; Pikuz, S. A.; Potter, W. M.; Schrafel, P. C.; Shelkovenko, T. A.

    2014-05-15

    Hall physics is often neglected in high energy density plasma jets due to the relatively high electron density of such jets (n{sub e}???10{sup 19}?cm{sup ?3}). However, the vacuum region surrounding the jet has much lower densities and is dominated by Hall electric field. This electric field redirects plasma flows towards or away from the axis, depending on the radial current direction. A resulting change in the jet density has been observed experimentally. Furthermore, if an axial field is applied on the jet, the Hall effect is enhanced and ignoring it leads to serious discrepancies between experimental results and numerical simulations. By combining high currents (?1 MA) and magnetic field helicity (15 angle) in a pulsed power generator such as COBRA, plasma jets can be magnetized with a 10?T axial field. The resulting field enhances the impact of the Hall effect by altering the density profile of current-free plasma jets and the stability of current-carrying plasma jets (e.g., Z-pinches)

  15. LOCALIZED PLASMA DENSITY ENHANCEMENTS OBSERVED IN STEREO COR1

    SciTech Connect (OSTI)

    Jones, Shaela I.; Davila, Joseph M.

    2009-08-20

    Measurements of solar wind speed in the solar corona, where it is primarily accelerated, have proven elusive. One of the more successful attempts has been the tracking of outward-moving density inhomogeneities in white-light coronagraph images. These inhomogeneities, or 'blobs', have been treated as passive tracers of the ambient solar wind. Here we report on the extension of these observations to lower altitudes using the STEREO COR1 coronagraph, and discuss the implications of these measurements for theories about the origin of these features.

  16. Investigation of physical processes limiting plasma density in H-mode on DIII-D

    SciTech Connect (OSTI)

    Maingi, R.; Mahdavi, M.A.; Jernigan, T.C.

    1996-12-01

    A series of experiments was conducted on the DIII-D tokamak to investigate the physical processes which limit density in high confinement mode (H-mode) discharges. The typical H-mode to low confinement mode (L-mode) transition limit at high density near the empirical Greenwald density limit was avoided by divertor pumping, which reduced divertor neutral pressure and prevented formation of a high density, intense radiation zone (MARFE) near the X-point. It was determined that the density decay time after pellet injection was independent of density relative to the Greenwald limit and increased non-linearly with the plasma current. Magnetohydrodynamic (MHD) activity in pellet-fueled plasmas was observed at all power levels, and often caused unacceptable confinement degradation, except when the neutral beam injected (NBI) power was {le} 3 MW. Formation of MARFEs on closed field lines was avoided with low safety factor (q) operation but was observed at high q, qualitatively consistent with theory. By using pellet fueling and optimizing discharge parameters to avoid each of these limits, an operational space was accessed in which density {approximately} 1.5 {times} Greenwald limit was achieved for 600 ms, and good H-mode confinement was maintained for 300 ms of the density flattop. More significantly, the density was successfully increased to the limit where a central radiative collapse was observed, the most fundamental density limit in tokamaks.

  17. 2012 APS-DPP Plasma Science Expo, Providence, RI | Princeton Plasma Physics

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

    Lab APS-DPP Plasma Science Expo, Providence, RI View larger image IMG 1847 View larger image IMG 1598 View larger image IMG 1608 View larger image IMG 1609 View larger image IMG 1614 View larger image IMG 1647 View larger image IMG 1650 View larger image IMG 1651 View larger image IMG 1657 View larger image IMG 1659 View larger image IMG 1662 View larger image IMG 1663 View larger image IMG 1664 View larger image IMG 1668 View larger image IMG 1672 View larger image IMG 1675 View larger

  18. DOE Office of Science Fact Sheet | Princeton Plasma Physics Lab

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

    DOE Office of Science Fact Sheet DOE Office of Science Fact Sheet Publication File: PDF icon DOE Office of Science Fact Sheet Publication Type: Fact Sheets

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

    SciTech Connect (OSTI)

    Sati, Priti; Tripathi, V. K.

    2012-12-15

    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.

  20. Strong self-focusing of a cosh-Gaussian laser beam in collisionless magneto-plasma under plasma density ramp

    SciTech Connect (OSTI)

    Nanda, Vikas; Kant, Niti

    2014-07-15

    The effect of plasma density ramp on self-focusing of cosh-Gaussian laser beam considering ponderomotive nonlinearity is analyzed using WKB and paraxial approximation. It is noticed that cosh-Gaussian laser beam focused earlier than Gaussian beam. The focusing and de-focusing nature of the cosh-Gaussian laser beam with decentered parameter, intensity parameter, magnetic field, and relative density parameter has been studied and strong self-focusing is reported. It is investigated that decentered parameter “b” plays a significant role for the self-focusing of the laser beam as for b=2.12, strong self-focusing is seen. Further, it is observed that extraordinary mode is more prominent toward self-focusing rather than ordinary mode of propagation. For b=2.12, with the increase in the value of magnetic field self-focusing effect, in case of extraordinary mode, becomes very strong under plasma density ramp. Present study may be very useful in the applications like the generation of inertial fusion energy driven by lasers, laser driven accelerators, and x-ray lasers. Moreover, plasma density ramp plays a vital role to enhance the self-focusing effect.

  1. Effect of the resonant growth of harmonics on the electron density in capacitively coupled plasma

    SciTech Connect (OSTI)

    Yamazawa, Yohei

    2009-11-09

    The growth of harmonics is known to occur under the condition of plasma series resonance (PSR). In an actual plasma process chamber, the external circuit also affects the PSR. We experimentally demonstrated the resonant growth of the third and fourth harmonics by tuning a variable capacitor attached to the electrode, and investigated the influence of the growth on the electron density. We observed significant increases in electron density as the amplitude of harmonics grows. The result clearly shows that nonlinear electron resonance heating actually takes place.

  2. Inhomogeneities of plasma density and electric field as sources of electrostatic turbulence in the auroral region

    SciTech Connect (OSTI)

    Ilyasov, Askar A.; Chernyshov, Alexander A. Mogilevsky, Mikhail M.; Golovchanskaya, Irina V. Kozelov, Boris V.

    2015-03-15

    Inhomogeneities of plasma density and non-uniform electric fields are compared as possible sources of a sort of electrostatic ion cyclotron waves that can be identified with broadband extremely low frequency electrostatic turbulence in the topside auroral ionosphere. Such waves are excited by inhomogeneous energy-density-driven instability. To gain a deeper insight in generation of these waves, computational modeling is performed with various plasma parameters. It is demonstrated that inhomogeneities of plasma density can give rise to this instability even in the absence of electric fields. By using both satellite-observed and model spatial distributions of plasma density and electric field in our modeling, we show that specific details of the spatial distributions are of minor importance for the wave generation. The solutions of the nonlocal inhomogeneous energy-density-driven dispersion relation are investigated for various ion-to-electron temperature ratios and directions of wave propagation. The relevance of the solutions to the observed spectra of broadband extremely low frequency emissions is shown.

  3. Power balance in a high-density field reversed configuration plasma

    SciTech Connect (OSTI)

    Renneke, R. M.; Intrator, T. P.; Hsu, S. C.; Wurden, G. A.; Waganaar, W. J.; Ruden, E. L.; Grabowski, T. C.

    2008-06-15

    A global power balance analysis has been performed for the Field Reversed Experiment with Liner high density (>5x10{sup 22} m{sup -3}) field reversed configuration (FRC) plasma. The analysis was based on a zero-dimensional power balance model [D. J. Rey and M. Tuszewski, Phys. Fluids 27, 1514 (1984)]. The key findings are as follows. First, the percentage of radiative losses relative to total loss is an order of magnitude lower than previous lower density FRC experiments. Second, Ohmic heating was found to correlate with the poloidal flux trapping at FRC formation, suggesting that poloidal flux dissipation is primarily responsible for plasma heating. Third, high density FRCs analyzed in this work reinforce the low-density adiabatic scaling, which shows that particle confinement time and flux confinement time are approximately equal.

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

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

    Plasma Technology Useful Links Presentations from the 45th Annual Meeting of the APS Division of Plasma Physics, Albuquerque, 2003 Invited Orals D. Ernst Role of Trapped...

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

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

    & Engineering Plasma Technology Waves & Beams Useful Links 49th Annual Meeting of the APS Division of Plasma Physics, Orlando, 2007 Invited Orals P. Bonoli Lower Hybrid Current...

  6. Multispecies density peaking in gyrokinetic turbulence simulations of low collisionality Alcator C-Mod plasmas

    SciTech Connect (OSTI)

    Mikkelsen, D. R. Bitter, M.; Delgado-Aparicio, L.; Hill, K. W.; Greenwald, M.; Howard, N. T.; Hughes, J. W.; Rice, J. E.; Reinke, M. L.; Podpaly, Y.; Ma, Y.; Candy, J.; Waltz, R. E.

    2015-06-15

    Peaked density profiles in low-collisionality AUG and JET H-mode plasmas are probably caused by a turbulently driven particle pinch, and Alcator C-Mod experiments confirmed that collisionality is a critical parameter. Density peaking in reactors could produce a number of important effects, some beneficial, such as enhanced fusion power and transport of fuel ions from the edge to the core, while others are undesirable, such as lower beta limits, reduced radiation from the plasma edge, and consequently higher divertor heat loads. Fundamental understanding of the pinch will enable planning to optimize these impacts. We show that density peaking is predicted by nonlinear gyrokinetic turbulence simulations based on measured profile data from low collisionality H-mode plasma in Alcator C-Mod. Multiple ion species are included to determine whether hydrogenic density peaking has an isotope dependence or is influenced by typical levels of low-Z impurities, and whether impurity density peaking depends on the species. We find that the deuterium density profile is slightly more peaked than that of hydrogen, and that experimentally relevant levels of boron have no appreciable effect on hydrogenic density peaking. The ratio of density at r/a = 0.44 to that at r/a = 0.74 is 1.2 for the majority D and minority H ions (and for electrons), and increases with impurity Z: 1.1 for helium, 1.15 for boron, 1.3 for neon, 1.4 for argon, and 1.5 for molybdenum. The ion temperature profile is varied to match better the predicted heat flux with the experimental transport analysis, but the resulting factor of two change in heat transport has only a weak effect on the predicted density peaking.

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

    SciTech Connect (OSTI)

    Jane Chang

    2012-07-27

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

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

    SciTech Connect (OSTI)

    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)

    2012-07-15

    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.

  9. Scattering of electromagnetic waves by vortex density structures associated with interchange instability: Analytical and large scale plasma simulation results

    SciTech Connect (OSTI)

    Sotnikov, V.; Kim, T.; Lundberg, J.; Paraschiv, I.; Mehlhorn, T. A.

    2014-05-15

    The presence of plasma turbulence can strongly influence propagation properties of electromagnetic signals used for surveillance and communication. In particular, we are interested in the generation of low frequency plasma density irregularities in the form of coherent vortex structures. Interchange or flute type density irregularities in magnetized plasma are associated with Rayleigh-Taylor type instability. These types of density irregularities play an important role in refraction and scattering of high frequency electromagnetic signals propagating in the earth ionosphere, in high energy density physics, and in many other applications. We will discuss scattering of high frequency electromagnetic waves on low frequency density irregularities due to the presence of vortex density structures associated with interchange instability. We will also present particle-in-cell simulation results of electromagnetic scattering on vortex type density structures using the large scale plasma code LSP and compare them with analytical results.

  10. Laser Plasma Interactions

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

    Laser Plasma Interactions Laser Plasma Interactions Understanding and controlling laser produced plasmas for fusion and basic science Contact David Montgomery (505) 665-7994 Email John Kline (505) 667-7062 Email Thomson scattering is widely used to measure plasma temperature, density, and flow velocity in laser-produced plasmas at Trident, and is also used to detect plasma waves driven by unstable and nonlinear processes. A typical configuration uses a low intensity laser beam (2nd, 3rd, or 4th

  11. A scheme to produce high density and high temperature plasma for opacity measurement

    SciTech Connect (OSTI)

    Xu, Yan; Wu, SiZhong; Zheng, WuDi

    2015-04-15

    The opacity of shock-compressed material is of general scientific interest for astrophysical plasmas and for inertial confinement fusion research. A proposal is suggested to produce high temperature plasma with density around 1 g/cm{sup −3}. Two types of opacity target (the sandwich target and the foam enhanced sandwich target) are investigated numerically. The foam enhanced sandwich target has structure of foam–solid-sample-solid-foam. The foam will increase laser absorption efficiency and the ablating pressure. Hydrodynamic simulations confirm that the laser can be fully absorbed by the under-critical-density foam and a faster shock is produced inside the CH layer. High intensity lasers heat opacity target from both sides. The CH layers must be thick enough to keep the laser away from the sample. The laser-driven shocks move inward and collide at the center. Part of their kinetic energy is converted into internal energy and high density and high temperature local thermodynamic equilibrium sample plasma is produced. The plasma produced by laser heating the foam enhanced sandwich target has higher sample temperature than by laser heating the sandwich target. It may be useful for measuring the opacity of shock compressed material in laboratory.

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

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

    of Lower Hybrid Wave Propagation in the Edge Plasma of a Tokamak D. Brunner Plasma Sheath Heat Flux Transmission in the Alcator C-Mod Divertor M. Garrett ICRF Antenna Design...

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

    SciTech Connect (OSTI)

    Marquez, Ariel; Gonzalez, Jose; Tarifeno-Saldivia, Ariel; Pavez, Cristian; Soto, Leopoldo; Clausse, Alejandro

    2012-01-15

    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.

  14. MIT Plasma Science & Fusion Center: research

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

    Research Program Information Publications & News Meetings & Seminars Contact Information Physics Research Fusion Technology & Engineering Plasma Technology Waves & Beams Useful...

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

    SciTech Connect (OSTI)

    Jung Yu, Dae; Kim, Kihong

    2013-12-15

    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.

  16. Science On Saturday Archive | Princeton Plasma Physics Lab

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

    Upcoming Events Events Calendar Colloquia Archive Science On Saturday Archive Research Education Organization Contact Us Upcoming Events Events Calendar Colloquia Archive Science On Saturday Archive Science On Saturday Archive EXTENDED! Science on Saturday: Using Physics and Chemistry to Understand the Genome March 19, 2016 Professor Mary Jo Ondrechen Northeastern University Science on Saturday: Taking the Universe's Baby Picture March 12, 2016 Professor David Spergel Princeton University

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

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

    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...

  18. Simulation Study of an Extended Density DC Glow Toroidal Plasma Source

    SciTech Connect (OSTI)

    Granda-Gutierrez, E. E.; Piedad-Beneitez, A. de la; Lopez-Callejas, R.; Godoy-Cabrera, O. G.; Benitez-Read, J. S.; Pacheco-Sotelo, J. O.; Pena-Eguiluz, R.; Mercado-Cabrera, A.; Valencia A, R.; Barocio, S. R.

    2006-12-04

    Conventional wisdom assigns the DC glow discharge regime to plasma currents below {approx}500 mA values, beyond which the discharge falls into the anomalous glow and the turbulent arc regimes. However, we have found evidence that, during toroidal discharges, this barrier can be ostensibly extended up to 800 mA. Thus, a computer simulation has been applied to the evolution of the main electrical characteristics of such a glow discharge plasma in a toroidal vessel in order to design and construct a respective voltage/current controlled source. This should be able to generate a DC plasma in the glow regime with which currents in the range 10-3-100 A can be experimented and 109-1010 cm-3 plasma densities can be achieved to PIII optimization purposes. The plasma is modelled as a voltage-controlled current source able to be turned on whenever the breakdown voltage is reached across the gap between the anode and the vessel wall. The simulation outcome fits well our experimental measurements showing that the plasma current obeys power laws that are dependent on the power current and other control variables such as the gas pressure.

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

    SciTech Connect (OSTI)

    Greenly, John B.; Seyler, Charles

    2014-03-30

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

  20. High-Density Plasma Arc Heating Studies of FePt Thin Films

    SciTech Connect (OSTI)

    Cole, Amanda C; Thompson, Gregory; Harrell, J. W.; Weston, James; Ott, Ronald D

    2006-01-01

    The effect of pulsed-thermal-processing with high-density plasma arc heating is discussed for 20 nm thick nanocrystalline FePt thin films. The dependence of the A1 {yields} L1{sub 0} phase transformation on pulsed time and radiant energy of the pulse is quantified through x-ray diffraction and alternating gradient magnetometry. For 100 ms and 250 ms pulse widths, the phase transformation was observed. Higher radiant energy densities resulted in a larger measured coercivity associated with the L1{sub 0} phase.

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

    SciTech Connect (OSTI)

    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)

    2014-02-24

    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.

  2. The response of plasma density to breaking inertial gravity wave in the lower regions of ionosphere

    SciTech Connect (OSTI)

    Tang, Wenbo Mahalov, Alex

    2014-04-15

    We present a three-dimensional numerical study for the E and lower F region ionosphere coupled with the neutral atmosphere dynamics. This model is developed based on a previous ionospheric model that examines the transport patterns of plasma density given a prescribed neutral atmospheric flow. Inclusion of neutral dynamics in the model allows us to examine the charge-neutral interactions over the full evolution cycle of an inertial gravity wave when the background flow spins up from rest, saturates and eventually breaks. Using Lagrangian analyses, we show the mixing patterns of the ionospheric responses and the formation of ionospheric layers. The corresponding plasma density in this flow develops complex wave structures and small-scale patches during the gravity wave breaking event.

  3. Current initiation in low-density foam z-pinch plasmas

    SciTech Connect (OSTI)

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

    1996-07-01

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

  4. A new method for determining the plasma electron density using three-color interferometer

    SciTech Connect (OSTI)

    Arakawa, Hiroyuki; Kawano, Yasunori; Itami, Kiyoshi

    2012-06-15

    A new method for determining the plasma electron density using the fractional fringes on three-color interferometer is proposed. Integrated phase shift on each interferometer is derived without using the temporal history of the fractional fringes. The dependence on the fringe resolution and the electrical noise are simulated on the wavelengths of CO{sub 2} laser. Short-time integrations of the fractional fringes enhance the reliability of this method.

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

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

    Science on Saturday starts Jan. 11 By Jeanne Jackson DeVoe January 10, 2014 Tweet Widget ... Goldston, discussed "Outer Space" at a Science on Saturday lecture in 2013. (Photo by ...

  6. Science on Saturday: Plastic Electronics | Princeton Plasma Physics...

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

    6, 2016 - 09:30 Science on Saturday: Plastic Electronics MBG Auditorium @ PPPL Speaker: Professor Lynn Loo...

  7. Worldwide conference on plasma science coming to Princeton area...

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

    on topics ranging from basic research to uses for plasma in microchip etching, nano- material manufacturing and other technologies. "This conference occupies a unique niche,"...

  8. Exploring Plasma Science Advances from Fusion Findings to Astrophysica...

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

    physics The meeting focused considerable attention on boundary physics and plasma-material wall interactions, an area of growing emphasis at PPPL. Dennis Whyte, a professor of...

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

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

    5th Annual Meeting of the APS Division of Plasma Physics, Denver, CO - 2013 Alcator Introduction Facility Information Tokamak Data & Real-Time Information Computer & Data Systems...

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

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

    6th Annual Meeting of the APS Division of Plasma Physics, new orleans, la - 2014 Alcator Introduction Facility Information Tokamak Data & Real-Time Information Computer & Data...

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

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

    4th Annual Meeting of the APS Division of Plasma Physics, Providence, RI - 2012 Alcator Introduction Facility Information Tokamak Data & Real-Time Information Computer & Data...

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

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

    Technology & Engineering Useful Links Presentations from the 46th Annual Meeting of the APS Division of Plasma Physics, Savannah, 2004 Invited Orals P. Bonoli Full-wave...

  13. NJ Regional Middle School Science Bowl | Princeton Plasma Physics Lab

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

    2, 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,

  14. Capillary plasma jet: A low volume plasma source for life science applications

    SciTech Connect (OSTI)

    Topala, I. E-mail: tmnagat@ipc.shizuoka.ac.jp; Nagatsu, M. E-mail: tmnagat@ipc.shizuoka.ac.jp

    2015-02-02

    In this letter, we present results from multispectroscopic analysis of protein films, after exposure to a peculiar plasma source, i.e., the capillary plasma jet. This plasma source is able to generate very small pulsed plasma volumes, in kilohertz range, with characteristic dimensions smaller than 1?mm. This leads to specific microscale generation and transport of all plasma species. Plasma diagnosis was realized using general electrical and optical methods. Depending on power level and exposure duration, this miniature plasma jet can induce controllable modifications to soft matter targets. Detailed discussions on protein film oxidation and chemical etching are supported by results from absorption, X-ray photoelectron spectroscopy, and microscopy techniques. Further exploitation of principles presented here may consolidate research interests involving plasmas in biotechnologies and plasma medicine, especially in patterning technologies, modified biomolecule arrays, and local chemical functionalization.

  15. Fast magnetic reconnection in low-density electron-positron plasmas

    SciTech Connect (OSTI)

    Bessho, Naoki; Bhattacharjee, A.

    2010-10-15

    Two-dimensional particle-in-cell simulations have been performed to study magnetic reconnection in low-density electron-positron plasmas without a guide magnetic field. Impulsive reconnection rates become of the order of unity when the background density is much smaller than 10% of the density in the initial current layer. It is demonstrated that the outflow speed is less than the upstream Alfven speed, and that the time derivative of the density must be taken into account in the definition of the reconnection rate. The reconnection electric fields in the low-density regime become much larger than the ones in the high-density regime, and it is possible to accelerate the particles to high energies more efficiently. The inertial term in the generalized Ohm's law is the most dominant term that supports a large reconnection electric field. An effective collisionless resistivity is produced and tracks the extension of the diffusion region in the late stage of the reconnection dynamics, and significant broadening of the diffusion region is observed. Because of the broadening of the diffusion region, no secondary islands, which have been considered to play a role to limit the diffusion region, are generated during the extension of the diffusion region in the outflow direction.

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

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

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

  17. Low Temperature Plasma Science: Not Only the Fourth State of Matter but All of Them. Report of the Department of Energy Office of Fusion Energy Sciences Workshop on Low Temperature Plasmas, March 25-57, 2008

    SciTech Connect (OSTI)

    2008-09-01

    Low temperature plasma science (LTPS) is a field on the verge of an intellectual revolution. Partially ionized plasmas (often referred to as gas discharges) are used for an enormous range of practical applications, from light sources and lasers to surgery and making computer chips, among many others. The commercial and technical value of low temperature plasmas (LTPs) is well established. Modern society would simply be less advanced in the absence of LTPs. Much of this benefit has resulted from empirical development. As the technology becomes more complex and addresses new fields, such as energy and biotechnology, empiricism rapidly becomes 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.

  18. New Jersey Regional Science Bowl | Princeton Plasma Physics Lab

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

    elimination contest with question and answer rounds in the fields of chemistry, biology, physics, astronomy, mathematics and general and earth sciences. Teams from middle, high...

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

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

    Garching, Germany 19-21 Oct. 19 June 17 July 18 Dec registration ends: 18 Sept 57th APS Div of Plasma Physics Meeting Savannah, GA 16-20 Nov. May 2015 July May June 30 Nov...

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

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

    3rd Annual Meeting of the APS Division of Plasma Physics, Salt Lake City, 2011 Invited Orals C. Fiore Production of Internal Transport Barriers via Self-Generated Mean Flows in...

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

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

    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...

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

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

    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...

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

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

    7th Annual Meeting of the APS Division of Plasma Physics, Denver, 2005 Invited Orals R. Granetz Gas Jet Disruption Mitigation Studies on AlcatorC-MOD J. Hughes Advances in...

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

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

    0th Annual Meeting of the APS Division of Plasma Physics, Dallas, 2008 Invited Orals E. Edlund Observation of Reversed Shear Alfvn Eigenmodes During the Sawtooth Cycle in Alcator...

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

    SciTech Connect (OSTI)

    Lin, M.-W.; Jovanovic, I.

    2012-11-15

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

  6. A comparison of parametric decay of oblique Langmuir wave in high and low density magneto-plasmas

    SciTech Connect (OSTI)

    Shahid, M.; Hussain, A.; Department of Physics, Government College University, Lahore-54000 ; Murtaza, G.

    2013-09-15

    The parametric decay instability of an obliquely propagating Langmuir wave into the low-frequency electromagnetic shear Alfven wave and the Left-Handed Circularly Polarized wave has been investigated in an electron-ion plasma, immersed in a uniform external magnetic field. Quantum magneto-hydrodynamic model has been used to find the linear and non-linear response of a high density quantum magneto-plasma. Going to the classical limit (??0) retrieves the results for low density classical plasma. Nonlinear dispersion relations and growth rates are derived with analytically and numerically. It is observed that growth rate in the high density degenerate magneto-plasma increases exponentially, while in the low density classical case it increases logarithmically.

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

    DOE Patents [OSTI]

    Thode, Lester E.

    1981-01-01

    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.

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

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

    Contact Information Physics Research High-Energy- Density Physics Waves & Beams Fusion Technology & Engineering Francis Bitter Magnet Laboratoroy Useful Links The links...

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

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

    & News Meetings & Seminars Contact Information Physics Research High-Energy- Density Physics Waves & Beams Technology & Engineering Useful Links APS Presentations New Orleans...

  10. Analysis by oxygen atom number density measurement of high-speed hydrophilic treatment of polyimide using atmospheric pressure microwave plasma

    SciTech Connect (OSTI)

    Ono, S.

    2015-03-30

    This paper describes the fundamental experimental data of the plasma surface modification of the polyimide using atmospheric pressure microwave plasma source. The experimental results were discussed from the point of view of the radicals behavior, which significantly affects the modification mechanism. The purpose of the study is to examine how the value of the oxygen atom density will affect the hydrophilic treatment in the upstream region of the plasma where gas temperature is very high. The surface modification experiments were performed by setting the polyimide film sample in the downstream region of the plasma. The degree of the modification was measured by a water contact angle measurement. The water contact angle decreased less than 30 degrees within 1 second treatment time in the upstream region. Very high speed modification was observed. The reason of this high speed modification seems that the high density radical which contributes the surface modification exist in the upstream region of the plasma. This tendency is supposed to the measured relatively high electron density (~10{sup 15}cm{sup ?3}) at the center of the plasma. We used the electric heating catalytic probe method for oxygen radical measurement. An absolute value of oxygen radical density was determined by catalytic probe measurement and the results show that ~10{sup 15}cm{sup ?3} of the oxygen radical density in the upstream region and decreases toward downstream region. The experimental results of the relation of the oxygen radical density and hydrophilic modification of polyimide was discussed.

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

    SciTech Connect (OSTI)

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

    2012-09-15

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

  12. Understanding the dramatic role of anomalous dispersion on the measurement of electron densities in plasmas using interferometers

    SciTech Connect (OSTI)

    Nilsen, J; Johnson, W R; Iglesias, C A; Scofield, J H

    2005-07-20

    For decades the electron density of plasmas has been measured using optical interferometers. With the availability of good X-ray laser sources in the last decade interferometers have been extended into the wavelength range 14-47 nm, which has enabled researchers to probe even higher density plasmas. The data analysis assumes the index of refraction is due only to the free electrons, which makes the index less than one. Recent interferometer experiments in Al plasmas observed plasmas with index of refraction greater than one at 14 nm and brought into question the validity of the usual formula for calculating the index. In this paper we show how the anomalous dispersion from bound electrons can dominate the free electron contribution to the index of refraction in many plasmas and make the index greater than one or enhance the contribution to the index such that one would greatly overestimate the density of the plasma using interferometers. Using a new average-atom code we calculate the index of refraction in many plasmas at different temperatures for photon energies from 0 to 100 eV and compare against calculations done with OPAL. We also present examples of other plasmas that may have index of refraction greater than one at X-ray laser energies. During the next decade X-ray free electron lasers and other X-ray sources will be available to probe a wider variety of plasmas at higher densities and shorter wavelengths so understanding the index of refraction in plasmas will be even more essential.

  13. Science on Saturday: Music and 3D Audio | Princeton Plasma Physics Lab

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

    February 13, 2016, 9:30am Science On Saturday MBG Auditorium, PPPL Science on Saturday: Music and 3D Audio Professor Edgar Choueiri Princeton University Abstract: PDF icon 06 Choueiri.pdf Science_on_Saturday13Feb2016_EChoueiri Contact Information Coordinator(s): Ms. Deedee Ortiz-Arias dortiz@pppl.gov Host(s): Dr. Andrew Zwicker azwicker@pppl.gov PPPL Entrance Procedures Visitor Information, Directions, Security at PPPL As a federal facility, the Princeton Plasma Physics Laboratory is operating

  14. 2012 USA Science & Engineering Festival | Princeton Plasma Physics Lab

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

    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 larger image IMG 0688 View larger image IMG 0698 View larger image IMG 0701 View larger image IMG 0696 View larger image IMG 0700 View larger image IMG 0712 View larger image IMG 0720 View larger image IMG 0729 View larger image IMG 0738 View larger image IMG 0735

  15. Note: Experimental platform for magnetized high-energy-density plasma studies at the omega laser facility

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Fiksel, G.; Agliata, A.; Barnak, D.; Brent, G.; Chang, P. -Y.; Folnsbee, L.; Gates, G.; Hasset, D.; Lonobile, D.; Magoon, J.; et al

    2015-01-12

    Here, an upgrade of the pulsed magnetic field generator magneto-inertial fusion electrical discharge system [O. Gotchev et al., Rev. Sci. Instrum. 80, 043504 (2009)] is described. The device is used to study magnetized high-energy-density plasma and is capable of producing a pulsed magnetic field of tens of tesla in a volume of a few cubic centimeters. The magnetic field is created by discharging a high-voltage capacitor through a small wire-wound coil. The coil current pulse has a duration of about 1 μs and a peak value of 40 kA. Compared to the original, the updated version has a larger energymore » storage and improved switching system. In addition, magnetic coils are fabricated using 3-D printing technology which allows for a greater variety of the magnetic field topology.« less

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

    SciTech Connect (OSTI)

    Guan Nana; Li Jianwei; He Zejun; Long Jiali; Cai Xiangzhou; Ma Yugang; Shen Wenqing

    2009-07-15

    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: qq{yields}ll, qq{yields}gll, Compton-like scattering (qg{yields}qll,qg{yields}qll), gluon fusion (gg{yields}cc), annihilation (qq{yields}cc), 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.

  17. Sandia National Laboratories: Research: Materials Science

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

    Research Bioscience Computing and Information Science Electromagnetics Engineering Science Geoscience Materials Science About Materials Science Research Image Gallery Video Gallery Facilities Nanodevices and Microsystems Radiation Effects and High Energy Density Science Research Research Materials Processing Sandia research staff understand, characterize, model, and ultimately control materials fabrication technologies that are critical to component development and production. Plasma Spray

  18. 2013 Pathways to Science Summit | Princeton Plasma Physics Lab

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

    Pathways to Science Summit View larger image IMG 2061 View larger image IMG 2063 View larger image IMG 2062 View larger image IMG 2067 View larger image IMG 2068 View larger image IMG 2069 View larger image IMG 2070 View larger image IMG 2073 View larger image IMG 2081 View larger image IMG 2085 View larger image IMG 2096 View larger image IMG 2101 View larger image IMG 2103 View larger image IMG 2104 View larger image IMG 2105 View larger image IMG 2106 View larger image IMG 2107

  19. Magnetic reconnection in high-energy-density laser-produced plasmas

    SciTech Connect (OSTI)

    Fox, W.; Bhattacharjee, A.; Germaschewski, K.

    2012-05-15

    Recently, novel experiments on magnetic reconnection have been conducted in laser-produced plasmas in a high-energy-density regime. Individual plasma bubbles self-generate toroidal, mega-gauss-scale magnetic fields through the Biermann battery effect. When multiple bubbles are created at small separation, they expand into one another, driving reconnection of this field. Reconnection in the experiments was reported to be much faster than allowed by both Sweet-Parker, and even Hall-MHD theories, when normalized to the nominal magnetic fields self-generated by single bubbles. Through particle-in-cell simulations (both with and without a binary collision operator), we model the bubble interaction at parameters and geometry relevant to the experiments. This paper discusses in detail the reconnection regime of the laser-driven experiments and reports the qualitative features of simulations. We find substantial flux-pileup effects, which boost the relevant magnetic field for reconnection in the current sheet. When this is accounted for, the normalized reconnection rates are much more in line with standard two-fluid theory of reconnection. At the largest system sizes, we additionally find that the current sheet is prone to breakup into plasmoids.

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

    SciTech Connect (OSTI)

    Gupta, Deepak K.; Deng, B. H.; Knapp, K.; Sun, X.; Thompson, M. C.

    2012-10-15

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

  1. Measurement of a density profile of a hot-electron plasma in RT-1 with three-chord interferometry

    SciTech Connect (OSTI)

    Saitoh, H.; Yano, Y.; Yoshida, Z.; Nishiura, M.; Morikawa, J.; Kawazura, Y.; Nogami, T.; Yamasaki, M.

    2015-02-15

    The electron density profile of a plasma in a magnetospheric dipole field configuration was measured with a multi-chord interferometry including a relativistic correction. In order to improve the accuracy of density reconstruction, a 75 GHz interferometer was installed at a vertical chord of the Ring Trap 1 (RT-1) device in addition to previously installed ones at tangential and another vertical chords. The density profile was calculated by using the data of three-chord interferometry including relativistic effects for a plasma consisting of hot and cold electrons generated by electron cyclotron resonance heating (ECH). The results clearly showed the effects of density peaking and magnetic mirror trapping in a strongly inhomogeneous dipole magnetic field.

  2. High-Energy Density science at the Linac Coherent Light Source

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Glenzer, S. H.; Fletcher, L. B.; Hastings, J. B.

    2016-03-01

    The Matter in Extreme Conditions end station at the Linac Coherent Light Source holds great promise for novel pump-probe experiments to make new discoveries in high- energy density science. Recently, our experiments have demonstrated the first spectrally- resolved measurements of plasmons using a seeded 8-keV x-ray laser beam. Forward x-ray Thomson scattering spectra from isochorically heated solid aluminum show a well-resolved plasmon feature that is down-shifted in energy by 19 eV from the incident 8 keV elastic scattering feature. In this spectral range, the simultaneously measured backscatter spectrum shows no spectral features indicating observation of collective plasmon oscillations on amore » scattering length comparable to the screening length. Moreover, this technique is a prerequisite for Thomson scattering measurements in compressed matter where the plasmon shift is a sensitive function of the free electron density and where the plasmon intensity provides information on temperature.« less

  3. Convergence of statistical moments of particle density time series in scrape-off layer plasmas

    SciTech Connect (OSTI)

    Kube, R. Garcia, O. E.

    2015-01-15

    Particle density fluctuations in the scrape-off layer of magnetically confined plasmas, as measured by gas-puff imaging or Langmuir probes, are modeled as the realization of a stochastic process in which a superposition of pulses with a fixed shape, an exponential distribution of waiting times, and amplitudes represents the radial motion of blob-like structures. With an analytic formulation of the process at hand, we derive expressions for the mean squared error on estimators of sample mean and sample variance as a function of sample length, sampling frequency, and the parameters of the stochastic process. Employing that the probability distribution function of a particularly relevant stochastic process is given by the gamma distribution, we derive estimators for sample skewness and kurtosis and expressions for the mean squared error on these estimators. Numerically, generated synthetic time series are used to verify the proposed estimators, the sample length dependency of their mean squared errors, and their performance. We find that estimators for sample skewness and kurtosis based on the gamma distribution are more precise and more accurate than common estimators based on the method of moments.

  4. Whistler wave radiation from a pulsed loop antenna located in a cylindrical duct with enhanced plasma density

    SciTech Connect (OSTI)

    Kudrin, Alexander V.; Shkokova, Natalya M.; Ferencz, Orsolya E.; Zaboronkova, Tatyana M.

    2014-11-15

    Pulsed radiation from a loop antenna located in a cylindrical duct with enhanced plasma density is studied. The radiated energy and its distribution over the spatial and frequency spectra of the excited waves are derived and analyzed as functions of the antenna and duct parameters. Numerical results referring to the case where the frequency spectrum of the antenna current is concentrated in the whistler range are reported. It is shown that under ionospheric conditions, the presence of an artificial duct with enhanced density can lead to a significant increase in the energy radiated from a pulsed loop antenna compared with the case where the same source is immersed in the surrounding uniform magnetoplasma. The results obtained can be useful in planning active ionospheric experiments with pulsed electromagnetic sources operated in the presence of artificial field-aligned plasma density irregularities that are capable of guiding whistler waves.

  5. Stewardship Science Academic Alliances Annual

    National Nuclear Security Administration (NNSA)

    Stewardship Science Academic Alliances National Laser Users' Facility High Energy Density Laboratory Plasmas A color composite (redH2, greenHI, blueOIII) of a small portion of ...

  6. Argon–germane in situ plasma clean for reduced temperature Ge on Si epitaxy by high density plasma chemical vapor deposition

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Douglas, Erica A.; Sheng, Josephine J.; Verley, Jason C.; Carroll, Malcolm S.

    2015-06-04

    We found that the demand for integration of near infrared optoelectronic functionality with silicon complementary metal oxide semiconductor (CMOS) technology has for many years motivated the investigation of low temperature germanium on silicon deposition processes. Our work describes the development of a high density plasma chemical vapor deposition process that uses a low temperature (<460 °C) in situ germane/argon plasma surface preparation step for epitaxial growth of germanium on silicon. It is shown that the germane/argon plasma treatment sufficiently removes SiOx and carbon at the surface to enable germanium epitaxy. Finally, the use of this surface preparation step demonstrates anmore » alternative way to produce germanium epitaxy at reduced temperatures, a key enabler for increased flexibility of integration with CMOS back-end-of-line fabrication.« less

  7. Argon–germane in situ plasma clean for reduced temperature Ge on Si epitaxy by high density plasma chemical vapor deposition

    SciTech Connect (OSTI)

    Douglas, Erica A.; Sheng, Josephine J.; Verley, Jason C.; Carroll, Malcolm S.

    2015-06-04

    We found that the demand for integration of near infrared optoelectronic functionality with silicon complementary metal oxide semiconductor (CMOS) technology has for many years motivated the investigation of low temperature germanium on silicon deposition processes. Our work describes the development of a high density plasma chemical vapor deposition process that uses a low temperature (<460 °C) in situ germane/argon plasma surface preparation step for epitaxial growth of germanium on silicon. It is shown that the germane/argon plasma treatment sufficiently removes SiOx and carbon at the surface to enable germanium epitaxy. Finally, the use of this surface preparation step demonstrates an alternative way to produce germanium epitaxy at reduced temperatures, a key enabler for increased flexibility of integration with CMOS back-end-of-line fabrication.

  8. Science

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

    Office of Science Office of Science * * * Office of Science Office of * * * * * Office of Science Office of Science * * * Office of Science * * * * 287 115 ...

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

    SciTech Connect (OSTI)

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

    2013-08-15

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

  10. Expert Topics | Princeton Plasma Physics Lab

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

    Plasma astrophysics Plasma diagnostics Plasma physics Power system design Power systems Quality assurance STEM Science literacy Stellarators Surface science Sustainability ...

  11. Density and x-ray emission profile relationships in highly ionized high-Z laser-produced plasmas

    SciTech Connect (OSTI)

    Yoshida, Kensuke; Fujioka, Shinsuke Ugomori, Teruyuki; Tanaka, Nozomi; Azechi, Hiroshi; Nishimura, Hiroaki; Higashiguchi, Takeshi Kawasaki, Masato; Suzuki, Yuhei; Suzuki, Chihiro; Tomita, Kentaro; Hirose, Ryoichi; Ejima, Takeo; Ohashi, Hayato; Nishikino, Masaharu; Sunahara, Atsushi; Li, Bowen; Dunne, Padraig; O'Sullivan, Gerry; Yanagida, Tatsuya

    2015-03-23

    We present a benchmark measurement of the electron density profile in the region where the electron density is 10{sup 19?}cm{sup 3} and where the bulk of extreme ultraviolet (EUV) emission occurs from isotropically expanding spherical high-Z gadolinium plasmas. It was found that, due to opacity effects, the observed EUV emission is mostly produced from an underdense region. We have analyzed time-resolved emission spectra with the aid of atomic structure calculations and find the multiple ion charge states around 18+ during the laser pulse irradiation.

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

    SciTech Connect (OSTI)

    Bokaei, B.; Niknam, A. R.

    2014-03-15

    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.

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

    SciTech Connect (OSTI)

    Moses, E

    2011-03-25

    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.

  14. One-dimensional time-dependent fluid model of a very high density low-pressure inductively coupled plasma

    SciTech Connect (OSTI)

    Chaplin, Vernon H.; Bellan, Paul M.

    2015-12-28

    A time-dependent two-fluid model has been developed to understand axial variations in the plasma parameters in a very high density (peak ne~ > 5x1019 m–3) argon inductively coupled discharge in a long 1.1 cm radius tube. The model equations are written in 1D, with radial losses to the tube walls accounted for by the inclusion of effective particle and energy sink terms. The ambipolar diffusion equation and electron energy equation are solved to find the electron density ne(z,t) and temperature Te(z,t), and the populations of the neutral argon 4s metastable, 4s resonant, and 4p excited state manifolds are calculated in order to determine the stepwise ionization rate and calculate radiative energy losses. The model has been validated through comparisons with Langmuir probe ion saturation current measurements; close agreement between the simulated and measured axial plasma density profiles and the initial density rise rate at each location was obtained at pAr = 30-60 mTorr. Lastly, we present detailed results from calculations at 60 mTorr, including the time-dependent electron temperature, excited state populations, and energy budget within and downstream of the radiofrequency (RF) antenna.

  15. Inductively Driven, 3D Liner Compression of a Magnetized Plasma to Megabar Energy Densities

    SciTech Connect (OSTI)

    Slough, John

    2015-02-01

    To take advantage of the smaller scale, higher density regime of fusion an efficient method for achieving the compressional heating required to reach fusion gain conditions must be found. What is proposed is a more flexible metallic liner compression scheme that minimizes the kinetic energy required to reach fusion. It is believed that it is possible to accomplish this at sub-megajoule energies. This however will require operation at very small scale. To have a realistic hope of inexpensive, repetitive operation, it is essential to have the liner kinetic energy under a megajoule which allows for the survivability of the vacuum and power systems. At small scale the implosion speed must be reasonably fast to maintain the magnetized plasma (FRC) equilibrium during compression. For limited liner kinetic energy, it becomes clear that the thinnest liner imploded to the smallest radius consistent with the requirements for FRC equilibrium lifetime is desired. The proposed work is directed toward accomplishing this goal. Typically an axial (Z) current is employed for liner compression. There are however several advantages to using a θ-pinch coil. With the θ-pinch the liner currents are inductively driven which greatly simplifies the apparatus and vacuum system, and avoids difficulties with the post implosion vacuum integrity. With fractional flux leakage, the foil liner automatically provides for the seed axial compression field. To achieve it with optimal switching techniques, and at an accelerated pace however will require additional funding. This extra expense is well justified as the compression technique that will be enabled by this funding is unique in the ability to implode individual segments of the liner at different times. This is highly advantageous as the liner can be imploded in a manner that maximizes the energy transfer to the FRC. Production of shaped liner implosions for additional axial compression can thus be readily accomplished with the modified power modules. The additional energy and switching capability proposed will thus provide for optimal utilization of the liner energy. The following tasks were outlined for the three year effort: (1) Design and assemble the foil liner compression test structure and chamber including the compression bank and test foils [Year 1]. (2) Perform foil liner compression experiments and obtain performance data over a range on liner dimensions and bank parameters [Year 2]. (3) Carry out compression experiments of the FRC plasma to Megagauss fields and measure key fusion parameters [Year 3]. (4) Develop numerical codes and analyze experimental results, and determine the physics and scaling for future work [Year 1-3]. The principle task of the project was to design and assemble the foil liner FRC formation chamber, the full compression test structure and chamber including the compression bank. This task was completed successfully. The second task was to test foils in the test facility constructed in year one and characterize the performance obtained from liner compression. These experimental measurements were then compared with analytical predictions, and numerical code results. The liner testing was completed and compared with both the analytical results as well as the code work performed with the 3D structural dynamics package of ANSYS Metaphysics®. This code is capable of modeling the dynamic behavior of materials well into the non-linear regime (e.g. a bullet hit plate glass). The liner dynamic behavior was found to be remarkably close to that predicted by the 3D structural dynamics results. Incorporating a code that can also include the magnetics and plasma physics has also made significant progress at the UW. The remaining test bed construction and assembly task is was completed, and the FRC formation and merging experiments were carried out as planned. The liner compression of the FRC to Megagauss fields was not performed due to not obtaining a sufficiently long lived FRC during the final year of the grant. Modifications planned to correct this deficiency included a larger FRC source as well as a much larger liner driver energy storage system. Due to discontinuation of the grant neither of these improvements were carried out.

  16. Generating end plug potentials in tandem mirror plasma confinement by heating thermal particles so as to escape low density end stoppering plasmas

    DOE Patents [OSTI]

    Baldwin, David E.; Logan, B. Grant

    1981-01-01

    The invention provides a method and apparatus for raising the potential of a magnetic mirror cell by pumping charged particles of the opposite sign of the potential desired out of the mirror cell through excitation, with the pumping being done by an externally imposed field at the bounce frequency of the above charged particles. These pumped simple mirror cells then provide end stoppering for a center mirror cell for the tandem mirror plasma confinement apparatus. For the substantially complete pumping case, the end plugs of a tandem mirror can be up to two orders of magnitude lower in density for confining a given center mirror cell plasma than in the case of end plugs without pumping. As a result the decrease in recirculating power required to keep the system going, the technological state of the art required, and the capital cost are all greatly lowered.

  17. Generating end plug potentials in tandem mirror plasma confinement by heating thermal particles so as to escape low density end stoppering plasmas

    DOE Patents [OSTI]

    Baldwin, D.E.; Logan, B.G.

    The invention provides a method and apparatus for raising the potential of a magnetic mirror cell by pumping charged particles of the opposite sign of the potential desired out of the mirror cell through excitation, with the pumping being done by an externally imposed field at the bounce frequence of the above charged particles. These pumped simple mirror cells then provide end stoppering for a center mirror cell for the tandem mirror plasma confinement apparatus. For the substantially complete pumping case, the end plugs of a tandem mirror can be up to two orders of magnitude lower in density for confining a given center mirror cell plasma than in the case of end plugs without pumping. As a result the decrease in recirculating power required to keep the system going, the technical state of the art required, and the capital cost are all greatly lowered.

  18. Enhanced relativistic self-focusing of Hermite-cosh-Gaussian laser beam in plasma under density transition

    SciTech Connect (OSTI)

    Nanda, Vikas; Kant, Niti

    2014-04-15

    Enhanced and early relativistic self-focusing of Hermite-cosh-Gaussian (HChG) beam in the plasmas under density transition has been investigated theoretically using Wentzel-Kramers-Brillouin and paraxial ray approximation for mode indices m=0, 1, and 2. The variation of beam width parameter with normalized propagation distance for m=0, 1, and 2 is reported, and it is observed that strong self-focusing occurs as the HChG beam propagates deeper inside the nonlinear medium as spot size shrinks due to highly dense plasmas and the results are presented graphically. A comparative study between self-focusing of HChG beam in the presence and absence of plasmas density transition is reported. The dependency of beam width parameter on the normalized propagation distance for different values of decentered parameter “b” has also been presented graphically. For m=0 and 1, strong self-focusing is reported for b=1.8, and for m=2 and b=1.8, beam gets diffracted. The results obtained indicate the dependency of the self-focusing of the HChG beam on the selected values of decentered parameter. Moreover, proper selection of decentered parameter results strong self-focusing of HChG beam. Stronger self-focusing of laser beam is observed due to the presence of plasma density transition which might be very useful in the applications like the generation of inertial fusion energy driven by lasers, laser driven accelerators, etc.

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

    SciTech Connect (OSTI)

    Shvets, Gennady

    2014-05-09

    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.

  20. Impact of the pedestal plasma density on dynamics of edge localized mode crashes and energy loss scaling

    SciTech Connect (OSTI)

    Xu, X. Q.; Ma, J. F.; Li, G. Q.

    2014-12-15

    The latest BOUT++ studies show an emerging understanding of dynamics of edge localized mode (ELM) crashes and the consistent collisionality scaling of ELM energy losses with the world multi-tokamak database. A series of BOUT++ simulations are conducted to investigate the scaling characteristics of the ELM energy losses vs collisionality via a density scan. Linear results demonstrate that as the pedestal collisionality decreases, the growth rate of the peeling-ballooning modes decreases for high n but increases for low n (1?plasma and yields an increasing ELM size with decreasing collisionality after a series of micro-bursts. The pedestal plasma density plays a major role in determining the ELM energy loss through its effect on the edge bootstrap current and ion diamagnetic stabilization. The critical trend emerges as a transition (1) linearly from ballooning-dominated states at high collisionality to peeling-dominated states at low collisionality with decreasing density and (2) nonlinearly from turbulence spreading dynamics at high collisionality into avalanche-like dynamics at low collisionality.

  1. Access to a New Plasma Edge State with High Density and Pressures using Quiescent H-mode

    SciTech Connect (OSTI)

    Solomon, Wayne M.; Snyder, P. B.; Burrell, K. H.; Fenstermacher, M. E.; Garofalo, A. M.; Grierson, B. A.; Loarte, A.; McKee, G. R.; Nazikian, R; Osborne, T. H.

    2014-07-01

    A path to a new high performance regime has been discovered in tokamaks that could improve the attractiveness of a fusion reactor. Experiments on DIII-D using a quiescent H-mode edge have navigated a valley of improved edge peeling-ballooning stability that opens up with strong plasma shaping at high density, leading to a doubling of the edge pressure over standard edge localized mode (ELM)ing H-mode at these parameters. The thermal energy confinement time increases both as a result of the increased pedestal height and improvements in the core transport and reduced low-k turbulence. Calculations of the pedestal height and width as a function of density using constraints imposed by peeling-ballooning and kinetic-ballooning theory are in quantitative agreement with the measurements.

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

    SciTech Connect (OSTI)

    Weller, M. E. 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.; Apruzese, J. P.; Giuliani, J. L.; Chuvatin, A. S.

    2014-03-15

    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.

  3. Analytical description of generation of the residual current density in the plasma produced by a few-cycle laser pulse

    SciTech Connect (OSTI)

    Silaev, A. A. Vvedenskii, N. V.

    2015-05-15

    When a gas is ionized by a few-cycle laser pulse, some residual current density (RCD) of free electrons remains in the produced plasma after the passage of the laser pulse. This quasi-dc RCD is an initial impetus to plasma polarization and excitation of the plasma oscillations which can radiate terahertz (THz) waves. In this work, the analytical model for calculation of RCD excited by a few-cycle laser pulse is developed for the first time. The dependences of the RCD on the carrier-envelope phase (CEP), wavelength, duration, and intensity of the laser pulse are derived. It is shown that maximum RCD corresponding to optimal CEP increases with the laser pulse wavelength, which indicates the prospects of using mid-infrared few-cycle laser pulses in the schemes of generation of high-power THz pulses. Analytical formulas for optimal pulse intensity and maximum efficiency of excitation of the RCD are obtained. Basing on numerical solution of the 3D time-dependent Schrödinger equation for hydrogen atoms, RCD dependence on CEP is calculated in a wide range of wavelengths. High accuracy of analytical formulas is demonstrated at the laser pulse parameters which correspond to the tunneling regime of ionization.

  4. Electron density measurements of atmospheric-pressure non-thermal N{sub 2} plasma jet by Stark broadening and irradiance intensity methods

    SciTech Connect (OSTI)

    Xiao, Dezhi; Shen, Jie; Lan, Yan; Xie, Hongbing; Shu, Xingsheng; Meng, Yuedong; Li, Jiangang; Cheng, Cheng E-mail: paul.chu@cityu.edu.hk; Chu, Paul K. E-mail: paul.chu@cityu.edu.hk

    2014-05-15

    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 10{sup 20}/m{sup 3} 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.

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

    SciTech Connect (OSTI)

    Chen, Hui E-mail: bitter@pppl.gov; Magee, E.; Nagel, S. R.; Park, J.; Schneider, M. B.; Stone, G.; Williams, G. J.; Beiersdorfer, P.; Bitter, M. E-mail: bitter@pppl.gov; Hill, K. W.; Kerr, S.

    2014-11-15

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

  6. DESTRUCTION OF NEUTRAL PARTICLES IN A DEVICE FOR PRODUCING A HIGH DENSITY PLASMA

    DOE Patents [OSTI]

    Simon, A.

    1962-05-01

    A method and apparatus are described for burning out neutral particles in an evacuated region and within a strong magnetic field. The method comprises injecting energetic molecular ions into the region perpendicular to the magnetic field and into the path of a dissociating, energetic arc discharge, the atomic ions formed in the dissociating process being trapped by the magnetic field, and then increasing the value of the trapped atomic ion current to such a value that the neutral particles are destroyed faster than they are formed, thereby causing a dense, energetic plasma to be built up and sustained by the magnetic field. (AEC)

  7. Science

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

    Science Stockpile Stewardship National Security National Competitiveness Fusion and Ignition Energy for the Future How to Make a Star Discovery Science Photon Science HAPLS

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

    SciTech Connect (OSTI)

    Ram, A. K.; Hizanidis, K.; Kominis, Y.

    2011-12-23

    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.

  9. Plasma Physics

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

    Plasma Physics (P-24) is committed to scientific excellence in basic and applied research. Our breadth and depth in experimental high energy density physics and plasma physics is ...

  10. THERMAL ANNEALING OF ZNO FILMS USING HIGH-DENSITY PLASMA ARC LAMPS

    SciTech Connect (OSTI)

    Sabau, Adrian S; Dinwiddie, Ralph Barton; Xu, Jun; Angelini, Joseph Attilio; Harper, David C

    2011-01-01

    Nanostructured materials are rarely synthesized with appropriate phase and/or morphology. In this study, critical additional of as-synthesized nanostructured materials, such as annealing and/or activation of dopants, are addressed using infrared plasma arc lamps (PAL) over areas as large as 1,000 cm2. The broad spectral range of the PAL and the spectral variation of light absorption in nanostructured materials make the selection of processing parameters extremely difficult, posing a major technological barrier. In this study, the measurement of the surface temperature using various techniques for ZnO films on crystalline silicon wafers is discussed. An energy transport model for the simulation of rapid thermal processing using PAL is presented. The experimental and computational results show that the surface temperature cannot be measured directly and that computer simulation results are an effective tool for obtaining accurate data on processing temperatures.

  11. A Radiative Transport Model for Heating Paints using High Density Plasma Arc Lamps

    SciTech Connect (OSTI)

    Sabau, Adrian S; Duty, Chad E; Dinwiddie, Ralph Barton; Nichols, Mark; Blue, Craig A; Ott, Ronald D

    2009-01-01

    The energy distribution and ensuing temperature evolution within paint-like systems under the influence of infrared radiation was studied. Thermal radiation effects as well as those due to heat conduction were considered. A complete set of material properties was derived and discussed. Infrared measurements were conducted to obtain experimental data for the temperature in the paint film. The heat flux of the incident radiation from the plasma arc lamp was measured using a heat flux sensor with a very short response time. The comparison between the computed and experimental results for temperature show that the models that are based on spectral four-flux RTE and accurate optical properties yield accurate results for the black paint systems.

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

    SciTech Connect (OSTI)

    Cairns, I. H.; Lobzin, V. V.; Li, B.; Robinson, P. A.; Warmuth, A.; Mann, G.

    2009-12-01

    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.

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

    Office of Scientific and Technical Information (OSTI)

    Office of Scientific and Technical Information 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

  14. Measurement of Electron Density near Plasma Grid of Large-scaled Negative Ion Source by Means of Millimeter-Wave Interferometer

    SciTech Connect (OSTI)

    Nagaoka, K.; Tokuzawa, T.; Tsumori, K.; Nakano, H.; Ito, Y.; Osakabe, M.; Ikeda, K.; Kisaki, M.; Shibuya, M.; Sato, M.; Komada, S.; Kondo, T.; Hayashi, H.; Asano, E.; Takeiri, Y.; Kaneko, O.

    2011-09-26

    A millimeter-wave interferometer with the frequency of 39 GHz ({lambda} 7.7 mm) was newly installed to a large-scaled negative ion source. The measurable line-integrated electron density (n{sub e}l) is from 2x10{sup 16} to 7x10{sup 18} m{sup -2}, where n{sub e} and l represent an electron density and the plasma length along the millimeter-wave path, respectively. Our interest in this study is behavior of negative ions and reduction of electron density in the beam extraction region near the plasma grid. The first results show the possibility of the electron density measurement by the millimeter-wave interferometer in this region. The line-averaged electron density increases proportional to the arc power under the condition without cesium seeding. The significant decrease of the electron density and significant increase of the negative ion density were observed just after the cesium seeding. The electron density measured with the interferometer agrees well with that observed with a Langmuir probe. The very high negative ion ratio of n{sub H-}/(n{sub e}+n{sub H-}) = 0.85 was achieved within 400 min. after the cesium seeding.

  15. Scaling of Microcavity Plasmas Toward 1 m: Science and Engineering of Spatially-Confined, Low Temperature Plasmas

    SciTech Connect (OSTI)

    Eden, J G

    2012-03-07

    The DOE has provided, by means of the American Recovery and Reinvestment Act (ARRA), $146,400 in funding for the purchase of scientific equipment. Specifically, these funds have enabled the purchase of two scientific cameras that have already been applied to the research in microcavity plasmas at the University of Illinois (Urbana). The first camera system that was purchased with these funds is a gated ICCD system that allows events as short as 5 ns in time to be captured. It is difficult to express the impact that this equipment has already had on our research. Despite having arrived just 6 - 7 months ago, this camera system has already been used by five graduate students and several undergraduates to capture phenomena that we simply could not see in the past. As an example, the low temperature plasma confined to a spiral structure we fabricate in the Al/Al?O? materials system appears, on long time scales such as those we see with our eyes, to be spatially uniform. However, when captured with the new camera system, the plasma actually is formed initially at the center of the spiral and then moves radially (literally, "jumping" over channels as it goes) at a velocity of a few km/sec. This is an exciting result and I should add that the camera shows that plasma standing waves are produced in some of the structures as well. We do not currently understand all of the phenomena we are witnessing but it is obvious that this new system has quite literally opened new areas of plasma research and application. The second system purchased under this ARRA grant is an infrared system that is far more sensitive than anything our laboratory (or the University of Illinois, for that matter) has had previously. Although fewer experiments have been completed to date with this second camera, it is already clear that it is, indeed, extremely sensitive and it is slated for several experiments in the near future in which we will be measuring the infrared spectra of several arrays of microcavity plasmas. In summary, let me express my thanks to the DOE for granting these funds. We are most grateful for the extraordinary scientific capability that thee funds provide our students. We expect that the scientific data already acquired by this equipment will result in several publications in the next 2 - 3 months (two are being written now). Furthermore, the ability we now have to watch plasmas evolve on the nanosecond time scale has given us several ideas that are likely to result in patent applications. On behalf of our students and myself, I thank the DOE for this exceptional equipment.

  16. Science

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

    Science /newsroom/_assets/images/science-icon.png Science Cutting edge, multidisciplinary national-security science. Health Space Computing Energy Earth Materials Science Technology The Lab All Jonathan Ward Engle Physicist wins early-career award for isotope work Jonathan Ward Engle, is among 49 winners, of the US Department of Energy's Early Career Research Program awards for 2016. - 5/12/16 Adaptive design framework. Machine learning accelerates the discovery of new materials Researchers

  17. ScienceLive chat page: on the future of fusion research | Princeton Plasma

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

    Physics Lab ScienceLive chat page: on the future of fusion research American Fusion News Category: U.S. Universities Link: ScienceLive chat page: on the future of fusion research

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

    SciTech Connect (OSTI)

    Niemi, K.; O'Connell, D.; Gans, T.; Oliveira, N. de; Joyeux, D.; Nahon, L.; Booth, J. P.

    2013-07-15

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

  19. SCIENCE ON SATURDAY-"Visualizing the Atomic World" | Princeton Plasma

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

    Physics Lab 2, 2013, 9:30am Science On Saturday MBG Auditorium SCIENCE ON SATURDAY-"Visualizing the Atomic World" Professor Udo Schwarz Department of Mechanical Engineering & Materials Science and Department of Chemical & Environmental Engineering, Yale University Presentation: Office presentation icon SOS12JAN2013_UDSchwarz.ppt Abstract: PDF icon U.Schwarz.pdf Science on Saturday is a series of lectures given by scientists, mathematicians, and other professionals involved

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

    ScienceCinema (OSTI)

    Andrei Seryi

    2010-01-08

    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.  

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

    Office of Science (SC) Website

    LP Home About Laboratory Appraisal Process FY 2015 Report Cards FY 2014 Report Cards FY ... FY 2015 SC Laboratory Performance Report Cards Princeton Plasma Physics Laboratory Print ...

  2. 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 2015 Report Cards FY 2014 Report Cards FY 2013 Report Cards Report Card ...

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

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

    graduate student, discussed his poster on dusty plasmas with PPPL physicist Erik Gilson. (Photo by Elle Starkman, PPPL Office of Communications) Jeff Walker, a University of...

  4. Science

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

    Science Science & Technology Images of Lab scientists and researchers at work. News Releases Science Briefs Photos Picture of the Week Publications Social Media Videos Fact Sheets PHOTOS BY TOPIC Careers Community Visitors Environment History Science The Lab Click thumbnails to enlarge. Photos arranged by most recent first, horizontal formats before vertical. See Flickr for more sizes and details. Astronomical simulation in the CAVE - 1 Astronomical simulation in the CAVE - 1 Scientist sees

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

    SciTech Connect (OSTI)

    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)

    2014-02-21

    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.

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

    SciTech Connect (OSTI)

    Prevosto, L.; Mancinelli, B.; Artana, G.; Kelly, H.

    2011-03-15

    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.

  7. SCIENCE ON SATURDAY- "Outer Space!" | Princeton Plasma Physics Lab

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

    January 19, 2013, 9:30am Science On Saturday MBG Auditorium SCIENCE ON SATURDAY- "Outer Space!" Joshua E. G. Peek, Hubble Fellow Department of Astronomy, Columbia University Presentation: Office presentation icon SOS19JAN2013_JPeek_outerspace.ppt Science on Saturday is a series of lectures given by scientists, mathematicians, and other professionals involved in cutting-edge research. Held on Saturday mornings throughout winter, the lectures are geared toward high school students. The

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

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

    Physics Lab The Ronald E. Hatcher SCIENCE ON SATURDAY Lecture Series In memory of our beloved Science on Saturday host, Ronald E. Hatcher. The 2016 Ronald E. Hatcher Science on Saturday Lecture Series is scheduled to run from January 9th through March 12th. Download a copy of our flyer here! Science on Saturday is a series of lectures given by scientists, engineers, and other professionals involved in cutting-edge research. Held on Saturday mornings throughout winter, the lectures are geared

  9. Physical Sciences 2007 Science & Technology Highlights

    SciTech Connect (OSTI)

    Hazi, A U

    2008-04-07

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

  10. Collaborative Research. Fundamental Science of Low Temperature Plasma-Biological Material Interactions

    SciTech Connect (OSTI)

    Graves, David Barry; Oehrlein, Gottlieb

    2014-09-01

    Low temperature plasma (LTP) treatment of biological tissue is a promising path toward sterilization of bacteria due to its versatility and ability to operate under well-controlled and relatively mild conditions. The present collaborative research of an interdisciplinary team of investigators at University of Maryland, College Park (UMD), and University of California, Berkeley (UCB) focused on establishing our knowledge based with regard to low temperature plasma-induced chemical modifications in biomolecules that result in inactivation due to various plasma species, including ions, reactive radicals, and UV/VUV photons. The overall goals of the project were to identify and quantify the mechanisms by which low and atmospheric pressure plasma deactivates endotoxic biomolecules. Additionally, we wanted to understand the mechanism by which atmospheric pressure plasmas (APP) modify surfaces and how these modifications depend on the interaction of APP with the environment. Various low pressure plasma sources, a vacuum beam system and several atmospheric pressure plasma sources were used to accomplish this. In our work we elucidated for the first time the role of ions, VUV photons and radicals in biological deactivation of representative biomolecules, both in a UHV beam system and an inductively coupled, low pressure plasma system, and established the associated atomistic biomolecule changes. While we showed that both ions and VUV photons can be very efficient in deactivation of biomolecules, significant etching and/or deep modification (~200 nm) accompanied these biological effects. One of the most important findings in this work is the significant radical-induced deactivation and surface modification can occur with minimal etching. However, if radical fluxes and corresponding etch rates are relatively high, for example at atmospheric pressure, endotoxic biomolecule film inactivation may require near-complete removal of the film. These findings motivated further work at atmospheric pressure using several types of low temperature plasma sources, for which radical induced interactions generally dominate due to short mean free paths of ions and VUV photons. For these conditions we demonstrated the importance of environmental interactions when atmospheric pressure plasma sources are used to modify biomolecules. This is evident from both gas phase characterization data and in-situ surface characterization of treated biomolecules. Environmental interactions can produce unexpected outcomes due to the complexity of reactions of reactive species with the atmosphere which determines the composition of reactive fluxes and atomistic changes of biomolecules. Overall, this work clarified a richer spectrum of scientific opportunities and challenges for the field of low temperature plasma-biomolecule surface interactions than initially anticipated, in particular for plasma sources operating at atmospheric pressure. The insights produced in this work, e.g. demonstration of the importance of environmental interactions, are generally important for applications of APP to materials modifications. Thus one major contributions of this research has been the establishment of methodologies to more systematically study the interaction of plasma with bio-molecules. In particular, our studies of atmospheric pressure plasma sources using very well-defined experimental conditions enabled to combine atomistic surface modifications of biomolecules with changes in their biological function. The clarification of the role of ions, VUV photons and radicals in deactivation of biomolecules during low pressure and atmospheric pressure plasma-biomolecule interaction has broad implications, e.g. for the emerging field of plasma medicine. The development of methods to detect the effects of plasma treatment on immune-active biomolecules will be helpful in many future studies.

  11. science

    National Nuclear Security Administration (NNSA)

    through the Predictive Capability Framework (PCF). The PCF is a long-term integrated roadmap to guide the science, technology and engineering activities and Directed Stockpile...

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

    SciTech Connect (OSTI)

    Habibi, M.; Ghamari, F.

    2014-05-15

    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.

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

    SciTech Connect (OSTI)

    Young, Bruce Kai Fong

    1988-09-01

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

  14. Microsoft Word - Defense Science Quarterly 03-09.doc

    National Nuclear Security Administration (NNSA)

    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

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

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

    Physics Lab Fusion through the eyes of a veteran science journalist July 15, 2013 Tweet Widget Google Plus One Share on Facebook 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

  16. Generation of very low energy-spread electron beams using low-intensity laser pulses in a low-density plasma

    SciTech Connect (OSTI)

    Upadhyay, Ajay K.; Samant, Sushil Arun; Sarkar, Deepangkar; Krishnagopal, Srinivas; Jha, Pallavi

    2011-03-15

    The possibility of obtaining high-energy electron beams of high quality by using a low-density homogeneous plasma and a low-intensity laser (just above the self-injection threshold in the bubble regime) has been explored. Three-dimensional simulations are used to demonstrate, for the first time, an energy-spread of less than 1%, from self-trapping. More specifically, for a plasma density of 2x10{sup 18} cm{sup -3} and a laser intensity of a{sub 0}=2, a high-energy (0.55 GeV), ultrashort (1.4 fs) electron beam with very low energy-spread (0.55%) and high current (3 kA) is obtained. These parameters satisfy the requirements for drivers of short-wavelength free-electron lasers. It is also found that the quality of the electron beam depends strongly on the plasma length, which therefore needs to be optimized carefully to get the best performance in the experiments.

  17. Time and space resolved measurement of the electron temperature, mass density and ionization state in the ablation plasma between two exploding Al wires

    SciTech Connect (OSTI)

    Knapp, P. F.; Pikuz, S. A.; Shelkovenko, T. A.; Hammer, D. A.; Hansen, S. B.

    2012-05-15

    We have determined the properties of plasma around and between two exploding wires using high-resolution x-ray absorption spectroscopy. Plasma densities and temperatures ranging from Greater-Than-Or-Equivalent-To 0.1g/cm{sup 3} and a few eV to less than 0.01 g/cm{sup 3} and 30 eV have been measured in experiments at Cornell University with two 40 {mu}m aluminum (Al) wires spaced 1 mm apart driven by {approx}150 kA peak current pulses with 100 ns rise time. The wire plasma was backlit by the 1.4-1.6 keV continuum radiation produced by a Mo wire X-pinch. The spectrometer employed two spherically bent quartz crystals to record the absorption and backlighter spectra simultaneously. The transition between the dense Al wire core and the coronal plasma is seen as a transition from cold K-edge absorption to Mg-, Na-, and finally Ne-like absorption at the boundary. In the plasma that accumulates between the wires, ionization states up to C-Like Al are observed. The spectrometer geometry and {approx}2{mu}m X-pinch source size provide 0.3 eV spectral resolution and 20 {mu}m spatial resolution enabling us to see 1s{yields} 2p satellite transitions as separate lines as well as O-, F-, and Ne-like 1s{yields} 3p transitions that have not been seen before. A step wedge was used to calibrate the transmission, enabling density to be measured within a factor of two and temperature to be measured within {+-}25%. A genetic algorithm was developed to fit synthetic spectra calculated using the collisional-radiative code SCRAM to the experimental spectra. In order to obtain agreement it was necessary to assume multiple plasma regions with variable thicknesses, thereby allowing the inferred plasma conditions to vary along the absorption path.

  18. Moiré deflectometry using the Talbot-Lau interferometer as refraction diagnostic for High Energy Density plasmas at energies below 10 keV

    SciTech Connect (OSTI)

    Valdivia, M. P.; Stutman, D.; Finkenthal, M.

    2014-07-15

    The highly localized density gradients expected in High Energy Density (HED) plasma experiments can be characterized by x-ray phase-contrast imaging in addition to conventional attenuation radiography. Moiré deflectometry using the Talbot-Lau grating interferometer setup is an attractive HED diagnostic due to its high sensitivity to refraction induced phase shifts. We report on the adaptation of such a system for operation in the sub-10 keV range by using a combination of free standing and ultrathin Talbot gratings. This new x-ray energy explored matches well the current x-ray backlighters used for HED experiments, while also enhancing phase effects at lower electron densities. We studied the performance of the high magnification, low energy Talbot-Lau interferometer, for single image phase retrieval using Moiré fringe deflectometry. Our laboratory and simulation studies indicate that such a device is able to retrieve object electron densities from phase shift measurements. Using laboratory x-ray sources from 7 to 15 μm size we obtained accurate simultaneous measurements of refraction and attenuation for both sharp and mild electron density gradients.

  19. Direct asymmetry measurement of temperature and density spatial distributions in inertial confinement fusion plasmas from pinhole space-resolved spectra

    SciTech Connect (OSTI)

    Nagayama, T.; Mancini, R. C.; Florido, R.; Mayes, D.; Tommasini, R.; Koch, J. A.; Delettrez, J. A.; Regan, S. P.; Smalyuk, V. A.

    2014-05-15

    Two-dimensional space-resolved temperature and density images of an inertial confinement fusion (ICF) implosion core have been diagnosed for the first time. Argon-doped, direct-drive ICF experiments were performed at the Omega Laser Facility and a collection of two-dimensional space-resolved spectra were obtained from an array of gated, spectrally resolved pinhole images recorded by a multi-monochromatic x-ray imager. Detailed spectral analysis revealed asymmetries of the core not just in shape and size but in the temperature and density spatial distributions, thus characterizing the core with an unprecedented level of detail.

  20. Controlling the interface charge density in GaN-based metal-oxide-semiconductor heterostructures by plasma oxidation of metal layers

    SciTech Connect (OSTI)

    Hahn, Herwig Kalisch, Holger; Vescan, Andrei; Pécz, Béla; Kovács, András; Heuken, Michael

    2015-06-07

    In recent years, investigating and engineering the oxide-semiconductor interface in GaN-based devices has come into focus. This has been driven by a large effort to increase the gate robustness and to obtain enhancement mode transistors. Since it has been shown that deep interface states act as fixed interface charge in the typical transistor operating regime, it appears desirable to intentionally incorporate negative interface charge, and thus, to allow for a positive shift in threshold voltage of transistors to realise enhancement mode behaviour. A rather new approach to obtain such negative charge is the plasma-oxidation of thin metal layers. In this study, we present transmission electron microscopy and energy dispersive X-ray spectroscopy analysis as well as electrical data for Al-, Ti-, and Zr-based thin oxide films on a GaN-based heterostructure. It is shown that the plasma-oxidised layers have a polycrystalline morphology. An interfacial amorphous oxide layer is only detectable in the case of Zr. In addition, all films exhibit net negative charge with varying densities. The Zr layer is providing a negative interface charge density of more than 1 × 10{sup 13 }cm{sup –2} allowing to considerably shift the threshold voltage to more positive values.

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

    SciTech Connect (OSTI)

    Potanin, E. P. Ustinov, A. L.

    2013-06-15

    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.

  2. Science

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    Wikipedia to forecast diseases November 13, 2014 Los Alamos research published in Public Library of Science LOS ALAMOS, N.M., Nov. 13, 2014-Scientists can now monitor and forecast diseases around the globe more effectively by analyzing views of Wikipedia articles, according to a team from Los Alamos National Laboratory. "A global disease-forecasting system will improve the way we respond to epidemics," scientist Sara Del Valle said. "In the same way we check the weather each

  3. Confinement analyses of the high-density field-reversed configuration plasma in the field-reversed configuration experiment with a liner

    SciTech Connect (OSTI)

    Zhang Shouyin; Intrator, T.P.; Wurden, G.A.; Waganaar, W.J.; Taccetti, J.M.; Renneke, R.; Grabowski, C.; Ruden, E.L.

    2005-05-15

    The focus of the field-reversed configuration (FRC) experiment with a liner (FRX-L) is the formation of a target FRC plasma for magnetized target fusion experiments. An FRC plasma with density of 10{sup 23} m{sup -3}, total temperature in the range of 150-300 eV, and a lifetime of {approx_equal}20 {mu}s is desired. Field-reversed {theta}-pinch technology is used with programed cusp fields at {theta}-coil ends to achieve non-tearing field line reconnections during FRC formation. Well-formed FRCs with density between (2-4)x10{sup 22} m{sup -3}, lifetime in the range of 15-20 {mu}s, and total temperature between 300-500 eV are reproducibly created. Key FRC parameters have standard deviation in the mean of 10% during consecutive shots. The FRCs are formed at 50 mTorr deuterium static fill using 2 kG net reversed bias field inside the {theta}-coil confinement region, with external main field unexpectedly ranging between 15-30 kG. The high-density FRCs confinement properties are approximately in agreement with empirical scaling laws obtained from previous experiments with fill pressure mostly less than 20 mTorr. Analyses in this paper reveal that reducing the external main field modulation and/or extending the {theta}-coil length in the FRX-L device are critical in achieving higher FRC parameters for application in magnetized target fusion.

  4. Time dependent Doppler shifts in high-order harmonic generation in intense laser interactions with solid density plasma and frequency chirped pulses

    SciTech Connect (OSTI)

    Welch, E. C.; Zhang, P.; He, Z.-H.; Dollar, F.; Krushelnick, K.; Thomas, A. G. R.

    2015-05-15

    High order harmonic generation from solid targets is a compelling route to generating intense attosecond or even zeptosecond pulses. However, the effects of ion motion on the generation of harmonics have only recently started to be considered. Here, we study the effects of ion motion in harmonics production at ultrahigh laser intensities interacting with solid density plasma. Using particle-in-cell simulations, we find that there is an optimum density for harmonic production that depends on laser intensity, which scales linearly with a{sub 0} with no ion motion but with a reduced scaling if ion motion is included. We derive a scaling for this optimum density with ion motion and also find that the background ion motion induces Doppler red-shifts in the harmonic structures of the reflected pulse. The temporal structure of the Doppler shifts is correlated to the envelope of the incident laser pulse. We demonstrate that by introducing a frequency chirp in the incident pulse we are able to eliminate these Doppler shifts almost completely.

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

    SciTech Connect (OSTI)

    Liu, Wen-Yao; Xu, Yong Peng, Fei; Gong, Fa-Ping; Li, Xiao-Song; Zhu, Ai-Min; Liu, Yong-Xin; Wang, You-Nian

    2014-10-15

    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.

  6. Plasma Physics

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

    Plasma Physics Almost all of the observable matter in the universe is in the plasma state. Formed at high temperatures, plasmas consist of freely moving ions and free electrons. They are often called the "fourth state of matter" because their unique physical properties distinguish them from solids, liquids and gases. Plasma densities and temperatures vary widely, from the cold gases of interstellar space to the extraordinarily hot, dense cores of stars and inside a detonating nuclear

  7. Research | Princeton Plasma Physics Lab

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    Overview Experimental Fusion Research Theoretical Fusion Research Basic Plasma Science Plasma Astrophysics Other Physics and Engineering Research PPPL Technical Reports NSTX-U ...

  8. Stark broadening for diagnostics of the electron density in non-equilibrium plasma utilizing isotope hydrogen alpha lines

    SciTech Connect (OSTI)

    Yang, Lin; Tan, Xiaohua; Wan, Xiang; Chen, Lei; Jin, Dazhi; Qian, Muyang; Li, Gongping

    2014-04-28

    Two Stark broadening parameters including FWHM (full width at half maximum) and FWHA (full width at half area) of isotope hydrogen alpha lines are simultaneously introduced to determine the electron density of a pulsed vacuum arc jet. To estimate the gas temperature, the rotational temperature of the C{sub 2} Swan system is fit to 2500??100?K. A modified Boltzmann-plot method with b{sub i}-factor is introduced to determine the modified electron temperature. The comparison between results of atomic and ionic lines indicates the jet is in partial local thermodynamic equilibrium and the electron temperature is close to 13?000??400?K. Based on the computational results of Gig-Card calculation, a simple and precise interpolation algorithm for the discrete-points tables can be constructed to obtain the traditional n{sub e}-T{sub e} diagnostic maps of two Stark broadening parameters. The results from FWHA formula by the direct use of FWHM?=?FWHA and these from the diagnostic map are different. It can be attributed to the imprecise FWHA formula form and the deviation between FWHM and FWHA. The variation of the reduced mass pair due to the non-equilibrium effect contributes to the difference of the results derived from two hydrogen isotope alpha lines. Based on the Stark broadening analysis in this work, a corrected method is set up to determine n{sub e} of (1.10??0.08)??10{sup 21}?m{sup ?3}, the reference reduced mass ?{sub 0} pair of (3.30??0.82 and 1.65??0.41), and the ion kinetic temperature of 7900??1800?K.

  9. Graduate Programs | Princeton Plasma Physics Lab

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

    Sciences. In addition, through the interdepartmental Program in Plasma Science and Technology, PPPL supports students in affiliated engineering and science departments, who...

  10. Igor Kaganovich | Princeton Plasma Physics Lab

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

    interests include: beam-plasma interaction, high energy density plasmas, nanotechnology, atomic physics, and physics of partially ionized plasmas. He is involved in...

  11. High Energy Density Microwaves

    SciTech Connect (OSTI)

    Phillips, R.M. [Stanford Linear Accelerator Center, Stanford, CA 94309 (United States)

    1999-04-01

    These proceedings represent papers presented at the RF98 Workshop entitled `High Energy Density Microwaves` held in California in October, 1998. The topics discussed were predominantly accelerator{minus}related. The Workshop dealt, for the most part, with the generation and control of electron beams, the amplification of RF signals, the design of mode converters, and the effect of very high RF field gradients. This Workshop was designed to address the concerns of the microwave tube industry worldwide, the plasma physicists who deal with very high beam currents and gigawatts of RF power, and researchers in accelerator centers around the world. Papers were presented on multibeam klystrons, gyrotron development, plasmas in microwave tubes, RF breakdown, and alternatives to conventional linear coliders at 1 TeV and above. The Workshop was partially sponsored by the US Department of Energy. There were 46 papers presented at the conference,out of which 19 have been abstracted for the Energy,Science and Technology database.(AIP)

  12. Fusion Energy Sciences

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

    Fusion Energy Sciences Fusion Energy Sciences Expanding the fundamental understanding of matter at very high temperatures and densities and to build the scientific foundation ...

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

    SciTech Connect (OSTI)

    Ju, J.; Dpp, A.; Cros, B.; Svensson, K.; Genoud, G.; Wojda, F.; Burza, M.; Persson, A.; Lundh, O.; Wahlstrm, C.-G.; Ferrari, H.

    2013-08-15

    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.

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

    SciTech Connect (OSTI)

    Niemann, Christoph; Gekelman, W.; Winske, D.; Larsen, D.

    2012-12-14

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

  15. Taming Plasma Fusion Snakes

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

    Taming Plasma Fusion Snakes Taming Plasma Fusion Snakes Supercomputer simulations move fusion energy closer to reality January 24, 2014 Kathy Kincade, +1 510 495 2124, kkincade@lbl.gov SugiSnakes_2.jpg Researchers have been able to see and measure plasma snakes - corkscrew-shaped concentrations of plasma density in the center of a fusion plasma -- for years. 3D nonlinear plasma simulations conducted at NERSC are providing new insights into the formation and stability of these structures. Image

  16. Frontiers for Discovery in High Energy Density Physics

    SciTech Connect (OSTI)

    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.

    2004-07-20

    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

  17. Research | Princeton Plasma Physics Lab

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

    Overview Experimental Fusion Research Theoretical Fusion Research Basic Plasma Science Plasma Astrophysics Other Physics and Engineering Research PPPL Technical Reports NSTX-U Education Organization Contact Us Overview Experimental Fusion Research Theoretical Fusion Research Basic Plasma Science Plasma Astrophysics Other Physics and Engineering Research PPPL Technical Reports NSTX-U Research The U.S. Department of Energy's Princeton Plasma Physics Laboratory is dedicated to developing fusion as

  18. Experimental investigations of electron density and ion energy distributions in dual-frequency capacitively coupled plasmas for Ar/CF{sub 4} and Ar/O{sub 2}/CF{sub 4} discharges

    SciTech Connect (OSTI)

    Liu, Jia; Liu, Yong-Xin; Gao, Fei; Wang, You-Nian, E-mail: ynwang@dlut.edu.cn [School of Physics and Optoelectronic Technology, Dalian University of Technology, Dalian 116024 (China); Bi, Zhen-Hua [School of Physics and Materials Engineering, Dalian Nationalities University, Dalian 116600 (China)

    2014-01-07

    The electron density and ion energy distribution (IED) are investigated in low-pressure dual-frequency capacitively coupled Ar/CF{sub 4} (90%/10%) and Ar/O{sub 2}/CF{sub 4} (80%/10%/10%) plasmas. The relations between controllable parameters, such as high-frequency (HF) power, low-frequency (LF) power and gas pressure, and plasma parameters, such as electron density and IEDs, are studied in detail by utilizing a floating hairpin probe and an energy resolved quadrupole mass spectrometer, respectively. In our experiment, the electron density is mainly determined by the HF power and slightly influenced by the LF power. With increasing gas pressure, the electron density first goes up rapidly to a maximum value and then decreases at various HF and LF powers. The HF power also plays a considerable role in affecting the IEDs under certain conditions and the ion energy independently controlled by the LF source is discussed here. For clarity, some numerical results obtained from a two-dimensional fluid model are presented.

  19. Biological Sciences

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    Science Energy Science Engineering Science Environmental Science Fusion Science Math & Computer Science Nuclear Science Share Your Research NERSC Citations Home Science at...

  20. DOEFES_Plasma_Frontiers_Townhall_Vay.pptx

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

    J.-L. Vay, E. Esarey, A. Koniges Lawrence Berkeley National Laboratory J. Barnard, A. Friedman, D. Grote Lawrence Livermore National Laboratory Frontiers of Plasma Science Workshops - Town Hall June 30-July 1, 2015 Predictive Community Computational Tools for Virtual Plasma Science Experiments 2 2 UNIVERSITY OF CALIFORNIA Office of Science Advanced simula.ons play an increasingly important role in plasma science . Plasmas exhibit very complex interrelated mul.-scale mul.-physics phenomena: è

  1. Sandia National Laboratories: Research: Materials Science: Image Gallery

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    Materials Science Bioscience Computing and Information Science Electromagnetics Engineering Science Geoscience Materials Science About Materials Science Research Image Gallery Video Gallery Facilities Nanodevices and Microsystems Radiation Effects and High Energy Density Science Research Image Gallery

  2. Sandia National Laboratories: Research: Materials Science: Video Gallery

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

    Materials Science Bioscience Computing and Information Science Electromagnetics Engineering Science Geoscience Materials Science About Materials Science Research Image Gallery Video Gallery Facilities Nanodevices and Microsystems Radiation Effects and High Energy Density Science Research Video Gallery

  3. Theoretical Fusion Research | Princeton Plasma Physics Lab

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    Theory & Computational Department Weekly Highlights Weekly Seminars Basic Plasma Science Plasma Astrophysics Other Physics and Engineering Research PPPL Technical Reports NSTX-U Education Organization Contact Us Overview Experimental Fusion Research Theoretical Fusion Research Theory & Computational Department Weekly Highlights Weekly Seminars Basic Plasma Science Plasma Astrophysics Other Physics and Engineering Research PPPL Technical Reports NSTX-U Theoretical Fusion Research About

  4. Technical Reports - Disclaimer | Princeton Plasma Physics Lab

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

    Overview Experimental Fusion Research Theoretical Fusion Research Basic Plasma Science Plasma Astrophysics Other Physics and Engineering Research PPPL Technical Reports Technical Reports - Disclaimer NSTX-U Education Organization Contact Us Overview Experimental Fusion Research Theoretical Fusion Research Basic Plasma Science Plasma Astrophysics Other Physics and Engineering Research PPPL Technical Reports Technical Reports - Disclaimer NSTX-U Technical Reports - Disclaimer Full Legal

  5. Princeton Plasma Physics Laboratory

    SciTech Connect (OSTI)

    Not Available

    1990-01-01

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

  6. Voyager 2 observations of plasmas and flows out to 104 AU

    SciTech Connect (OSTI)

    Richardson, J. D.; Decker, R. B. E-mail: robert.decker@apljhu.edu

    2014-09-10

    Voyager 2 has crossed through 20 AU of the heliosheath; assuming the same heliosheath thickness as at Voyager 1, it is now two-thirds of the way to the heliopause. The plasma data are generally of good quality, although the increasing flow angle of the plasma makes analysis more difficult. The average plasma speed has remained constant but the flow angles have increased to almost 60 in the RT plane and to almost 30 in the RN plane. The average density and thermal speed have been constant since a density increase observed in 2011. Comparison of V2 plasma flows derived from plasma science experiment (PLS) data and Low Energy Charged Particle (LECP) proton anisotropies give good agreement except when heavy ion contributions or non-convective proton anisotropies are observed in the LECP data.

  7. About NIF & Photon Science

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

    NIF users include scientists from the U.S. Department of Energy national laboratories, worldwide fusion energy and high energy density science research centers, academia, and other ...

  8. Science & Technology - 2015

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

    example is the use of betatron x-ray radiation for research in the growing field of high energy density (HED) science on extremely short time and length scales (energy density is...

  9. Intense Magnetized Plasma-Wall Interaction

    SciTech Connect (OSTI)

    Bauer, Bruno S.; Fuelling, Stephan

    2013-11-30

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

  10. Galleries | Princeton Plasma Physics Lab

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

  11. Effect on plasma rotation of lower hybrid (LH) waves in Alcator...

    Office of Scientific and Technical Information (OSTI)

    the plasma current is low, which may explain the rotation reversal for low plasma current. ... L. 1 + Show Author Affiliations Plasma Science and Fusion Center, MIT, Cambridge, MA ...

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

    SciTech Connect (OSTI)

    Sun, K. X.

    2011-05-31

    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.

  13. Sandia National Laboratories: Research: Materials Science

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

    Materials Science Bioscience Computing and Information Science Electromagnetics Engineering Science Geoscience Materials Science About Materials Science Research Image Gallery Video Gallery Facilities Nanodevices and Microsystems Radiation Effects and High Energy Density Science Research Materials Science Creating materials for energy applications and defense needs Aries Applying innovative characterization and diagnostic techniques Hongyou Fan Development of new materials to support national

  14. Plasma Boundary Colloquium.key

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

    ... Edge Harmonic Oscillations EHO's limit density rise in QH modes on DIII-D. They are ... FIG. 3. Plasma displacement profiles associated with the edge harmonic oscillations in ...

  15. Science and Technology Day

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

    Science and Technology Day Science and Technology Day February 24, 2015 Tuesday, Feb. 24 Berkeley Lab Building 50 Auditorium Attendance is open to anyone. Remote streaming is available at hosting.epresence.tv/lbl (Broadcast only) Time Title Speaker 8:15 Registration 8:55 Welcome Sudip Dosanjh, NERSC Director 9:00 The Year in Science at NERSC Richard Gerber, NERSC Senior Science Advisor 9:30 Science Keynote: Efficient modeling of laser-plasma accelerators using the ponderomotive-based code

  16. Chemical Science

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

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

  17. Materials Science

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

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

  18. Energy in density gradient

    SciTech Connect (OSTI)

    Vranjes, J.; Kono, M.

    2015-01-15

    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 cylindrical 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 volume (per second) in quiet regions in the corona. Consequently, within the life-time of a magnetic structure such energy losses can easily be compensated by the stochastic drift wave heating.

  19. Science satellites seek Santa

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

    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

  20. Beam Matching to a Plasma Wakefield Accelerator Using a Ramped...

    Office of Scientific and Technical Information (OSTI)

    Conference: Beam Matching to a Plasma Wakefield Accelerator Using a Ramped Density Profile at the Plasma Boundary Citation Details In-Document Search Title: Beam Matching to a ...

  1. Final Report of “Collaborative research: Fundamental science of low temperature plasma-biological material interactions” (Award# DE-SC0005105)

    SciTech Connect (OSTI)

    Oehrlein, Gottlieb S.; Seog, Joonil; Graves, David; Chu, J. -W.

    2014-09-24

    Low temperature plasma (LTP) treatment of biological tissue is a promising path toward sterilization of bacteria due to its versatility and ability to operate under well-controlled and relatively mild conditions. The present collaborative research of an interdisciplinary team of investigators at University of Maryland, College Park (UMD), and University of California, Berkeley (UCB) focused on establishing our knowledge on low temperature plasma-induced chemical modifications in biomolecules that result in inactivation due to various plasma species, including ions, reactive radicals, and UV/VUV photons. The overall goals of the project were to identify the mechanisms by which low and atmospheric pressure plasma (APP) deactivates endotoxic biomolecules. Additionally, we wanted to understand how deactivation processes depend on the interaction of APP with the environment. Various low pressure plasma sources, a vacuum beam system and several atmospheric pressure plasma sources were used to accomplish these objectives. In our work we elucidated for the first time the role of ions, VUV photons and radicals in biological deactivation of model endotoxic biomolecules, both in a UHV beam system and an inductively coupled, low pressure plasma system, and established the associated atomistic modifications in biomolecules. While we showed that both ions and VUV photons can be very efficient in deactivation of biomolecules, significant etching and/or deep modification (~200 nm) were accompanied by these biological effects. One of the most important findings in this work is that the significant deactivation and surface modification can occur with minimal etching using radical species. However, if radical fluxes and corresponding etch rates are relatively high, for example, at atmospheric pressure, inactivation of endotoxic biomolecule film may require near-complete removal of the film. These findings motivated further work at atmospheric pressure using several types of low temperature plasma sources with modified geometry where radical induced interactions generally dominate due to short mean free paths of ions and VUV photons. In these conditions we demonstrated the importance of environmental interactions of plasma species when APP sources are used to modify biomolecules. This is evident from both gas phase characterization data and in-situ surface characterization of treated biomolecules. Environmental interactions can produce unexpected outcomes due to the complex reactions of reactive species with the atmosphere which determine the composition of reactive fluxes and atomistic changes in biomolecules. Overall, this work elucidated a richer spectrum of scientific opportunities and challenges for the field of low temperature plasma-biomolecule surface interactions than initially anticipated, in particular, for plasma sources operating at atmospheric pressure. The insights produced in this work, e.g. demonstration of the importance of environmental interactions, are generally important for applications of APP to materials modifications. Thus one major contributions of this research has been the establishment of methodologies to study the interaction of plasma with bio-molecules in a systemic and rigorous manner. In particular, our studies of atmospheric pressure plasma sources using very well-defined experimental conditions enabled us to correlate atomistic surface modifications of biomolecules with changes in their biological function. The clarification of the role of ions, VUV photons and radicals in deactivation of biomolecules during low pressure and atmospheric pressure plasma-biomolecule interaction has broad implications, e.g. for the emerging field of plasma medicine. The development of methods to detect the effects of plasma treatment on immune-active biomolecules will lay a fundamental foundation to enhance our understanding of the effect of plasma on biological systems. be helpful in many future studies.

  2. Theory & Computational Department | Princeton Plasma Physics Lab

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

    Overview Experimental Fusion Research Theoretical Fusion Research Theory & Computational Department Weekly Highlights Weekly Seminars Basic Plasma Science Plasma Astrophysics Other Physics and Engineering Research PPPL Technical Reports NSTX-U Education Organization Contact Us Overview Experimental Fusion Research Theoretical Fusion Research Theory & Computational Department Weekly Highlights Weekly Seminars Basic Plasma Science Plasma Astrophysics Other Physics and Engineering Research

  3. Sandia National Laboratories: Research: Materials Science: About Us

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

    Materials Science Bioscience Computing and Information Science Electromagnetics Engineering Science Geoscience Materials Science About Materials Science Research Image Gallery Video Gallery Facilities Nanodevices and Microsystems Radiation Effects and High Energy Density Science Research About Materials Science Xunhu Dai Sandia excels in innovative fundamental materials science research - developing and integrating the theoretical insights, computational simulation tools and deliberate

  4. An innovative high-power constant-current pulsed-arc power-supply for a high-density pulsed-arc-plasma ion-source using a LaB{sub 6}-filament

    SciTech Connect (OSTI)

    Ueno, A.; Oguri, H.; Ikegami, K.; Namekawa, Y.; Ohkoshi, K.; Tokuchi, A.

    2010-02-15

    An innovative high-power constant-current (CC) pulsed-arc (PA) power-supply (PS) indispensable for a high-density PA plasma ion-source using a lanthanum hexaboride (LaB{sub 6}) filament was devised by combining a constant-voltage (CV) PA-PS, which is composed of an insulated gate bipolar transistor (IGBT) switch, a CV direct-current (dc) PS and a 270 mF capacitor with a CC-PA-PS, which is composed of an IGBT-switch, a CC-dc-PS and a 400 {mu}H inductor, through the inductor. The hybrid-CC-PA-PS succeeded in producing a flat arc-pulse with a peak power of 56 kW (400 Ax140 V) and a duty factor of more than 1.5%(600 {mu}sx25 Hz) for Japan Proton Accelerator Research Complex (J-PARC) H{sup -} ion-source stably. It also succeeded in shortening the 99% rising-time of the arc-pulse-current to about 20 {mu}s and tilting up or down the arc-pulse-current arbitrarily and almost linearly by changing the setting voltage of its CV-dc-PS.

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

    SciTech Connect (OSTI)

    Phillips, Jonathan; Luhrs, Claudia C; Richard, Monique

    2009-01-01

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

  6. Education | Princeton Plasma Physics Lab

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

    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 science education programs to create a center of excellence for students, teachers and the general public. We contribute to the training of the next generation of scientists and engineers, collaborate with K-12 teachers on ways to improve science teaching using an inquiry-based approach to learning, and improve the

  7. DOE New Jersey Regional High School Science Bowl! NO SCIENCE ON SATURDAY

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

    LECTURE | Princeton Plasma Physics Lab 2, 2014 (All day) Science On Saturday DOE New Jersey Regional High School Science Bowl! NO SCIENCE ON SATURDAY LECTURE DUE TO THE NEW JERSEY REGIONAL SCIENCE BOWL COMPETITION, THERE WILL BE NO SCIENCE ON SATURDAY LECTURE TODAY.

  8. Applied Mathematics and Plasma Physics

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

    5 Applied Mathematics and Plasma Physics Maintaining mathematic, theory, modeling, and simulation capabilities in a broad set of areas Leadership Group Leader Pieter Swart Email Deputy Group Leader (Acting) Luis Chacon Email Contact Us Administrator Charlotte Lehman Email Electron density simulation Electron density from an orbital-free quantum molecular dynamics simulation for a warm dense plasma of deuterium at density 10 g/cc and temperature 10 eV. Mathematical, theory, modeling, and

  9. Heavy Ion Fusion Science Virtual National Laboratory1st Quarter FY08 Milestone Report: Report Initial Work on Developing Plasma Modeling Capability in WARP for NDCX ExperimentsReport Initial work on developing Plasma Modeling Capability in WARP for NDCX Experiments

    SciTech Connect (OSTI)

    Friedman, A.; Cohen, R.H.; Grote, D.P.; Vay, J.-L.

    2007-12-10

    This milestone has been accomplished. The Heavy Ion Fusion Science Virtual National Laboratory (HIFS-VNL) has developed and implemented an initial beam-in-plasma implicit modeling capability in Warp; has carried out tests validating the behavior of the models employed; has compared the results of electrostatic and electromagnetic models when applied to beam expansion in an NDCX-I relevant regime; has compared Warp and LSP results on a problem relevant to NDCX-I; has modeled wave excitation by a rigid beam propagating through plasma; and has implemented and begun testing a more advanced implicit method that correctly captures electron drift motion even when timesteps too large to resolve the electron gyro-period are employed. The HIFS-VNL is well on its way toward having a state-of-the-art source-to-target simulation capability that will enable more effective support of ongoing experiments in the NDCX series and allow more confident planning for future ones.

  10. Los Alamos researchers create 'map of science'

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

    bioscience, sustainable energy sources, to plasma physics ... in PLoS ONE (the Public Library of Science). "This ... Fe Institute collected usage-log data gathered from a ...

  11. Chemical Sciences

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

    Chemical Sciences - Sandia Energy Energy Search Icon Sandia Home Locations Contact Us ... ARPA-E Basic Energy Sciences Materials Sciences and Engineering Chemical Sciences ...

  12. Thomson Scattering Lineshape Fitting for Plasma Diagnostics

    Energy Science and Technology Software Center (OSTI)

    1994-02-04

    HFIT30 is used for interpreting lineshape (intensity versus frequency) data from Thomson and Rayleigh light scattering from a plasma, to obtain temperatures and number densities of the component species in the plasma.

  13. Princeton Plasma Physics Lab - Nanotechnology

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

    at the U.S. Department of Energy's (DOE) Princeton Plasma Physics Laboratory (PPPL), Adam Cohen has been named Deputy Under Secretary for Science and Energy in Washington D.C....

  14. Sandia National Laboratories: Research: Materials Science: Facilities

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

    Facilities Bioscience Computing and Information Science Electromagnetics Engineering Science Geoscience Materials Science About Materials Science Research Image Gallery Video Gallery Facilities Nanodevices and Microsystems Radiation Effects and High Energy Density Science Research Facilities Center for Integrated Nanotechnologies (CINT) CINT Ion Beam Laboratory Ion Beam Laboratory MESA High Performance Computing Processing and Environmental Technology Laboratory Processing and Environmental

  15. Response to FESAC survey, non-fusion connections to Fusion Energy Sciences. Applications of the FES-supported beam and plasma simulation code, Warp

    SciTech Connect (OSTI)

    Friedman, A.; Grote, D. P.; Vay, J. L.

    2015-05-29

    The Fusion Energy Sciences Advisory Committee’s subcommittee on non-fusion applications (FESAC NFA) is conducting a survey to obtain information from the fusion community about non-fusion work that has resulted from their DOE-funded fusion research. The subcommittee has requested that members of the community describe recent developments connected to the activities of the DOE Office of Fusion Energy Sciences. Two questions in particular were posed by the subcommittee. This document contains the authors’ responses to those questions.

  16. Device for plasma confinement and heating by high currents and nonclassical plasma transport properties

    DOE Patents [OSTI]

    Coppi, B.; Montgomery, D.B.

    1973-12-11

    A toroidal plasma containment device having means for inducing high total plasma currents and current densities and at the same time emhanced plasma heating, strong magnetic confinement, high energy density containment, magnetic modulation, microwaveinduced heating, and diagnostic accessibility is described. (Official Gazette)

  17. Neutral depletion and the helicon density limit

    SciTech Connect (OSTI)

    Magee, R. M.; Galante, M. E.; Carr, J. Jr.; Lusk, G.; McCarren, D. W.; Scime, E. E.

    2013-12-15

    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.

  18. Research | Princeton Plasma Physics Lab

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

    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. Experimental Fusion Research Fusion powers the sun and stars. The process takes

  19. Science Briefs - 2012

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

    /newsroom/_assets/images/newsroom-icon.jpg Science Briefs - 2012 Read in detail about specific Los Alamos science achievements, and the honors our scientists are accruing. 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. AAAS elects four LANL scientists as Fellows The American

  20. National Ignition Facility & Photon Science

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

    9 National Ignition Facility & Photon Science a new era of science a new era of experimental science laboratory experiments at the National Ignition Facility will enable researchers for the first time to study the effects on matter of extreme temperatures, pressures, and densities that exist naturally only in stars and deep inside planets. Results from this relatively new field of research, known as high-energy- density (hed) science, will mark the dawn of a new era of experimental science.

  1. Closed inductively coupled plasma cell

    DOE Patents [OSTI]

    Manning, T.J.; Palmer, B.A.; Hof, D.E.

    1990-11-06

    A closed inductively coupled plasma cell generates a relatively high power, low noise plasma for use in spectroscopic studies is disclosed. A variety of gases can be selected to form the plasma to minimize spectroscopic interference and to provide a electron density and temperature range for the sample to be analyzed. Grounded conductors are placed at the tube ends and axially displaced from the inductive coil, whereby the resulting electromagnetic field acts to elongate the plasma in the tube. Sample materials can be injected in the plasma to be excited for spectroscopy. 1 fig.

  2. Closed inductively coupled plasma cell

    DOE Patents [OSTI]

    Manning, Thomas J.; Palmer, Byron A.; Hof, Douglas E.

    1990-01-01

    A closed inductively coupled plasma cell generates a relatively high power, low noise plasma for use in spectroscopic studies. A variety of gases can be selected to form the plasma to minimize spectroscopic interference and to provide a electron density and temperature range for the sample to be analyzed. Grounded conductors are placed at the tube ends and axially displaced from the inductive coil, whereby the resulting electromagnetic field acts to elongate the plasma in the tube. Sample materials can be injected in the plasma to be excited for spectroscopy.

  3. Lab grants Decision Sciences Corporation exclusive commercial...

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

    identify concealed nuclear threat materials based on their atomic number and density. ... from bioscience, sustainable energy sources, to plasma physics and new materials. ...

  4. Science and Science Fiction

    ScienceCinema (OSTI)

    Scherrer, Robert [Vanderbilt University, Nashville, Tennessee, United States

    2009-09-01

    I will explore the similarities and differences between the process of writing science fiction and the process of 'producing' science, specifically theoretical physics. What are the ground rules for introducing unproven new ideas in science fiction, and how do they differ from the corresponding rules in physics? How predictive is science fiction? (For that matter, how predictive is theoretical physics?) I will also contrast the way in which information is presented in science fiction, as opposed to its presentation in scientific papers, and I will examine the relative importance of ideas (as opposed to the importance of the way in which these ideas are presented). Finally, I will discuss whether a background as a research scientist provides any advantage in writing science fiction.

  5. PLASMA GENERATOR

    DOE Patents [OSTI]

    Foster, J.S. Jr.

    1958-03-11

    This patent describes apparatus for producing an electricity neutral ionized gas discharge, termed a plasma, substantially free from contamination with neutral gas particles. The plasma generator of the present invention comprises a plasma chamber wherein gas introduced into the chamber is ionized by a radiofrequency source. A magnetic field is used to focus the plasma in line with an exit. This magnetic field cooperates with a differential pressure created across the exit to draw a uniform and uncontaminated plasma from the plasma chamber.

  6. Creating, Diagnosing and Controlling High-energy-density Matter with Lasers

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

    | Princeton Plasma Physics Lab October 22, 2013, 3:00pm to 4:15pm Colloquia MBG Auditorium Creating, Diagnosing and Controlling High-energy-density Matter with Lasers Dr. Yuan Ping Lawrence Livermore National Laboratory Abstract: PDF icon COLL.10.22.13A.pdf *** PLEASE NOTE SPECIAL DATE AND TIME OF THIS COLLOQUIUM *** Since their invention in 1960's, lasers with power spanning from KiloWatt to PetaWatt have been widely used in almost every branch of science, leading to numerous discoveries

  7. Aerodynamic Focusing Of High-Density Aerosols

    SciTech Connect (OSTI)

    Ruiz, D. E.; Fisch, Nathaniel

    2014-02-24

    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.

  8. Multispecies density peaking in gyrokinetic turbulence simulations of low

    Office of Scientific and Technical Information (OSTI)

    collisionality Alcator C-Mod plasmas (Journal Article) | SciTech Connect Multispecies density peaking in gyrokinetic turbulence simulations of low collisionality Alcator C-Mod plasmas Citation Details In-Document Search This content will become publicly available on June 4, 2016 Title: Multispecies density peaking in gyrokinetic turbulence simulations of low collisionality Alcator C-Mod plasmas Authors: Mikkelsen, D. R. [1] Search SciTech Connect for author "Mikkelsen, D. R."

  9. Plasma Simulation Program

    SciTech Connect (OSTI)

    Greenwald, Martin

    2011-10-04

    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.

  10. Site map for the E-print Network -- Energy, science, and technology...

    Office of Scientific and Technical Information (OSTI)

    Nuclear Technologies Fossil Fuels Geosciences Materials Science Mathematics Physics Plasma Physics and Fusion Power Transmission, Distribution and Plants Renewable Energy ...

  11. Development and Optimization of Modular Hybrid Plasma Reactor...

    Office of Scientific and Technical Information (OSTI)

    Optimization of Modular Hybrid Plasma Reactor N A 36 MATERIALS SCIENCE INL developed a bench-scale, modular hybrid plasma system for gas-phase nanomaterials synthesis. The system...

  12. Alcator C-Mod | U.S. DOE Office of Science (SC)

    Office of Science (SC) Website

    at the plasma boundary, fuel retention in plasma-facing components, and impurity seeding are conducted at conditions of high parallel heat flux and high absolute density. ...

  13. Plasma diagnostic reflectometry

    SciTech Connect (OSTI)

    Cohen, B.I.; Afeyan, B.B.; Garrison, J.C.; Kaiser, T.B.; Luhmann, N.C. Jr.; Domier, C.W.; Chou, A.E.; Baang, S.

    1996-02-26

    Theoretical and experimental studies of plasma diagnostic reflectometry have been undertaken as a collaborative research project between the Lawrence Livermore National Laboratory (LLNL) and the University of California Department of Applied Science Plasma Diagnostics Group under the auspices of the Laboratory Directed Research and Development Program at LLNL. Theoretical analyses have explored the basic principles of reflectometry to understand its limitations, to address specific gaps in the understanding of reflectometry measurements in laboratory experiments, and to explore extensions of reflectometry such as ultra-short-pulse reflectometry. The theory has supported basic laboratory reflectometry experiments where reflectometry measurements can be corroborated by independent diagnostic measurements.

  14. Honey, I Shrunk the Plasma: Studying Astrophysical Processes in Laboratory

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

    Experiments | Princeton Plasma Physics Lab February 14, 2015, 9:30am to 11:00am Science On Saturday MBG Auditorium Honey, I Shrunk the Plasma: Studying Astrophysical Processes in Laboratory Experiments Dr. Clayton Myers, Associate Research Physicist PPPL Abstract: PDF icon Myers.pdf Science on Saturday, 14FEB2015, "Honey, I Shrunk the Plasma: Studying Astrophysical Processess in Laboratory Experiments", Dr. Clayton Myers, PPPL Contact Information Website: Science on Saturday

  15. NSTX-U Press Kit | Princeton Plasma Physics Lab

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

    Overview Experimental Fusion Research Theoretical Fusion Research Basic Plasma Science Plasma Astrophysics Other Physics and Engineering Research PPPL Technical Reports NSTX-U Education Organization Contact Us Overview Experimental Fusion Research Theoretical Fusion Research Basic Plasma Science Plasma Astrophysics Other Physics and Engineering Research PPPL Technical Reports NSTX-U NSTX-U Press Kit Upgraded NSTX center stack. (photo by Elle Starkman/ PPPL Office of Communications The NSTX-U

  16. Merging of high speed argon plasma jets

    SciTech Connect (OSTI)

    Case, A.; Messer, S.; Brockington, S.; Wu, L.; Witherspoon, F. D.; Elton, R.

    2013-01-15

    Formation of an imploding plasma liner for the plasma liner experiment (PLX) requires individual plasma jets to merge into a quasi-spherical shell of plasma converging on the origin. Understanding dynamics of the merging process requires knowledge of the plasma phenomena involved. We present results from the study of the merging of three plasma jets in three dimensional geometry. The experiments were performed using HyperV Technologies Corp. 1 cm Minirailguns with a preionized argon plasma armature. The vacuum chamber partially reproduces the port geometry of the PLX chamber. Diagnostics include fast imaging, spectroscopy, interferometry, fast pressure probes, B-dot probes, and high speed spatially resolved photodiodes, permitting measurements of plasma density, temperature, velocity, stagnation pressure, magnetic field, and density gradients. These experimental results are compared with simulation results from the LSP 3D hybrid PIC code.

  17. Browse by Discipline -- E-print Network Subject Pathways: Plasma...

    Office of Scientific and Technical Information (OSTI)

    Plasma Physics and Fusion Go to Research Groups Preprints Provided by Individual ... Science and Engineering & School of Physics, University of Edinburgh Go back to ...

  18. Highly Charged Ions in Magnetic Fusion Plasmas: Research Opportunities...

    Office of Scientific and Technical Information (OSTI)

    Highly Charged Ions in Magnetic Fusion Plasmas: Research Opportunities and Diagnostic ... Visit OSTI to utilize additional information resources in energy science and technology. A ...

  19. PLASMA PHYSICS AND FUSION TECHNOLOGY; GRAPHITE; CREEP; PHYSICAL...

    Office of Scientific and Technical Information (OSTI)

    creep of graphite) Kennedy, C.R. 36 MATERIALS SCIENCE; 70 PLASMA PHYSICS AND FUSION TECHNOLOGY; GRAPHITE; CREEP; PHYSICAL RADIATION EFFECTS; JAPAN; MEETINGS; TRAVEL; ASIA; CARBON;...

  20. Beam Loading by Distributed Injection of Electrons in a Plasma...

    Office of Scientific and Technical Information (OSTI)

    Journal Article: Beam Loading by Distributed Injection of Electrons in a Plasma Wakefield ... Visit OSTI to utilize additional information resources in energy science and technology. A ...

  1. Choong-Seock Chang | Princeton Plasma Physics Lab

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

    Plasma Physics Laboratory, Princeton University, awarded by US Department of Energy, Office of Fusion Energy Science and Office of Advanced Scientific Computing Research, jointly. ...

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

    SciTech Connect (OSTI)

    Schroeder, C. B.; Esarey, E.; Benedetti, C.; Leemans, W. P.

    2013-08-15

    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.

  3. Science Briefs

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

    Science Briefs /newsroom/_assets/images/newsroom-icon.jpg Science Briefs Read in detail about specific Los Alamos science achievements, and the honors our scientists are accruing. Science Briefs - 2016» Science Briefs - 2015» Science Briefs - 2014» Science Briefs - 2013» Science Briefs - 2012» Science Briefs - 2011» The event titled "If I Only Knew Then What I Know Now" is from 2:30 to 5 p.m. in the Student Center Lecture Hall of the University of New Mexico-Los Alamos. Panel

  4. Plasma generating apparatus for large area plasma processing

    DOE Patents [OSTI]

    Tsai, Chin-Chi; Gorbatkin, Steven M.; Berry, Lee A.

    1991-01-01

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

  5. Plasma generating apparatus for large area plasma processing

    DOE Patents [OSTI]

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

    1991-07-16

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

  6. Fusion Science to Prepare

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

    DIII-D Explorations of Fusion Science to Prepare for ITER and FNSF Dr. Richard Buttery General Atomics Tuesday, Dec 10, 2013 - 11:00AM MBG AUDITORIUM Refreshments at 10:45AM The PrinceTon Plasma Physics laboraTory is a U.s. DeParTmenT of energy faciliTy Recent DIII-D research has provided significant new in- formation for the physics basis of key scientific issues for successful operation of ITER and future steady state fu- sion tokamaks, including control of edge localized modes (ELMs), plasma

  7. Community Petascale Project for Accelerator Science and Simulation...

    Office of Scientific and Technical Information (OSTI)

    Title: Community Petascale Project for Accelerator Science and Simulation The UCLA Plasma Simulation Group is a major partner of the "Community Petascale Project for Accelerator ...

  8. Researcher, Los Alamos National Laboratory - Space Science and...

    National Nuclear Security Administration (NNSA)

    Joaquin Birn of the Space Science and Applications Group studies complex plasma physics phenomena and reconnection, particularly in the Earth's magnetosphere and solar corona. ...

  9. Russell Hulse, the First Binary Pulsar, and Science Education

    Office of Scientific and Technical Information (OSTI)

    of Texas at Dallas (UTD) as a visiting professor of physics and of science and math education, beginning in January 2004. Russell Hulse Courtesy Princeton Plasma Physics ...

  10. Purpose | Princeton Plasma Physics Lab

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

    Purpose This program enables PPPL to provide scientific outreach to a broad range of U.S. colleges and universities in various areas of plasma science and technology. It routinely supports approximately 25 U.S. colleges and universities every year. Our goal is to support as many projects as possible. As a DOE National Laboratory, the Princeton Plasma Physics Laboratory maintains an experienced staff of scientists, engineers, and technicians who are available to participate in the Off-Site

  11. Science Highlights

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

    Science Highlights Science Highlights Print Science Highlights Featured scientific research based on publications resulting from work done at the ALS. Highlights are nominated by management and beamline scientists for their scientific significance. Current highlights (2004-present), highlight archives (1995-2004), and Summary Slides of ALS Science Highlights are also available. Science Briefs Short reports on recent research submitted by ALS beamline scientists and users. Science Cafés Informal

  12. Science Events

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

    Science Science Events Learn about our science by coming to Frontiers in Science lectures, catch Cafe Scientific events in your community, or come to sicence events at the Bradbury Science Museum. Jun 13 Mon 8:00 AM Excited State Processes in Electronic and Bio Nanomaterials (ESP-2016) Hilton Santa Fe Historic Plaza This interdisciplinary conference will provide an open forum for active interactions between researchers from different subfields. May 16 Mon 8:00 AM Data Science and Optimal

  13. Accelerator Science

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

    Accelerator Science Accelerator Science ReframAccelerator.jpg Particle accelerators are among the largest, most complex, and most important scientific instruments in the world....

  14. Nuclear Science

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

    Nuclear Science Nuclear Science Experimental and theoretical nuclear research carried out at NERSC is driven by the quest for improving our understanding of the building blocks of...

  15. Computer Science

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

    Cite Seer Department of Energy provided open access science research citations in chemistry, physics, materials, engineering, and computer science IEEE Xplore Full text...

  16. Plasma Couette Experiment - Cary Forest Group - UW Plasma Physics

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

    PCX Home UW Madison Plasma Couette Experiment PCX Home PCX HomeResearch MissionPhysics TopicsDeviceDiagnosticsContacts LinksPCX People CPLA Home Directory Publications Links University of Wisconsin Physics Department Department of Energy National Science Foundation The Plasma Couette Experiment (PCX). A magnet assembly consisting of 1.5 kG dipole magnets fastened to water cooled aluminum rings is dropped inside a vacuum vessel. Plasma is created with a LaB6 cathode heated and biased with respect

  17. Is sustainability science really a science?

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

    Is sustainability science really a science? Is sustainability science really a science? The team's work shows that although sustainability science has been growing explosively ...

  18. Robert J Goldston | Princeton Plasma Physics Lab

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

    is a Professor of Astrophysical Sciences at Princeton University and an international leader in the fields of plasma physics and magnetic fusion energy. He is the author of 220...

  19. Princeton Plasma Physics Lab - Magnetic reconnection

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

    can learn a lot of solar and space science, as well as astrophysics, through the common language of plasma physics," he said.

    Reconnection can have powerful consequences...

  20. American Fusion News | Princeton Plasma Physics Lab

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

    April 5, 2013 Applying physics, teamwork to fusion energy science February 22, 2013 A Tour of Plasma Physics in Downtown Cambridge December 4, 2012 Placing Fusion Power on a ...

  1. Quest | Princeton Plasma Physics Lab

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

    Quest Subscribe to RSS - Quest Welcome to Quest, the annual magazine of the U.S. Department of Energy's Princeton Plasma Physics Laboratory (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 world. Image: Quest Quest Magazine Summer 2015 Welcome to the third issue of Quest, the annual magazine of the U.S. Department of Energy's Princeton Plasma Physics Laboratory (PPPL).

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

    SciTech Connect (OSTI)

    Witherspoon, F. Douglas; Welch, Dale R.; Thompson, John R.; MacFarlane, Joeseph J.; Phillips, Michael W.; Bruner, Nicki; Mostrom, Chris; Thoma, Carsten; Clark, R. E.; Bogatu, Nick; Kim, Jin-Soo; Galkin, Sergei; Golovkin, Igor E.; Woodruff, P. R.; Wu, Linchun; Messer, Sarah J.

    2014-05-20

    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 measurements was made by modeling plasma jet experiments on PLX to support benchmarking of the code. A large number of upgrades and improvements advancing hybrid PIC algorithms were implemented in LSP during the second funding cycle. These include development of fully 3D radiation transport algorithms, new boundary conditions for plasma-electrode interactions, and a charge conserving equation of state that permits multiply ionized high-Z ions. The final funding cycle focused on 1) mitigating the effects of a slow-growing grid instability which is most pronounced in plasma jet frame expansion problems using the two-fluid Eulerian remap algorithm, 2) extension of the Eulerian Smoothing Algorithm to allow EOS/Radiation modeling, 3) simulations of collisionless shocks formed by jet merging, 4) simulations of merging jets using high-Z gases, 5) generation of PROPACEOS EOS/Opacity databases, 6) simulations of plasma jet transport experiments, 7) simulations of plasma jet penetration through transverse magnetic fields, and 8) GPU PIC code development The tools developed during this project are applicable not only to the study of plasma jets, but also to a wide variety of HEDP plasmas of interest to DOE, including plasmas created in short-pulse laser experiments performed to study fast ignition concepts for inertial confinement fusion.

  3. INTERACTION OF MUON BEAM WITH PLASMA DEVELOPED DURING IONIZATION COOLING

    SciTech Connect (OSTI)

    S. Ahmed, D. Kaplan, T. Roberts, L. Spentzouris, K. Beard

    2012-07-01

    Particle-in-cell simulations involving the interaction of muon beam (peak density 10{sup 18} m{sup 3}) with Li plasma (ionized medium) of density 10{sup 16}-10{sup 22} m{sup -3} have been performed. This study aimed to understand the effects of plasma on an incoming beam in order to explore scenario developed during the process of ionization cooling. The computer code takes into account the self-consistent electromagnetic effects of beam interacting with plasma. This study shows that the beam can pass through the plasma of densities four order of magnitude higher than its peak density. The low density plasmas are wiped out by the beam, however, the resonance is observed for densities of similar order. Study reveals the signature of plasma wakefield acceleration.

  4. Science Gateways

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

    Gateways Science Gateways About Science Gateways A science gateway is a web-based interface to access HPC computers and storage systems. Gateways allow science teams to access data, perform shared computations, and generally interact with NERSC resources over the web. Common gateway goals are to improve ease of use in HPC so that more scientists can benefit from NERSC resources to create collaborative workspaces around data and computing for science teams that use NERSC to make your data

  5. Science Highlights

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

    Science Highlights Print Science Highlights Featured scientific research based on publications resulting from work done at the ALS. Highlights are nominated by management and beamline scientists for their scientific significance. Current highlights (2004-present), highlight archives (1995-2004), and Summary Slides of ALS Science Highlights are also available. Science Briefs Short reports on recent research submitted by ALS beamline scientists and users. Science Cafés Informal lecture series

  6. Science Highlights

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

    Science Highlights Print Science Highlights Featured scientific research based on publications resulting from work done at the ALS. Highlights are nominated by management and beamline scientists for their scientific significance. Current highlights (2004-present), highlight archives (1995-2004), and Summary Slides of ALS Science Highlights are also available. Science Briefs Short reports on recent research submitted by ALS beamline scientists and users. Science Cafés Informal lecture series

  7. Energy Sciences

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

    Sciences Our Vision National User Facilities Research Areas In Focus Global Solutions ⇒ Navigate Section Our Vision National User Facilities Research Areas In Focus Global Solutions Chemical Sciences Division Chemistry is the study of matter and the changes it can undergo. Chemical Sciences Division researchers tackle critical scientific issues in chemistry at both the theoretical and experimental levels. Materials Sciences Division Materials Scientists are advancing the fundamental science of

  8. Explore Science

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

    Explore Explore Science Create your own science adventure by exploring our varied exhibits, and learn what inspired our scientists, engineers and technicians to discover new things. August 18, 2014 boys conducting experiment [Science is] a great game. It is inspiring and refreshing. The playing field is the universe itself. -I.I. Rabi Science is thinking in an organized way about things. You don't need a license or permission to practice science. Scientists are interested in just about anything

  9. Science Highlights

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

    Science Highlights Print Science Highlights Featured scientific research based on publications resulting from work done at the ALS. Highlights are nominated by management and beamline scientists for their scientific significance. Current highlights (2004-present), highlight archives (1995-2004), and Summary Slides of ALS Science Highlights are also available. Science Briefs Short reports on recent research submitted by ALS beamline scientists and users. Science Cafés Informal lecture series

  10. Science Highlights

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

    Science Highlights Print Science Highlights Featured scientific research based on publications resulting from work done at the ALS. Highlights are nominated by management and beamline scientists for their scientific significance. Current highlights (2004-present), highlight archives (1995-2004), and Summary Slides of ALS Science Highlights are also available. Science Briefs Short reports on recent research submitted by ALS beamline scientists and users. Science Cafés Informal lecture series

  11. PPPL Experts | Princeton Plasma Physics Lab

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

    PPPL Experts Fusion. Energy. Plasma. Physics. Tokamaks. Stellarators. Radioactivity. Nanotechnology. Astrophysics. Computational simulations. Vacuum technology. Materials Science. Electronics. STEM education. These are some of the areas of expertise of staff at the Princeton Plasma Physics Laboratory. PPPL is devoted to creating new knowledge about the physics of plasmas - ultra-hot, charged gases - and to developing practical solutions for the creation of fusion energy. In addition, results of

  12. Allan H Reiman | Princeton Plasma Physics Lab

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

    Allan H Reiman Principal Research Physicist, Plasma Physics Laboratory. Lecture Allan Reiman is head of the stellarator theory group in the Theory Department. He is a Principal Research Physicist in the Theory Department, a Distinguished Research Fellow at the plasma physics laboratory, and a Lecturer with Rank of Professor in the Department of Astrophysical Sciences at Princeton University. He is a Fellow of the American Physical Society. From 1997 to 2000 he headed the plasma configuration

  13. Defocusing of an ion beam propagating in background plasma due...

    Office of Scientific and Technical Information (OSTI)

    and have a wide range of applications in inertial fusion and high energy density physics. ... Language: English Subject: 70 PLASMA PHYSICS AND FUSION TECHNOLOGY; APERTURES; BEAM ...

  14. Staff Research Physicist (X-Ray Spectroscopy) | Princeton Plasma...

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

    of X-ray spectrometers for high energy density plasma at the National Ignition Facility (NIF) at the Lawrence Livermore National Laboratory (LLNL, Livermore, California). In...

  15. Neutrino oscillations in a turbulent plasma

    SciTech Connect (OSTI)

    Mendona, J. T.; Haas, F.

    2013-07-15

    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.

  16. Science Engagement

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (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) 1 800-333-7638 (Inside US) 1 510-486-7600 (Globally) 1 510-486-7607 (Globally) Report Network Problems: trouble@es.net Provide Web Site Feedback: info@es.net Science Engagement The ESnet Science Engagement team's mission is to ensure that science collaborations at every scale, in every domain, have the information and

  17. SCIENCE ON SATURDAY- "The Large Hadron Collider: big science for big

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

    questions" | Princeton Plasma Physics Lab January 5, 2013, 9:30am Science On Saturday MBG Auditorium SCIENCE ON SATURDAY- "The Large Hadron Collider: big science for big questions" Professor James Olsen Department of Physics, Princeton University Science on Saturday is a series of lectures given by scientists, mathematicians, and other professionals involved in cutting-edge research. Held on Saturday mornings throughout winter, the lectures are geared toward high school

  18. LANL announces top 10 science stories of 2009

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

    from bioscience, sustainable energy sources, to plasma physics and new materials. ... from that boundary, specifically the density and temperature of atoms that form the ...

  19. NNSA announces winners of Stewardship Science Academic Programs...

    National Nuclear Security Administration (NNSA)

    Alliances Program, the NNSA-supported grants from the Joint Program for High Energy Density Laboratory Plasmas, and grants awarded under the National Laser Users' Facility. ...

  20. Princeton Plasma Physics Lab - Surface science

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

    in the complex edge region, an important research area in fusion energy research. "We're learning more and more that to some extent the edge is the dog that wags the tail of the...

  1. 2013 Science Bowl | Princeton Plasma Physics Lab

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

    SciTech Connect Program Document: 2013 Progress Report -- DOE Joint Genome Institute Citation Details In-Document Search Title: 2013 Progress Report -- DOE Joint Genome Institute In October 2012, we introduced a 10-Year Strategic Vision [http://bit.ly/JGI-Vision] for the Institute. A central focus of this Strategic Vision is to bridge the gap between sequenced genomes and an understanding of biological functions at the organism and ecosystem level. This involves the continued massive-scale

  2. Science Education Blog | Princeton Plasma Physics Lab

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

    "What is Fusion" features interviews with PPPL physicists on location and employs animation to allow the scientists to explain magnetic fusion. The eight-minute "Fusion Energy...

  3. Plasma accelerator

    DOE Patents [OSTI]

    Wang, Zhehui; Barnes, Cris W.

    2002-01-01

    There has been invented an apparatus for acceleration of a plasma having coaxially positioned, constant diameter, cylindrical electrodes which are modified to converge (for a positive polarity inner electrode and a negatively charged outer electrode) at the plasma output end of the annulus between the electrodes to achieve improved particle flux per unit of power.

  4. Plasma valve

    DOE Patents [OSTI]

    Hershcovitch, Ady; Sharma, Sushil; Noonan, John; Rotela, Elbio; Khounsary, Ali

    2003-01-01

    A plasma valve includes a confinement channel and primary anode and cathode disposed therein. An ignition cathode is disposed adjacent the primary cathode. Power supplies are joined to the cathodes and anode for rapidly igniting and maintaining a plasma in the channel for preventing leakage of atmospheric pressure through the channel.

  5. Science Museum

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

    open July 26 at the Bradbury Science Museum July 22, 2013 LOS ALAMOS, N.M., July 22, 2013-Los Alamos National Laboratory's Bradbury Science Museum is opening two new exhibits ...

  6. Science Magazine

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

    MAY 2013 VOL 340 SCIENCE www.sciencemag.org 914 EIGHT NUCLEAR ENGINEERS SIT IN HIGH- ... But their future is uncertain Published by AAAS www.sciencemag.org SCIENCE VOL 340 24 MAY ...

  7. PLASMA ENERGIZATION

    DOE Patents [OSTI]

    Furth, H.P.; Chambers, E.S.

    1962-03-01

    BS>A method is given for ion cyclotron resonance heatthg of a magnetically confined plasma by an applied radio-frequency field. In accordance with the invention, the radiofrequency energy is transferred to the plasma without the usual attendent self-shielding effect of plasma polarlzatlon, whereby the energy transfer is accomplished with superior efficiency. More explicitly, the invention includes means for applying a radio-frequency electric field radially to an end of a plasma column confined in a magnetic mirror field configuration. The radio-frequency field propagates hydromagnetic waves axially through the column with the waves diminishing in an intermediate region of the column at ion cyclotron resonance with the fleld frequency. In such region the wave energy is converted by viscous damping to rotational energy of the plasma ions. (AEC)

  8. PLASMA DEVICE

    DOE Patents [OSTI]

    Baker, W.R.

    1961-08-22

    A device is described for establishing and maintaining a high-energy, rotational plasma for use as a fast discharge capacitor. A disc-shaped, current- conducting plasma is formed in an axinl magnetic field and a crossed electric field, thereby creating rotational kinetic enengy in the plasma. Such energy stored in the rotation of the plasma disc is substantial and is convertible tc electrical energy by generator action in an output line electrically coupled to the plasma volume. Means are then provided for discharging the electrical energy into an external circuit coupled to the output line to produce a very large pulse having an extremely rapid rise time in the waveform thereof. (AE C)

  9. Boundary Plasma Turbulence Simulations for Tokamaks

    SciTech Connect (OSTI)

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

    2008-05-15

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

  10. Fact Sheets | Princeton Plasma Physics Lab

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

    Fact Sheets Subscribe to RSS - Fact Sheets Image: DOE Office of Science Fact Sheet DOE Office of Science Fact Sheet Read more about DOE Office of Science Fact Sheet Building the Most Powerful Spherical Tokamak Two major new components power the National Spherical Torus Experiment-Upgrade: A widened center stack that doubles the magnetic field strength and plasma current and quintuples the length of fusion experiments, and a second neutral beam injector that doubles the tokamak's heating power.

  11. Big Science

    ScienceCinema (OSTI)

    Dr. Thomas Zacharia

    2010-01-08

    Big science seeks big solutions for the most urgent problems of our times. Video courtesy Cray, Inc.

  12. Science Facilities

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

    Facilities /science-innovation/_assets/images/icon-science.jpg Science Facilities The focal point for basic and applied R&D programs with a primary focus on energy but also encompassing medical, biotechnology, high-energy physics, and advanced scientific computing programs. Center for Integrated Nanotechnologies» Dual Axis Radiographic Hydrodynamic Test Facility (DARHT)» Electron Microscopy Lab» Ion Beam Materials Lab» Isotope Production Facility» Los Alamos Neutron Science Center»

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

    SciTech Connect (OSTI)

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

    2011-03-28

    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.

  14. Huazhong Science Technology University Yongtai Science Technology...

    Open Energy Info (EERE)

    Huazhong Science Technology University Yongtai Science Technology Co Ltd Jump to: navigation, search Name: Huazhong Science & Technology University Yongtai Science & Technology Co...

  15. High-density carbon ablator ignition path with low-density gas-filled rugby hohlraum

    SciTech Connect (OSTI)

    Amendt, Peter; Ho, Darwin D.; Jones, Ogden S.

    2015-04-15

    A recent low gas-fill density (0.6 mg/cc {sup 4}He) cylindrical hohlraum experiment on the National Ignition Facility has shown high laser-coupling efficiency (>96%), reduced phenomenological laser drive corrections, and improved high-density carbon capsule implosion symmetry [Jones et al., Bull. Am. Phys. Soc. 59(15), 66 (2014)]. In this Letter, an ignition design using a large rugby-shaped hohlraum [Amendt et al., Phys. Plasmas 21, 112703 (2014)] for high energetics efficiency and symmetry control with the same low gas-fill density (0.6 mg/cc {sup 4}He) is developed as a potentially robust platform for demonstrating thermonuclear burn. The companion high-density carbon capsule for this hohlraum design is driven by an adiabat-shaped [Betti et al., Phys. Plasmas 9, 2277 (2002)] 4-shock drive profile for robust high gain (>10) 1-D ignition performance and large margin to 2-D perturbation growth.

  16. Plasma response to electron energy filter in large volume plasma device

    SciTech Connect (OSTI)

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

    2013-12-15

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

  17. Spectroscopic absorption measurements of an iron plasma

    SciTech Connect (OSTI)

    Springer, P.T.; Fields, D.J.; Wilson, B.G.; Nash, J.K.; Goldstein, W.H.; Iglesias, C.A.; Rogers, F.J.; Swenson, J.K.; Chen, M.H.; Bar-Shalom, A.; Stewart, R.E. Nuclear Research Center Negev, P.O. Box 9001, Beer-Sheva 84190 )

    1992-12-28

    The first quantitative measurement of photoabsorption in the region determining the Rosseland and Planck mean opacities is obtained for a well-characterized, radiatively heated iron plasma using new techniques and instrumentation. The plasma density and temperature are simultaneously constrained with high accuracy, allowing unambiguous comparisons with opacity models used in modeling radiative transfer in equilibrium astrophysical and laboratory plasmas. The experimental Rosseland and Planck group means are constrained to an accuracy of 15%.

  18. Snowflake Science

    Broader source: Energy.gov [DOE]

    Physicists at the Princeton Plasma Physics Laboratory are using a device called a "snowflake divertor” to solve one of the grand challenges of magnetic fusion.

  19. Stewardship Science Academic Alliances | National Nuclear Security

    National Nuclear Security Administration (NNSA)

    Administration Stewardship Science Academic Alliances Established in 2002, the Stewardship Science Academic Alliances Program funds academic research in the areas of materials under extreme conditions, low energy nuclear science, radiochemistry, and high energy density physics. One of the goals of the program is to fund research projects at universities that conduct fundamental science and technology research that is of relevance to stockpile stewardship. An important focus of the program is

  20. Climate & Earth Science

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

    Human-Induced Climate Change Reduces Chance of Flooding in Okavango Delta Energy Science Engineering Science Environmental Science Fusion Science Math & Computer Science Nuclear...

  1. Science DMZ for ALS

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

    ALS Science Engagement Move your data Programs & Workshops Science Requirements Reviews Case Studies OSCARS Case Studies Science DMZ Case Studies Science DMZ @ UF Science DMZ @ CU ...

  2. Earth, Space Sciences

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

    Earth, Space Sciences science-innovationassetsimagesicon-science.jpg Earth, Space Sciences National security depends on science and technology. The United States relies on Los ...

  3. Science satellites scour skies for Santa

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

    Science satellites scour skies for Santa Science satellites scour skies for Santa Beginning at 6 a.m. Monday, Dec. 24, scientists will use two advanced science satellites to mark the path of the elfin traveler. December 20, 2007 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

  4. Plasma source ion implantation research and applications at Los Alamos National Laboratory

    SciTech Connect (OSTI)

    Munson, C.P.; Faehl, R.J.; Henins, I.

    1996-12-31

    Plasma Source Ion Implantation research at Los Alamos Laboratory includes direct investigation of the plasma and materials science involved in target surface modification, numerical simulations of the implantation process, and supporting hardware engineering. Target materials of Al, Cr, Cu-Zn, Mg, Ni, Si, Ti, W, and various Fe alloys have been processed using plasmas produced from Ar, NH{sub 3}, N{sub 2}, CH{sub 4}, and C{sub 2}H{sub 2} gases. Individual targets with surface areas as large as {approximately}4 m{sup 2}, or weighing up to 1200 kg, have been treated in the large LANL facility. In collaboration with General Motors and the University of Wisconsin, a process has been developed for application of hard, low friction, diamond-like-carbon layers on assemblies of automotive pistons. Numerical simulations have been performed using a 2{1/2}-D particle- in-cell code, which yields time-dependent implantation energy, dose, and angle of arrival for ions at the target surface for realistic geometries. Plasma source development activities include the investigation of pulsed, inductively coupled sources capable of generating highly dissociated N{sup +} with ion densities n{sub i} {approximately} 10{sup 11}/cm{sup 3}, at {approximately}100 W average input power. Cathodic arc sources have also been used to produce filtered metallic and C plasmas for implantation and deposition either in vacuum, or in conjunction with a background gas for production of highly adherent ceramic coatings.

  5. Science on Saturday: Starlight Detectives: How Astronomers, Inventors, and

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

    Eccentrics Discovered the Modern Universe | Princeton Plasma Physics Lab January 9, 2016, 9:30am Science On Saturday Princeton Plasma Physics Laboratory, MBG Auditorium Science on Saturday: Starlight Detectives: How Astronomers, Inventors, and Eccentrics Discovered the Modern Universe Professor Alan Hirshfeld University of Massachusetts Abstract: PDF icon 01 Hirshfeld.pdf Science_on_Saturday09Jan2016_A.Hirshfield Contact Information Coordinator(s): Ms. Deedee Ortiz-Arias dortiz@pppl.gov

  6. Application of Plasma Waveguides to High Energy Accelerators

    SciTech Connect (OSTI)

    Milchberg, Howard M

    2013-03-30

    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.

  7. Laser beat wave excitation of terahertz radiation in a plasma slab

    SciTech Connect (OSTI)

    Chauhan, Santosh; Parashar, Jetendra

    2014-10-15

    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 μm, one obtains the THz intensity ∼1 GW/cm{sup 2} at 3 THz radiation frequency.

  8. At Plasma Camp, teachers experience research front and center | Princeton

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

    Plasma Physics Lab At Plasma Camp, teachers experience research front and center By Constance Kaita August 12, 2013 Tweet Widget Google Plus One Share on Facebook Wendy Dlakic, a physics and earth science teacher from Livingston, Mont., examines a plasma with Nick Guilbert, a master teacher and collaborator from The Peddie School, at this year's Plasma Camp for physics teachers at PPPL from July 15 to 19. (Photo by Photo by Elle Starkman/ PPPL Office of Communications) Wendy Dlakic, a

  9. Vortex stabilized electron beam compressed fusion grade plasma

    SciTech Connect (OSTI)

    Hershcovitch, Ady

    2014-03-19

    Most inertial confinement fusion schemes are comprised of highly compressed dense plasmas. Those schemes involve short, extremely high power, short pulses of beams (lasers, particles) applied to lower density plasmas or solid pellets. An alternative approach could be to shoot an intense electron beam through very dense, atmospheric pressure, vortex stabilized plasma.

  10. L-Mode Plasmas in Alcator C-Mod I. Cziegler, J. L. Terry, B....

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

    C-Mod I. Cziegler, J. L. Terry, B. LaBombard MIT - Plasma Science and Fusion Center APS Division of Plasma Physics Orlando FL, November 2007 Background and Motivation Both L-...

  11. Photon Science

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (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 research and development projects to innovate and develop cutting-edge technologies in support of those missions. This effort strategically invests in new technologies and development of large-scale photon systems for various federal agencies and industry sponsors. NIF&PS researchers are developing world-class

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

    SciTech Connect (OSTI)

    Jun, Hyun-Su Lee, Yun-Seong

    2014-02-15

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

  13. Science Briefs

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

    Science Briefs /newsroom/_assets/images/newsroom-icon.jpg Science Briefs Read in detail about specific Los Alamos science achievements, and the honors our scientists are accruing. News Releases Science Briefs Photos Picture of the Week Publications Social Media Videos Fact Sheets The event titled "If I Only Knew Then What I Know Now" is from 2:30 to 5 p.m. in the Student Center Lecture Hall of the University of New Mexico-Los Alamos. Panel discussion to explore transitions in women's

  14. Fermilab | Science

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

    Science History Organization Photo and video gallery Diversity Education Safety Sustainability and environment Contact Newsroom Spotlight Press releases Fact sheets and...

  15. Computational Science

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

    ... Advanced Materials Laboratory Center for Integrated Nanotechnologies Combustion Research Facility Computational Science Research Institute Joint BioEnergy Institute About EC News ...

  16. Information Science

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

    Information Science and Technology (ASIS&T) American Society for Indexing (ASI) Digital Library Federation (DLF) National Archives and Records Administration (NARA) Special...

  17. Energy Science

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

    Energy Science Print Our current fossil-fuel-based system ... X-Ray Microscopy Reveals How Crystal Mechanics Drive ... Breakthrough Research on Platinum-Nickel Alloys Hydrogen Storage ...

  18. Shock compression of low-density foams

    SciTech Connect (OSTI)

    Holmes, N.C.

    1993-07-01

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

  19. Method of accelerating photons by a relativistic plasma wave

    DOE Patents [OSTI]

    Dawson, John M.; Wilks, Scott C.

    1990-01-01

    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.

  20. NSTX Plasma Response to Lithium Coated Divertor

    SciTech Connect (OSTI)

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

    2011-01-21

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

  1. One-dimensional time-dependent fluid model of a very high density

    Office of Scientific and Technical Information (OSTI)

    low-pressure inductively coupled plasma (Journal Article) | DOE PAGES One-dimensional time-dependent fluid model of a very high density low-pressure inductively coupled plasma This content will become publicly available on December 28, 2016 Title: One-dimensional time-dependent fluid model of a very high density low-pressure inductively coupled plasma A time-dependent two-fluid model has been developed to understand axial variations in the plasma parameters in a very high density (peak ne~

  2. Characteristic of a triple-cathode vacuum arc plasma source

    SciTech Connect (OSTI)

    Xiang, W.; Li, M.; Chen, L.

    2012-02-15

    In order to generate a better ion beam, a triple-cathode vacuum arc plasma source has been developed. Three plasma generators in the vacuum arc plasma source are equally located on a circle. Each generator initiated by means of a high-voltage breakdown between the cathode and the anode could be operated separately or simultaneously. The arc plasma expands from the cathode spot region in vacuum. In order to study the behaviors of expanding plasma plume generated in the vacuum arc plasma source, a Langmuir probe array is employed to measure the saturated ion current of the vacuum arc plasma source. The time-dependence profiles of the saturated current density of the triple vacuum arc plasma source operated separately and simultaneously are given. Furthermore, the plasma characteristic of this vacuum arc plasma source is also presented in the paper.

  3. Characteristics of plasma properties in an ablative pulsed plasma thruster

    SciTech Connect (OSTI)

    Schoenherr, Tony; Nees, Frank; Arakawa, Yoshihiro; Komurasaki, Kimiya; Herdrich, Georg

    2013-03-15

    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.

  4. Vignettes | U.S. DOE Office of Science (SC)

    Office of Science (SC) Website

    ... Large Area, High Density Arrays of Nanopillars Achieved. Control of the chemical ... Chemical Sciences, Geosciences, and Energy Biosciences Subprogram Controlling x-rays with ...

  5. Solitary and shock waves in magnetized electron-positron plasma

    SciTech Connect (OSTI)

    Lu, Ding; Li, Zi-Liang; Abdukerim, Nuriman; Xie, Bai-Song

    2014-02-15

    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.

  6. Thermal Sciences

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

    Thermal Sciences NETL's Thermal Sciences competency provides the scientific, engineering, and technology development community with innovative and efficient approaches to measure, harness, and convert thermal energy. Research includes sensors, advanced energy concepts, and thermodynamic optimization, specifically: Sensors and Diagnostics Advanced sensor and diagnostic technology to develop and evaluate advanced methods for non-intrusive measurement and measurement in extreme environments.

  7. Rate Of Oxidation Of Plasma Polymer (GDP or CH) (Technical Report...

    Office of Scientific and Technical Information (OSTI)

    Subject: 36 MATERIALS SCIENCE; 42 ENGINEERING; ATOMS; COATINGS; DESIGN; OXIDATION; PLASMA; PLASTICS; POLYMERS; REMOVAL; SPECIFICATIONS Word Cloud More Like This Full Text preview ...

  8. McComas named vice president for the Princeton Plasma Physics...

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

    David McComas, an executive leader in managing various complex technical projects and ... PPPL is the nation's leading center for the exploration of plasma science and magnetic ...

  9. RECENT PROGRESS IN THE DEVELOPMENT OF DUCTILE-PHASE TOUGHENED TUNGSTEN FOR PLASMA-FACING MATERIALS

    SciTech Connect (OSTI)

    Henager, Charles H.; Kurtz, Richard J.; Roosendaal, Timothy J.; Borlaug, Brennan A.; Odette, George R.; Cunningham, Kevin; Fields, Kirk A.; Gragg, David; Zok, Frank W.

    2014-03-03

    The objective of this study is to develop the materials science of fiber-reinforced tungsten composites as candidates for plasma-facing components in future fusion reactors.

  10. PLASMA DEVICE

    DOE Patents [OSTI]

    Baker, W.R.; Brathenahl, A.; Furth, H.P.

    1962-04-10

    A device for producing a confined high temperature plasma is described. In the device the concave inner surface of an outer annular electrode is disposed concentrically about and facing the convex outer face of an inner annular electrode across which electrodes a high potential is applied to produce an electric field there between. Means is provided to create a magnetic field perpendicular to the electric field and a gas is supplied at reduced pressure in the area therebetween. Upon application of the high potential, the gas between the electrodes is ionized, heated, and under the influence of the electric and magnetic fields there is produced a rotating annular plasma disk. The ionized plasma has high dielectric constant properties. The device is useful as a fast discharge rate capacitor, in controlled thermonuclear research, and other high temperature gas applications. (AEC)

  11. The Olympics of science knowledge at DOE's New Jersey Regional Science Bowl

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

    at PPPL | Princeton Plasma Physics Lab The Olympics of science knowledge at DOE's New Jersey Regional Science Bowl at PPPL By Jeanne Jackson DeVoe March 3, 2014 Tweet Widget Google Plus One Share on Facebook The J Droids, a science club in Warren, N.J., at the end of a long day of competing with the Science Bowl trophies in the foreground. They took home the largest of the trophies after winning the U.S. Department of Energy's New Jersey Regional Middle School Science Bowl on Feb. 21. (Photo

  12. The Olympics of science knowledge at PPPL's NJ Regional Science Bowl |

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

    Princeton Plasma Physics Lab The Olympics of science knowledge at PPPL's NJ Regional Science Bowl By Jeanne Jackson DeVoe March 3, 2014 Tweet Widget Google Plus One Share on Facebook The J Droids, a science club in Warren, N.J., at the end of a long day of competing with the Science Bowl trophies in the foreground. They took home the largest of the trophies after winning the U.S. Department of Energy's New Jersey Regional Middle School Science Bowl on Feb. 21. (Photo by Elle Starkman/PPPL

  13. Information Science, Computing, Applied Math

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

    Information Science, Computing, Applied Math science-innovationassetsimagesicon-science.jpg Information Science, Computing, Applied Math National security depends on science ...

  14. Production of plasmas by long-wavelength lasers

    DOE Patents [OSTI]

    Dawson, J.M.

    1973-10-01

    A long-wavelength laser system for heating low-density plasma to high temperatures is described. In one embodiment, means are provided for repeatedly receiving and transmitting long-wavelength laser light in successive stages to form a laser-light beam path that repeatedly intersects with the equilibrium axis of a magnetically confined toroidal plasma column for interacting the laser light with the plasma for providing controlled thermonuclear fusion. Embodiments for heating specific linear plasmas are also provided. (Official Gazette)

  15. Runaway electrons in a fully and partially ionized nonideal plasma

    SciTech Connect (OSTI)

    Ramazanov, T.S.; Turekhanova, K.M.

    2005-10-01

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

  16. Science DMZ Case Studies

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

    Science DMZ Case Studies Science DMZ @ UF Science DMZ @ CU Science DMZ @ Penn & VTTI Science DMZ @ NOAA Science DMZ @ NERSC Science DMZ @ ALS Multi-facility Workflow Case Study News & Publications ESnet News Publications and Presentations Galleries ESnet Awards and Honors Blog ESnet Live Home » Science Engagement » Case Studies » Science DMZ Case Studies Science Engagement Move your data Programs & Workshops Science Requirements Reviews Case Studies OSCARS Case Studies Science

  17. NREL: Energy Sciences - Chemical and Materials Science

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

    in the U.S. Department of Energy (DOE) National Photovoltaic Program and DOE Basic Energy Sciences Program. Materials Science. The Materials Science Group's research...

  18. News | Princeton Plasma Physics Lab

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

    Top-5 Achievements at the Princeton Plasma Physics Laboratory in 2015 Click on an image below to view the high resolution image. Then right click on the image and select "Save Image" or "Save Image As..." From top left: 1.Magnetic island geometry revealing the mechanism for the density limit. (Reprinted with permission from Phys. Plasmas 22, 022514 2015); 2.Carlos Paz-Soldan and Raffi Nazikian advanced understanding of the control of heat bursts; 3.interior of the NSTX-U

  19. Plasma technology

    SciTech Connect (OSTI)

    Herlitz, H.G.

    1986-11-01

    This paper describes the uses of plasma technology for the thermal destruction of hazardous wastes such as PCBs, dioxins, hydrocarbons, military chemicals and biological materials; for metals recovery from steel making dusts. One advantage of the process is that destruction of wastes can be carried out on site. Systems in several countries use the excess thermal energy for district heating.

  20. Capabilities: Science Pillars

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

    Pillars science-innovationassetsimagesicon-science.jpg Capabilities: Science Pillars The Lab's four Science Pillars harness our scientific capabilities for national security ...

  1. Basic Energy Sciences

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

    Basic Energy Sciences Basic Energy Sciences Supporing research to understand, predict and ... The DOE Office of Science's Basic Energy Sciences program equips scientists with a ...

  2. Visualization of electronic density

    SciTech Connect (OSTI)

    Grosso, Bastien; Cooper, Valentino R.; Pine, Polina; Hashibon, Adham; Yaish, Yuval; Adler, Joan

    2015-04-22

    An atoms volume depends on its electronic density. Although this density can only be evaluated exactly for hydrogen-like atoms, there are many excellent numerical algorithms and packages to calculate it for other materials. 3D visualization of charge density is challenging, especially when several molecular/atomic levels are intertwined in space. We explore several approaches to 3D charge density visualization, including the extension of an anaglyphic stereo visualization application based on the AViz package to larger structures such as nanotubes. We will describe motivations and potential applications of these tools for answering interesting questions about nanotube properties.

  3. Visualization of electronic density

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Grosso, Bastien; Cooper, Valentino R.; Pine, Polina; Hashibon, Adham; Yaish, Yuval; Adler, Joan

    2015-04-22

    An atom’s volume depends on its electronic density. Although this density can only be evaluated exactly for hydrogen-like atoms, there are many excellent numerical algorithms and packages to calculate it for other materials. 3D visualization of charge density is challenging, especially when several molecular/atomic levels are intertwined in space. We explore several approaches to 3D charge density visualization, including the extension of an anaglyphic stereo visualization application based on the AViz package to larger structures such as nanotubes. We will describe motivations and potential applications of these tools for answering interesting questions about nanotube properties.

  4. Science Briefs

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

    Science Briefs Science Briefs ALS Science Briefs are short (200 words maximum) descriptions of recently published ALS-related work. These "brief" highlights also include one image, a caption (50 words), and the publication citation. All ALS users and beamline scientists are invited to fill out the short submission form here and send a hi-res image to This e-mail address is being protected from spambots. You need JavaScript enabled to view it . Reducing Plant Lignin for Cheaper Biofuels

  5. Outreach Efforts | Princeton Plasma Physics Lab

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

    Outreach Efforts Excitement about plasmas and fusion comes alive when members of PPPL go out into the community or invite the public inside to sample the world of fusion research. The Laboratory has a variety of portable and at-home scientific demonstrations, laboratories and experiments that explain the beauty and wonder of science, fusion, and plasmas. The Laboratory hosts Open Houses and exhibits at local, regional, and national events such as Communiversity and the American Physical

  6. PPPL Technical Reports | Princeton Plasma Physics Lab

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

    Technical Reports - Disclaimer NSTX-U Education Organization Contact Us Overview Experimental Fusion Research Theoretical Fusion Research Basic Plasma Science Plasma Astrophysics Other Physics and Engineering Research PPPL Technical Reports Technical Reports - Disclaimer NSTX-U PPPL Technical Reports PPPL Technical Reports are scientific papers authored by PPPL scientists on research performed under U.S. Department of Energy contract. The reports are posted to the PPPL Publications website and

  7. Fatima Ebrahimi | Princeton Plasma Physics Lab

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

    Fatima Ebrahimi Fatima Ebrahimi is the topical science group leader for theory/modeling of solenoid-free startup & ramp-up in NSTX-U. She has many years of experience in theoretical and global computational extended (magnetohydrodynamic) MHD with wide applications to astrophysical, laboratory and fusion plasmas. Studies of MHD stability in fusion plasmas, momentum transport, dynamo, and magnetic reconnection in fusion/laboratory and astrophysical plas- mas constitute her main research

  8. Nanotube array controlled carbon plasma deposition

    SciTech Connect (OSTI)

    Qian, Shi; Cao, Huiliang; Liu, Xuanyong; Ding, Chuanxian

    2013-06-17

    Finding approaches to control the elementary processes of plasma-solid interactions and direct the fluxes of matter at nano-scales becomes an important aspect in science. This letter reports that, by taking advantages of the spacing characteristics of discrete TiO{sub 2} nanotube arrays, the flying trajectories and the subsequent implantation and deposition manner of energetic carbon ions can be directed and controlled to fabricate hollow conical arrays. The study provides an alternative method for plasma nano-manufacturing.

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

    SciTech Connect (OSTI)

    Kakati, B. Kausik, S. S.; Saikia, B. K.; Bandyopadhyay, M.; Saxena, Y. C.

    2014-10-28

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

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

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

    Budget Fusion Energy Sciences (FES) FES Home About Organization Chart .pdf file (78KB) Staff 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) Community 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: Email

  11. Jobs | U.S. DOE Office of Science (SC)

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

    Jobs Fusion Energy Sciences (FES) FES Home About Organization Chart .pdf file (78KB) Staff 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) Community 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: Email

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

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

    About Fusion Energy Sciences (FES) FES Home About Organization Chart .pdf file (78KB) Staff 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) Community 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: Email

  13. Science on Saturday: Reimagining the Possible: Scientific Transformations

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

    Shaping the Path Towards Fusion Energy | Princeton Plasma Physics Lab March 5, 2016, 9:30am Science On Saturday MBG Auditorium at PPPL Science on Saturday: Reimagining the Possible: Scientific Transformations Shaping the Path Towards Fusion Energy Dr. Edmund Synakowski Department of Energy, Office of Science Abstract: PDF icon Synakowski.pdf Science_on_Saturday05Mar2016_ESynakowski Contact Information Coordinator(s): Ms. Deedee Ortiz-Arias dortiz@pppl.gov Host(s): Dr. Andrew Zwicker

  14. Staff | U.S. DOE Office of Science (SC)

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

    About » Staff Fusion Energy Sciences (FES) FES Home About Organization Chart .pdf file (78KB) Staff Edmund J Synakowski 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) Community Resources Contact Information Fusion Energy Sciences U.S. Department of Energy SC-24/Germantown Building 1000 Independence Ave., SW Washington, DC 20585 P: (301)

  15. Density-dependent covariant energy density functionals

    SciTech Connect (OSTI)

    Lalazissis, G. A.

    2012-10-20

    Relativistic nuclear energy density functionals are applied to the description of a variety of nuclear structure phenomena at and away fromstability line. Isoscalar monopole, isovector dipole and isoscalar quadrupole giant resonances are calculated using fully self-consistent relativistic quasiparticle randomphase approximation, based on the relativistic Hartree-Bogoliubovmodel. The impact of pairing correlations on the fission barriers in heavy and superheavy nuclei is examined. The role of pion in constructing desnity functionals is also investigated.

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

    SciTech Connect (OSTI)

    Yang Min; Li Xiaoping; Xie Kai; Liu Donglin; Liu Yanming

    2013-01-15

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

  17. Science Magazine

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

    & ANALYSIS www.sciencemag.org SCIENCE VOL 339 8 FEBRUARY 2013 635 Steven Chu, the fi rst Nobel-winning scien- tist to lead the sprawling U.S. Department of Energy (DOE), has rarely...

  18. Stewardship Science Academic Alliances Program | National Nuclear Security

    National Nuclear Security Administration (NNSA)

    Administration Stewardship Science Academic Alliances Program Stewardship Science Academic Alliances (SSAA) Program Overview Established in 2002, the Stewardship Science Academic Alliances Program funds academic research in the areas of materials under extreme conditions, low energy nuclear science, radiochemistry, and high energy density physics. One of the goals of the program is to fund research projects at universities that conduct fundamental science and technology research that is of

  19. Flush-mounted probe diagnostics for argon glow discharge plasma

    SciTech Connect (OSTI)

    Xu, Liang Cao, Jinxiang; Liu, Yu; Wang, Jian; Du, Yinchang; Zheng, Zhe; Zhang, Xiao; Wang, Pi; Zhang, Jin; Li, Xiao; Qin, Yongqiang; Zhao, Liang

    2014-09-15

    A comparison is made between plasma parameters measured by a flush-mounted probe (FP) and a cylindrical probe (CP) in argon glow discharge plasma. Parameters compared include the space potential, the plasma density, and the effective electron temperature. It is found that the ion density determined by the FP agrees well with the electron density determined by the CP in the quasi-neutral plasma to better than 10%. Moreover, the space potential and effective electron temperature calculated from electron energy distribution function measured by the FP is consistent with that measured by the CP over the operated discharge current and pressure ranges. These results present the FP can be used as a reliable diagnostic tool in the stable laboratory plasma and also be anticipated to be applied in other complicated plasmas, such as tokamaks, the region of boundary-layer, and so on.

  20. PPPL's science lecture debuts Jan. 10 with new name honoring long-time

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

    organizer | Princeton Plasma Physics Lab PPPL's science lecture debuts Jan. 10 with new name honoring long-time organizer By Jeanne Jackson DeVoe December 22, 2014 Tweet Widget Google Plus One Share on Facebook The late Ron Hatcher hosted PPPL's Science on Saturday lectures. (Photo by Photo by Elle Starkman/ PPPL Office of Communications) The late Ron Hatcher hosted PPPL's Science on Saturday lectures. The U.S. Department of Energy's Princeton Plasma Laboratory's popular Science on Saturday

  1. Nuclear Science

    Energy Savers [EERE]

    and Engineering Education Sourcebook 2013 American Nuclear Society US Department of Energy Nuclear Science & Engineering Education Sourcebook 2013 North American Edition American Nuclear Society Education, Training, and Workforce Division US Department of Energy Office of Nuclear Energy Editor and Founder John Gilligan Professor of Nuclear Engineering North Carolina State University Version 5.13 Welcome to the 2013 Edition of the Nuclear Science and Engineering Education (NS&EE)

  2. Molecular Science

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

    Molecular Science NETL's Molecular Science competency provides technology-enabling computational and experimental insight into the atomic-level processes occurring in condensed matter and gas phase systems or at the heterogeneous surface-gas interfaces used for energy applications. Research includes molecular optimization as well as both classical and high-throughput material design, specifically: Molecular Optimization Development and application of new computational approaches in the general

  3. Measurement Science

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

    wins 2016 Joseph F. Keithley Award for Advances in Measurement Science October 15, 2015 Honors to Albert Migliori, developer of resonant ultrasound spectroscopy LOS ALAMOS, N.M., Oct. 15, 2015-Los Alamos National Laboratory physicist Albert Migliori, having led the development of a powerful tool for important measurements in condensed matter physics including superconductivity, is being given the Joseph F. Keithley Award For Advances in Measurement Science, the top instrumentation prize of the

  4. Isotope Science

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

    Science and Production 35 years of experience in isotope production, processing, and applications. Llllll Committed to the safe and reliable production of radioisotopes, products, and services. Contact: Kevin John LANL Isotope Program Manager kjohn@lanl.gov 505-667-3602 Sponsored by the Department of Energy National Isotope Program http://www.nuclear.energy.gov/isotopes/nelsotopes2a.html Isotopes for Environmental Science Isotopes produced at Los Alamos National Laboratory are used as

  5. Science Museum

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

    Nanotechnology and algae biofuels exhibits open July 26 at the Bradbury Science Museum July 22, 2013 LOS ALAMOS, N.M., July 22, 2013-Los Alamos National Laboratory's Bradbury Science Museum is opening two new exhibits July 26 as part of the Laboratory's 70th Anniversary celebration. One is a nanotechnology exhibit featuring the Laboratory's Center for Integrated Nanotechnologies (CINT) and the other is an algae biofuel exhibit from the Laboratory and the New Mexico Consortium. An opening

  6. Kando, M.; Esirkepov, T.Zh.; and others 70 PLASMA PHYSICS AND...

    Office of Scientific and Technical Information (OSTI)

    targets Pirozhkov, A.S.; Kando, M.; Esirkepov, T.Zh.; and others 70 PLASMA PHYSICS AND FUSION TECHNOLOGY; BEAM-PLASMA SYSTEMS; ELECTRON DENSITY; EV RANGE; HARMONIC GENERATION;...

  7. Students Sharpen Science and Math Skills at Middle School Science...

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

    Students Sharpen Science and Math Skills at Middle School Science Bowl March 8, 2004 ... questions about earth science, physical science, life science, math, and general science. ...

  8. What Makes Science, Science? Research, Shared Effort ... & A...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Makes Science, Science? Research, Shared Effort ... & A New Office of Science Website What Makes Science, Science? Research, Shared Effort ... & A New Office of Science Website ...

  9. Secretary Steven Chu Visits Princeton Plasma Physics Laboratory...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    said has been at the center of the intellectual birth and coming of age of plasma and fusion science. Discussing our need for scientists to address our country's energy issues,...

  10. DOE New Jersey Regional High School Science Bowl *NO LECTURE* | Princeton

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

    Plasma Physics Lab 1, 2015, 9:00am to 4:00pm Science Education Lab-wide DOE New Jersey Regional High School Science Bowl *NO LECTURE* Contact Information Coordinator(s): Deedee Ortiz-Arias, Science Education Department Program Administraor dortiz@ppl.gov Host(s): Dr. Andrew Zwicker, Science Education Department Head azwicker@pppl.gov

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

    SciTech Connect (OSTI)

    Cheong, Hee-Woon; Lee, Woohyun; Kim, Ji-Won; Whang, Ki-Woong; Kim, Hyuk; Park, Wanjae

    2015-07-15

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

  12. EXECUTIVE SUMMARY

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

    FUSION ENERGY SCIENCE ADVISORY COMMITTEE Panel on High Energy Density Laboratory Plasmas ADVANCING THE SCIENCE OF HIGH ENERGY DENSITY LABORATORY PLASMAS January 2009 UNITED STATES ...

  13. Using Radio Waves to Control Fusion Plasma Density

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

    Using Passive Solar Design to Save Money and Energy Using Passive Solar Design to Save Money and Energy October 17, 2014 - 9:45am Q&A What do you want to know about solar energy at home? Tell Us Addthis Passive solar design uses carefully designed overhangs and reflective coatings on windows, exterior walls, and roofs to provide comfort during the cooling season. | Photo courtesy of Jason Flakes, U.S. Department of Energy Passive solar design uses carefully designed overhangs and reflective

  14. Adam Cohen becomes Deputy Under Secretary for Science and Energy...

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

    at the U.S. Department of Energy's (DOE) Princeton Plasma Physics Laboratory (PPPL), Adam Cohen has been named Deputy Under Secretary for Science and Energy in Washington D.C....

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

    SciTech Connect (OSTI)

    Thio, Francis Y.C.

    2008-01-01

    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.

  16. Multi-Scale Investigation of Sheared Flows In Magnetized Plasmas

    SciTech Connect (OSTI)

    Edward, Jr., Thomas

    2014-09-19

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

  17. Science & Technology

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

    ... providing critical new information for inertial confinement fusion and high energy density experiments-the size of the LEH as a function of time, the growth of the gold ...

  18. NERSC-ScienceHighlightsMarch2013.pptx

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

    March 2013 NERSC Science Highlights --- 1 --- NERSC User Science Highlights Materials High-temp superconductivity findings net researchers the first NERSC Award for High Impact Scientific Achievement (T. Das, LANL) Fusion Simulations show for the first time intrinsic stochasticity in magnetically confined toroidal plasma edges (L. Sugiyama, MIT) Fusion Direct simulation of freely decaying turbulence in 2-D electrostatic gyrokinetics (W. Dorland, U. Maryland) Fusion NIMROD simulations explain

  19. NERSC-ScienceHighlightsMarch2015.pptx

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

    March 2015 NERSC Science Highlights - 1 - NERSC User Science Highlights Climate Climate change effects on the wind turbine industry are being evaluated at NERSC (S. Capp, Vertum.com) Fusion Simulations under conditions relevant to the ITER device describe unwelcome plasma edge electromagnetic effects (W. Lee, UCSD) Fusion Modeling at NERSC is helping to optimize the operation of another DOE facility (S. Veltzer, Tech-X, Inc.) Nuclear Physics Theoretical investigation of element 106 predicts

  20. International science conferences in Santa Fe

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

    International science conferences International science conferences in Santa Fe The conference are 2012 International Conference on Defects in Insulating Materials and Computer Simulation of Radiation Effects in Solids. June 22, 2012 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

  1. Volumetric plasma source development and characterization.

    SciTech Connect (OSTI)

    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

    2008-09-01

    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.

  2. Science Highlights

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

    Highlights Science Highlights Science highlights feature research conducted by staff and users at the ALS. If a Power Point summary slide or a PDF handout of the highlight is available, you will find it linked beneath the highlight listing and on the highlight's page. You may also print a version of a highlight by clicking the print icon associated with each highlight. An Atomic-Level Understanding of Copper-Based Catalysts Print Thursday, 05 May 2016 12:20 Copper-based catalysts are widely used

  3. Science Museum

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

    Maintaining nuclear stability in times of transition focus of talk at Bradbury Science Museum January 9, 2014 First in series of evening lectures open to public LOS ALAMOS, N.M., Jan. 9, 2014-Los Alamos National Laboratory Senior Fellow Houston "Terry" Hawkins talks about the role that the nation's nuclear weapons stockpile plays in maintaining the nation's defense - and that of our allies - in a talk at 5:30 p.m., Jan. 15 at the Bradbury Science Museum. The talk is the first in a

  4. Science Museum

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

    Emerging threats to global security focus of March 12 talk at Bradbury Science Museum March 6, 2014 Terry Wallace to address Lab's role in helping the government meet national security challenges LOS ALAMOS, N.M., March 6, 2014-Terry Wallace, principal associate director for Global Security at Los Alamos National Laboratory, will talk about potential emerging threats in a lecture at 5:30 p.m., March 12 at the Bradbury Science Museum. The talk is the third in a series of evening lectures planned

  5. University of Maryland component of the Center for Multiscale Plasma

    Office of Scientific and Technical Information (OSTI)

    Dynamics: Final Technical Report (Technical Report) | SciTech Connect SciTech Connect Search Results Technical Report: University of Maryland component of the Center for Multiscale Plasma Dynamics: Final Technical Report Citation Details In-Document Search Title: University of Maryland component of the Center for Multiscale Plasma Dynamics: Final Technical Report The Center for Multiscale Plasma Dynamics (CMPD) was a five-year Fusion Science Center. The University of Maryland (UMD) and UCLA

  6. Multinational achievement: PPPL collaborates on record fusion plasma in

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

    tokamak in China | Princeton Plasma Physics Lab Multinational achievement: PPPL collaborates on record fusion plasma in tokamak in China By John Greenwald November 25, 2013 Tweet Widget Google Plus One Share on Facebook Interior view of EAST tokamak (Photo by Institute of Plasma Physics, Chinese Academy of Sciences ) Interior view of EAST tokamak A multinational team led by Chinese researchers in collaboration with U.S. and European partners has successfully demonstrated a novel technique

  7. Multinational achievement: PPPL collaborates on record fusion plasma in

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

    tokamak in China | Princeton Plasma Physics Lab Multinational achievement: PPPL collaborates on record fusion plasma in tokamak in China By John Greenwald December 9, 2013 Tweet Widget Google Plus One Share on Facebook Interior view of EAST tokamak (Photo by Institute of Plasma Physics, Chinese Academy of Sciences ) Interior view of EAST tokamak A multinational team led by Chinese researchers in collaboration with U.S. and European partners has successfully demonstrated a novel technique for

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

    SciTech Connect (OSTI)

    Hammer, David A.

    2013-12-19

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

  9. Plasma wake field XUV radiation source

    DOE Patents [OSTI]

    Prono, Daniel S.; Jones, Michael E.

    1997-01-01

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

  10. Langmuir Probe Measurements in Plasma Shadows

    SciTech Connect (OSTI)

    Waldmann, O.; Koch, B.; Fussmann, G.

    2006-01-15

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

  11. ?Linear Gas Jet with Tailored Density Profile"

    SciTech Connect (OSTI)

    KRISHNAN, Mahadevan

    2012-12-10

    Supersonic, highly collimated gas jets and gas-filled capillary discharge waveguides are two primary targets of choice for Laser Plasma Accelerators (LPA) . Present gas jets have lengths of only 2-4 mm at densities of 1-4E19 cm-3, sufficient for self trapping and electron acceleration to energies up to ~150 MeV. Capillary structures 3 cm long have been used to accelerate beams up to 1 GeV. Capillary discharges used in LPAs serve to guide the pump laser and optimize the energy gain. A wall-stabilized capillary discharge provides a transverse profile across the channel that helps guide the laser and combat diffraction. Gas injection via a fast nozzle at one end provides some longitudinal density control, to improve the coupling. Gas jets with uniform or controlled density profiles may be used to control electron bunch injection and are being integrated into capillary experiments to add tuning of density. The gas jet for electron injection has not yet been optimized. Our Ph-I results have provided the LPA community with an alternative path to realizing a 2-3GeV electron bunch using just a gas jet. For example, our slit/blade combination gives a 15-20mm long acceleration path with tunable density profile, serving as an alternative to a 20-mm long capillary discharge with gas injection at one end. In Ph-II, we will extend these results to longer nozzles, to see whether we can synthesize 30 or 40-mm long plasma channels for LPAs.

  12. Microsoft Word - Defense Science Quarterly 05-08.doc

    National Nuclear Security Administration (NNSA)

    Office of Defense Science May 2008 Defense Science Quarterly Inside This Issue 1 Message from the Director 2 Advanced Certification 3 Delivering High Energy Density Physics Data on the National Ignition Facility to Validate Predictive Physics Models 5 Texas Petawatt Laser Achieves Power Milestone 6 Sandia Light Gas Gun Tests Demonstrate the Ability to Deliver an Engineered Shock Wave Using a Graded-Density Thermal Spray Coating 7 Stewardship Science Academic Alliances Symposium Highlights 9

  13. Computing Sciences

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

    Computing Sciences Our Vision National User Facilities Research Areas In Focus Global Solutions ⇒ Navigate Section Our Vision National User Facilities Research Areas In Focus Global Solutions Computational Research Division The Computational Research Division conducts research and development in mathematical modeling and simulation, algorithm design, data storage, management and analysis, computer system architecture and high-performance software implementation. Scientific Networking

  14. Nanodiamonds in dusty low-pressure plasmas

    SciTech Connect (OSTI)

    Vandenbulcke, L.; Gries, T.; Rouzaud, J. N.

    2009-01-26

    Dusty plasmas composed of carbon, hydrogen, and oxygen have been evidenced by optical emission spectroscopy and microwave interferometry, due to the increase in electron energy and the decrease in electron density. These plasmas allow homogeneous synthesis of nanodiamond grains composed of either pure diamond nanocrystals only (2-10 nm in size) or of diamond nanocrystals and some sp{sup 2}-hybridized carbon entities. The control of their size and their microstructure could open ways for a wide range of fields. Their formation from a plasma-activated gaseous phase is also attractive because the formation of nanodiamonds in the universe is still a matter of controversy.

  15. Reproducing continuous radio blackout using glow discharge plasma

    SciTech Connect (OSTI)

    Xie, Kai; Li, Xiaoping; Liu, Donglin; Shao, Mingxu [School of Aerospace Science and Technology, Xidian University, Xi'an 710071 (China)] [School of Aerospace Science and Technology, Xidian University, Xi'an 710071 (China); Zhang, Hanlu [School of Communication and Information Engineering, Xi'an University of Posts and Telecommunications, Xi'an 710121 (China)] [School of Communication and Information Engineering, Xi'an University of Posts and Telecommunications, Xi'an 710121 (China)

    2013-10-15

    A novel plasma generator is described that offers large-scale, continuous, non-magnetized plasma with a 30-cm-diameter hollow structure, which provides a path for an electromagnetic wave. The plasma is excited by a low-pressure glow discharge, with varying electron densities ranging from 10{sup 9} to 2.5 10{sup 11} cm{sup ?3}. An electromagnetic wave propagation experiment reproduced a continuous radio blackout in UHF-, L-, and S-bands. The results are consistent with theoretical expectations. The proposed method is suitable in simulating a plasma sheath, and in researching communications, navigation, electromagnetic mitigations, and antenna compensation in plasma sheaths.

  16. ECR apparatus with magnetic coil for plasma refractive index control

    DOE Patents [OSTI]

    Berry, Lee A.

    1994-01-01

    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.

  17. Optimized ECR plasma apparatus with varied microwave window thickness

    DOE Patents [OSTI]

    Berry, L.A.

    1995-11-14

    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.

  18. Optimized ECR plasma apparatus with varied microwave window thickness

    DOE Patents [OSTI]

    Berry, Lee A.

    1995-01-01

    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.

  19. ECR apparatus with magnetic coil for plasma refractive index control

    DOE Patents [OSTI]

    Berry, L.A.

    1994-04-26

    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.

  20. COHERENCE AND INTERMITTENCY OF ELECTRON DENSITY IN SMALL-SCALE

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

    COHERENCE AND INTERMITTENCY 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 Department of Physics, University of WisconsinYMadison, Madison, WI 53706; pwterry@wisc.edu Received 2006 December 14; accepted 2007 April 19 ABSTRACT Spatial intermittency in decaying kinetic Alfve ´n wave turbulence is investigated to determine if it produces non- Gaussian density fluctuations in

  1. A Space-Charge-Neutralizing Plasma for Beam Drift Compression

    SciTech Connect (OSTI)

    Roy, P.K.; Seidl, P.A.; Anders, A.; Bieniosek, F.M.; Coleman, J.E.; Gilson, E.P.; Greenway, W.; Grote, D.P.; Jung, J.Y.; Leitner, M.; Lidia, S.M.; Logan, B.G.; Sefkow, A.B.; Waldron, W.L.; Welch, D.R.

    2008-08-01

    Simultaneous radial focusing and longitudinal compression of intense ion beams are being studied to heat matter to the warm dense matter, or strongly coupled plasma regime. Higher compression ratios can be achieved if the beam compression takes place in a plasma-filled drift region in which the space-charge forces of the ion beam are neutralized. Recently, a system of four cathodic arc plasma sources has been fabricated and the axial plasma density has been measured. A movable plasma probe array has been developed to measure the radial and axial plasma distribution inside and outside of a {approx} 10 cm long final focus solenoid (FFS). Measured data show that the plasma forms a thin column of diameter {approx} 5 mm along the solenoid axis when the FFS is powered with an 8T field. Measured plasma density of {ge} 1 x 10{sup 13} cm{sup -3} meets the challenge of n{sub p}/Zn{sub b} > 1, where n{sub p} and n{sub b} are the plasma and ion beam density, respectively, and Z is the mean ion charge state of the plasma ions.

  2. Siegfried H. Glenzer, 2013 | U.S. DOE Office of Science (SC)

    Office of Science (SC) Website

    Thomson X-ray scattering as an in situ microscopic characterization technique of dense plasma, and for its use to advance fundamental understanding in high energy density physics. ...

  3. Plasma 101 | Princeton Plasma Physics Lab

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

    Plasma 101 10 Facts You Should Know About Plasma By Larry Bernard February 22, 2016 Tweet Widget Google Plus One Share on Facebook The Aurora Borealis (Northern Lights) (Photo by Philippe Moussette for Nasa.gov) The Aurora Borealis (Northern Lights) Gallery: NSTX interior NSTX interior W7-X plasma W7-X plasma The sun (Photo by nasa.gov) The sun It's the fourth state of matter: Solid, liquid, gas, and plasma. Plasma is a super-heated gas, so hot that its electrons get out of the atom's orbit and

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

    SciTech Connect (OSTI)

    Not Available

    1991-12-31

    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.

  5. Density Equalizing Map Projections

    Energy Science and Technology Software Center (OSTI)

    1995-07-01

    A geographic map is mathematically transformed so that the subareas of the map are proportional to a given quantity such as population. In other words, population density is equalized over the entire map. The transformed map can be used as a display tool, or it can be statistically analyzed. For example, cases of disease plotted on the transformed map should be uniformly distributed at random, if disease rates are everywhere equal. Geographic clusters of diseasemore » can be readily identified, and their statistical significance determined, on a density equalized map.« less

  6. Computer tomography of large dust clouds in complex plasmas

    SciTech Connect (OSTI)

    Killer, Carsten; Himpel, Michael; Melzer, Andr

    2014-10-15

    The dust density is a central parameter of a dusty plasma. Here, a tomography setup for the determination of the three-dimensionally resolved density distribution of spatially extended dust clouds is presented. The dust clouds consist of micron-sized particles confined in a radio frequency argon plasma, where they fill almost the entire discharge volume. First, a line-of-sight integrated dust density is obtained from extinction measurements, where the incident light from an LED panel is scattered and absorbed by the dust. Performing these extinction measurements from many different angles allows the reconstruction of the 3D dust density distribution, analogous to a computer tomography in medical applications.

  7. Supercomputers Predict New Turbulent Interactions in Fusion Plasmas | U.S.

    Office of Science (SC) Website

    DOE Office of Science (SC) Supercomputers Predict New Turbulent Interactions in Fusion Plasmas Fusion Energy Sciences (FES) FES Home About Research Facilities Science Highlights Benefits of FES Funding Opportunities Fusion Energy Sciences Advisory Committee (FESAC) Community 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: Email Us More Information »

  8. Nuclear Science & Technology

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

    Nuclear Science & Technology Nuclear Science & Technology1354608000000Nuclear Science & TechnologySome of these resources are LANL-only and will require Remote Access. No...

  9. Top Science of 2013

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

    RAPTOR telescope witnesses black hole birth science-innovationassetsimagesicon-science.jpg Top Science of 2013 Our strong interdisciplinary teaming and unique research...

  10. Bradbury Science Museum

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

    Bradbury Science Museum Bradbury Science Museum Providing a window into the history of LANL, its national security mission, and the broad range of exciting science and technology ...

  11. NERSC Science Engagements

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

    NERSC Science Engagements NERSC Science Engagements At NERSC, science comes first. NERSC systems and services are designed to enable and support cutting-edge research within the ...

  12. ORISE: Forensic Science

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

    Forensic Science Forensic Science The Oak Ridge Institute for Science and Education (ORISE) provides direct forensic analytical support, consulting and training services to United...

  13. Top Science of 2013

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

    Liquid-scanning technology boosts airport security science-innovationassetsimagesicon-science.jpg Top Science of 2013 Our strong interdisciplinary teaming and unique research...

  14. Ultra-High Intensity Magnetic Field Generation in Dense Plasma

    SciTech Connect (OSTI)

    Fisch, Nathaniel J

    2014-01-08

    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.

  15. Spatial diagnostics of the laser induced lithium fluoride plasma

    SciTech Connect (OSTI)

    Baig, M. A.; Qamar, Aisha; Fareed, M. A.; Anwar-ul-Haq, M.; Ali, Raheel

    2012-06-15

    We present spatial characteristics of the lithium fluoride plasma generated by the fundamental and second harmonic of a Nd:YAG laser. The plume emission has been recorded spatially using five spectrometers covering the spectral region from 200 nm to 720 nm. The electron density is measured from the Stark broadened line profile of the line at 610.37 nm, whereas the plasma temperature has been determined using the Boltzmann plot method including all the observed spectral lines of lithium. Both the plasma parameters; electron density and plasma temperature decrease with the increase of the distance from the target surface. The thermal conduction towards the target, the radiative cooling of the plasma, and the conversion of thermal energy into kinetic energy are the main mechanisms responsible for the spatially decrease of the plasma parameters.

  16. Radio frequency discharge with control of plasma potential distribution

    SciTech Connect (OSTI)

    Dudnikov, Vadim; Dudnikov, A.

    2012-02-15

    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.

  17. MAGNETIC END CLOSURES FOR PLASMA CONFINING AND HEATING DEVICES

    DOE Patents [OSTI]

    Post, R.F.

    1963-08-20

    More effective magnetic closure field regions for various open-ended containment magnetic fields used in fusion reactor devices are provided by several spaced, coaxially-aligned solenoids utilized to produce a series of nodal field regions of uniform or, preferably, of incrementally increasing intensity separated by lower intensity regions outwardly from the ends of said containment zone. Plasma sources may also be provided to inject plasma into said lower intensity areas to increase plasma density therein. Plasma may then be transported, by plasma diffusion mechanisms provided by the nodal fields, into the containment field. With correlated plasma densities and nodal field spacings approximating the mean free partl cle collision path length in the zones between the nodal fields, optimum closure effectiveness is obtained. (AEC)

  18. Plasma physics | Princeton Plasma Physics Lab

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

    physics Subscribe to RSS - Plasma physics The study of plasma, a partially-ionized gas that is electrically conductive and able to be confined within a magnetic field, and how it ...

  19. Plasma astrophysics | Princeton Plasma Physics Lab

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

    Subscribe to RSS - Plasma astrophysics A field of physics that is growing in interest ... McComas named vice president for the Princeton Plasma Physics Laboratory David McComas, an ...

  20. Impact of anomalous dispersion on the interferometer measurements of plasmas

    SciTech Connect (OSTI)

    Nilsen, J; Johnson, W R; Iglesias, C A; Scofield, J H

    2004-12-16

    For many decades optical interferometers have been used to measure the electron density of plasmas. During the last ten years X-ray lasers in the wavelength range 14 to 47 nm have enabled researchers to use interferometers to probe even higher density plasmas. The data analysis assumes that the index of refraction is due only to the free electrons, which makes the index of refraction less than one and the electron density proportional to the number of fringe shifts. Recent experiments in Al plasmas observed plasmas with an index of refraction greater than one and made us question the validity of the usual formula for calculating the index of refraction. Recent calculations showed how the anomalous dispersion from the bound electrons can dominate the index of refraction in many types of plasma and make the index greater than one or enhance the index such that one would greatly overestimate the electron density of the plasma using interferometers. In this work we calculate the index of refraction of C, Al, Ti, and Pd plasmas for photon energies from 0 to 100 eV (12.4 nm) using a new average-atom code. The results show large variations from the free electron approximation under many different plasma conditions. We validate the average-atom code against the more detailed OPAL code for carbon and aluminum plasmas. During the next decade X-ray free electron lasers and other sources will be available to probe a wider variety of plasmas at higher densities and shorter wavelengths so understanding the index of refraction in plasmas will be even more essential.

  1. Information Sciences

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

    3 Information Sciences Uncovering actionable knowledge and generating insight into exascale datasets from heterogeneous sources in real time Leadership Group Leader Patrick M. Kelly Email Deputy Group Leader Amy Larson Email Contact Us Administrator Yvonne McKelvey Email Conceptual illustration of futuristic data stream processing. Developing methods and tools for understanding complex interactions and extracting actionable information from massive data streams. Basic and applied research

  2. Science Pillars

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

    Pillars Harnessing our scientific capabilities for national security solutions Los Alamos National Laboratory LA-UR-15-27068 Benefits of the Science Pillars The Laboratory's greatest strength is in our multidisciplinary capabilities. The Pillars draw on these capabilities- across traditional organizational and disciplinary boundaries-to help us accomplish our missions. The LDRD Strategic Investment Plan is built around the Pillars. The Laboratory's External Reviews are organized by Pillar.

  3. Science Summary

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

    Energy, Office of Scientific and Technical Information Science Showcase: George F. Smoot and Roger D. Kornberg Feature Archive George Smoot George F. Smoot won the 2006 Nobel Prize in Physics. George F. Smoot and Roger D. Kornberg have joined the growing list of Nobel Laureates associated with DOE. Smoot won the 2006 Nobel Prize in Physics for his work in blackbody and anisotropy of the cosmic microwave background radiation. Smoot is an astrophysicist at DOE's Lawrence Berkeley National Lab

  4. Fire Science

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

    Science - Sandia Energy Energy Search Icon Sandia Home Locations Contact Us Employee Locator Energy & Climate Secure & Sustainable Energy Future Stationary Power Energy Conversion Efficiency Solar Energy Wind Energy Water Power Supercritical CO2 Geothermal Natural Gas Safety, Security & Resilience of the Energy Infrastructure Energy Storage Nuclear Power & Engineering Grid Modernization Battery Testing Nuclear Fuel Cycle Defense Waste Management Programs Advanced Nuclear Energy

  5. Multiple density layered insulator

    DOE Patents [OSTI]

    Alger, Terry W.

    1994-01-01

    A multiple density layered insulator for use with a laser is disclosed wh provides at least two different insulation materials for a laser discharge tube, where the two insulation materials have different thermoconductivities. The multiple layer insulation materials provide for improved thermoconductivity capability for improved laser operation.

  6. Multiple density layered insulator

    DOE Patents [OSTI]

    Alger, T.W.

    1994-09-06

    A multiple density layered insulator for use with a laser is disclosed which provides at least two different insulation materials for a laser discharge tube, where the two insulation materials have different thermoconductivities. The multiple layer insulation materials provide for improved thermoconductivity capability for improved laser operation. 4 figs.

  7. Global coherence of dust density waves

    SciTech Connect (OSTI)

    Killer, Carsten; Melzer, Andr

    2014-06-15

    The coherence of self-excited three-dimensional dust density waves has been experimentally investigated by comparing global and local wave properties. For that purpose, three-dimensional dust clouds have been confined in a radio frequency plasma with thermophoretic levitation. Global wave properties have been measured from the line-of-sight integrated dust density obtained from homogenous light extinction measurements. Local wave properties have been obtained from thin, two-dimensional illuminated laser slices of the cloud. By correlating the simultaneous global and local wave properties, the spatial coherence of the waves has been determined. We find that linear waves with small amplitudes tend to be fragmented, featuring an incoherent wave field. Strongly non-linear waves with large amplitudes, however, feature a strong spatial coherence throughout the dust cloud, indicating a high level of synchronization.

  8. Bradbury Science Museum - Science on Wheels

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

    science, technology, engineering and mathematics and promote public understanding and ... science, technology, engineering and mathematics, and the work of Los Alamos National ...

  9. Computing and Computational Sciences Directorate - Computer Science...

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

    Computer Science and Mathematics Division The Computer Science and Mathematics Division (CSMD) is ORNL's premier source of basic and applied research in high-performance computing, ...

  10. Computing and Computational Sciences Directorate - Computer Science...

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

    Computer Science and Mathematics Division Citation: For exemplary administrative secretarial support to the Computer Science and Mathematics Division and to the ORNL ...

  11. Materials Science Research | Materials Science | NREL

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

    Science Research For photovoltaics and other energy applications, NREL's primary research in materials science includes the following core competencies. A photo of laser light rays...

  12. Ion Beam Neutralization by a Tenuous Background Plasma ---- Inventors Igor

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

    Kaganovich and William Berdanier | Princeton Plasma Physics Lab Ion Beam Neutralization by a Tenuous Background Plasma ---- Inventors Igor Kaganovich and William Berdanier The neutralization and focusing of intense charged particle beam pulses by electrons form the basis for a wide range of applications for accelerators, heavy ion fusion, and astrophysics. This invention shows that for intense ion beam pulses, a background plasma with a low relative density can be used to effectively

  13. Plasma research shows promise for future compact accelerators

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

    Plasma research shows promise for future compact accelerators Plasma research shows promise for future compact accelerators A transformative breakthrough in controlling ion beams allows small-scale laser-plasma accelerators to deliver unprecedented power densities. December 21, 2015 The team in front of the Trident Target Chamber. Back, from left: Tom Shimada, Sha-Marie Reid, Adam Sefkow, Miguel Santiago, and Chris Hamilton. Front, from left: Russ Mortensen, Chengkun Huang, Sasi Palaniyappan,

  14. Optical Spectroscopic Diagnostics Of Dusty Plasma In RF Discharge

    SciTech Connect (OSTI)

    Orazbayev, S. A.; Jumagulov, M. N.; Dosbolayev, M. K.; Silamiya, M.; Ramazanov, T. S.; Boufendi, L.

    2011-11-29

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

  15. Interparticle interaction and transport processes in dense semiclassical plasmas

    SciTech Connect (OSTI)

    Baimbetov, F.B.; Giniyatova, Sh.G.

    2005-04-15

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

  16. Density gradient effects on transverse shear driven lower hybrid waves

    SciTech Connect (OSTI)

    DuBois, Ami M.; Thomas, Edward; Amatucci, William E.; Ganguli, Gurudas

    2014-06-15

    Shear driven instabilities are commonly observed in the near-Earth space, particularly in boundary layer plasmas. When the shear scale length (L{sub E}) is much less than the ion gyro-radius (?{sub i}) but greater than the electron gyro-radius (?{sub e}), the electrons are magnetized in the shear layer, but the ions are effectively un-magnetized. The resulting shear driven instability, the electron-ion hybrid (EIH) instability, is investigated in a new interpenetrating plasma configuration in the Auburn Linear EXperiment for Instability Studies. In order to understand the dynamics of magnetospheric boundary layers, the EIH instability is studied in the presence of a density gradient located at the boundary layer between two plasmas. This paper reports on a recent experiment in which electrostatic lower hybrid waves are identified as the EIH instability, and the effect of a density gradient on the instability properties are investigated.

  17. Science DMZ Implemented at NERSC

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

    NERSC Science Engagement Move your data Programs & Workshops Science Requirements Reviews Case Studies OSCARS Case Studies Science DMZ Case Studies Science DMZ @ UF Science DMZ @ ...

  18. External control of ion waves in a plasma by high frequency fields

    DOE Patents [OSTI]

    Kaw, P.K.; Dawson, J.M.

    1973-12-18

    An apparatus and method are described for stabilizing plasma instabilities, in a magnetically confined plasma column by transmitting into the plasma high frequency electromagnetic waves at a frequency close to the electron plasma frequency. The said frequencies, e.g., are between the plasma frequency and 1.5 times the plasma frequency at a power level below the level for producing parametric instabilities in a plasma having temperatures from below 10 eV to about 10 keV or more, at densities from below 10/sup 13/ to above 10/sup 18/ particles/cm/sup 3/. (Official Gazette)

  19. Faces of Science

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

    Science aboutassetsimagesicon-70th2.jpg Faces of Science Meet the scientists behind the science at Los Alamos. Many of them felt a calling to science at an early age...now ...

  20. One-dimensional time-dependent fluid model of a very high density...

    Office of Scientific and Technical Information (OSTI)

    Journal Article: One-dimensional time-dependent fluid model of a very high density low-pressure inductively coupled plasma Citation Details In-Document Search This content will ...

  1. Density Log | Open Energy Information

    Open Energy Info (EERE)

    Density Log Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Technique: Density Log Details Activities (7) Areas (6) Regions (0) NEPA(0) Exploration...

  2. Rock Density | Open Energy Information

    Open Energy Info (EERE)

    Density Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Technique: Rock Density Details Activities (2) Areas (2) Regions (0) NEPA(0) Exploration Technique...

  3. Science on Saturday: Brutal Efficiency: How Mating and Reproduction

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

    Influence C. Elegans Longevity | Princeton Plasma Physics Lab 7, 2016, 9:30am Science On Saturday MBG Auditorium, PPPL Science on Saturday: Brutal Efficiency: How Mating and Reproduction Influence C. Elegans Longevity Professor Coleen Murphy Princeton University Abstract: PDF icon 07 Murphy.pdf Science_on_Saturday27Feb2016_CMurphy Contact Information Coordinator(s): Ms. Deedee Ortiz-Arias dortiz@pppl.gov Host(s): Dr. Andrew Zwicker azwicker@pppl.gov PPPL Entrance Procedures Visitor

  4. Christina Behr-Andres named science advisor to governor

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

    Science advisor to governor Christina Behr-Andres named science advisor to governor Behr-Andres will aid indevelopment and promotion of science and technology policies for economic and educational opportunities. June 9, 2011 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

  5. Life sciences and environmental sciences

    SciTech Connect (OSTI)

    Not Available

    1992-02-01

    The DOE laboratories play a unique role in bringing multidisciplinary talents -- in biology, physics, chemistry, computer sciences, and engineering -- to bear on major problems in the life and environmental sciences. Specifically, the laboratories utilize these talents to fulfill OHER's mission of exploring and mitigating the health and environmental effects of energy use, and of developing health and medical applications of nuclear energy-related phenomena. At Lawrence Berkeley Laboratory (LBL) support of this mission is evident across the spectrum of OHER-sponsored research, especially in the broad areas of genomics, structural biology, basic cell and molecular biology, carcinogenesis, energy and environment, applications to biotechnology, and molecular, nuclear and radiation medicine. These research areas are briefly described.

  6. Life sciences and environmental sciences

    SciTech Connect (OSTI)

    Not Available

    1992-02-01

    The DOE laboratories play a unique role in bringing multidisciplinary talents -- in biology, physics, chemistry, computer sciences, and engineering -- to bear on major problems in the life and environmental sciences. Specifically, the laboratories utilize these talents to fulfill OHER`s mission of exploring and mitigating the health and environmental effects of energy use, and of developing health and medical applications of nuclear energy-related phenomena. At Lawrence Berkeley Laboratory (LBL) support of this mission is evident across the spectrum of OHER-sponsored research, especially in the broad areas of genomics, structural biology, basic cell and molecular biology, carcinogenesis, energy and environment, applications to biotechnology, and molecular, nuclear and radiation medicine. These research areas are briefly described.

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

    SciTech Connect (OSTI)

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

    2013-03-15

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

  8. Science Brief Submission Form

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

    Science Brief Submission Form Science Brief Submission Form Print Tuesday, 01 May 2007 00:00 Loading... < Prev

  9. Inductively generated streaming plasma ion source

    DOE Patents [OSTI]

    Glidden, Steven C.; Sanders, Howard D.; Greenly, John B.

    2006-07-25

    A novel pulsed, neutralized ion beam source is provided. The source uses pulsed inductive breakdown of neutral gas, and magnetic acceleration and control of the resulting plasma, to form a beam. The beam supplies ions for applications requiring excellent control of ion species, low remittance, high current density, and spatial uniformity.

  10. Preface: Special Topic on Advances in Density Functional Theory

    SciTech Connect (OSTI)

    Yang, Weitao

    2014-05-14

    This Special Topic Issue on the Advances in Density Functional Theory, published as a celebration of the fifty years of density functional theory, contains a retrospective article, a perspective article, and a collection of original research articles that showcase recent theoretical advances in the field. It provides a timely discussion reflecting a cross section of our understanding, and the theoretical and computational developments, which have significant implications in broad areas of sciences and engineering.

  11. Laser Propagation in Nanostructured Ultra-Low-Density Materials (Technical

    Office of Scientific and Technical Information (OSTI)

    Report) | SciTech Connect Laser Propagation in Nanostructured Ultra-Low-Density Materials Citation Details In-Document Search Title: Laser Propagation in Nanostructured Ultra-Low-Density Materials × You are accessing a document from the Department of Energy's (DOE) SciTech Connect. This site is a product of DOE's Office of Scientific and Technical Information (OSTI) and is provided as a public service. Visit OSTI to utilize additional information resources in energy science and technology.

  12. Science Cafe

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

    Cafés Science Cafe April 27, 2015-Special ALS Colloquium Print Wednesday, 22 April 2015 13:19 Special Event on Monday, April 27 @ 12 noon, USB 15-253 X-Ray Microscopy: The First 120 Years Janos Kirz, ALS Abstract Röntgen's great discovery became an instant public sensation. Fascination with the "new kind of rays" that could reveal the structure of opaque objects swept the world in 1896. Fifty years later it was widely recognized that the short wavelength of the radiation should open

  13. Science News

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

    News Science News Filter by Year All 2016 2015 2014 2013 2012 2011 2010 2009 2008 2007 2006 2005 2004 2003 2002 2001 2000 1999 1998 1997 1 2 3 | Next » Graphical Abstract AlN Sci Rep no logo cropped Could Aluminum Nitride Produce Quantum Bits? May 2, 2016 The leading method for creating quantum bits, or qubits, currently involves exploiting the structural defects in diamonds. But using NERSC resources, University of Chicago researchers found that the same defect could be engineered in cheaper

  14. Numerical Studies of Impurities in Fusion Plasmas

    DOE R&D Accomplishments [OSTI]

    Hulse, R. A.

    1982-09-01

    The coupled partial differential equations used to describe the behavior of impurity ions in magnetically confined controlled fusion plasmas require numerical solution for cases of practical interest. Computer codes developed for impurity modeling at the Princeton Plasma Physics Laboratory are used as examples of the types of codes employed for this purpose. These codes solve for the impurity ionization state densities and associated radiation rates using atomic physics appropriate for these low-density, high-temperature plasmas. The simpler codes solve local equations in zero spatial dimensions while more complex cases require codes which explicitly include transport of the impurity ions simultaneously with the atomic processes of ionization and recombination. Typical applications are discussed and computational results are presented for selected cases of interest.

  15. Three regimes of relativistic beam - plasma interaction

    SciTech Connect (OSTI)

    Muggli, P.; Allen, B.; Fang, Y.; Yakimenko, V.; Babzien, M.; Kusche, K.; Fedurin, M.; Vieira, J.; Martins, J.; Silva, L.

    2012-12-21

    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.

  16. The density gradient effect on quantum Weibel instability

    SciTech Connect (OSTI)

    Mahdavi, M. Khodadadi Azadboni, F.

    2015-03-15

    The Weibel instability plays an important role in stopping the hot electrons and energy deposition mechanism in the fast ignition of inertial fusion process. In this paper, the effects of the density gradient and degeneracy on Weibel instability growth rate are investigated. Calculations show that decreasing the density degenerate in the plasma corona, near the relativistic electron beam emitting region by 8.5% leads to a 92% reduction in the degeneracy parameter and about 90% reduction in Weibel instability growth rate. Also, decreasing the degenerate density near the fuel core by 8.5% leads to 1% reduction in the degeneracy parameter and about 8.5% reduction in Weibel instability growth rate. The Weibel instability growth rate shrinks to zero and the deposition condition of relativistic electron beam energy can be shifted to the fuel core for a suitable ignition by increasing the degeneracy parameter in the first layer of plasma corona.

  17. Passive Spectroscopic Diagnostics for Magnetically-confined Fusion Plasmas

    SciTech Connect (OSTI)

    Stratton, B. C.; Biter, M.; Hill, K. W.; Hillis, D. L.; Hogan, J. T.

    2007-07-18

    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.

  18. Gedanken densities and exact constraints in density functional theory

    SciTech Connect (OSTI)

    Perdew, John P.; Department of Chemistry, Temple University, Philadelphia, Pennsylvania 19122 ; Ruzsinszky, Adrienn; Sun, Jianwei; Burke, Kieron

    2014-05-14

    Approximations to the exact density functional for the exchange-correlation energy of a many-electron ground state can be constructed by satisfying constraints that are universal, i.e., valid for all electron densities. Gedanken densities are designed for the purpose of this construction, but need not be realistic. The uniform electron gas is an old gedanken density. Here, we propose a spherical two-electron gedanken density in which the dimensionless density gradient can be an arbitrary positive constant wherever the density is non-zero. The Lieb-Oxford lower bound on the exchange energy can be satisfied within a generalized gradient approximation (GGA) by bounding its enhancement factor or simplest GGA exchange-energy density. This enhancement-factor bound is well known to be sufficient, but our gedanken density shows that it is also necessary. The conventional exact exchange-energy density satisfies no such local bound, but energy densities are not unique, and the simplest GGA exchange-energy density is not an approximation to it. We further derive a strongly and optimally tightened bound on the exchange enhancement factor of a two-electron density, which is satisfied by the local density approximation but is violated by all published GGA's or meta-GGA’s. Finally, some consequences of the non-uniform density-scaling behavior for the asymptotics of the exchange enhancement factor of a GGA or meta-GGA are given.

  19. Plasma wave aided two photon decay of an electromagnetic wave in a plasma

    SciTech Connect (OSTI)

    Kumar, K. K. Magesh; Singh, Rohtash; Krishan, Vinod

    2014-11-15

    The presence of a Langmuir wave in an unmagnetized plasma is shown to allow parametric decay of an electromagnetic wave into two electromagnetic waves, which is otherwise not allowed due to wave number mismatch. The decay occurs at plasma densities below one ninth the critical density and the decay waves propagate at finite angles to the pump laser. Above the threshold, the growth rate scales linearly with the amplitude of the Langmuir wave and the amplitude of the pump electromagnetic wave. The frequency ω of the lower frequency decay wave increases with the angle its propagation vector makes with that of the pump. The growth rate, however, decreases with ω.

  20. Plasma sweeper. [Patents

    DOE Patents [OSTI]

    Motley, R.W.; Glanz, J.

    1982-10-25

    A device is described for coupling RF power (a plasma sweeper) from RF power introducing means to a plasma having a magnetic field associated therewith comprises at least one electrode positioned near the plasma and near the RF power introducing means. Means are described for generating a static electric field at the electrode directed into the plasma and having a component substantially perpendicular to the plasma magnetic field such that a non-zero vector cross-product of the electric and magnetic fields exerts a force on the plasma causing the plasma to drift.