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1

Ultra-High Gradient Dielectric Wakefield Accelerator Experiments  

SciTech Connect (OSTI)

Ultra-high gradient dielectric wakefield accelerators are a potential option for a linear collider afterburner since they are immune to the ion collapse and electron/positron asymmetry problems implicit in a plasma based afterburner. The first phase of an experiment to study the performance of dielectric Cerenkov wakefield accelerating structures at extremely high gradients in the GV/m range has been completed. The experiment took advantage of the unique SLAC FFTB electron beam and its ultra-short pulse lengths and high currents (e.g., {sigma}{sub z} = 20 {micro}m at Q = 3 nC). The FFTB electron beam was successfully focused down and sent through short lengths of fused silica capillary tubing (ID = 200 {micro}m/OD = 325 {micro}m). The pulse length of the electron beam was varied to produce a range of electric fields between 2 and 20 GV/m at the inner surface of the dielectric tubes. We observed a sharp increase in optical emissions from the capillaries in the middle part of this surface field range which we believe indicates the transition between sustainable field levels and breakdown. If this initial interpretation is correct, the surfaced fields that were sustained equate to on axis accelerating field of several GV/m. In future experiments being developed for the SLAC SABER and BNL ATF we plan to use the coherent Cerenkov radiation emitted from the capillary tube as a field strength diagnostic and demonstrate GV/m range particle energy gain.

Thompson, M C; Badakov, H; Rosenzweig, J B; Travish, G; Hogan, M; Ischebeck, R; Kirby, N; Siemann, R; Walz, D; Muggli, P; Scott, A; Yoder, R

2006-08-04T23:59:59.000Z

2

Ultra-High Gradient Dielectric Wakefield Accelerator Experiments  

SciTech Connect (OSTI)

Ultra-high gradient dielectric wakefield accelerators are a potential option for a linear collider afterburner since they are immune to the ion collapse and electron/positron asymmetry problems implicit in a plasma based afterburner. The first phase of an experiment to study the performance of dielectric Cerenkov wakefield accelerating structures at extremely high gradients in the GV/m range has been completed. The experiment took advantage of the unique SLAC FFTB electron beam and its ultra-short pulse lengths and high currents (e.g., {sigma}z = 20 {mu}m at Q = 3 nC). The FFTB electron beam was successfully focused down and sent through short lengths of fused silica capillary tubing (ID = 200 {mu}m / OD = 325 {mu}m). The pulse length of the electron beam was varied to produce a range of electric fields between 2 and 20 GV/m at the inner surface of the dielectric tubes. We observed a sharp increase in optical emissions from the capillaries in the middle part of this surface field range which we believe indicates the transition between sustainable field levels and breakdown. If this initial interpretation is correct, the surfaced fields that were sustained equate to on axis accelerating field of several GV/m. In future experiments being developed for the SLAC SABER and BNL ATF we plan to use the coherent Cerenkov radiation emitted from the capillary tube as a field strength diagnostic and demonstrate GV/m range particle energy gain.

Thompson, M. C. [Lawrence Livermore National Laboratory, Livermore, California, 90095 (United States); Badakov, H.; Rosenzweig, J. B.; Travis, G. [UCLA Department of Physics and Astronomy, Los Angeles, California, 90095 (United States); Hogan, M.; Ischebeck, R.; Kirby, N.; Siemann, R.; Walz, D. [Stanford Linear Accelerator Center, Stanford, California, 94309 (United States); Muggli, P. [University of Southern California Los Angeles, California, 90089 (United States); Scott, A. [UCSB Department of Physics, Santa Barbara, California, 93106 (United States); Yoder, R. [Manhattan College, Riverdale, New York, 10471 (United States)

2006-11-27T23:59:59.000Z

3

Numerical modeling of multi-GeV laser wakefield electron acceleration inside a dielectric capillary tube  

SciTech Connect (OSTI)

Numerical modeling of laser wakefield electron acceleration inside a gas filled dielectric capillary tube is presented. Guiding of a short pulse laser inside a dielectric capillary tube over a long distance (?1 m) and acceleration of an externally injected electron bunch to ultra-relativistic energies (?5-10 GeV) are demonstrated in the quasi-linear regime of laser wakefield acceleration. Two dimensional axisymmetric simulations were performed with the code WAKE-EP (Extended Performances), which allows computationally efficient simulations of such long scale plasma. The code is an upgrade of the quasi-static particle code, WAKE [P. Mora and T. M. Antonsen, Jr., Phys. Plasmas 4, 217 (1997)], to simulate the acceleration of an externally injected electron bunch (including beam loading effect) and propagation of the laser beam inside a dielectric capillary. The influence of the transverse electric field of the plasma wake on the radial loss of the accelerated electrons to the dielectric wall is investigated. The stable acceleration of electrons to multi-GeV energy with a non-resonant laser pulse with a large spot-size is demonstrated.

Paradkar, B. S.; Cros, B.; Maynard, G. [Laboratoire de Physique des Gaz et des Plasmas, University Paris Sud 11-CNRS, Orsay (France)] [Laboratoire de Physique des Gaz et des Plasmas, University Paris Sud 11-CNRS, Orsay (France); Mora, P. [Centre de Physique Theorique, CNRS, Ecole Polytechnique, 91128 Palaiseau Cedex (France)] [Centre de Physique Theorique, CNRS, Ecole Polytechnique, 91128 Palaiseau Cedex (France)

2013-08-15T23:59:59.000Z

4

Computational studies and optimization of wakefield accelerators  

E-Print Network [OSTI]

optimization of wakefield accelerators C. G. R. Geddes 1 ,from the U.S. -LHC Accelerator Research Program (LARP),driven plasma wakefield accelerators produce accelerating

Geddes, C.G.R.

2010-01-01T23:59:59.000Z

5

Computational studies and optimization of wakefield accelerators  

E-Print Network [OSTI]

Computational studies and optimization of wakefield accelerators C G R Geddes1 , D L Bruhwiler2 , J-driven plasma wakefield accelerators produce accelerating fields thousands of times higher than radio-frequency accelerators, offering compactness and ultrafast bunches to extend the frontiers of high energy physics

Geddes, Cameron Guy Robinson

6

GeV electrons due to a transition from laser wakefield acceleration to plasma wakefield acceleration  

E-Print Network [OSTI]

We show through experiments that a transition from laser wakefield acceleration (LWFA) regime to a plasma wakefield acceleration (PWFA) regime can drive electrons up to energies close to the GeV level. Initially, the acceleration mechanism is dominated by the bubble created by the laser in the nonlinear regime of LWFA, leading to an injection of a large number of electrons. After propagation beyond the depletion length, leading to a depletion of the laser pulse, whose transverse ponderomotive force is not able to sustain the bubble anymore, the high energy dense bunch of electrons propagating inside bubble will drive its own wakefield by a PWFA regime. This wakefield will be able to trap and accelerate a population of electrons up to the GeV level during this second stage. Three dimensional (3D) particle-in-cell (PIC) simulations support this analysis, and confirm the scenario.

P. E. Masson-Laborde; M. Z. Mo; A. Ali; S. Fourmaux; P. Lassonde; J. C. Kieffer; W. Rozmus; D. Teychenne; R. Fedosejevs

2014-08-06T23:59:59.000Z

7

Development of high gradient laser wakefield accelerators towards nuclear detection applications at LBNL  

E-Print Network [OSTI]

laser wakefield accelerators towards nuclear detectionRecent laser wakefield accelerator experiments at LBNLscaling of laser driven accelerators to GeV energies. Stable

Geddes, Cameron GR

2010-01-01T23:59:59.000Z

8

Laser Wakefield Particle Accelerators Project at NERSC  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsruc DocumentationP-SeriesFlickrinformationPostdocs spaceLaser Wakefield Particle Acceleration Laser

9

COAXIAL TWO-CHANNEL DIELECTRIC WAKE FIELD ACCELERATOR  

SciTech Connect (OSTI)

Theory, computations, and experimental apparatus are presented that describe and are intended to confirm novel properties of a coaxial two-channel dielectric wake field accelerator. In this configuration, an annular drive beam in the outer coaxial channel excites multimode wakefields which, in the inner channel, can accelerate a test beam to an energy much higher than the energy of the drive beam. This high transformer ratio is the result of judicious choice of the dielectric structure parameters, and of the phase separation between drive bunches and test bunches. A structure with cm-scale wakefields has been build for tests at the Argonne Wakefield Accelerator Laboratory, and a structure with mm-scale wakefields has been built for tests at the SLAC FACET facility. Both tests await scheduling by the respective facilities.

Hirshfield, Jay L. [Omega-P, Inc.

2013-04-30T23:59:59.000Z

10

TWO-CHANNEL DIELECTRIC WAKE FIELD ACCELERATOR  

SciTech Connect (OSTI)

Experimental results are reported for test beam acceleration and deflection in a two-channel, cm-scale, rectangular dielectric-lined wakefield accelerator structure energized by a 14-MeV drive beam. The dominant waveguide mode of the structure is at {approx}30 GHz, and the structure is configured to exhibit a high transformer ratio ({approx}12:1). Accelerated bunches in the narrow secondary channel of the structure are continuously energized via Cherenkov radiation that is emitted by a drive bunch moving in the wider primary channel. Observed energy gains and losses, transverse deflections, and changes in the test bunch charge distribution compare favorably with predictions of theory.

Jay L. Hirshfield

2012-05-30T23:59:59.000Z

11

Multiple pulse resonantly enhanced laser plasma wakefield acceleration  

SciTech Connect (OSTI)

We present an outline of experiments being conducted at Oxford University on multiple-pulse, resonantly-enhanced laser plasma wakefield acceleration. This method of laser plasma acceleration uses trains of optimally spaced low energy short pulses to drive plasma oscillations and may enable laser plasma accelerators to be driven by compact and efficient fibre laser sources operating at high repetition rates.

Corner, L.; Walczak, R.; Nevay, L. J.; Dann, S.; Hooker, S. M.; Bourgeois, N.; Cowley, J. [John Adams Institute for Accelerator Science, Oxford University, Denys Wilkinson Building, Keble Road, Oxford OX1 3RH (United Kingdom); Department of Physics, University of Oxford, Clarendon Laboratory, Parks Road, Oxford OX1 3PU (United Kingdom)

2012-12-21T23:59:59.000Z

12

Cast dielectric composite linear accelerator  

DOE Patents [OSTI]

A linear accelerator having cast dielectric composite layers integrally formed with conductor electrodes in a solventless fabrication process, with the cast dielectric composite preferably having a nanoparticle filler in an organic polymer such as a thermosetting resin. By incorporating this cast dielectric composite the dielectric constant of critical insulating layers of the transmission lines of the accelerator are increased while simultaneously maintaining high dielectric strengths for the accelerator.

Sanders, David M. (Livermore, CA); Sampayan, Stephen (Manteca, CA); Slenes, Kirk (Albuquerque, NM); Stoller, H. M. (Albuquerque, NM)

2009-11-10T23:59:59.000Z

13

Outline History Basic Theory Research Future Accelerators References Brief Overview of Wakefield  

E-Print Network [OSTI]

Outline History Basic Theory Research Future Accelerators References Brief Overview of Wakefield Acceleration Eugene S. Evans1 November 9, 2010 1 University of California, Berkeley Eugene S. Evans Brief Overview of Wakefield Acceleration #12;Outline History Basic Theory Research Future Accelerators References

Budker, Dmitry

14

Transverse effects in plasma wakefield acceleration at FACET - Simulation studies  

SciTech Connect (OSTI)

We investigate transverse effects in the plasma-wakefield acceleration experiments planned and ongoing at FACET. We use PIC simulation tools, mainly QuickPIC, to simulate the interaction of the drive electron beam and the plasma. In FACET a number of beam dynamics knobs, including dispersion and bunch length knobs, can be used to vary the beam transverse characteristics in the plasma. We present simulation results and the status of the FACET experimental searches.

Adli, E.; Hogan, M.; Frederico, J.; Litos, M. D.; An, W.; Mori, W. [Department of Physics, University of Oslo, N-0316 Oslo (Norway); SLAC National Accelerator Laboratory, Menlo Park, CA 94025 (United States); University of California Los Angeles, Los Angeles, CA 90024 (United States)

2012-12-21T23:59:59.000Z

15

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

ScienceCinema (OSTI)

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

Andrei Seryi

2010-01-08T23:59:59.000Z

16

RECENT PROGRESS AT LBNL ON CHARACTERIZATION OF LASER WAKEFIELD ACCELERATED ELECTRON BUNCHES USING  

E-Print Network [OSTI]

RECENT PROGRESS AT LBNL ON CHARACTERIZATION OF LASER WAKEFIELD ACCELERATED ELECTRON BUNCHES USING. Schroeder, J. van Tilborg, Cs. T´oth Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA 94720, USA Abstract At LBNL, laser wakefield accelerators (LWFA) can now produce ultra-short electron bunches

Geddes, Cameron Guy Robinson

17

Application of High-performance Visual Analysis Methods to Laser Wakefield Particle Acceleration Data  

E-Print Network [OSTI]

Application of High-performance Visual Analysis Methods to Laser Wakefield Particle Acceleration, time- varying laser wakefield particle accelerator simulation data. We ex- tend histogramBit, a state-of-the-art index/query technology, to acceler- ate data mining and multi-dimensional histogram

18

Multimode Analysis of the Hollow Plasma Channel Wakefield Accelerator C. B. Schroeder,1  

E-Print Network [OSTI]

by resonant excitation [1]. In conventional accelerators, the size of these accel- erating fields is limited particle beam. For the laser wakefield accelerator one of the most se- vere limitations is the weakening- neous plasma. These properties make it well suited as a structure for both particle beam wakefield

Geddes, Cameron Guy Robinson

19

Unphysical kinetic effects in particle-in-cell modeling of laser wakefield accelerators Estelle Cormier-Michel,1,2  

E-Print Network [OSTI]

Unphysical kinetic effects in particle-in-cell modeling of laser wakefield accelerators Estelle of laser wakefield accelerators using particle-in-cell codes are investigated. A dark current free laser wakefield accelerator stage, in which no trapping of background plasma electrons into the plasma wave should

Geddes, Cameron Guy Robinson

20

Beam Head Erosion in Self-Ionized Plasma Wakefield Accelerators  

SciTech Connect (OSTI)

In the recent plasma wakefield accelerator experiments at SLAC, the energy of the particles in the tail of the 42 GeV electron beam were doubled in less than one meter [1]. Simulations suggest that the acceleration length was limited by a new phenomenon--beam head erosion in self-ionized plasmas. In vacuum, a particle beam expands transversely in a distance given by {beta}*. In the blowout regime of a plasma wakefield [2], the majority of the beam is focused by the ion channel, while the beam head slowly spreads since it takes a finite time for the ion channel to form. It is observed that in self-ionized plasmas, the head spreading is exacerbated compared to that in pre-ionized plasmas, causing the ionization front to move backward (erode). A simple theoretical model is used to estimate the upper limit of the erosion rate for a bi-gaussian beam by assuming free expansion of the beam head before the ionization front. Comparison with simulations suggests that half this maximum value can serve as an estimate for the erosion rate. Critical parameters to the erosion rate are discussed.

Berry, M.K.; Blumenfeld, I.; Decker, F.J.; Hogan, M.J.; Ischebeck, R.; Iverson, R.H.; Kirby, N.A.; Siemann, Robert H.; Walz, D.R.; /SLAC; Clayton, C.E.; Huang, C.; Joshi, C.; Lu, W.; Marsh, K.A.; Mori, W.B.; Zhou, M.; /UCLA; Katsouleas, T.C.; Muggli, P.; Oz, E.; /Southern California U.

2008-01-28T23:59:59.000Z

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


21

Efficient operating mode of the plasma wakefield accelerator  

SciTech Connect (OSTI)

A new operating mode of the plasma wakefield accelerator is found at which high efficiency of the driver-to-witness energy exchange can be achieved simultaneously with high transformer ratio and low energy spread. The efficient acceleration is realized in the blowout regime with a high-current moderate-length driver, if most of the driver and the whole witness are inside the cavern, and the beams are shaped to flatten the profile of the longitudinal electric field. The efficient regime can be demonstrated with state-of-the-art electron beams, but requires a longitudinal compression of the drive beam, high density plasma, and precise control of driver and witness shapes.

Lotov, K.V. [Budker Institute of Nuclear Physics, 630090 Novosibirsk (Russian Federation)

2005-05-15T23:59:59.000Z

22

Wakefield Damping in a Pair of X-Band Accelerators for Linear Colliders  

SciTech Connect (OSTI)

We consider means to damp the wake-field left behind ultra-relativistic charges. In particular, we focus on a pair of travelling wave accelerators operating at an X-band frequency of 11.424 GHz. In order to maximize the efficiency of acceleration, in the context of a linear collider, multiple bunches of charged particles are accelerated within a given pulse of the electromagnetic field. The wake-field left behind successive bunches, if left unchecked, can seriously disturb the progress of trailing bunches and can lead to an appreciable dilution in the emittance of the beam. We report on a method to minimize the influence of the wake-field on trailing bunches. This method entails detuning the characteristic mode frequencies which make-up the electromagnetic field, damping the wake-field, and interleaving the frequencies of adjacent accelerating structures. Theoretical predictions of the wake-field and modes, based on a circuit model, are compared with experimental measurements of the wake-field conducted within the ASSET facility at SLAC. Very good agreement is obtained between theory and experiment and this allows us to have some confidence in designing the damping of wake-fields in a future linear collider consisting of several thousand of these accelerating structures.

Jones, R.M.; Adolphsen, C.E.; Wang, J.W.; Li, Z.; /SLAC

2006-12-18T23:59:59.000Z

23

UNDULATOR-BASED LASER WAKEFIELD ACCELERATOR ELECTRON BEAM DIAGNOSTIC  

SciTech Connect (OSTI)

to couple the THUNDER undulator to the LOASIS Lawrence Berkeley National Laboratory (LBNL) laser wakefield accelerator (LWFA). Currently the LWFA has achieved quasi-monoenergetic electron beams with energies up to 1 GeV. These ultra-short, high-peak-current, electron beams are ideal for driving a compact XUV free electron laser (FEL). Understanding the electron beam properties such as the energy spread and emittance is critical for achieving high quality light sources with high brightness. By using an insertion device such as an undulator and observing changes in the spontaneous emission spectrum, the electron beam energy spread and emittance can be measured with high precision. The initial experiments will use spontaneous emission from 1.5 m of undulator. Later experiments will use up to 5 m of undulator with a goal of a high gain, XUV FEL.

Bakeman, M.S.; Fawley, W.M.; Leemans, W. P.; Nakamura, K.; Robinson, K.E.; Schroeder, C.B.; Toth, C.

2009-05-04T23:59:59.000Z

24

Calculation of wakefields in a 17 GHz beam-driven photonic band-gap accelerator structure  

E-Print Network [OSTI]

We present the theoretical analysis and computer simulation of the wakefields in a 17 GHz photonic band-gap (PBG) structure for accelerator applications. Using the commercial code CST Particle Studio, the fundamental ...

Hu, Min

25

Measurement of wakefields generated in accelerator test structures using the SLC  

SciTech Connect (OSTI)

Research is underway at SLAC to develop accelerator structures for the next generation linear collider. An important feature of the design is a detuning of the dipole modes of the cells to suppress the long-range transverse wakefield by two orders of magnitude. This paper describes a facility, called ASSET, that will be incorporated into the SLAC Linear Collider (SLC) to test the long-range wakefield suppression and also to measure the other components of the wakefields generated in accelerator test structures.

Adolphsen, C.; Bane, K.; Loew, G.; Ruth, R.; Thompson, K.; Wang, J.

1992-10-01T23:59:59.000Z

26

A proposal for a 1 GeV plasma-wakefield acceleration experiment at SLAC  

SciTech Connect (OSTI)

A plasma-based wakefield acceleration (PWFA) experiment is proposed that will accelerate parts of an SLC bunch by up to 1 GeV/m over a length of 1 m. A single SLC bunch is used to both induce wakefields in the one meter long plasma and to witness the resulting beam acceleration. The proposed experiment will explore and further develop the techniques that are needed to apply high-gradient plasma wakefield acceleration to large scale accelerators. The one meter length of the experiment is about two orders of magnitude larger than other high-gradient PWFA experiments and the 1 GeV/m accelerating gradient is roughly ten times larger than that achieved with conventional metallic structures. Using existing SLAC facilities, the proposed experiment will allow the study of high-gradient acceleration at the forefront of advanced accelerator research.

Katsouleas, T.; Lee, S. [Univ. of Southern California, Los Angeles, CA (United States); Assmann, R. [Stanford Linear Accelerator Center, Menlo Park, CA (United States)] [and others

1997-07-01T23:59:59.000Z

27

Automatic Beam Path Analysis of Laser Wakefield Particle Acceleration Data  

SciTech Connect (OSTI)

Numerical simulations of laser wakefield particle accelerators play a key role in the understanding of the complex acceleration process and in the design of expensive experimental facilities. As the size and complexity of simulation output grows, an increasingly acute challenge is the practical need for computational techniques that aid in scientific knowledge discovery. To that end, we present a set of data-understanding algorithms that work in concert in a pipeline fashion to automatically locate and analyze high energy particle bunches undergoing acceleration in very large simulation datasets. These techniques work cooperatively by first identifying features of interest in individual timesteps, then integrating features across timesteps, and based on the information derived perform analysis of temporally dynamic features. This combination of techniques supports accurate detection of particle beams enabling a deeper level of scientific understanding of physical phenomena than hasbeen possible before. By combining efficient data analysis algorithms and state-of-the-art data management we enable high-performance analysis of extremely large particle datasets in 3D. We demonstrate the usefulness of our methods for a variety of 2D and 3D datasets and discuss the performance of our analysis pipeline.

Rubel, Oliver; Geddes, Cameron G.R.; Cormier-Michel, Estelle; Wu, Kesheng; Prabhat,; Weber, Gunther H.; Ushizima, Daniela M.; Messmer, Peter; Hagen, Hans; Hamann, Bernd; Bethel, E. Wes

2009-10-19T23:59:59.000Z

28

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

SciTech Connect (OSTI)

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

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

2013-01-15T23:59:59.000Z

29

Properties of Trapped Electron Bunches in a Plasma Wakefield Accelerator  

SciTech Connect (OSTI)

Plasma-based accelerators use the propagation of a drive bunch through plasma to create large electric fields. Recent plasma wakefield accelerator (PWFA) experiments, carried out at the Stanford Linear Accelerator Center (SLAC), successfully doubled the energy for some of the 42 GeV drive bunch electrons in less than a meter; this feat would have required 3 km in the SLAC linac. This dissertation covers one phenomenon associated with the PWFA, electron trapping. Recently it was shown that PWFAs, operated in the nonlinear bubble regime, can trap electrons that are released by ionization inside the plasma wake and accelerate them to high energies. These trapped electrons occupy and can degrade the accelerating portion of the plasma wake, so it is important to understand their origins and how to remove them. Here, the onset of electron trapping is connected to the drive bunch properties. Additionally, the trapped electron bunches are observed with normalized transverse emittance divided by peak current, {epsilon}{sub N,x}/I{sub t}, below the level of 0.2 {micro}m/kA. A theoretical model of the trapped electron emittance, developed here, indicates that the emittance scales inversely with the square root of the plasma density in the non-linear 'bubble' regime of the PWFA. This model and simulations indicate that the observed values of {epsilon}{sub N,x}/I{sub t} result from multi-GeV trapped electron bunches with emittances of a few {micro}m and multi-kA peak currents. These properties make the trapped electrons a possible particle source for next generation light sources. This dissertation is organized as follows. The first chapter is an overview of the PWFA, which includes a review of the accelerating and focusing fields and a survey of the remaining issues for a plasma-based particle collider. Then, the second chapter examines the physics of electron trapping in the PWFA. The third chapter uses theory and simulations to analyze the properties of the trapped electron bunches. Chapters four and five present the experimental diagnostics and measurements for the trapped electrons. Next, the sixth chapter introduces suggestions for future trapped electron experiments. Then, Chapter seven contains the conclusions. In addition, there is an appendix chapter that covers a topic which is extraneous to electron trapping, but relevant to the PWFA. This chapter explores the feasibility of one idea for the production of a hollow channel plasma, which if produced could solve some of the remaining issues for a plasma-based collider.

Kirby, Neil; /SLAC

2009-10-30T23:59:59.000Z

30

Coherent seeding of self-modulated plasma wakefield accelerators  

SciTech Connect (OSTI)

The growth of the beam self-modulation and hosing instabilities initiated by a seed wakefield is examined. Although the growth rates for the self-modulation and hosing instabilities are comparable, it is shown that an externally excited wakefield can be effective in selectively seeding the beam radial self-modulation, enabling the beam to fully modulate before strong beam hosing develops. Methods for coherent seeding are discussed.

Schroeder, C. B.; Benedetti, C.; Esarey, E.; Leemans, W. P. [Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States)] [Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Grüner, F. J. [Universität Hamburg, Luruper Chaussee 149, 22761 Hamburg (Germany)] [Universität Hamburg, Luruper Chaussee 149, 22761 Hamburg (Germany)

2013-05-15T23:59:59.000Z

31

A multi-beam, multi-terawatt Ti:sapphire laser system for laser wake-field acceleration studies  

E-Print Network [OSTI]

­plasma interaction studies, such as development of laser wake-field accelerators [1-4], X-ray lasers, and laserA multi-beam, multi-terawatt Ti:sapphire laser system for laser wake-field acceleration studies 71R0259, 1 Cyclotron Rd., Berkeley, CA 94720, USA, e-mail: ctoth@lbl.gov Abstract. The Lasers

Geddes, Cameron Guy Robinson

32

EXPERIMENTAL DEMONSTRATION OF WAKEFIELD EFFECTS IN A 250 GHZ PLANAR DIAMOND ACCELERATING STRUCTURE*  

E-Print Network [OSTI]

of a rectangular waveguide loaded with polycrystalline CVD diamond plates as an accelerating structure. It should polycrystalline diamond plates loaded in a 6 cm long waveguide (Fig. 2). The beam gap was 200 microns (Fig. TM11EXPERIMENTAL DEMONSTRATION OF WAKEFIELD EFFECTS IN A 250 GHZ PLANAR DIAMOND ACCELERATING STRUCTURE

Brookhaven National Laboratory

33

Laser-driven plasma-based accelerators: Wakefield excitation, channel guiding, and laser triggered particle injection*  

E-Print Network [OSTI]

Laser-driven plasma-based accelerators: Wakefield excitation, channel guiding, and laser triggered; accepted 18 February 1998 Plasma-based accelerators are discussed in which high-power short pulse lasers are the power source, suitably tailored plasma structures provide guiding of the laser beam and support large

Wurtele, Jonathan

34

Characteristics of a tapered capillary plasma waveguide for laser wakefield acceleration  

SciTech Connect (OSTI)

We developed a gas-filled capillary with a tapered density for laser wakefield acceleration, of which the tapering was realized by employing gas feed-lines with different cross-sections. Plasma diagnostics show that the capillary plasma has a significant longitudinal density tapering and a transverse parabolic profile. By using the tapered capillary plasma, high transmission (over 90%) of laser beams, meaning good optical guiding, was observed. These results demonstrate the potential of the tapered plasma source for high-energy laser wakefield acceleration, where the dephasing problem is minimized.

Kim, M. S.; Jang, D. G.; Lee, T. H.; Nam, I. H. [Department of Physics and Photon Science, Gwangju Institute of Science and Technology (GIST), Cheomdan-gwagiro, Buk-gu, Gwangju 500-712 (Korea, Republic of)] [Department of Physics and Photon Science, Gwangju Institute of Science and Technology (GIST), Cheomdan-gwagiro, Buk-gu, Gwangju 500-712 (Korea, Republic of); Lee, I. W.; Suk, H. [Department of Physics and Photon Science, Gwangju Institute of Science and Technology (GIST), Cheomdan-gwagiro, Buk-gu, Gwangju 500-712 (Korea, Republic of) [Department of Physics and Photon Science, Gwangju Institute of Science and Technology (GIST), Cheomdan-gwagiro, Buk-gu, Gwangju 500-712 (Korea, Republic of); APRI, Gwangju Institute of Science and Technology (GIST), Cheomdan-gwagiro, Buk-gu, Gwangju 500-712 (Korea, Republic of)

2013-05-20T23:59:59.000Z

35

Measurement of wakefield suppression in a detuned x-band accelerator structure  

SciTech Connect (OSTI)

Research is underway at SLAC to develop accelerator structures for a next generation linear collider. A full-scale prototype X-band structure has been built in which the dipole mode frequencies were detuned to suppress the long-range transverse wakefield by about two orders of magnitude. To verify that the detuning works as expected, a facility to measure the long-range wakefield, called the Accelerator Structure SETup, or ASSET, was constructed in the SLAC Linear Collider (SLC). This paper presents the results from the measurement of the prototype X-band structure with this facility.

Adolphsen, C.; Bane, K.; Higo, T.; Kubo, K.; Miller, R.; Ruth, R.; Thompson, K.; Wang, J.

1994-08-01T23:59:59.000Z

36

Virtual gap dielectric wall accelerator  

DOE Patents [OSTI]

A virtual, moving accelerating gap is formed along an insulating tube in a dielectric wall accelerator (DWA) by locally controlling the conductivity of the tube. Localized voltage concentration is thus achieved by sequential activation of a variable resistive tube or stalk down the axis of an inductive voltage adder, producing a "virtual" traveling wave along the tube. The tube conductivity can be controlled at a desired location, which can be moved at a desired rate, by light illumination, or by photoconductive switches, or by other means. As a result, an impressed voltage along the tube appears predominantly over a local region, the virtual gap. By making the length of the tube large in comparison to the virtual gap length, the effective gain of the accelerator can be made very large.

Caporaso, George James; Chen, Yu-Jiuan; Nelson, Scott; Sullivan, Jim; Hawkins, Steven A

2013-11-05T23:59:59.000Z

37

Observation of laser multiple filamentation process and multiple electron beams acceleration in a laser wakefield accelerator  

SciTech Connect (OSTI)

The multiple filaments formation process in the laser wakefield accelerator (LWFA) was observed by imaging the transmitted laser beam after propagating in the plasma of different density. During propagation, the laser first self-focused into a single filament. After that, it began to defocus with energy spreading in the transverse direction. Two filaments then formed from it and began to propagate independently, moving away from each other. We have also demonstrated that the laser multiple filamentation would lead to the multiple electron beams acceleration in the LWFA via ionization-induced injection scheme. Besides, its influences on the accelerated electron beams were also analyzed both in the single-stage LWFA and cascaded LWFA.

Li, Wentao; Liu, Jiansheng; Wang, Wentao; Chen, Qiang; Zhang, Hui; Tian, Ye; Zhang, Zhijun; Qi, Rong; Wang, Cheng; Leng, Yuxin; Li, Ruxin; Xu, Zhizhan [State Key Laboratory of High Field Laser Physics, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, P.O. Box 800-211, Shanghai 201800 (China)] [State Key Laboratory of High Field Laser Physics, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, P.O. Box 800-211, Shanghai 201800 (China)

2013-11-15T23:59:59.000Z

38

Role of stochastic heating in wakefield acceleration when optical injection is used  

SciTech Connect (OSTI)

The dynamics of an electron in two counterpropagating waves is investigated. Conditions for stochastic acceleration are derived. The possibility of stochastic heating is confirmed when two waves interact with low density plasma by performing PIC (Particle In Cell) code simulations. It is shown that stochastic heating can play an important role in laser wakefield acceleration. When considering low density plasma interacting with a high intensity wave perturbed by a low intensity counterpropagating wave, stochastic heating can provide electrons with the right momentum for trapping in the wakefield. The influence of stochastic acceleration on the trapping of electrons is compared to the one of the beatwave force which is responsible for cold injection. To do so, several polarizations for the colliding pulses are considered. For some value of the plasma density and pulse duration, a transition from an injection due to stochastic acceleration to a cold injection dominated regime—regarding the trapped charge—has been observed from 2D and 3D PIC code simulations. This transition is ruled by the ratio of the interaction length of the pulses to the longitudinal size of the bubble. When the interaction length of the laser pulses reaches the radius of the accelerating cavity stochastic heating becomes dominant, and might be necessary to get electrons trapped into the wakefield, when wakefield inhibition grows with plasma density.

Rassou, S.; Bourdier, A.; Drouin, M. [CEA, DAM, DIF, 91297 Arpajon (France)

2014-08-15T23:59:59.000Z

39

Spectroscopy of betatron radiation emitted from laser-produced wakefield accelerated electronsa...  

E-Print Network [OSTI]

laser facilities in which the nature divergence and total x-ray flux of the betatron radiation has been is able to discern changes of the betatron emission x-ray spec- trum with differing laser parametersSpectroscopy of betatron radiation emitted from laser-produced wakefield accelerated electronsa

Geddes, Cameron Guy Robinson

40

Generation of electron beams from a laser wakefield acceleration in pure neon gas  

SciTech Connect (OSTI)

We report on the generation of quasimonoenergetic electron beams by the laser wakefield acceleration of 17–50 TW, 30 fs laser pulses in pure neon gas jet. The generated beams have energies in the range 40–120?MeV and up to ?430 pC of charge. At a relatively high density, we observed multiple electron beamlets which has been interpreted by simulations to be the result of breakup of the laser pulse into multiple filaments in the plasma. Each filament drives its own wakefield and generates its own electron beamlet.

Li, Song; Hafz, Nasr A. M., E-mail: nasr@sjtu.edu.cn; Mirzaie, Mohammad; Elsied, Ahmed M. M.; Ge, Xulei; Liu, Feng; Sokollik, Thomas; Chen, Min; Sheng, Zhengming; Zhang, Jie, E-mail: jzhang1@sjtu.edu.cn [Key Laboratory for Laser Plasmas (MOE) and Department of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240 (China); Tao, Mengze; Chen, Liming [Bejing National Laboratory of Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190 (China)

2014-08-15T23:59:59.000Z

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


41

A Proposal for a 1 GeV Plasma-Wakefield Acceleration Experiment at SLAC T. Katsouleas, S. Lee, USC  

E-Print Network [OSTI]

on the size and the cost of linear colliders can only be overcome if the acceleration per unit length limitations are avoided and very high gradients can be achieved. A recent laser-driven plasma wakefield

42

Injection and acceleration of electron bunch in a plasma wakefield produced by a chirped laser pulse  

SciTech Connect (OSTI)

An ultrashort laser pulse propagating in plasma can excite a nonlinear plasma wakefield which can trap and accelerate charged particles up to GeV. One-dimensional analysis of electron injection, trapping, and acceleration by different chirped pulses propagating in plasma is investigated numerically. In this paper, we inject electron bunches in front of the chirped pulses. It is indicated that periodical chirped laser pulse can trap electrons earlier than other pulses. It is shown that periodical chirped laser pulses lead to decrease the minimum momentum necessary to trap the electrons. This is due to the fact that periodical chirped laser pulses are globally much efficient than nonchirped pulses in the wakefield generation. It is found that chirped laser pulses could lead to much larger electron energy than that of nonchirped pulses. Relative energy spread has a lower value in the case of periodical chirped laser pulses.

Afhami, Saeedeh; Eslami, Esmaeil, E-mail: eeslami@iust.ac.ir [Department of Physics, Iran University of Science and Technology (IUST), Narmak, Tehran 16846-13114 (Iran, Islamic Republic of)

2014-06-15T23:59:59.000Z

43

Emittance and Current of Electrons Trapped in a Plasma Wakefield Accelerator  

SciTech Connect (OSTI)

In recent experiments plasma electrons became trapped in a plasma wakefield accelerator (PWFA). The transverse size of these trapped electrons on a downstream diagnostic yields an upper limit measurement of transverse normalized emittance divided by peak current, {var_epsilon}{sub N,x}/I. The lowest upper limit for {var_epsilon}{sub N,x}/I measured in the experiment is 1.3 {center_dot} 10{sup -10} m/A.

Kirby, N; Blumenfeld, I; Clayton, C.E.; Decker, F.J.; Hogan, M.J.; Huang, C.; Ischebeck, R.; Iverson, R.H.; Joshi, C.; Katsouleas, T.; Lu, W.; Marsh, K.A.; Mori, W.B.; Muggli, P; Oz, E.; Siemann, R.H.; Walz, D.R.; Zhou, M.; /SLAC /UCLA /USC

2008-09-24T23:59:59.000Z

44

Spectrum bandwidth narrowing of Thomson scattering X-rays with energy chirped electron beams from laser wakefield acceleration  

SciTech Connect (OSTI)

We study incoherent Thomson scattering between an ultrashort laser pulse and an electron beam accelerated from a laser wakefield. The energy chirp effects of the accelerated electron beam on the final radiation spectrum bandwidth are investigated. It is found that the scattered X-ray radiation has the minimum spectrum width and highest intensity as electrons are accelerated up to around the dephasing point. Furthermore, it is proposed that the electron acceleration process inside the wakefield can be studied by use of 90° Thomson scattering. The dephasing position and beam energy chirp can be deduced from the intensity and bandwidth of the scattered radiation.

Xu, Tong; Chen, Min, E-mail: minchen@sjtu.edu.cn; Li, Fei-Yu; Yu, Lu-Le [Key Laboratory for Laser Plasmas (Ministry of Education), Department of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240 (China)] [Key Laboratory for Laser Plasmas (Ministry of Education), Department of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240 (China); Sheng, Zheng-Ming, E-mail: zmsheng@sjtu.edu.cn [Key Laboratory for Laser Plasmas (Ministry of Education), Department of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240 (China) [Key Laboratory for Laser Plasmas (Ministry of Education), Department of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240 (China); SUPA, Department of Physics, University of Strathclyde, Glasgow G4 0NG (United Kingdom); Zhang, Jie [Key Laboratory for Laser Plasmas (Ministry of Education), Department of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240 (China) [Key Laboratory for Laser Plasmas (Ministry of Education), Department of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240 (China); Beijing National Laboratory of Condensed Matter Physics, Institute of Physics, CAS, Beijing 100190 (China)

2014-01-06T23:59:59.000Z

45

Proton-driven plasma wakefield acceleration: a path to the future of high-energy particle physics  

E-Print Network [OSTI]

New acceleration technology is mandatory for the future elucidation of fundamental particles and their interactions. A promising approach is to exploit the properties of plasmas. Past research has focused on creating large-amplitude plasma waves by injecting an intense laser pulse or an electron bunch into the plasma. However, the maximum energy gain of electrons accelerated in a single plasma stage is limited by the energy of the driver. Proton bunches are the most promising drivers of wakefields to accelerate electrons to the TeV energy scale in a single stage. An experimental program at CERN -- the AWAKE experiment -- has been launched to study in detail the important physical processes and to demonstrate the power of proton-driven plasma wakefield acceleration. Here we review the physical principles and some experimental considerations for a future proton-driven plasma wakefield accelerator.

AWAKE Collaboration; R. Assmann; R. Bingham; T. Bohl; C. Bracco; B. Buttenschon; A. Butterworth; A. Caldwell; S. Chattopadhyay; S. Cipiccia; E. Feldbaumer; R. A. Fonseca; B. Goddard; M. Gross; O. Grulke; E. Gschwendtner; J. Holloway; C. Huang; D. Jaroszynski; S. Jolly; P. Kempkes; N. Lopes; K. Lotov; J. Machacek; S. R. Mandry; J. W. McKenzie; M. Meddahi; B. L. Militsyn; N. Moschuering; P. Muggli; Z. Najmudin; T. C. Q. Noakes; P. A. Norreys; E. Oz; A. Pardons; A. Petrenko; A. Pukhov; K. Rieger; O. Reimann; H. Ruhl; E. Shaposhnikova; L. O. Silva; A. Sosedkin; R. Tarkeshian; R. M. G. N. Trines; T. Tuckmantel; J. Vieira; H. Vincke; M. Wing; G. Xia

2014-04-02T23:59:59.000Z

46

Proton-driven plasma wakefield acceleration: a path to the future of high-energy particle physics  

E-Print Network [OSTI]

New acceleration technology is mandatory for the future elucidation of fundamental particles and their interactions. A promising approach is to exploit the properties of plasmas. Past research has focused on creating large-amplitude plasma waves by injecting an intense laser pulse or an electron bunch into the plasma. However, the maximum energy gain of electrons accelerated in a single plasma stage is limited by the energy of the driver. Proton bunches are the most promising drivers of wakefields to accelerate electrons to the TeV energy scale in a single stage. An experimental program at CERN -- the AWAKE experiment -- has been launched to study in detail the important physical processes and to demonstrate the power of proton-driven plasma wakefield acceleration. Here we review the physical principles and some experimental considerations for a future proton-driven plasma wakefield accelerator.

Assmann, R; Bohl, T; Bracco, C; Buttenschon, B; Butterworth, A; Caldwell, A; Chattopadhyay, S; Cipiccia, S; Feldbaumer, E; Fonseca, R A; Goddard, B; Gross, M; Grulke, O; Gschwendtner, E; Holloway, J; Huang, C; Jaroszynski, D; Jolly, S; Kempkes, P; Lopes, N; Lotov, K; Machacek, J; Mandry, S R; McKenzie, J W; Meddahi, M; Militsyn, B L; Moschuering, N; Muggli, P; Najmudin, Z; Noakes, T C Q; Norreys, P A; Oz, E; Pardons, A; Petrenko, A; Pukhov, A; Rieger, K; Reimann, O; Ruhl, H; Shaposhnikova, E; Silva, L O; Sosedkin, A; Tarkeshian, R; Trines, R M G N; Tuckmantel, T; Vieira, J; Vincke, H; Wing, M; Xia, G

2014-01-01T23:59:59.000Z

47

Proton-driven plasma wakefield acceleration: a path to the future of high-energy particle physics  

E-Print Network [OSTI]

New acceleration technology is mandatory for the future elucidation of fundamental particles and their interactions. A promising approach is to exploit the properties of plasmas. Past research has focused on creating large-amplitude plasma waves by injecting an intense laser pulse or an electron bunch into the plasma. However, the maximum energy gain of electrons accelerated in a single plasma stage is limited by the energy of the driver. Proton bunches are the most promising drivers of wakefields to accelerate electrons to the TeV energy scale in a single stage. An experimental program at CERN { the AWAKE experiment { has been launched to study in detail the important physical processes and to demonstrate the power of proton-driven plasma wakefield acceleration. Here we review the physical principles and some experimental considerations for a future proton-driven plasma wakefield accelerator.

Assmann, R; Bohl, T; Bracco, C; Buttenschon, B; Butterworth, A; Caldwell, A; Chattopadhyay, S; Cipiccia, S; Feldbaumer, E; Fonseca, R A; Goddard, B; Gross, M; Grulke, O; Gschwendtner, E; Holloway, J; Huang, C; Jaroszynski, D; Jolly, S; Kempkes, P; Lopes, N; Lotov, K; Machacek, J; Mandry, S R; McKenzie, J W; Meddahi, M; Militsyn, B L; Moschuering, N; Muggli, P; Najmudin, Z; Noakes, T C Q; Norreys, P A; Oz, E; Pardons, A; Petrenko, A; Pukhov, A; Rieger, K; Reimann, O; Ruhl, H; Shaposhnikova, E; Silva, L O; Sosedkin, A; Tarkeshian, R; Trines, R M G N; Tuckmantel, T; Vieira, J; Vincke, H; Wing, M; Xia G , G

2014-01-01T23:59:59.000Z

48

Energy Doubling of 42 GeV Electrons in a Meter-scale Plasma Wakefield Accelerator  

SciTech Connect (OSTI)

The energy frontier of particle physics is several trillion electron volts, but colliders capable of reaching this regime (such as the Large Hadron Collider and the International Linear Collider) are costly and time-consuming to build; it is therefore important to explore new methods of accelerating particles to high energies. Plasma-based accelerators are particularly attractive because they are capable of producing accelerating fields that are orders of magnitude larger than those used in conventional colliders. In these accelerators, a drive beam (either laser or particle) produces a plasma wave (wakefield) that accelerates charged particles. The ultimate utility of plasma accelerators will depend on sustaining ultrahigh accelerating fields over a substantial length to achieve a significant energy gain. Here we show that an energy gain of more than 42 GeV is achieved in a plasma wakefield accelerator of 85 cm length, driven by a 42 GeV electron beam at the Stanford Linear Accelerator Center (SLAC). The results are in excellent agreement with the predictions of three-dimensional particle-in-cell simulations. Most of the beam electrons lose energy to the plasma wave, but some electrons in the back of the same beam pulse are accelerated with a field of {approx} 52GV m{sup -1}. This effectively doubles their energy, producing the energy gain of the 3-km-long SLAC accelerator in less than a meter for a small fraction of the electrons in the injected bunch. This is an important step towards demonstrating the viability of plasma accelerators for high-energy physics applications.

Blumenfeld, Ian; Clayton, Christopher E.; Decker, Franz-Josef; Hogan, Mark J.; Huang, Chengkun; Ischebeck, Rasmus; Iverson, Richard; Joshi, Chandrashekhar; Katsouleas,; Kirby, Neil; Lu, Wei; Marsh, Kenneth A.; Mori, Warren B.; Muggli, Patric; Oz, Erdem; Siemann, Robert H.; Walz, Dieter; Zhou, Miaomiao; /SLAC /UCLA /Southern California U.

2007-03-14T23:59:59.000Z

49

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

SciTech Connect (OSTI)

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

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

2013-08-15T23:59:59.000Z

50

Laser-PlasmaWakefield Acceleration with Higher Order Laser Modes  

E-Print Network [OSTI]

Design considerations for a laser-plasma linear collider,"E.Esarey, and W.P.Leemans, "Free-electron laser driven bythe LBNL laser-plasma accelerator," in Proc. Adv. Acc. Con.

Geddes, C.G.R.

2011-01-01T23:59:59.000Z

51

Detailed dynamics of electron beams self-trapped and accelerated in a self-modulated laser wakefield  

E-Print Network [OSTI]

. These features are explained by analysis and test particle simulations of electron dynamics during acceleration wave,1 such as the plasma wakefield accel- erator, the plasma beat-wave accelerator, the Laser Wake the linear dephasing limit, and explained it, using Particle-In-Cell PIC simulations, as a result

Umstadter, Donald

52

Correlation of Beam Parameters to Decelerating Gradient in the E-167 Plasma Wakefield Acceleration Experiment  

SciTech Connect (OSTI)

Recent experiments at SLAC have shown that high gradient acceleration of electrons is achievable in meter scale plasmas [1,2]. Results from these experiments show that the wakefield is sensitive to parameters in the electron beam which drives it. In the experiment the bunch length and beam waist location were varied systematically at constant charge. Here we investigate the correlation of peak beam current to the decelerating gradient. Limits on the transformer ratio will also be discussed. The results are compared to simulation.

Blumenfeld, I.; Berry, M.; Decker, F.-J.; Hogan, M.J.; Ischebeck, R.; Iverson, R.; Kirby, N.; Siemann, R.; Walz, D.; /SLAC; Clayton, C.E.; Huang, C.; Joshi, C.; Lu, W.; Marsh, K.A.; Mori, W.B.; Zhou, M.; /UCLA; Katsouleas, T.C.; Muggli, P.; Oz, E.; /Southern California U.

2007-06-27T23:59:59.000Z

53

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

SciTech Connect (OSTI)

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

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

2012-12-21T23:59:59.000Z

54

Laser red shifting based characterization of wakefield excitation in a laser-plasma accelerator  

SciTech Connect (OSTI)

Optical spectra of a drive laser exiting a channel guided laser-plasma accelerator (LPA) are analyzed through experiments and simulations to infer the magnitude of the excited wakefields. The experiments are performed at sufficiently low intensity levels and plasma densities to avoid electron beam generation via self-trapping. Spectral redshifting of the laser light is studied as an indicator of the efficiency of laser energy transfer into the plasma through the generation of coherent plasma wakefields. Influences of input laser energy, plasma density, temporal and spatial laser profiles, and laser focal location in a plasma channel are analyzed. Energy transfer is found to be sensitive to details of laser pulse shape and focal location. The experimental conditions for these critical parameters are modeled and included in particle-in-cell simulations. Simulations reproduce the redshift of the laser within uncertainties of the experiments and produce an estimate of the wake amplitudes in the experiments as a function of amount of redshift. The results support the practical use of laser redshifting to quantify the longitudinally averaged accelerating field that a particle would experience in an LPA powered below the self-trapping limit.

Shiraishi, S.; Benedetti, C.; Gonsalves, A. J.; Nakamura, K.; Shaw, B. H.; Sokollik, T.; Tilborg, J. van; Geddes, C. G. R.; Schroeder, C. B.; Tóth, Cs.; Esarey, E.; Leemans, W. P. [Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States)] [Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States)

2013-06-15T23:59:59.000Z

55

Laser-seeded modulation instability in a proton driver plasma wakefield accelerator  

SciTech Connect (OSTI)

A new method for initiating the modulation instability (MI) of a proton beam in a proton driver plasma wakefield accelerator using a short laser pulse preceding the beam is presented. A diffracting laser pulse is used to produce a plasma wave that provides a seeding modulation of the proton bunch with the period equal to that of the plasma wave. Using the envelope description of the proton beam, this method of seeding the MI is analytically compared with the earlier suggested seeding technique that involves an abrupt truncation of the proton bunch. The full kinetic simulation of a realistic proton bunch is used to validate the analytic results. It is further used to demonstrate that a plasma density ramp placed in the early stages of the laser-seeded MI leads to its stabilization, resulting in sustained accelerating electric fields (of order several hundred MV/m) over long propagation distances (?100–1000 m)

Siemon, Carl; Khudik, Vladimir; Austin Yi, S.; Shvets, Gennady [Department of Physics and Institute for Fusion Studies, The University of Texas at Austin, Austin, Texas 78712 (United States)] [Department of Physics and Institute for Fusion Studies, The University of Texas at Austin, Austin, Texas 78712 (United States); Pukhov, Alexander [Institut für Theoretische Physik I, Universität Düsseldorf, Düsseldorf 40225 (Germany)] [Institut für Theoretische Physik I, Universität Düsseldorf, Düsseldorf 40225 (Germany)

2013-10-15T23:59:59.000Z

56

Application of High-performance Visual Analysis Methods to Laser Wakefield Particle Acceleration Data  

SciTech Connect (OSTI)

Our work combines and extends techniques from high-performance scientific data management and visualization to enable scientific researchers to gain insight from extremely large, complex, time-varying laser wakefield particle accelerator simulation data. We extend histogram-based parallel coordinates for use in visual information display as well as an interface for guiding and performing data mining operations, which are based upon multi-dimensional and temporal thresholding and data subsetting operations. To achieve very high performance on parallel computing platforms, we leverage FastBit, a state-of-the-art index/query technology, to accelerate data mining and multi-dimensional histogram computation. We show how these techniques are used in practice by scientific researchers to identify, visualize and analyze a particle beam in a large, time-varying dataset.

Rubel, Oliver; Prabhat, Mr.; Wu, Kesheng; Childs, Hank; Meredith, Jeremy; Geddes, Cameron G.R.; Cormier-Michel, Estelle; Ahern, Sean; Weber, Gunther H.; Messmer, Peter; Hagen, Hans; Hamann, Bernd; Bethel, E. Wes

2008-08-28T23:59:59.000Z

57

Electron self-injection in the proton-driven-plasma-wakefield acceleration  

SciTech Connect (OSTI)

The self-injection process of plasma electrons in the proton-driven-plasma-wakefield acceleration scheme is investigated using a two-dimensional, electromagnetic particle-in-cell method. Plasma electrons are self-injected into the back of the first acceleration bucket during the initial bubble formation period, where the wake phase velocity is low enough to trap sufficient electrons. Most of the self-injected electrons are initially located within a distance of the skin depth c/?{sub pe} to the beam axis. A decrease (or increase) in the beam radius (or length) leads to a significant reduction in the total charges of self-injected electron bunch. Compared to the uniform plasma, the energy spread, emittance and total charges of the self-injected bunch are reduced in the plasma channel case, due to a reduced injection of plasma electrons that initially located further away from the beam axis.

Hu, Zhang-Hu; Wang, You-Nian [School of Physics and Optoelectronic Technology, Dalian University of Technology, Dalian 116024 (China)] [School of Physics and Optoelectronic Technology, Dalian University of Technology, Dalian 116024 (China)

2013-12-15T23:59:59.000Z

58

Simulations of laser-wakefield acceleration with external electron-bunch injection for REGAE experiments at DESY  

SciTech Connect (OSTI)

We present particle-in-cell simulations for future laser-plasma wakefield experiments with external bunch injection at the REGAE accelerator facility at DESY, Hamburg, Germany. Two effects have been studied in detail: emittance evolution of electron bunches externally injected into a wake, and longitudinal bunch compression inside the wakefield. Results show significant transverse emittance growth during the injection process, if the electron bunch is not matched to its intrinsic betatron motion inside the wakefield. This might introduce the necessity to include beam-matching sections upstream of each plasma-accelerator section with fundamental implications on the design of staged laser wakefield accelerators. When externally injected at the zero-field crossing of the laser-driven wake, the electron bunch may undergo significant compression in longitudinal direction and be accelerated simultaneously due to the gradient in the acting force. The mechanism would allow for production of single high-energy, ultra-short (on the order of one femtosecond) bunches at REGAE. The optimal conditions for maximal bunch compression are discussed in the presented studies.

Grebenyuk, Julia; Mehrling, Timon; Tsung, Frank S.; Floettman, Klaus; Osterhoff, Jens [Deutsches Elektronen-Synchrotron DESY, 22607 Hamburg (Germany); Institut fuer Experimentalphysik, Universitaet Hamburg, 22761 Hamburg (Germany); University of California, Los Angeles, CA 90095 (United States); Deutsches Elektronen-Synchrotron DESY, 22607 Hamburg (Germany); Institut fuer Experimentalphysik, Universitaet Hamburg, 22761 Hamburg (Germany)

2012-12-21T23:59:59.000Z

59

Analytic model of electron self-injection in a plasma wakefield accelerator in the strongly nonlinear bubble regime  

SciTech Connect (OSTI)

Self-injection of background electrons in plasma wakefield accelerators in the highly nonlinear bubble regime is analyzed using particle-in-cell and semi-analytic modeling. It is shown that the return current in the bubble sheath layer is crucial for accurate determination of the trapped particle trajectories.

Yi, S. A.; Khudik, V.; Siemon, C.; Shvets, G. [Department of Physics and Institute for Fusion Studies, University of Texas at Austin, One University Station C1500, Austin, Texas (United States)

2012-12-21T23:59:59.000Z

60

Enhanced dielectric-wall linear accelerator  

DOE Patents [OSTI]

A dielectric-wall linear accelerator is enhanced by a high-voltage, fast e-time switch that includes a pair of electrodes between which are laminated alternating layers of isolated conductors and insulators. A high voltage is placed between the electrodes sufficient to stress the voltage breakdown of the insulator on command. A light trigger, such as a laser, is focused along at least one line along the edge surface of the laminated alternating layers of isolated conductors and insulators extending between the electrodes. The laser is energized to initiate a surface breakdown by a fluence of photons, thus causing the electrical switch to close very promptly. Such insulators and lasers are incorporated in a dielectric wall linear accelerator with Blumlein modules, and phasing is controlled by adjusting the length of fiber optic cables that carry the laser light to the insulator surface. 6 figs.

Sampayan, S.E.; Caporaso, G.J.; Kirbie, H.C.

1998-09-22T23:59:59.000Z

Note: This page contains sample records for the topic "dielectric wakefield accelerator" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
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61

Measurements of the critical power for self-injection of electrons in a laser wakefield accelerator  

SciTech Connect (OSTI)

A laser wakefield acceleration study has been performed in the matched, self-guided, blow-out regime where a 10 J, 60 fs laser produced 720 {+-} 50 MeV quasi-monoenergetic electrons with a divergence of {Delta}{theta} = 2.85 {+-} 0.15 mRad. While maintaining a nearly constant plasma density (3 x 10{sup 18} cm{sup -3}), a linear electron energy gain was measured from 100 MeV to 700 MeV when the plasma length was scaled from 3 mm to 8 mm. Absolute charge measurements indicate that self-injection occurs when P/P{sub cr} > 4 and saturates around 100 pC for P/P{sub cr} > 12. The results are compared with both analytical scalings and full 3D particle-in-cell simulations.

Froula, D H; Clayton, C E; Doppner, T; Fonseca, R A; Marsh, K A; Barty, C J; Divol, L; Glenzer, S H; Joshi, C; Lu, W; Martins, S F; Michel, P; Mori, W; Palastro, J P; Pollock, B B; Pak, A; Ralph, J E; Ross, J S; Siders, C; Silva, L O; Wang, T

2009-06-02T23:59:59.000Z

62

Self-truncated ionization injection and consequent monoenergetic electron bunches in laser wakefield acceleration  

SciTech Connect (OSTI)

The ionization-induced injection in laser wakefield acceleration has been recently demonstrated to be a promising injection scheme. However, the energy spread controlling in this mechanism remains a challenge because continuous injection in a mixed gas target is usually inevitable. Here, we propose that by use of certain initially unmatched laser pulses, the electron injection can be constrained to the very front region of the mixed gas target, typically in a length of a few hundreds micrometers determined by the laser self-focusing and the wake deformation. As a result, the produced electron beam has narrow energy spread and meanwhile contains tens of pC in charge. Both multidimensional simulations and theoretical analysis illustrate the effectiveness of this scheme.

Zeng, Ming; Zhang, Jie [Key Laboratory for Laser Plasmas (Ministry of Education), Department of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240 (China)] [Key Laboratory for Laser Plasmas (Ministry of Education), Department of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240 (China); Chen, Min, E-mail: minchen@sjtu.edu.cn [Key Laboratory for Laser Plasmas (Ministry of Education), Department of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240 (China) [Key Laboratory for Laser Plasmas (Ministry of Education), Department of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240 (China); Department of Mathematics, Institute of Natural Sciences, and MOE-LSC, Shanghai Jiao Tong University, Shanghai 20040 (China); Sheng, Zheng-Ming, E-mail: zmsheng@sjtu.edu.cn [Key Laboratory for Laser Plasmas (Ministry of Education), Department of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240 (China) [Key Laboratory for Laser Plasmas (Ministry of Education), Department of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240 (China); SUPA, Department of Physics, University of Strathclyde, Glasgow G4 0NG (United Kingdom); Mori, Warren B. [University of California, Los Angeles, California 90095 (United States)] [University of California, Los Angeles, California 90095 (United States)

2014-03-15T23:59:59.000Z

63

An ultrashort pulse ultra-violet radiation undulator source driven by a laser plasma wakefield accelerator  

SciTech Connect (OSTI)

Narrow band undulator radiation tuneable over the wavelength range of 150–260?nm has been produced by short electron bunches from a 2?mm long laser plasma wakefield accelerator based on a 20?TW femtosecond laser system. The number of photons measured is up to 9?×?10{sup 6} per shot for a 100 period undulator, with a mean peak brilliance of 1?×?10{sup 18} photons/s/mrad{sup 2}/mm{sup 2}/0.1% bandwidth. Simulations estimate that the driving electron bunch r.m.s. duration is as short as 3 fs when the electron beam has energy of 120–130?MeV with the radiation pulse duration in the range of 50–100 fs.

Anania, M. P. [SUPA, Department of Physics, University of Strathclyde, Glasgow G4 0NG (United Kingdom); INFN, Laboratori Nazionali di Frascati, I-00044 Frascati (Italy); Brunetti, E.; Wiggins, S. M.; Grant, D. W.; Welsh, G. H.; Issac, R. C.; Cipiccia, S.; Shanks, R. P.; Manahan, G. G.; Aniculaesei, C.; Jaroszynski, D. A., E-mail: d.a.jaroszynski@strath.ac.uk [SUPA, Department of Physics, University of Strathclyde, Glasgow G4 0NG (United Kingdom); Geer, S. B. van der; Loos, M. J. de [Pulsar Physics, Burghstraat 47, 5614 BC Eindhoven (Netherlands); Poole, M. W.; Shepherd, B. J. A.; Clarke, J. A. [ASTeC, STFC, Daresbury Laboratory, Warrington WA4 4AD (United Kingdom); Gillespie, W. A. [SUPA, School of Engineering, Physics and Mathematics, University of Dundee, Dundee DD1 4HN (United Kingdom); MacLeod, A. M. [School of Computing and Creative Technologies, University of Abertay Dundee, Dundee DD1 1HG (United Kingdom)

2014-06-30T23:59:59.000Z

64

High-quality electron beam from laser wake-field acceleration in laser produced plasma plumes  

SciTech Connect (OSTI)

Generation of highly collimated ({theta}{sub div}{approx}10 mrad), quasi-monoenergetic electron beam with peak energy 12 MeV and charge {approx}50 pC has been experimentally demonstrated from self-guided laser wake-field acceleration (LWFA) in a plasma plume produced by laser ablation of solid nylon (C{sub 12}H{sub 22}N{sub 2}O{sub 2}){sub n} target. A 7 TW, 45 fs Ti:sapphire laser system was used for LWFA, and the plasma plume forming pulse was derived from the Nd:YAG pump laser of the same system. The results show that a reproducible, high quality electron beam could be produced from this scheme which is simple, low cost and has the capability for high repetition rate operation.

Sanyasi Rao, Bobbili; Moorti, Anand; Rathore, Ranjana; Ali Chakera, Juzer; Anant Naik, Prasad; Dass Gupta, Parshotam [Laser Plasma Division, Raja Ramanna Centre for Advanced Technology, Indore 452013 (India)] [Laser Plasma Division, Raja Ramanna Centre for Advanced Technology, Indore 452013 (India)

2013-06-10T23:59:59.000Z

65

DIELECTRIC WAKE FIELD RESONATOR ACCELERATOR MODULE  

SciTech Connect (OSTI)

Results are presented from experiments, and numerical analysis of wake fields set up by electron bunches passing through a cylindrical or rectangular dielectric-lined structure. These bunches excite many TM-modes, with Ez components of the wake fields sharply localized on the axis of the structure periodically behind the bunches. The experiment with the cylindrical structure, carried out at ATF Brookhaven National Laboratory, used up to three 50 MeV bunches spaced by one wake field period (21 cm) to study the superposition of wake fields by measuring the energy loss of each bunch after it passed through the 53-cm long dielectric element. The millimeter-wave spectrum of radiation excited by the passage of bunches is also studied. Numerical analysis was aimed not only to simulate the behavior of our device, but in general to predict dielectric wake field accelerator performance. It is shown that one needs to match the radius of the cylindrical dielectric channel with the bunch longitudinal rms-length to achieve optimal performance.

Hirshfield, Jay L.

2013-11-06T23:59:59.000Z

66

Quasimonoenergetic collimated electron beams from a laser wakefield acceleration in low density pure nitrogen  

SciTech Connect (OSTI)

A laser wakefield acceleration (LWFA) experiment is performed using 30 TW, 30 fs, and 800?nm laser pulses, focused onto pure nitrogen plasma having relatively low densities in the range of 0.8×10{sup 18}?cm{sup ?3} to 2.7×10{sup 18}?cm{sup ?3}. Electron beams having a low divergence of ?3??mrad (full-width at half-maximum) and quasi-monoenergetic peak energies of ?105??MeV are achieved over 4-mm interaction length. The total electron beam charge reached to 2 nC, however, only 1%–2% of this (tens of pC) had energies >35?MeV. We tried different conditions to optimize the electron beam acceleration; our experiment verifies that lower nitrogen plasma densities are generating electron beams with high quality in terms of divergence, charge, pointing stability, and maximum energy. In addition, if LWFA is to be widely used as a basis for compact particle accelerators in the future, therefore, from the economic and safety points of view we propose the use of nitrogen gas rather than helium or hydrogen.

Tao, Mengze [Key Laboratory for Laser Plasmas (MOE) and Department of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240 (China); Bejing National Laboratory of Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190 (China); Hafz, Nasr A. M., E-mail: nasr@sjtu.edu.cn; Li, Song; Mirzaie, Mohammad; Elsied, Ahmed M. M.; Ge, Xulei; Liu, Feng; Sokollik, Thomas; Sheng, Zhengming; Zhang, Jie, E-mail: jzhang1@sjtu.edu.cn [Key Laboratory for Laser Plasmas (MOE) and Department of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240 (China); Chen, Liming [Bejing National Laboratory of Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190 (China)

2014-07-15T23:59:59.000Z

67

Wakefield and RF Kicks Due to Coupler Asymmetry in TESLA-Type Accelerating Cavities  

SciTech Connect (OSTI)

In a future linear collider, such as the International Linear Collider (ILC), trains of high current, low emittance bunches will be accelerated in a linac before colliding at the interaction point. Asymmetries in the accelerating cavities of the linac will generate fields that will kick the beam transversely and degrade the beam emittance and thus the collider performance. In the main linac of the ILC, which is filled with TESLA-type superconducting cavities, it is the fundamental (FM) and higher mode (HM) couplers that are asymmetric and thus the source of such kicks. The kicks are of two types: one, due to (the asymmetry in) the fundamental RF fields and the other, due to transverse wakefields that are generated by the beam even when it is on axis. In this report we calculate the strength of these kicks and estimate their effect on the ILC beam. The TESLA cavity comprises nine cells, one HM coupler in the upstream end, and one (identical, though rotated) HM coupler and one FM coupler in the downstream end (for their shapes and location see Figs. 1, 2) [1]. The cavity is 1.1 m long, the iris radius 35 mm, and the coupler beam pipe radius 39 mm. Note that the couplers reach closer to the axis than the irises, down to a distance of 30 mm.

Bane, K.L.F.; Adolphsen, C.; Li, Z.; /SLAC; Dohlus, M.; Zagorodnov, I.; /DESY; Gonin, I.; Lunin, A.; Solyak, N.; Yakovlev, V.; /Fermilab; Gjonaj, E.; Weiland, T.; /Darmstadt, Tech. Hochsch.

2008-07-07T23:59:59.000Z

68

Modeling Self-Ionized Plasma Wakefield Acceleration for Afterburner Parameters Using QuickPIC  

SciTech Connect (OSTI)

For the parameters envisaged in possible afterburner stages[1] of a plasma wakefield accelerator (PWFA), the self-fields of the particle beam can be intense enough to tunnel ionize some neutral gases. Tunnel ionization has been investigated as a way for the beam itself to create the plasma, and the wakes generated may differ from those generated in pre-ionized plasmas[2],[3]. However, it is not practical to model the whole stage of PWFA with afterburner parameters using the models described in [2] and [3]. Here we describe the addition of a tunnel ionization package using the ADK model into QuickPIC, a highly efficient quasi-static particle in cell (PIC) code which can model a PWFA with afterburner parameters. Comparison between results from OSIRIS (a full PIC code with ionization) and from QuickPIC with the ionization package shows good agreement. Preliminary results using parameters relevant to the E164X experiment and the upcoming E167 experiment at SLAC are shown.

Zhou, M.; Clayton, C.E.; Decyk, V.K.; Huang, C.; Johnson, D.K.; Joshi, C.; Lu, W.; Mori, W.B.; Tsung, F.S.; /UCLA; Deng, S.; Katsouleas, T.; Muggli, P.; Oz, E.; /Southern; Decker, F.-J.; Iverson, R.; O'Connel, C.; Walz, D.; /SLAC

2006-01-25T23:59:59.000Z

69

VOLUME 82, NUMBER 6 P H Y S I C A L R E V I E W L E T T E R S 8 FEBRUARY 1999 Multimode Analysis of the Hollow Plasma Channel Wakefield Accelerator  

E-Print Network [OSTI]

]. In conventional accelerators, the size of these accel- erating fields is limited by breakdown. For two decades wakefield accelerator, the plasma wave is excited by the self-fields of an intense relativistic particle- neous plasma. These properties make it well suited as a structure for both particle beam wakefield

Wurtele, Jonathan

70

Electron diffraction using ultrafast electron bunches from a laser-wakefield accelerator at kHz repetition rate  

SciTech Connect (OSTI)

We show that electron bunches in the 50-100 keV range can be produced from a laser wakefield accelerator using 10 mJ, 35 fs laser pulses operating at 0.5 kHz. It is shown that using a solenoid magnetic lens, the electron bunch distribution can be shaped. The resulting transverse and longitudinal coherence is suitable for producing diffraction images from a polycrystalline 10 nm aluminum foil. The high repetition rate, the stability of the electron source, and the fact that its uncorrelated bunch duration is below 100 fs make this approach promising for the development of sub-100 fs ultrafast electron diffraction experiments.

He, Z.-H.; Thomas, A. G. R.; Nees, J. A.; Hou, B.; Krushelnick, K. [Center for Ultrafast Optical Science, University of Michigan, Ann Arbor, Michigan 48106-2099 (United States)] [Center for Ultrafast Optical Science, University of Michigan, Ann Arbor, Michigan 48106-2099 (United States); Beaurepaire, B.; Malka, V.; Faure, J. [Laboratoire d'Optique Appliquee, ENSTA-CNRS-Ecole Polytechnique, UMR 7639, 91761 Palaiseau (France)] [Laboratoire d'Optique Appliquee, ENSTA-CNRS-Ecole Polytechnique, UMR 7639, 91761 Palaiseau (France)

2013-02-11T23:59:59.000Z

71

Laser Wakefield Acceleration: Structural and Dynamic Studies. Final Technical Report ER40954  

SciTech Connect (OSTI)

Particle accelerators enable scientists to study the fundamental structure of the universe, but have become the largest and most expensive of scientific instruments. In this project, we advanced the science and technology of laser-plasma accelerators, which are thousands of times smaller and less expensive than their conventional counterparts. In a laser-plasma accelerator, a powerful laser pulse exerts light pressure on an ionized gas, or plasma, thereby driving an electron density wave, which resembles the wake behind a boat. Electrostatic fields within this plasma wake reach tens of billions of volts per meter, fields far stronger than ordinary non-plasma matter (such as the matter that a conventional accelerator is made of) can withstand. Under the right conditions, stray electrons from the surrounding plasma become trapped within these “wake-fields”, surf them, and acquire energy much faster than is possible in a conventional accelerator. Laser-plasma accelerators thus might herald a new generation of compact, low-cost accelerators for future particle physics, x-ray and medical research. In this project, we made two major advances in the science of laser-plasma accelerators. The first of these was to accelerate electrons beyond 1 gigaelectronvolt (1 GeV) for the first time. In experimental results reported in Nature Communications in 2013, about 1 billion electrons were captured from a tenuous plasma (about 1/100 of atmosphere density) and accelerated to 2 GeV within about one inch, while maintaining less than 5% energy spread, and spreading out less than ½ milliradian (i.e. ½ millimeter per meter of travel). Low energy spread and high beam collimation are important for applications of accelerators as coherent x-ray sources or particle colliders. This advance was made possible by exploiting unique properties of the Texas Petawatt Laser, a powerful laser at the University of Texas at Austin that produces pulses of 150 femtoseconds (1 femtosecond is 10-15 seconds) in duration and 150 Joules in energy (equivalent to the muzzle energy of a small pistol bullet). This duration was well matched to the natural electron density oscillation period of plasma of 1/100 atmospheric density, enabling efficient excitation of a plasma wake, while this energy was sufficient to drive a high-amplitude wake of the right shape to produce an energetic, collimated electron beam. Continuing research is aimed at increasing electron energy even further, increasing the number of electrons captured and accelerated, and developing applications of the compact, multi-GeV accelerator as a coherent, hard x-ray source for materials science, biomedical imaging and homeland security applications. The second major advance under this project was to develop new methods of visualizing the laser-driven plasma wake structures that underlie laser-plasma accelerators. Visualizing these structures is essential to understanding, optimizing and scaling laser-plasma accelerators. Yet prior to work under this project, computer simulations based on estimated initial conditions were the sole source of detailed knowledge of the complex, evolving internal structure of laser-driven plasma wakes. In this project we developed and demonstrated a suite of optical visualization methods based on well-known methods such as holography, streak cameras, and coherence tomography, but adapted to the ultrafast, light-speed, microscopic world of laser-driven plasma wakes. Our methods output images of laser-driven plasma structures in a single laser shot. We first reported snapshots of low-amplitude laser wakes in Nature Physics in 2006. We subsequently reported images of high-amplitude laser-driven plasma “bubbles”, which are important for producing electron beams with low energy spread, in Physical Review Letters in 2010. More recently, we have figured out how to image laser-driven structures that change shape while propagating in a single laser shot. The latter techniques, which use the methods of computerized tomography, were demonstrated on test objects – e.g. laser-d

Downer, Michael C.

2014-12-19T23:59:59.000Z

72

Improvements to laser wakefield accelerated electron beam stability, divergence, and energy spread using three-dimensional printed two-stage gas cell targets  

SciTech Connect (OSTI)

High intensity, short pulse lasers can be used to accelerate electrons to ultra-relativistic energies via laser wakefield acceleration (LWFA) [T. Tajima and J. M. Dawson, Phys. Rev. Lett. 43, 267 (1979)]. Recently, it was shown that separating the injection and acceleration processes into two distinct stages could prove beneficial in obtaining stable, high energy electron beams [Gonsalves et al., Nat. Phys. 7, 862 (2011); Liu et al., Phys. Rev. Lett. 107, 035001 (2011); Pollock et al., Phys. Rev. Lett. 107, 045001 (2011)]. Here, we use a stereolithography based 3D printer to produce two-stage gas targets for LWFA experiments on the HERCULES laser system at the University of Michigan. We demonstrate substantial improvements to the divergence, pointing stability, and energy spread of a laser wakefield accelerated electron beam compared with a single-stage gas cell or gas jet target.

Vargas, M.; Schumaker, W.; He, Z.-H.; Zhao, Z.; Behm, K.; Chvykov, V.; Hou, B.; Krushelnick, K.; Maksimchuk, A.; Yanovsky, V.; Thomas, A. G. R., E-mail: agrt@umich.edu [Center for Ultrafast Optical Science, University of Michigan, Ann Arbor, Michigan 48109 (United States)

2014-04-28T23:59:59.000Z

73

Silicon buried gratings for dielectric laser electron accelerators  

SciTech Connect (OSTI)

This paper describes design and simulations of dielectric laser electron accelerators that achieve Gigavolt-per-meter (GV/m) accelerating gradients and wide electron channels (>1??m). The accelerator design is based on a silicon buried grating structure that enables flexible phase synchronization, large electron channel fields, and low standing-wave ratio in the material. This design increases the accelerating gradients to more than double those of reported quartz grating accelerators, thereby reducing the input laser fluence by 60% for the same accelerating gradient. With a 100 fs pulsed laser, our silicon buried gratings can achieve a maximum gradient of 1.1 GV/m, indicating that these accelerators have potential for numerous electron-accelerator applications.

Chang, Chia-Ming, E-mail: cachang@alumni.stanford.edu [Bell Labs, Alcatel-Lucent, 791 Holmdel Road, Holmdel, New Jersey 07733 (United States); Solgaard, Olav [E. L. Ginzton Lab., Stanford University, Stanford, California 94305 (United States)

2014-05-05T23:59:59.000Z

74

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

SciTech Connect (OSTI)

he wakefield generated in a plasma by incoherently combining a large number of low energy laser pulses (i.e.,without constraining the pulse phases) is studied analytically and by means of fully-self-consistent particle-in-cell simulations. The structure of the wakefield has been characterized and its amplitude compared with the amplitude of the wake generated by a single (coherent) laser pulse. We show that, in spite of the incoherent nature of the wakefield within the volume occupied by the laser pulses, behind this region the structure of the wakefield can be regular with an amplitude comparable or equal to that obtained from a single pulse with the same energy. Wake generation requires that the incoherent structure in the laser energy density produced by the combined pulses exists on a time scale short compared to the plasma period. Incoherent combination of multiple laser pulses may enable a technologically simpler path to high-repetition rate, high-average power laser-plasma accelerators and associated applications.

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

2014-05-01T23:59:59.000Z

75

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

SciTech Connect (OSTI)

The wakefield generated in a plasma by incoherently combining a large number of low energy laser pulses (i.e., without constraining the pulse phases) is studied analytically and by means of fully self-consistent particle-in-cell simulations. The structure of the wakefield has been characterized and its amplitude compared with the amplitude of the wake generated by a single (coherent) laser pulse. We show that, in spite of the incoherent nature of the wakefield within the volume occupied by the laser pulses, behind this region, the structure of the wakefield can be regular with an amplitude comparable or equal to that obtained from a single pulse with the same energy. Wake generation requires that the incoherent structures in the laser energy density produced by the combined pulses exist on a time scale short compared to the plasma period. Incoherent combination of multiple laser pulses may enable a technologically simpler path to high-repetition rate, high-average power laser-plasma accelerators, and associated applications.

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

2014-05-15T23:59:59.000Z

76

Single Bunch Wakefields in the CERN-PSI-ELETTRA X-band Linear Accelerator  

E-Print Network [OSTI]

FERMI@ELETTRA and PSI-XFEL are 4th Generation Light Sources that require high quality electron beam at the entrance of the undulator chains. In this context, a specially developed X-band structure with integrated alignment monitors will be used to mitigate the nonlinearities in the longitudinal phase space due to the second order RF time curvature and the second order momentum compaction term of chicane compressor. The knowledge of the transverse and longitudinal short range wakefields in the X-band structure is essential to evaluate the beam quality in terms of longitudinal energy spread and transverse kick spread. We have used the ABCI code to numerically evaluate the transverse and longitudinal wake potentials for short bunches in this structure

El-Ashmawy, Mostafa; Dehler, Micha; Raguin, Jean-Yves; Riddone, Germana; Zennaro, Riccardo

2010-01-01T23:59:59.000Z

77

Dielectric-Lined High-Gradient Accelerator Structure  

SciTech Connect (OSTI)

Rectangular particle accelerator structures with internal planar dielectric elements have been studied, with a view towards devising structures with lower surface fields for a given accelerating field, as compared with structures without dielectrics. Success with this concept is expected to allow operation at higher accelerating gradients than otherwise on account of reduced breakdown probabilities. The project involves studies of RF breakdown on amorphous dielectrics in test cavities that could enable high-gradient structures to be built for a future multi-TeV collider. The aim is to determine what the limits are for RF fields at the surfaces of selected dielectrics, and the resulting acceleration gradient that could be achieved in a working structure. The dielectric of principal interest in this study is artificial CVD diamond, on account of its advertised high breakdown field ({approx}2 GV/m for dc), low loss tangent, and high thermal conductivity. Experimental studies at mm-wavelengths on materials and structures for achieving high acceleration gradient were based on the availability of the 34.3 GHz third-harmonic magnicon amplifier developed by Omega-P, and installed at the Yale University Beam Physics Laboratory. Peak power from the magnicon was measured to be about 20 MW in 0.5 {micro}s pulses, with a gain of 54 dB. Experiments for studying RF high-field effects on CVD diamond samples failed to show any evidence after more than 10{sup 5} RF pulses of RF breakdown up to a tangential surface field strength of 153 MV/m; studies at higher fields were not possible due to a degradation in magnicon performance. A rebuild of the tube is underway at this writing. Computed performance for a dielectric-loaded rectangular accelerator structure (DLA) shows highly competitive properties, as compared with an existing all-metal structure. For example, comparisons were made of a DLA structure having two planar CVD diamond elements with a all-metal CERN structure HDS operating at 30 GHz. It was shown that the ratio of maximum surface electric field to accelerating field at the metal wall is only 0.35-0.4 for DLA, much smaller than the value 2.2 for HDS; and the ratio of surface magnetic field to accelerating field is 3.0 mA/V for DLA, compared with 3.45 mA/V for HDS. These values bode well for DLA in helping to avoid breakdown and to reducing pulsed surface heating and fatigue. The shunt impedance is found to be 160-175 M{Omega}/m for DLA, as compared to 99 M{Omega}/m for HDS. Conclusions are reached from this project that CVD diamond appears promising as a dielectric with a high threshold for RF breakdown, and that rectangular accelerator structures can be devised using planar CVD diamond elements that could be operated at higher acceleration gradients with low probability of RF breakdown, as compared with corresponding all-metallic structures.

Jay L. Hirshfield

2012-04-24T23:59:59.000Z

78

E-Print Network 3.0 - argonne wakefield accelerator Sample Search...  

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

Accelerator System (ATLAS) facility at Argonne. Pure samples of neptunium, americium and curium... InsIde ArgonneDirector:Americaneedstoreigniteinnovationecology'-Page2 ......

79

Recent Progress at LBNL on Characterization of Laser Wakefield Accelerated Electron Bunches using Coherent Transition Radiation  

E-Print Network [OSTI]

RECENT PROGRESS AT LBNL ON CHARACTERIZATION OF LASERBerkeley National Laboratory (LBNL), Berkeley, CA 94720,USA Abstract At LBNL, laser wake?eld accelerators (LWFA) can

2007-01-01T23:59:59.000Z

80

Development of high gradient laser wakefield accelerators towards nuclear detection applications at LBNL  

E-Print Network [OSTI]

detection applications at LBNL Cameron G.R. Geddes 1 , DavidLeemans 1,4 LOASIS Program, LBNL, 1 Cyclotron Rd MS 71-259,accelerator experiments at LBNL demonstrated narrow energy

Geddes, Cameron GR

2010-01-01T23:59:59.000Z

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


81

Undulator-Based Laser Wakefield Accelerator Electron Beam Energy Spread and Emittance Diagnostic  

SciTech Connect (OSTI)

The design and current status of experiments to couple the Tapered Hybrid Undulator (THUNDER) to the Lawrence Berkeley National Laboratory (LBNL) laser plasma accelerator (LPA) to measure electron beam energy spread and emittance are presented.

Bakeman, M.S.; Van Tilborg, J.; Nakamura, K.; Gonsalves, A.; Osterhoff, J.; Sokollik, T.; Lin, C.; Robinson, K.E.; Schroeder, C.B.; Toth, Cs.; Weingartner, R.; Gruner, F.; Esarey, E.; Leemans, W.P.

2010-06-01T23:59:59.000Z

82

Plasma Acceleration from RF Discharge in Dielectric Capillary  

SciTech Connect (OSTI)

Plasma acceleration from rf discharge in dielectric capillary was demonstrated. Observed plasma flow had ion energies of approximately 100 eV and electron energies of approximately 20 eV. The discharge was powered by a MHz-range rf generator and fed by Ar. Experimental results indicate possible validity of assumptions about formation of a potential difference at the open end of the capillary and presence of hot electron fraction in the capillary discharge. Simplicity and small dimensions of the source are attractive for micro-propulsion applications.

A. Dunaevsky; Y. Raitses; N. J. Fisch

2005-08-09T23:59:59.000Z

83

An Experimental Test of the Theory of the Stimulated Dielectric Wake-Field Accelerator  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsruc DocumentationP-Series to someone by E-mail ShareRed Cross BloodU.S. DepartmentRevised

84

Acceleration and Focusing Measurements in Beam-Driven Plasma Wakefields at ATF  

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

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85

Visualizing Particle-in-Cell Simulation of Laser Wakefield Particle...  

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

of times greater than those obtained in conventional particle accelerators. LWFAs use the electric field of a plasma wave - the wakefield - driven by the radiation pressure of an...

86

Terahertz radiation as a bunch diagnostic for laser-wakefield-accelerated electron bunches  

SciTech Connect (OSTI)

Experimental results are reported from two measurement techniques (semiconductor switching and electro-optic sampling) that allow temporal characterization of electron bunches produced by a laser-driven plasma-based accelerator. As femtosecond electron bunches exit the plasma-vacuum interface, coherent transition radiation (at THz frequencies) is emitted. Measuring the properties of this radiation allows characterization of the electron bunches. Theoretical work on the emission mechanism is presented, including a model that calculates the THz wave form from a given bunch profile. It is found that the spectrum of the THz pulse is coherent up to the 200 {micro}m thick crystal (ZnTe) detection limit of 4 THz, which corresponds to the production of sub-50 fs (rms) electron bunch structure. The measurements demonstrate both the shot-to-shot stability of bunch parameters that are critical to THz emission (such as total charge and bunch length), as well as femtosecond synchronization among bunch, THz pulse, and laser beam.

van Tilborg, Jeroen; Schroeder, Carl; Filip, Catalin; Toth, Csaba; Geddes, Cameron; Fubiani, Gwenael; Esarey, Eric; Leemans, Wim

2011-06-17T23:59:59.000Z

87

Wake field in dielectric acceleration structures L. Schachter,1  

E-Print Network [OSTI]

particle accel- erators relies on dielectric slow-wave structures confining a laser field. Conceptually

Byer, Robert L.

88

X-ray phase contrast imaging of biological specimens with femtosecond pulses of betatron radiation from a compact laser plasma wakefield accelerator  

SciTech Connect (OSTI)

We show that x-rays from a recently demonstrated table top source of bright, ultrafast, coherent synchrotron radiation [Kneip et al., Nat. Phys. 6, 980 (2010)] can be applied to phase contrast imaging of biological specimens. Our scheme is based on focusing a high power short pulse laser in a tenuous gas jet, setting up a plasma wakefield accelerator that accelerates and wiggles electrons analogously to a conventional synchrotron, but on the centimeter rather than tens of meter scale. We use the scheme to record absorption and phase contrast images of a tetra fish, damselfly and yellow jacket, in particular highlighting the contrast enhancement achievable with the simple propagation technique of phase contrast imaging. Coherence and ultrafast pulse duration will allow for the study of various aspects of biomechanics.

Kneip, S. [Blackett Laboratory, Imperial College London, London SW7 2AZ (United Kingdom); Center for Ultrafast Optical Science, University of Michigan, Ann Arbor 48109 (United States); McGuffey, C.; Dollar, F.; Chvykov, V.; Kalintchenko, G.; Krushelnick, K.; Maksimchuk, A.; Mangles, S. P. D.; Matsuoka, T.; Schumaker, W.; Thomas, A. G. R.; Yanovsky, V. [Center for Ultrafast Optical Science, University of Michigan, Ann Arbor 48109 (United States); Bloom, M. S.; Najmudin, Z.; Palmer, C. A. J.; Schreiber, J. [Blackett Laboratory, Imperial College London, London SW7 2AZ (United Kingdom)

2011-08-29T23:59:59.000Z

89

VOLUME 78, NUMBER 16 P H Y S I C A L R E V I E W L E T T E R S 21 APRIL 1997 Electron Acceleration by a Laser Wakefield in a Relativistically Self-Guided Channel  

E-Print Network [OSTI]

, x-ray lasers, and ultrahigh-gradient electron accelerators [2]. In the latter case, the field by a Laser Wakefield in a Relativistically Self-Guided Channel R. Wagner, S.-Y. Chen, A. Maksimchuk, and D-modulated laser wakefield is discussed. Above a power threshold, a relativistically self-guided channel from

Umstadter, Donald

90

Development of High-Gradient Dielectric Laser-Driven Particle Accelerator Structures  

SciTech Connect (OSTI)

The thrust of Stanford's program is to conduct research on high-gradient dielectric accelerator structures driven with high repetition-rate, tabletop infrared lasers. The close collaboration between Stanford and SLAC (Stanford Linear Accelerator Center) is critical to the success of this project, because it provides a unique environment where prototype dielectric accelerator structures can be rapidly fabricated and tested with a relativistic electron beam.

Byer, Robert L.

2013-11-07T23:59:59.000Z

91

Induction of electron injection and betatron oscillation in a plasma-waveguide-based laser wakefield accelerator by modification of waveguide structure  

SciTech Connect (OSTI)

By adding a transverse heater pulse into the axicon ignitor-heater scheme for producing a plasma waveguide, a variable three-dimensionally structured plasma waveguide can be fabricated. With this technique, electron injection in a plasma-waveguide-based laser wakefield accelerator was achieved and resulted in production of a quasi-monoenergetic electron beam. The injection was correlated with a section of expanding cross-section in the plasma waveguide. Moreover, the intensity of the X-ray beam produced by the electron bunch in betatron oscillation was greatly enhanced with a transversely shifted section in the plasma waveguide. The technique opens a route to a compact hard-X-ray pulse source.

Ho, Y.-C.; Hung, T.-S.; Chen, W.-H. [Department of Physics, National Central University, Jhong-Li 320, Taiwan (China) [Department of Physics, National Central University, Jhong-Li 320, Taiwan (China); Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 106, Taiwan (China); Jhou, J.-G. [Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 106, Taiwan (China) [Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 106, Taiwan (China); Department of Physics, National Taiwan University, Taipei 106, Taiwan (China); Qayyum, H.; Chen, S.-Y. [Department of Physics, National Central University, Jhong-Li 320, Taiwan (China) [Department of Physics, National Central University, Jhong-Li 320, Taiwan (China); Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 106, Taiwan (China); Molecular Science and Technology Program, Taiwan International Graduate Program, Academia Sinica, Taipei 115, Taiwan (China); Chu, H.-H. [Department of Physics, National Central University, Jhong-Li 320, Taiwan (China)] [Department of Physics, National Central University, Jhong-Li 320, Taiwan (China); Lin, J.-Y. [Department of Physics, National Chung Cheng University, Chia-Yi 621, Taiwan (China)] [Department of Physics, National Chung Cheng University, Chia-Yi 621, Taiwan (China); Wang, J. [Department of Physics, National Central University, Jhong-Li 320, Taiwan (China) [Department of Physics, National Central University, Jhong-Li 320, Taiwan (China); Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 106, Taiwan (China); Department of Physics, National Taiwan University, Taipei 106, Taiwan (China)

2013-08-15T23:59:59.000Z

92

17 GHz High Gradient Accelerator Research  

SciTech Connect (OSTI)

This is a report on the MIT High Gradient Accelerator Research program which has included: Operation of the 17 GHz, 25 MeV MIT/Haimson Research Corp. electron accelerator at MIT, the highest frequency, stand-alone accelerator in the world; collaboration with members of the US High Gradient Collaboration, including the design and test of novel structures at SLAC at 11.4 GHz; the design, construction and testing of photonic bandgap structures, including metallic and dielectric structures; the investigation of the wakefields in novel structures; and the training of the next generation of graduate students and postdoctoral associates in accelerator physics.

Temkin, Richard J. [MIT] [MIT; Shapiro, Michael A. [MIT] [MIT

2013-07-10T23:59:59.000Z

93

Use of dielectric material in muon accelerator RF cavities  

E-Print Network [OSTI]

The building of a muon collider is motivated by the desire to collide point-like particles while reducing the limitations imposed by synchrotron radiation. The many challenges unique to muon accelerators are derived from ...

French, Katheryn Decker

2011-01-01T23:59:59.000Z

94

Characterization and Application of Hard X-Ray Betatron Radiation Generated by Relativistic Electrons from a Laser-Wakefield Accelerator  

E-Print Network [OSTI]

The necessity for compact table-top x-ray sources with higher brightness, shorter wavelength and shorter pulse duration has led to the development of complementary sources based on laser-plasma accelerators, in contrast to conventional accelerators. Relativistic interaction of short-pulse lasers with underdense plasmas results in acceleration of electrons and in consequence in the emission of spatially coherent radiation, which is known in the literature as betatron radiation. In this article we report on our recent results in the rapidly developing field of secondary x-ray radiation generated by high-energy electron pulses. The betatron radiation is characterized with a novel setup allowing to measure the energy, the spatial energy distribution in the far-field of the beam and the source size in a single laser shot. Furthermore, the polarization state is measured for each laser shot. In this way the emitted betatron x-rays can be used as a non-invasive diagnostic tool to retrieve very subtle information of t...

Schnell, Michael; Uschmann, Ingo; Jansen, Oliver; Kaluza, Malte Christoph; Spielmann, Christian

2015-01-01T23:59:59.000Z

95

Plasma Wakefield Experiments at FACET  

SciTech Connect (OSTI)

FACET, the Facility for Advanced Accelerator and Experimental Tests, is a new facility being constructed in sector 20 of the SLAC linac primarily to study beam driven plasma wakefield acceleration beginning in summer 2011. The nominal FACET parameters are 23GeV, 3nC electron bunches compressed to {approx}20{micro}m long and focused to {approx}10{micro}m wide. The intense fields of the FACET bunches will be used to field ionize neutral lithium or cesium vapor produced in a heat pipe oven. Previous experiments at the SLAC FFTB facility demonstrated 50GeV/m gradients in an 85cm field ionized lithium plasma where the interaction distance was limited by head erosion. Simulations indicate the lower ionization potential of cesium will decrease the rate of head erosion and increase single stage performance. The initial experimental program will compare the performance of lithium and cesium plasma sources with single and double bunches. Later experiments will investigate improved performance with a pre-ionized cesium plasma. The status of the experiments and expected performance are reviewed. The FACET Facility is being constructed in sector 20 of the SLAC linac primarily to study beam driven plasma wakefield acceleration. The facility will begin commissioning in summer 2011 and conduct an experimental program over the coming five years to study electron and positron beam driven plasma acceleration with strong wake loading in the non-linear regime. The FACET experiments aim to demonstrate high-gradient acceleration of electron and positron beams with high efficiency and negligible emittance growth.

Hogan, M.J.; England, R.J.; Frederico, J.; Hast, C.; Li, S.Z.; Litos, M.; Walz, D.; /SLAC; An, W.; Clayton, C.E.; Joshi, C.; Lu, W.; Marsh, K.A.; Mori, W.; Tochitsky, S.; /UCLA; Muggli, P.; Pinkerton, S.; Shi, Y.; /Southern California U.

2011-08-19T23:59:59.000Z

96

Ultrafast Diagnostics for Electron Beams from Laser Plasma Accelerators  

E-Print Network [OSTI]

for Laser Plasma Accelerators," in this proceedings, 2010.Based Laser Wakefield Accelerator Electron Beam EnergyMotion in a Laser-Plasma Accelerator," in this proceedings,

Matlis, N. H.

2011-01-01T23:59:59.000Z

97

Results from Plasma Wakefield Experiments at FACET  

SciTech Connect (OSTI)

We report initial results of the Plasma Wakefield Acceleration (PWFA) Experiments performed at FACET - Facility for Advanced aCcelertor Experimental Tests at SLAC National Accelerator Laboratory. At FACET a 23 GeV electron beam with 1.8 x 10{sup 10} electrons is compressed to 20 {mu}m longitudinally and focused down to 10 {mu}m x 10 {mu}m transverse spot size for user driven experiments. Construction of the FACET facility completed in May 2011 with a first run of user assisted commissioning throughout the summer. The first PWFA experiments will use single electron bunches combined with a high density lithium plasma to produce accelerating gradients > 10 GeV/m benchmarking the FACET beam and the newly installed experimental hardware. Future plans for further study of plasma wakefield acceleration will be reviewed. The experimental hardware and operation of the plasma heat-pipe oven have been successfully commissioned. Plasma wakefield acceleration was not observed because the electron bunch density was insufficient to ionize the lithium vapor. The remaining commissioning time in summer 2011 will be dedicated to delivering the FACET design parameters for the experimental programs which will begin in early 2012. PWFA experiments require the shorter bunches and smaller transverse sizes to create the plasma and drive large amplitude wakefields. Low emittance and high energy will minimize head erosion which was found to be a limiting factor in acceleration distance and energy gain. We will run the PWFA experiments with the design single bunch conditions in early 2012. Future PWFA experiments at FACET are discussed in [5][6] and include drive and witness bunch production for high energy beam manipulation, ramped bunch to optimize tranformer ratio, field-ionized cesium plasma, preionized plasmas, positron acceleration, etc.. We will install a notch collimator for two-bunch operation as well as new beam diagnostics such as the X-band TCAV [7] to resolve the two bunches. With these new instruments and desired beam parameters in place next year, we will be able to complete the studies of plasma wakefield acceleration in the next few years.

Li, S.Z.; Clarke, C.I.; England, R.J.; Frederico, J.; Gessner, S.J.; Hogan, M.J.; Jobe, R.K.; Litos, M.D.; Walz, D.R.; /SLAC; Muggli, P.; /Munich, Max Planck Inst.; An, W.; Clayton, C.E.; Joshi, C.; Lu, W.; Marsh, K.A.; Mori, W.; Tochitsky, S.; /UCLA; Adli, E.; /U. Oslo

2011-12-13T23:59:59.000Z

98

Beam dynamics and wakefield suppression in interleaved damped and detuned structures for CLIC  

E-Print Network [OSTI]

Acceleration of multiple bunches of charged particles in the main linacs of the Compact Linear Collider (CLIC) with high accelerating fields provides two major challenges: firstly, to ensure the surface electromagnetic fields do not cause electrical breakdown and subsequent surface damage, and secondly, to ensure the beam-excited wakefields are sufficiently suppressed to avoid appreciable emittance dilution. In the baseline design for CLIC, heavy wakefield suppression is used (Q ~ 10) [1] and this ensures the beam quality is well-preserved [2]. Here we discuss an alternative means to suppress the wakefield which relies on strong detuning of the cell dipole frequencies, together with moderate damping, effected by manifolds which are slot-coupled to each accelerating cell. This damped and detuned wakefield suppression scheme is based on the methodology developed for the Japanese Linear Collider/Next Linear Collider (JLC/NLC) [3]. Here we track the multi-bunch beam down the complete collider, u...

D'Elia, A; Khan, V F; Jones, R M; Latina, A; Nesmiyan, I; Riddone, G

2013-01-01T23:59:59.000Z

99

E-Print Network 3.0 - accelerating beam stability Sample Search...  

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

(ARD) has the mission to develop accelerator Summary: between rf systems and particle beams, applications of control techniques to asses system stability... Wakefield Accelerator...

100

ONE GEV BEAM ACCELERATION IN A ONE METER LONG  

E-Print Network [OSTI]

ONE GEV BEAM ACCELERATION IN A ONE METER LONG PLASMA CELL A Proposal to the Stanford Linear. A single SLC bunch is used to both induce wakefields in the one meter long plasma and to witness that are needed to apply high-gradient plasma wakefield acceleration to large scale accelerators. The one meter

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


101

ELECTRON INJECTION INTO CYCLIC ACCELERATOR USING  

E-Print Network [OSTI]

ELECTRON INJECTION INTO CYCLIC ACCELERATOR USING LASER WAKEFIELD ACCELERATION Ya. V. Getmanov, O. A acceleration #12;Storage ring with laser injection CYCLIC ACCELERATOR RF Electron injection The LWFA beam ­ accelerating light, 5 ­ accelerated electrons, 6 ­fast kicker - + accelerating laser pulse evaporatinglaser

102

all-dielectric electron accelerator: Topics by E-print Network  

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

are byproducts of the acceleration process. CHARGE DIAGNOSTICS Integrating Current Transformers (ICTs) have of their ease of use, precision and non invasiveness. More recently,...

103

An Accelerated Multiboson Algorithm for Coulomb Gases with Dynamical Dielectric Effects  

E-Print Network [OSTI]

A recent reformulation [1] of the problem of Coulomb gases in the presence of a dynamical dielectric medium showed that finite temperature simulations of such systems can be accomplished on the basis of completely local Hamiltonians on a spatial lattice by including additional bosonic fields. For large systems, the Monte Carlo algorithm proposed in Ref. [1] becomes inefficient due to a low acceptance rate for particle moves in a fixed background multiboson field. We show here how this problem can be circumvented by use of a coupled particle-multiboson update procedure that improves acceptance rates on large lattices by orders of magnitude. The method is tested on a one-component plasma with neutral dielectric particles for a variety of system sizes.

A. Duncan; R. D. Sedgewick

2006-02-15T23:59:59.000Z

104

PLASMA WAKEFIELD ACCELERATION UTILIZING MULTIPLE ELECTRON BUNCHES  

E-Print Network [OSTI]

. Yakimenko, Brookhaven National Lab., Upton, NY W. D. Kimura, STI Optronics, Bellevue, WA Abstract We

Brookhaven National Laboratory

105

Design of a subnanometer resolution beam position monitor for dielectric laser accelerators  

E-Print Network [OSTI]

of the first laser-powered particle accel- erators "on a chip" [1,2]. These devices are specifically designed present a new concept for a beam position monitor with the unique ability to map particle beam position, this device is ideal for future x-ray sources and laser-driven particle accelerators "on a chip." © 2012

Byer, Robert L.

106

E-Print Network 3.0 - accelerator applications university Sample...  

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

university Page: << < 1 2 3 4 5 > >> 1 The Application of Radiation and Particle Beams from Laser Plasma Wakefield Accelerators to Oncology Summary: The Application of...

107

Automated analysis for detecting beams in laser wakefield simulations  

SciTech Connect (OSTI)

Laser wakefield particle accelerators have shown the potential to generate electric fields thousands of times higher than those of conventional accelerators. The resulting extremely short particle acceleration distance could yield a potential new compact source of energetic electrons and radiation, with wide applications from medicine to physics. Physicists investigate laser-plasma internal dynamics by running particle-in-cell simulations; however, this generates a large dataset that requires time-consuming, manual inspection by experts in order to detect key features such as beam formation. This paper describes a framework to automate the data analysis and classification of simulation data. First, we propose a new method to identify locations with high density of particles in the space-time domain, based on maximum extremum point detection on the particle distribution. We analyze high density electron regions using a lifetime diagram by organizing and pruning the maximum extrema as nodes in a minimum spanning tree. Second, we partition the multivariate data using fuzzy clustering to detect time steps in a experiment that may contain a high quality electron beam. Finally, we combine results from fuzzy clustering and bunch lifetime analysis to estimate spatially confined beams. We demonstrate our algorithms successfully on four different simulation datasets.

Ushizima, Daniela M.; Rubel, Oliver; Prabhat, Mr.; Weber, Gunther H.; Bethel, E. Wes; Aragon, Cecilia R.; Geddes, Cameron G.R.; Cormier-Michel, Estelle; Hamann, Bernd; Messmer, Peter; Hagen, Hans

2008-07-03T23:59:59.000Z

108

Characterisation of electron beams from laser-driven particle accelerators  

SciTech Connect (OSTI)

The development, understanding and application of laser-driven particle accelerators require accurate measurements of the beam properties, in particular emittance, energy spread and bunch length. Here we report measurements and simulations showing that laser wakefield accelerators can produce beams of quality comparable to conventional linear accelerators.

Brunetti, E.; Manahan, G. G.; Shanks, R. P.; Islam, M. R.; Ersfeld, B.; Anania, M. P.; Cipiccia, S.; Issac, R. C.; Vieux, G.; Welsh, G. H.; Wiggins, S. M.; Jaroszynski, D. A. [Physics Department, University of Strathclyde, Glasgow G4 0NG (United Kingdom)

2012-12-21T23:59:59.000Z

109

Dielectric-wall linear accelerator with a high voltage fast rise time switch that includes a pair of electrodes between which are laminated alternating layers of isolated conductors and insulators  

DOE Patents [OSTI]

A dielectric-wall linear accelerator is improved by a high-voltage, fast rise-time switch that includes a pair of electrodes between which are laminated alternating layers of isolated conductors and insulators. A high voltage is placed between the electrodes sufficient to stress the voltage breakdown of the insulator on command. A light trigger, such as a laser, is focused along at least one line along the edge surface of the laminated alternating layers of isolated conductors and insulators extending between the electrodes. The laser is energized to initiate a surface breakdown by a fluence of photons, thus causing the electrical switch to close very promptly. Such insulators and lasers are incorporated in a dielectric wall linear accelerator with Blumlein modules, and phasing is controlled by adjusting the length of fiber optic cables that carry the laser light to the insulator surface. 12 figs.

Caporaso, G.J.; Sampayan, S.E.; Kirbie, H.C.

1998-10-13T23:59:59.000Z

110

PROTOPLASMA - Proton-driven plasma-wakefield experiment at Fermilab: Stages and approach  

SciTech Connect (OSTI)

Generation of TeV-scale electron beams using conventional RF technology appears expensive for building the next generation of colliders. Proton-driven plasma-wakefield acceleration of electrons promises an alternative route to generate TeV-scale electron beams using existing proton machines. PROTOPLASMA is the proposed R and D project at Fermilab that plans to use a proton beam driven plasma-wakefield to accelerate electrons. The project is planned in stages with the project's path guided by simulations. First, a 60-120 GeV proton beam will be injected into 1-2 meters of plasma to observe selfmodulation instability in the proton beam. Next, an injected 5 MeV electron beam will be accelerated by the plasma. In this paper, we report on the basic project plan and outline our staged approach. We report on first simulation results that show self-modulation of a proton bunch and discuss beam optics requirements and other limits.

Thangaraj, J. C. T.; Park, C. S.; Lewis, J. D.; Spentzouris, P.; An, W.; Mori, W.; Joshi, C. [Fermi National Accelerator Laboratory, IL (United States); Univ. of California, Los Angeles, CA (United States)

2012-12-21T23:59:59.000Z

111

Recent Advances in Plasma Acceleration  

SciTech Connect (OSTI)

The costs and the time scales of colliders intended to reach the energy frontier are such that it is important to explore new methods of accelerating particles to high energies. Plasma-based accelerators are particularly attractive because they are capable of producing accelerating fields that are orders of magnitude larger than those used in conventional colliders. In these accelerators a drive beam, either laser or particle, produces a plasma wave (wakefield) that accelerates charged particles. The ultimate utility of plasma accelerators will depend on sustaining ultra-high accelerating fields over a substantial length to achieve a significant energy gain. More than 42 GeV energy gain was achieved in an 85 cm long plasma wakefield accelerator driven by a 42 GeV electron drive beam in the Final Focus Test Beam (FFTB) Facility at SLAC. Most of the beam electrons lose energy to the plasma wave, but some electrons in the back of the same beam pulse are accelerated with a field of {approx}52 GV/m. This effectively doubles their energy, producing the energy gain of the 3 km long SLAC accelerator in less than a meter for a small fraction of the electrons in the injected bunch. Prospects for a drive-witness bunch configuration and high-gradient positron acceleration experiments planned for the SABER facility will be discussed.

Hogan, Mark

2007-03-19T23:59:59.000Z

112

Modeling laser wakefield accelerators in a Lorentz boosted frame  

E-Print Network [OSTI]

on axis, beam average energy history and momentum spread aton the mean beam energy histories and on the longitudinalgave the same beam energy history within a few percents, and

Vay, J.-L.

2010-01-01T23:59:59.000Z

113

Modeling laser wakefield accelerators in a Lorentz boosted frame  

E-Print Network [OSTI]

on axis, beam average energy history and momentum spread aton the mean beam energy histories and on the lon- gitudinalgave the same beam energy history within a few percents, and

Vay, J.-L.

2010-01-01T23:59:59.000Z

114

Modeling laser wakefield accelerators in a Lorentz boosted frame  

E-Print Network [OSTI]

1:2:4) Mean beam position (m) VAX Sen c >SA- i— s( i) c 3- a2) - - - S(1:2:3)! S(1:2:4); VAX c c 3 0J u xi E2i SO) S(l:4) Mean beam position (m) VAX Figure 20: (left) Average beam

Vay, J.-L.

2010-01-01T23:59:59.000Z

115

Modeling Laser Wakefield Accelerators in a Lorentz Boosted Frame  

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

of experiments on new lasers such as BELLA. Principal Investigator: Cameron Geddes, LBNL More Information: See J.-L. Vay, C. G. R. Geddes, E. Cormier-Michel, and D. P. Grote,...

116

Analysis of Laser Wakefield Particle Acceleration Data at NERSC  

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

Data LWFAIllustrationSmall.png In collaboration with researchers of the LOASIS program (LBNL) and the SciDAC SDM center (LBNL) we have been working on various efforts aimed at...

117

PLASMA WAKEFIELD ACCELERATION EXPERIMENTS USING TWO SUBPICOSECOND ELECTRON BUNCHES*  

E-Print Network [OSTI]

. Yakimenko,3 1 University of Southern California, Los Angeles, CA, USA 2 STI Optronics, Inc., Bellevue, WA

Brookhaven National Laboratory

118

Multi-bunch Plasma Wakefield Acceleration at ATF  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsrucLas Conchas recovery challenge fundProject8MistakesAdministration AboutMovingNOV 0bunch

119

ATF Plasma Sources for Wakefield Electron Acceleration ATF User's Meeting  

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

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

120

Modeling Laser Wakefield Accelerators in a Lorentz Boosted Frame  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsrucLas Conchas recovery challenge fundProject8Mistakes to Avoid Mistakes toU.S.Limitations.

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


121

Analysis of Laser Wakefield Particle Acceleration Data at NERSC  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsruc DocumentationP-Series to someone by E-mail ShareRed CrossAnPulsed-Voltage Bias. | EMSLLaser

122

Physics of laser-driven plasma-based electron accelerators E. Esarey, C. B. Schroeder, and W. P. Leemans  

E-Print Network [OSTI]

Physics of laser-driven plasma-based electron accelerators E. Esarey, C. B. Schroeder, and W. P Laser-driven plasma-based accelerators, which are capable of supporting fields in excess of 100 GV/m, are reviewed. This includes the laser wakefield accelerator, the plasma beat wave accelerator, the self

Geddes, Cameron Guy Robinson

123

Modeling of 10 GeV-1 TeV laser-plasma accelerators using Lorentz boosted simulations  

E-Print Network [OSTI]

Modeling of 10 GeV-1 TeV laser-plasma accelerators using Lorentz boosted simulations J.-L. Vay,1,a-plasma wakefield accelerators in an optimal frame of reference [J.-L. Vay, Phys. Rev. Lett. 98, 130405 (2007 of plasma accelerators to very high energies and accurately models the laser evolution and the accelerated

Geddes, Cameron Guy Robinson

124

AUGMENTING COMPUTER MUSIC WITH JUST-IN-TIME COMPILATION Wesley Smith, Graham Wakefield  

E-Print Network [OSTI]

AUGMENTING COMPUTER MUSIC WITH JUST-IN-TIME COMPILATION Wesley Smith, Graham Wakefield University of California Santa Barbara Media Arts and Technology whsmith|wakefield@mat.ucsb.edu ABSTRACT We discuss

California at Santa Barbara, University of

125

MuSiC: a Multibunch and multiparticle Simulation Code with an alternative approach to wakefield effects  

E-Print Network [OSTI]

The simulation of beam dynamics in presence of collective effects requires a strong computational effort to take into account, in a self consistent way, the wakefield acting on a given charge and produced by all the others. Generally this is done by means of a convolution integral or sum. Moreover, if the electromagnetic fields consist of resonant modes with high quality factors, responsible, for example, of coupled bunch instabilities, a charge is also affected by itself in previous turns, and a very long record of wakefield must be properly taken into account. In this paper we present a new simulation code for the longitudinal beam dynamics in a circular accelerator, which exploits an alternative approach to the currently used convolution sum, reducing the computing time and avoiding the issues related to the length of wakefield for coupled bunch instabilities. With this approach it is possible to simulate, without the need of a large computing power, simultaneously, the single and multi-bunch beam dynamics...

Migliorati, M

2015-01-01T23:59:59.000Z

126

Beam Coupling to Optical Scale Accelerating Structures  

SciTech Connect (OSTI)

Current research efforts into structure based laser acceleration of electrons utilize beams from standard RF linacs. These beams must be coupled into very small structures with transverse dimensions comparable to the laser wavelength. To obtain decent transmission, a permanent magnet quadrupole (PMQ) triplet with a focusing gradient of 560 T/m is used to focus into the structure. Also of interest is the induced wakefield from the structure, useful for diagnosing potential accelerator structures or as novel radiation sources.

Sears, C.M.; Byer, R.L.; Colby, E.R.; Cowan, B.M.; Ischebeck, R.; Lincoln, M.R.; Siemann, R.H.; Spencer, J.E.; /SLAC; Plettner, T.; /Stanford U., Phys. Dept.

2007-03-27T23:59:59.000Z

127

Beam Coupling to Optical Scale Accelerating Structures  

SciTech Connect (OSTI)

Current research efforts into structure based laser acceleration of electrons utilize beams from standard RF linacs. These beams must be coupled into very small structures with transverse dimensions comparable to the laser wavelength. To obtain decent transmission, a permanent magnet quadrupole (PMQ) triplet with a focusing gradient of 560 T/m is used to focus into the structure. Also of interest is the induced wakefield from the structure, useful for diagnosing potential accelerator structures or as novel radiation sources.

Sears, Christopher M. S.; Colby, Eric R.; Cowan, Benjamin M.; Ischebeck, Rasmus; Lincoln, Melissa R.; Siemann, Robert H.; Spencer, James E. [Stanford Linear Accelerator Center, Menlo Park, CA 94025 (United States); Byer, Robert L.; Plettner, Tomas [Stanford University, Stanford, CA 94305 (United States)

2006-11-27T23:59:59.000Z

128

Shielding effect and wakefield pattern of a moving test charge in a non-Maxwellian dusty plasma  

SciTech Connect (OSTI)

By using the Vlasov-Poisson equations, we calculate an expression for the electrostatic potential caused by a test charge in an unmagnetized non-Maxwellian dusty plasma, whose constituents are the superthermal hot-electrons, the mobile cold-electrons with a neutralizing background of cold ions, and charge fluctuating isolated dust grains. The superthermality effects due to hot electrons not only modify the dielectric constant of the electron-acoustic waves but also significantly affect the electrostatic potential. The latter can be decomposed into the Debye-Hückel and oscillatory wake potentials. Analytical and numerical results reveal that the Debye-Hückel and wakefield potentials converge to the Maxwellian case for large values of superthermality parameter. Furthermore, the plasma parameters play a vital role in the formation of shielding and wakefield pattern in a two-electron temperature plasma. The present results should be important for laboratory and space dusty plasmas, where hot-electrons can be assumed to follow the non-Maxwellian distribution function.

Ali, S. [National Centre for Physics (NCP), Quaid-e-Azam University Campus, Shahdra Valley Road, Islamabad 44000 (Pakistan)] [National Centre for Physics (NCP), Quaid-e-Azam University Campus, Shahdra Valley Road, Islamabad 44000 (Pakistan); Khan, S. [National Centre for Physics (NCP), Quaid-e-Azam University Campus, Shahdra Valley Road, Islamabad 44000 (Pakistan) [National Centre for Physics (NCP), Quaid-e-Azam University Campus, Shahdra Valley Road, Islamabad 44000 (Pakistan); Department of Physics, Gomal University, Dera Ismail Khan 29050 (Pakistan)

2013-07-15T23:59:59.000Z

129

RF cavity using liquid dielectric for tuning and cooling  

DOE Patents [OSTI]

A system for accelerating particles includes an RF cavity that contains a ferrite core and a liquid dielectric. Characteristics of the ferrite core and the liquid dielectric, among other factors, determine the resonant frequency of the RF cavity. The liquid dielectric is circulated to cool the ferrite core during the operation of the system.

Popovic, Milorad (Warrenville, IL); Johnson, Rolland P. (Newport News, VA)

2012-04-17T23:59:59.000Z

130

USING LUA FOR AUDIOVISUAL COMPOSTION Graham Wakefield Wesley Smith  

E-Print Network [OSTI]

USING LUA FOR AUDIOVISUAL COMPOSTION Graham Wakefield Wesley Smith University of California Santa Barbara Media Arts and Technology Program Santa Barbara, California, USA ABSTRACT In this paper, we/MSP/Jitter [27], PureData [19], etc.) are popular choices for composing interactive digital media works because

California at Santa Barbara, University of

131

Studies of Intense Laser Propagation in Channels for Extended Length Plasma Accelerators  

E-Print Network [OSTI]

. Wurtele, G. Shvets Massachusetts Institute of Technology, Cambridge, MA 02139 Abstract Progress profile. That is, n0(y) = 0 for y a In this section we consider the more that the wakefield accelerator scheme can be effective, but only if the beam load is placed on the first accelerating

Wurtele, Jonathan

132

Submillimeter-resolution radiography of shielded structures with laser-accelerated electron beams  

E-Print Network [OSTI]

Submillimeter-resolution radiography of shielded structures with laser-accelerated electron beams (Received 24 March 2010; published 14 October 2010) We investigate the use of energetic electron beams beam (with energy >100 MeV) was generated by the process of laser-wakefield acceleration through

Umstadter, Donald

133

Town of Wakefield, Massachusetts (Utility Company) | Open Energy  

Open Energy Info (EERE)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Office of InspectorConcentrating SolarElectric Coop, IncTipmont RuralMiddletownSpiceland,Information Wakefield

134

Stable laser–plasma accelerators at low densities  

SciTech Connect (OSTI)

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

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

2014-07-28T23:59:59.000Z

135

City of Wakefield, Michigan (Utility Company) | Open Energy Information  

Open Energy Info (EERE)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home5b9fcbce19 NoPublic Utilities Address: 160Benin:Energy NebraskaStanhope, Iowa (Utility Company)ThomastonVineland,Wakefield

136

Enhancement of proton acceleration field in laser double-layer target interaction  

SciTech Connect (OSTI)

A mechanism is proposed to enhance a proton acceleration field in laser plasma interaction. A double-layer plasma with different densities is illuminated by an intense short pulse. Electrons are accelerated to a high energy in the first layer by the wakefield. The electrons accelerated by the laser wakefield induce the enhanced target normal sheath (TNSA) and breakout afterburner (BOA) accelerations through the second layer. The maximum proton energy reaches about 1 GeV, and the total charge with an energy higher than 100 MeV is about several tens of ?C/?m. Both the acceleration gradient and laser energy transfer efficiency are higher than those in single-target-based TNSA or BOA. The model has been verified by 2.5D-PIC simulations.

Gu, Y. J. [Applied Ion Beam Physics Laboratory, Key Laboratory of the Ministry of Education, Institute of Modern Physics, Fudan University, Shanghai 200433 (China) [Applied Ion Beam Physics Laboratory, Key Laboratory of the Ministry of Education, Institute of Modern Physics, Fudan University, Shanghai 200433 (China); Department of Advanced Interdisciplinary Sciences, Utsunomiya University, Yohtoh 7-1-2, Utsunomiya 321-8585 (Japan); Kong, Q.; Li, X. F.; Yu, Q.; Wang, P. X. [Applied Ion Beam Physics Laboratory, Key Laboratory of the Ministry of Education, Institute of Modern Physics, Fudan University, Shanghai 200433 (China)] [Applied Ion Beam Physics Laboratory, Key Laboratory of the Ministry of Education, Institute of Modern Physics, Fudan University, Shanghai 200433 (China); Kawata, S.; Izumiyama, T. [Department of Advanced Interdisciplinary Sciences, Utsunomiya University, Yohtoh 7-1-2, Utsunomiya 321-8585 (Japan)] [Department of Advanced Interdisciplinary Sciences, Utsunomiya University, Yohtoh 7-1-2, Utsunomiya 321-8585 (Japan); Ma, Y. Y. [College of Science, National University of Defense Technology, Changsha 410073 (China)] [College of Science, National University of Defense Technology, Changsha 410073 (China)

2013-07-15T23:59:59.000Z

137

Excitation of two-dimensional plasma wakefields by trains of equidistant particle bunches  

SciTech Connect (OSTI)

Nonlinear effects responsible for elongation of the plasma wave period are numerically studied with the emphasis on two-dimensionality of the wave. The limitation on the wakefield amplitude imposed by detuning of the wave and the driver is found.

Lotov, K. V. [Budker Institute of Nuclear Physics SB RAS, 630090 Novosibirsk, Russia and Novosibirsk State University, 630090 Novosibirsk (Russian Federation)] [Budker Institute of Nuclear Physics SB RAS, 630090 Novosibirsk, Russia and Novosibirsk State University, 630090 Novosibirsk (Russian Federation)

2013-08-15T23:59:59.000Z

138

Collimator Wakefield Calculations for ILC-TRC Report(LCC-0101)  

SciTech Connect (OSTI)

We summarize the formalism of collimator wakefields and their effect on beams that are near the center of the collimator gap, and apply the formalism to the TESLA, NLC, and CLIC collimation systems.

Tenenbaum, P

2003-10-07T23:59:59.000Z

139

Comparative Wakefield Analysis of a First Prototype of a DDS Structure for CLIC Main Linac  

E-Print Network [OSTI]

A Damped Detuned Structure (DDS) for CLIC main linac has been proposed as an alternative to the present baseline design which is based on heavy damping. A first prototype, CLIC_DDS_A, for high power tests has been already designed and is under construction. It is also foreseen to design a further prototype, CLIC_DDS_B, to test both the wakefield suppression and high power performances. Wakefield calculations for DDS are, in the early design stage, based on single infinitely periodic cells. Though cell-to-cell interaction is taken into account to calculate the wakefields, it is important to study full structure properties using computational tools. In particular this is fundamental for defining the input parameters for the HOM coupler that is crucial for the performances of DDS. In the following a full analysis of wakefields and impedances based on simulations conducted with finite difference based electromagnetic computer code GdfidL will be presented.

D'Elia, A; Khan, V F; Grudiev, A; Wuensch, W

2011-01-01T23:59:59.000Z

140

Particle-In-Cell Modeling of Plasma-Based Accelerators in Two and Three Dimensions  

E-Print Network [OSTI]

In this dissertation, a fully object-oriented, fully relativistic, multi-dimensional Particle-In-Cell code was developed and applied to answer key questions in plasma-based accelerator research. The simulations increase the understanding of the processes in laser plasma and beam-plasma interaction, allow for comparison with experiments, and motivate the development of theoretical models. The simulations support the idea that the injection of electrons in a plasma wave by using a transversely propagating laser pulse is possible. The beam parameters of the injected electrons found in the simulations compare reasonably with beams produced by conventional methods and therefore laser injection is an interesting concept for future plasma-based accelerators. Simulations of the optical guiding of a laser wakefield driver in a parabolic plasma channel support the idea that electrons can be accelerated over distances much longer than the Rayleigh length in a channel. Simulations of plasma wakefield acceleration in the ...

Hemker, Roy G

2015-01-01T23:59:59.000Z

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


141

Proposed dielectric-based microstructure laser-driven undulator T. Plettner and R. L. Byer  

E-Print Network [OSTI]

by the possibility of future dielectric-based laser-driven particle accelerators that are expected to produce GeV=m accel- eration gradients accompanied by a low-emittance, low- energy spread, and high-repetition rate electron sources [8,9] as well as for dielectric-structure laser-driven particle accelerators are underway

Byer, Robert L.

142

ALL OPTICAL ACCELERATOR EXPERIMENTS AT LBNL/ W.P. Leemans, D. Rodgers, P.E. Catravas, G. Fubiani, C.G.R. Geddes, E. Esarey, B.A.Shadwick,  

E-Print Network [OSTI]

ALL OPTICAL ACCELERATOR EXPERIMENTS AT LBNL/ W.P. Leemans, D. Rodgers, P.E. Catravas, G. Fubiani, C wakefield acceleration research at the l'OASIS laboratory of the Cen- ter for Beam Physics at LBNL]- [14]. In this article we describe experiments performed at the l'OASIS laboratory of LBNL [15

Wurtele, Jonathan

143

High-gradient compact linear accelerator  

DOE Patents [OSTI]

A high-gradient linear accelerator comprises a solid-state stack in a vacuum of five sets of disc-shaped Blumlein modules each having a center hole through which particles are sequentially accelerated. Each Blumlein module is a sandwich of two outer conductive plates that bracket an inner conductive plate positioned between two dielectric plates with different thicknesses and dielectric constants. A third dielectric core in the shape of a hollow cylinder forms a casing down the series of center holes, and it has a dielectric constant different that the two dielectric plates that sandwich the inner conductive plate. In operation, all the inner conductive plates are charged to the same DC potential relative to the outer conductive plates. Next, all the inner conductive plates are simultaneously shorted to the outer conductive plates at the outer diameters. The signal short will propagate to the inner diameters at two different rates in each Blumlein module. A faster wave propagates quicker to the third dielectric core across the dielectric plates with the closer spacing and lower dielectric constant. When the faster wave reaches the inner extents of the outer and inner conductive plates, it reflects back outward and reverses the field in that segment of the dielectric core. All the field segments in the dielectric core are then in unipolar agreement until the slower wave finally propagates to the third dielectric core across the dielectric plates with the wider spacing and higher dielectric constant. During such unipolar agreement, particles in the core are accelerated with gradients that exceed twenty megavolts per meter.

Carder, Bruce M. (205 Rogue River Hwy., Gold Hill, OR 97525)

1998-01-01T23:59:59.000Z

144

High-gradient compact linear accelerator  

DOE Patents [OSTI]

A high-gradient linear accelerator comprises a solid-state stack in a vacuum of five sets of disc-shaped Blumlein modules each having a center hole through which particles are sequentially accelerated. Each Blumlein module is a sandwich of two outer conductive plates that bracket an inner conductive plate positioned between two dielectric plates with different thicknesses and dielectric constants. A third dielectric core in the shape of a hollow cylinder forms a casing down the series of center holes, and it has a dielectric constant different that the two dielectric plates that sandwich the inner conductive plate. In operation, all the inner conductive plates are charged to the same DC potential relative to the outer conductive plates. Next, all the inner conductive plates are simultaneously shorted to the outer conductive plates at the outer diameters. The signal short will propagate to the inner diameters at two different rates in each Blumlein module. A faster wave propagates quicker to the third dielectric core across the dielectric plates with the closer spacing and lower dielectric constant. When the faster wave reaches the inner extents of the outer and inner conductive plates, it reflects back outward and reverses the field in that segment of the dielectric core. All the field segments in the dielectric core are then in unipolar agreement until the slower wave finally propagates to the third dielectric core across the dielectric plates with the wider spacing and higher dielectric constant. During such unipolar agreement, particles in the core are accelerated with gradients that exceed twenty megavolts per meter. 10 figs.

Carder, B.M.

1998-05-26T23:59:59.000Z

145

Accelerators and the Accelerator Community  

E-Print Network [OSTI]

of electrostatic accelerators, while Ernest O. Lawrence (CBP 820 LBNL TBA ACCELERATORS ANDTHE ACCELERATOR COMMUNITY 1 ANDREW SESSLER Lawrence Berkeley

Malamud, Ernest

2009-01-01T23:59:59.000Z

146

Using Surface Impedance for Calculating Wakefields in Flat Geometry  

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

Beginning with Maxwell's equations and assuming only that the wall interaction can be approximated by a surface impedance, we derive formulas for the generalized longitudinal and transverse impedance in flat geometry, from which the wakefields can also be obtained. From the generalized impedances, by taking the proper limits, we obtain the normal longitudinal, dipole, and quad impedances in flat geometry. These equations can be applied to any surface impedance, such as the known dc, ac, and anomalous skin models of wall resistance, a model of wall roughness, or one for a pipe with small, periodic corrugations. We show that, for the particular case of dc wall resistance, the longitudinal impedance obtained here agrees with a known result in the literature, a result that was derived from a very general formula by Henke and Napoly. As concrete example, we apply our results to representative beam and machine parameters in the undulator region of LCLS-II and estimate the impact of the transverse wakes on the machine performance.

Bane, Karl; Stupakov, Gennady

2015-03-01T23:59:59.000Z

147

Resonant dielectric metamaterials  

DOE Patents [OSTI]

A resonant dielectric metamaterial comprises a first and a second set of dielectric scattering particles (e.g., spheres) having different permittivities arranged in a cubic array. The array can be an ordered or randomized array of particles. The resonant dielectric metamaterials are low-loss 3D isotropic materials with negative permittivity and permeability. Such isotropic double negative materials offer polarization and direction independent electromagnetic wave propagation.

Loui, Hung; Carroll, James; Clem, Paul G; Sinclair, Michael B

2014-12-02T23:59:59.000Z

148

Development of high gradient laser wakefield accelerators towards nuclear detection applications at LBNL  

E-Print Network [OSTI]

at LBNL Cameron G.R. Geddes1 , David L. Bruhwiler2 , John R. Cary2,3 , Eric H. Esarey1,4 , Anthony J Program, LBNL, 1 Cyclotron Rd MS 71-259, Berkeley CA 94720, United States 2 Tech-X Corp., 5621 Arapahoe experiments at LBNL demonstrated narrow energy spread beams, now with energies of up to 1 GeV in 3 cm using

Geddes, Cameron Guy Robinson

149

EXPERIMENTAL RESULTS OF A PLASMA WAKEFIELD ACCELERATOR USING MULTIPLE ELECTRON BUNCHES  

E-Print Network [OSTI]

. Yakimenko, BNL, Upton, NY, USA W. D. Kimura STI Optronics, Inc., Bellevue, WA, USA Abstract We present some

Brookhaven National Laboratory

150

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

E-Print Network [OSTI]

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

Jalali. Bahram

151

Betatron radiation based measurement of the electron-beam size in a wakefield accelerator  

SciTech Connect (OSTI)

We present a spatial and spectral characterization of a laser-plasma based betatron source which allows us to determine the betatron oscillation amplitude of the electrons which decreases with increasing electron energies. Due to the observed oscillation amplitude and the independently measured x-ray source size of (1.8{+-}0.3){mu}m we are able to estimate the electron bunch diameter to be (1.6{+-}0.3){mu}m.

Schnell, Michael; Saevert, Alexander; Reuter, Maria [Institut fuer Optik und Quantenelektronik, Friedrich- Schiller- Universitaet, Jena (Germany); and others

2012-07-09T23:59:59.000Z

152

Study of electron trapping by a transversely ellipsoidal bubble in the laser wake-field acceleration  

SciTech Connect (OSTI)

We present electron trapping in an ellipsoidal bubble which is not well explained by the spherical bubble model by [Kostyukov et al., Phys. Rev. Lett. 103, 175003 (2009)]. The formation of an ellipsoidal bubble, which is elongated transversely, frequently occurs when the spot size of the laser pulse is large compared to the plasma wavelength. First, we introduce the relation between the bubble size and the field slope inside the bubble in longitudinal and transverse directions. Then, we provide an ellipsoidal model of the bubble potential and investigate the electron trapping condition by numerical integration of the equations of motion. We found that the ellipsoidal model gives a significantly less restrictive trapping condition than that of the spherical bubble model. The trapping condition is compared with three-dimensional particle-in-cell simulations and the electron trajectory in test potential simulations.

Cho, Myung-Hoon [School of Natural Science, UNIST, BanYeon-Ri 100, Ulju-gun, Ulsan 689-798 (Korea, Republic of)] [School of Natural Science, UNIST, BanYeon-Ri 100, Ulju-gun, Ulsan 689-798 (Korea, Republic of); Kim, Young-Kuk; Hur, Min Sup [School of Electrical and Computer Engineering, UNIST, BanYeon-Ri 100, Ulju-gun, Ulsan 689-798 (Korea, Republic of)] [School of Electrical and Computer Engineering, UNIST, BanYeon-Ri 100, Ulju-gun, Ulsan 689-798 (Korea, Republic of)

2013-09-15T23:59:59.000Z

153

SciTech Connect: Beam Matching to a Plasma Wakefield Accelerator Using a  

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

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154

Driving laser pulse evolution in a hollow channel laser wakefield accelerator  

E-Print Network [OSTI]

of different methods for laser accel- eration and summaries of experimental and theoretical progress can particle in the LWFA to about one Rayleigh range. Laser guiding in plasma channels has been proposed

Wurtele, Jonathan

155

STABLE, MONOENERGETIC 50-400 MeV ELECTRON BEAMS WITH A MATCHED LASER WAKEFIELD ACCELERATOR  

E-Print Network [OSTI]

progress in laser-based particle accelera- tors [1]. Early breakthroughs in laser-based electron accel

Umstadter, Donald

156

Experimental demonstration of wakefield effects in a THz planar diamond accelerating structure  

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

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157

Experimental demonstration of wakefield effects in a THz planar diamond accelerating structure  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsruc DocumentationP-Series toESnet4:Epitaxial Thin FilmEquipment SSRL plans the1Experimental

158

Two GeV Electrons Achieved by Laser Plasma Wakefield Acceleration | U.S.  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear SecurityTensile Strain Switched Ferromagnetism in Layeredof Energy Two Companies Recognized forDOE Office of

159

Visual Exploration of Turbulent Combustion and Laser-Wakefield Accelerator Simulations  

E-Print Network [OSTI]

hydrogen flames under different levels of turbulence ­ Lean combustion reduces emissions Important-dependent, difficult to characterize) · Scientific Goal: ­ Understanding the temporal evolution of burning cells Simulations 4 Feature Tracking in Combustion Simulations · Isotherm represents "flame surface" · Fuel

160

DEVELOPMENT OF ONE METER-LONG LITHIUM PLASMA SOURCE AND EXCIMER MODE REDUCTION FOR PLASMA WAKEFIELD  

E-Print Network [OSTI]

DEVELOPMENT OF ONE METER-LONG LITHIUM PLASMA SOURCE AND EXCIMER MODE REDUCTION FOR PLASMA WAKEFIELD 94720 K. Marsh, P. Muggli, S. Wang, and C. Joshi, UCLA, Los Angeles, CA 90024 Abstract A one meter long reduction. 1 INTRODUCTION A one-meter long plasma source has been constructed which will permit

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


161

Frequency chirp and pulse shape effects in self-modulated laser wakefield acceleratorsa...  

E-Print Network [OSTI]

laser-plasma-based harmonic generation,2 x-ray lasers,3 and laser-driven inertial confinement fusionFrequency chirp and pulse shape effects in self-modulated laser wakefield acceleratorsa... C. B Received 7 November 2002; accepted 20 January 2003 The effect of asymmetric laser pulses on plasma wave

Geddes, Cameron Guy Robinson

162

Monte Carlo Characterization of a Pulsed Laser-Wakefield Driven Monochromatic  

E-Print Network [OSTI]

Monte Carlo Characterization of a Pulsed Laser-Wakefield Driven Monochromatic X-Ray Source S. D determination of the incident X-ray energy by using unfolding techniques. I. INTRODUCTION HE Diocles laser light from the same laser system, producing monochromatic X-rays with energy and spectral width

Umstadter, Donald

163

Wakefield induced Losses in the Manual Valves of the TESLA Cryomodule  

E-Print Network [OSTI]

1 Wakefield induced Losses in the Manual Valves of the TESLA Cryomodule M.Dohlus,H.-P.Wedekind,K.Zapfe DeutschesElektronenSynchrotron Notkestr.85,D-22603Hamburg,Germany Abstract The beam pipe of the TESLA valves with spring type rf-shield which are presently used in the linac of the TESLA Test Facility

164

LuaAV: Extensibility and Heterogeneity for Audiovisual Graham WAKEFIELD and Wesley SMITH and Charles ROBERTS  

E-Print Network [OSTI]

LuaAV: Extensibility and Heterogeneity for Audiovisual Computing Graham WAKEFIELD and Wesley SMITH and Charles ROBERTS Media Arts and Technology, University of California Santa Barbara Santa Barbara, CA 93110 providing the flexibility and temporal accuracy demanded by interactive audio-visual media. Code generation

California at Santa Barbara, University of

165

Dielectric properties of aerogels  

SciTech Connect (OSTI)

We have measured the real (dielectric constant) and imaginary (loss factor) components of the complex relative permittivity at 298 [degree]K using microwave frequencies (2, 10, and 18--40 GHz), for bulk SiO[sub 2]-aerogels and for two types of organic aerogels, resorcinol-formaldehyde (RF) and melamine-formaldehyde (MF). Measured dielectric constants are found to vary linearly between values of 1.0 and 2.0 for aerogel densities from 10 to 500 kg/m[sup 3]. For the same range of densities, the measured loss tangents vary linearly between values of 2[times]10[sup [minus]4] and 7[times]10[sup [minus]2]. The observed linearity of the dielectric properties with density in aerogels at microwave frequencies shows that their dielectric behavior is more gas-like than solid-like. The dielectric properties of aerogels are shown to be significantly affected by the adsorbed water internal to the bulk material. For example, water accounts for 7% of the dielectric constant and 70% of the loss at microwave frequencies for silica aerogels. Because of their very high porosity, even with the water content, the aerogels are among the few materials exhibiting such low dielectric properties. Our measurements show that aerogels with greater than 99% porosity have dielectric constants less than 1.03; these are the lowest values ever reported for a bulk solid material.

Hrubesh, L.W.; Keene, L.E.; Latorre, V.R. (Chemistry and Material Sciences Department, Lawrence Livermore National Laboratory, Livermore, California 94550 (United States))

1993-07-01T23:59:59.000Z

166

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

SciTech Connect (OSTI)

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

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

2013-08-06T23:59:59.000Z

167

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

SciTech Connect (OSTI)

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

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

2013-08-15T23:59:59.000Z

168

Production, Characterization, and Acceleration of Optical Microbunches  

SciTech Connect (OSTI)

Optical microbunches with a spacing of 800 nm have been produced for laser acceleration research. The microbunches are produced using a inverse Free-Electron-Laser (IFEL) followed by a dispersive chicane. The microbunched electron beam is characterized by coherent optical transition radiation (COTR) with good agreement to the analytic theory for bunch formation. In a second experiment the bunches are accelerated in a second stage to achieve for the first time direct net acceleration of electrons traveling in a vacuum with visible light. This dissertation presents the theory of microbunch formation and characterization of the microbunches. It also presents the design of the experimental hardware from magnetostatic and particle tracking simulations, to fabrication and measurement of the undulator and chicane magnets. Finally, the dissertation discusses three experiments aimed at demonstrating the IFEL interaction, microbunch production, and the net acceleration of the microbunched beam. At the close of the dissertation, a separate but related research effort on the tight focusing of electrons for coupling into optical scale, Photonic Bandgap, structures is presented. This includes the design and fabrication of a strong focusing permanent magnet quadrupole triplet and an outline of an initial experiment using the triplet to observe wakefields generated by an electron beam passing through an optical scale accelerator.

Sears, Christopher M.S.; /Stanford U. /SLAC

2008-06-20T23:59:59.000Z

169

LASER ACCELERATORS  

E-Print Network [OSTI]

UNIVERSITY OF CALIFORNIA Accelerator & Fusion Researchat the 1983 Particle Accelerator Conference, Santa Fe, NM,March 21-23, 1983 LASER ACCELERATORS A.M. Sessler TWO-WEEK

Sessler, A.M.

2008-01-01T23:59:59.000Z

170

Thermally switchable dielectrics  

DOE Patents [OSTI]

Precursor polymers to conjugated polymers, such as poly(phenylene vinylene), poly(poly(thiophene vinylene), poly(aniline vinylene), and poly(pyrrole vinylene), can be used as thermally switchable capacitor dielectrics that fail at a specific temperature due to the non-conjugated precursor polymer irreversibly switching from an insulator to the conjugated polymer, which serves as a bleed resistor. The precursor polymer is a good dielectric until it reaches a specific temperature determined by the stability of the leaving groups. Conjugation of the polymer backbone at high temperature effectively disables the capacitor, providing a `built-in` safety mechanism for electronic devices.

Dirk, Shawn M.; Johnson, Ross S.

2013-04-30T23:59:59.000Z

171

Photonic laser-driven accelerator for GALAXIE  

SciTech Connect (OSTI)

We report on the design and development of an all-dielectric laser-driven accelerator to be used in the GALAXIE (GV-per-meter Acce Lerator And X-ray-source Integrated Experiment) project's compact free-electron laser. The approach of our working design is to construct eigenmodes, borrowing from the field of photonics, which yield the appropriate, highly demanding dynamics in a high-field, short wavelength accelerator. Topics discussed include transverse focusing, power coupling, bunching, and fabrication.

Naranjo, B.; Ho, M.; Hoang, P.; Putterman, S.; Valloni, A.; Rosenzweig, J. B. [UCLA Dept. of Physics and Astronomy Los Angeles, CA 90095-1547 (United States)

2012-12-21T23:59:59.000Z

172

Future Accelerators (?)  

E-Print Network [OSTI]

I describe the future accelerator facilities that are currently foreseen for electroweak scale physics, neutrino physics, and nuclear structure. I will explore the physics justification for these machines, and suggest how the case for future accelerators can be made.

John Womersley

2003-08-09T23:59:59.000Z

173

Meter scale plasma source for plasma wakefield experiments  

SciTech Connect (OSTI)

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

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

2012-12-21T23:59:59.000Z

174

Tomorrow's cities -the lamp-posts watching every move1 by Jane Wakefield for BBC News2  

E-Print Network [OSTI]

the city council is looking to upgrade its23 streetlights to more energy-efficient LED lights - likely in the area. The pilot project will be integrated with the newly built City Operations Centre, where CCTVTomorrow's cities - the lamp-posts watching every move1 by Jane Wakefield for BBC News2 3 Imagine

South Bohemia, University of

175

Photonic Crystal Laser-Driven Accelerator Structures  

SciTech Connect (OSTI)

Laser-driven acceleration holds great promise for significantly improving accelerating gradient. However, scaling the conventional process of structure-based acceleration in vacuum down to optical wavelengths requires a substantially different kind of structure. We require an optical waveguide that (1) is constructed out of dielectric materials, (2) has transverse size on the order of a wavelength, and (3) supports a mode with speed-of-light phase velocity in vacuum. Photonic crystals---structures whose electromagnetic properties are spatially periodic---can meet these requirements. We discuss simulated photonic crystal accelerator structures and describe their properties. We begin with a class of two-dimensional structures which serves to illustrate the design considerations and trade-offs involved. We then present a three-dimensional structure, and describe its performance in terms of accelerating gradient and efficiency. We discuss particle beam dynamics in this structure, demonstrating a method for keeping a beam confined to the waveguide. We also discuss material and fabrication considerations. Since accelerating gradient is limited by optical damage to the structure, the damage threshold of the dielectric is a critical parameter. We experimentally measure the damage threshold of silicon for picosecond pulses in the infrared, and determine that our structure is capable of sustaining an accelerating gradient of 300 MV/m at 1550 nm. Finally, we discuss possibilities for manufacturing these structures using common microfabrication techniques.

Cowan, Benjamin M.

2007-08-22T23:59:59.000Z

176

Dielectric Elastomers for Actuation and Energy Harvesting  

E-Print Network [OSTI]

1.23 Arm wrestling robot using dielectric elastomer springdemonstration of the arm wrestling robot. [265] Smart MaterMichael Wissler. An arm wrestling robot driven by dielectric

Brochu, Paul

2012-01-01T23:59:59.000Z

177

American Institute of Aeronautics and Astronautics Exploration of Ceramic Dielectrics for Microscale Dielectric  

E-Print Network [OSTI]

American Institute of Aeronautics and Astronautics 1 Exploration of Ceramic Dielectrics silicon dioxide for the dielectric barrier with thicknesses of 5 and 10 µm. Using a ceramic dielectric by a dielectric material, the dielectric barrier discharge, or DBD, is capable of generating a weakly ionized, non-thermal

Roy, Subrata

178

Dielectric microscopy with submillimeter resolution  

E-Print Network [OSTI]

In analogy with optical near-field scanning methods, we use tapered dielectric waveguides as probes for a millimeter wave vector network analyzer. By scanning thin samples between two such probes we are able to map the spatially varying dielectric properties of materials with sub-wavelength resolution; using a 150 GHz probe in transmision mode we see spatial resolution of around 500 microns. We have applied this method to a variety of highly heterogeneous materials. Here we show dielectric maps of granite and oil shale.

Nathan S. Greeney; John A. Scales

2007-06-20T23:59:59.000Z

179

Towards all-dielectric metamaterials and nanophotonics  

E-Print Network [OSTI]

We review a new, rapidly developing field of all-dielectric nanophotonics which allows to control both magnetic and electric response of structured matter by engineering the Mie resonances in high-index dielectric nanoparticles. We discuss optical properties of such dielectric nanoparticles, methods of their fabrication, and also recent advances in all-dielectric metadevices including couple-resonator dielectric waveguides, nanoantennas, and metasurfaces.

Krasnok, Alexander; Petrov, Mikhail; Savelev, Roman; Belov, Pavel; Kivshar, Yuri

2015-01-01T23:59:59.000Z

180

Accelerate Energy  

Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

Accelerate Energy Productivity 2030 Over the next year, the U.S. Department of Energy, the Council on Competitiveness and the Alliance to Save Energy will join forces to undertake...

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


181

ACCELERATE ENERGY  

Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

ACCELERATE ENERGY PRODUCTIVITY 2030 A Partnership To Double U.S. Energy Productivity By 2030 LEARN MORE AT: www.energy2030.org "I'm issuing a new goal for America: let's cut in...

182

Acceleration Fund  

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

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

183

Pleistocene and Recent environments of the Central Great Plains. Edited by Wakefield Dort, Jr., and J. Knox Jones, Jr.  

E-Print Network [OSTI]

PLEISTOCENE AND RECENT ENVIRONMENTS OF THE CENTRAL GREAT PLAINS PLEISTOCENE AND RECE T ENVIRONMENTS OF THE CENTRAL GREAT PLAINS Edited byJ Wakefield :Dort,' J"r., ,a:pdiJ. Knox Jones, Jr. ~l.,,"..,..... I!~ \\ ' .~ , Departlllent of Geolog... an interdisciplinary sympo.. sium on the natural and physical environments of the grasslands region-one that would stress the contributions of the various disci­ plines, with particular reference to the kinds of information useful to scientists with differing basic...

1970-01-01T23:59:59.000Z

184

Maximal acceleration or maximal accelerations?  

E-Print Network [OSTI]

We review the arguments supporting the existence of a maximal acceleration for a massive particle and show that different values of this upper limit can be predicted in different physical situations.

A. Feoli

2002-10-12T23:59:59.000Z

185

Accelerated Testing Validation  

E-Print Network [OSTI]

the University of California. Accelerated Testing Validationmaterials requires relevant Accelerated Stress Tests (ASTs),

Mukundan, Rangachary

2013-01-01T23:59:59.000Z

186

Terahertz electromagnetic wave generation and amplification by an electron beam in the elliptical plasma waveguides with dielectric rod  

SciTech Connect (OSTI)

The propagation of electromagnetic waves in an elliptical plasma waveguide including strongly magnetized plasma column and a dielectric rod is investigated. The dispersion relation of guided hybrid electromagnetic waves is obtained. Excitation of the waves by a thin annular relativistic elliptical electron beam will be studied. The time growth rate of electromagnetic waves is obtained. The effects of relative permittivity constant of dielectric rod, radius of dielectric rod, accelerating voltage, and current density of the annular elliptical beam on the growth rate and the frequency spectra are numerically presented.

Rahmani, Z., E-mail: z.rahmani@kashanu.ac.ir; Jazi, B. [Department of Laser and Photonics, Faculty of Physics, University of Kashan, Kashan (Iran, Islamic Republic of); Heidari-Semiromi, E. [Department of Condense Matter, Faculty of Physics, University of Kashan, Kashan (Iran, Islamic Republic of)

2014-09-15T23:59:59.000Z

187

COLLIDING PULSE INJECTION EXPERIMENTS IN NON-COLLINEAR GEOMETRY FOR CONTROLLED LASER PLASMA WAKEFIELD  

E-Print Network [OSTI]

emittance) is important for future plasma based accelerators and for applications. In any particle accelerator, particle injection into the accelerating structure is a key technology. In all cur- rent laser with acceler- Work supported by DOE grant DE-AC02-05CH11231, DARPA, and INCITE computational grant. CToth

Geddes, Cameron Guy Robinson

188

Dielectric Elastomers for Actuation and Energy Harvesting  

E-Print Network [OSTI]

152 10 Acrylic Interpenetrating Polymer Network DielectricSilicone Interpenetrating Polymer Network Elastomers withbased on interpenetrating polymer networks. Proceedings of

Brochu, Paul

2012-01-01T23:59:59.000Z

189

Electric and Magnetic Walls on Dielectric Interfaces  

E-Print Network [OSTI]

Sufficient conditions of the existence of electric or magnetic walls on dielectric interfaces are given for a multizone uniform dielectric waveguiding system. If one of two adjacent dielectric zones supports a TEM field distribution while the other supports a TM (TE) field distribution, then the common dielectric interface behaves as an electric (magnetic) wall, that is, the electric (magnetic) field line is perpendicular to the interface while the magnetic (electric) field line is parallel to the interface.

Changbiao Wang

2010-07-20T23:59:59.000Z

190

GPU accelerated cardiac electrophysiology  

E-Print Network [OSTI]

OF THE THESIS GPU Accelerated Cardiac Electrophysiology bySAN DIEGO GPU Accelerated Cardiac Electrophysiology A thesistoolkit for developing GPU accelerated programs called CUDA,

Lionetti, Fred

2010-01-01T23:59:59.000Z

191

Effect of the laser wavefront in a laser-plasma accelerator  

E-Print Network [OSTI]

A high repetition rate electron source was generated by tightly focusing kHz, few-mJ laser pulses into an underdense plasma. This high intensity laser-plasma interaction led to stable electron beams over several hours but with strikingly complex transverse distributions even for good quality laser focal spots. Analysis of the experimental data, along with results of PIC simulations demonstrate the role of the laser wavefront on the acceleration of electrons. Distortions of the laser wavefront cause spatial inhomogeneities in the out-of-focus laser distribution and consequently, the laser pulse drives an inhomogenous transverse wakefield whose focusing/defocusing properties affect the electron distribution. These findings explain the experimental results and suggest the possibility of controlling the electron spatial distribution in laser-plasma accelerators by tailoring the laser wavefront.

Beaurepaire, B; Bocoum, M; Böhle, F; Jullien, A; Rousseau, J-P; Lefrou, T; Douillet, D; Iaquaniello, G; Lopez-Martens, R; Lifschitz, A; Faure, J

2015-01-01T23:59:59.000Z

192

Accelerator Systems  

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

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

193

Advances in laser driven accelerator R&D  

SciTech Connect (OSTI)

Current activities (last few years) at different laboratories, towards the development of a laser wakefield accelerator (LWFA) are reviewed, followed by a more in depth discussion of results obtained at the L'OASIS laboratory of LBNL. Recent results on laser guiding of relativistically intense beams in preformed plasma channels are discussed. The observation of mono-energetic beams in the 100 MeV energy range, produced by a channel guided LWFA at LBNL, is described and compared to results obtained in the unguided case at LOA, RAL and LBNL. Analysis, aided by particle-in-cell simulations, as well as experiments with various plasma lengths and densities, indicate that tailoring the length of the accelerator has a very beneficial impact on the electron energy distribution. Progress on laser triggered injection is reviewed. Results are presented on measurements of bunch duration and emittance of the accelerated electron beams, that indicate the possibility of generating femtosecond duration electron bunches. Future challenges and plans towards the development of a 1 GeV LWFA module are discussed.

Leemans, Wim

2004-08-23T23:59:59.000Z

194

Methods and apparatus for vertical coupling from dielectric waveguides  

SciTech Connect (OSTI)

A frequency-chirped nano-antenna provides efficient sub-wavelength vertical emission from a dielectric waveguide. In one example, this nano-antenna includes a set of plasmonic dipoles on the opposite side of a SiYV.sub.4 waveguide from a ground plane. The resulting structure, which is less than half a wavelength long, emits a broadband beam (e.g., >300 nm) that can be coupled into an optical fiber. In some embodiments, a diffractive optical element with unevenly shaped regions of high- and low-index dielectric material collimates the broadband beam for higher coupling efficiency. In some cases, a negative lens element between the nano-antenna and the diffractive optical element accelerates the emitted beam's divergence (and improves coupling efficiency), allowing for more compact packaging. Like the diffractive optical element, the negative lens element includes unevenly shaped regions of high- and low-index dielectric material that can be designed to compensate for aberrations in the beam emitted by the nano-antenna.

Yaacobi, Ami; Cordova, Brad Gilbert

2014-06-17T23:59:59.000Z

195

Accelerators and the Accelerator Community  

SciTech Connect (OSTI)

In this paper, standing back--looking from afar--and adopting a historical perspective, the field of accelerator science is examined. How it grew, what are the forces that made it what it is, where it is now, and what it is likely to be in the future are the subjects explored. Clearly, a great deal of personal opinion is invoked in this process.

Malamud, Ernest; Sessler, Andrew

2008-06-01T23:59:59.000Z

196

Accelerators, Electrodynamics  

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

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

197

Application Acceleration  

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

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

198

Tailoring dielectric properties of ferroelectric-dielectric multilayers  

SciTech Connect (OSTI)

We develop a nonlinear thermodynamic model for multilayer ferroelectric heterostructures that takes into account electrostatic and electromechanical interactions between layers. We concentrate on the effect of relative layer fractions and in-plane thermal stresses on dielectric properties of Ba{sub 0.6}Sr{sub 0.4}TiO{sub 3}-, BaTiO{sub 3}-, and PbZr{sub 0.2}Ti{sub 0.8}O{sub 3} (PZT)-SrTiO{sub 3} (STO) multilayers on Si and c-sapphire. We show that dielectric properties of such multilayers can be significantly enhanced by tailoring the growth/processing temperature and the STO layer fraction. Our computations show that large tunabilities (?90% at 400?kV/cm) are possible in carefully designed barium strontium titanate-STO and PZT-STO even on Si for which there exist substantially large in-plane strains.

Kesim, M. T.; Zhang, J. [Department of Materials Science and Engineering and Institute of Materials Science, University of Connecticut, Storrs, Connecticut 06269 (United States); Cole, M. W. [U.S. Army Research Laboratory, Weapons and Materials Research Directorate, Aberdeen Proving Ground, Maryland 21005 (United States); Misirlioglu, I. B. [Faculty of Engineering and Natural Sciences, Sabanc? University, Orhanl?/Tuzla, 34956 Istanbul (Turkey); Alpay, S. P., E-mail: p.alpay@ims.uconn.edu [Department of Materials Science and Engineering and Institute of Materials Science, University of Connecticut, Storrs, Connecticut 06269 (United States); Department of Physics, University of Connecticut, Storrs, Connecticut 06269 (United States)

2014-01-13T23:59:59.000Z

199

PNL-SA-22914 Presented at the 48th Meeting of the Mechanical Failures Prevention Group (MFPG 48) 19-21 April 1994 in Wakefield, MA  

E-Print Network [OSTI]

-21 April 1994 in Wakefield, MA AN ARTIFICIAL NEURAL NETWORK SYSTEM FOR DIAGNOSING GAS TURBINE ENGINE FUEL until it produces an accurate diagnosis. For example, troubleshooting the AGT-1500 gas turbine engine Laboratory are developing a turbine engine diagnostic system for the M1A1 Abrams tank. This system employs

200

Electromechanics of dielectric particles in dielectric liquids acted on by a microelectrode array  

E-Print Network [OSTI]

Arrays of microelectrodes were used to apply forces to dielectric (soda lime glass) spheres in a thin (200 micrometer thick) layer of a dielectric liquid polymer (EOPN 8021). The microelectrodes were fabricated using standard photolithographic...

Seo, Cheong Soo

2006-04-12T23:59:59.000Z

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


201

Teleportation of Accelerated Information  

E-Print Network [OSTI]

A theoretical quantum teleportation protocal is suggested to teleport accelerated and non-accelerated information over different classes of accelerated quantum channels. For the accelerated information, it is shown that the fidelity of the teleported state increases as the entanglement of the initial quantum channel increases. However as the difference between the accelerated channel and the accelerated information decreases the fidelity increases. The fidelity of the non accelerated information increases as the entanglement of the initial quantum channel increases, while the accelerations of the quantum channel has a little effect. The possibility of sending quantum information over accelerated quantum channels is much better than sending classical information.

N. Metwally

2012-06-17T23:59:59.000Z

202

Energy-momentum balance in quantum dielectrics  

E-Print Network [OSTI]

We calculate the energy-momentum balance in quantum dielectrics such as Bose-Einstein condensates. In agreement with the experiment [G. K. Campbell et al. Phys. Rev. Lett. 94, 170403 (2005)] variations of the Minkowski momentum are imprinted onto the phase, whereas the Abraham tensor drives the flow of the dielectric. Our analysis indicates that the Abraham-Minkowski controversy has its root in the Roentgen interaction of the electromagnetic field in dielectric media.

Ulf Leonhardt

2005-12-21T23:59:59.000Z

203

Time growth rate and field profiles of hybrid modes excited by a relativistic elliptical electron beam in an elliptical metallic waveguide with dielectric rod  

SciTech Connect (OSTI)

The dispersion relation of guided electromagnetic waves propagating in an elliptical metallic waveguide with a dielectric rod driven by relativistic elliptical electron beam (REEB) is investigated. The electric field profiles and the growth rates of the waves are numerically calculated by using Mathieu functions. The effects of relative permittivity constant of dielectric rod, accelerating voltage, and current density of REEB on the growth rate are presented.

Jazi, B.; Rahmani, Z.; Abdoli-Arani, A. [Faculty of Physics, Department of Laser and Photonics, University of Kashan, Kashan (Iran, Islamic Republic of); Heidari-Semiromi, E. [Faculty of Physics, Department of Condense Matter, University of Kashan, Kashan (Iran, Islamic Republic of)

2012-10-15T23:59:59.000Z

204

Laser wakefield simulation using a speed-of-light frame envelope model  

E-Print Network [OSTI]

Laser wake?eld simulation using a speed-of-light frameAbstract. Simulation of laser wake?eld accelerator (LWFA)extend hundreds of laser wave- lengths transversely and many

Cowan, B.

2010-01-01T23:59:59.000Z

205

Mechanical constraints enhance electrical energy densities of soft dielectrics  

E-Print Network [OSTI]

Mechanical constraints enhance electrical energy densities of soft dielectrics Lin Zhang, Qiming, the dielectric will breakdown electrically. The breakdown limits the electrical energy density of the dielectric electric fields and thus increase their electrical energy densities. The mechanical constraints suppress

Ferrari, Silvia

206

for sequence accelerators  

E-Print Network [OSTI]

Wynn's -algorithm for sequence accelerators using high precision arithmetic Rachel Baumann University of Arizona Wynn's -algorithm for sequence accelerators using high precision arithmetic Rachel Baumann University of Arizona April 17, 2012 #12;Wynn's -algorithm for sequence accelerators using high

Zakharov, Vladimir

207

COLLECTIVE PHENOMENA IN ACCELERATORS  

E-Print Network [OSTI]

Proc. 1971 Particle Accelerator Conference, IEEE Trans. onConference on High-Energy Accelerators) 1971 (CERN, Geneva,and P. R. Zenkevich, Particle Accelerators b 1 (1972). M. S.

Sessler, Andrew M.

2008-01-01T23:59:59.000Z

208

High-Current Accelerators  

E-Print Network [OSTI]

F i g . 13 F i g . 14 A 48 ACCELERATOR F i g . 25 F i g . 16supply. Extrapolation of accelerator energy and current9 . A-48 high-current accelerator, low-velocity end. Fig.

Lawrence, Ernest O.

1955-01-01T23:59:59.000Z

209

Pulsed mid-infrared radiation from spectral broadening in laser wakefield simulations  

SciTech Connect (OSTI)

Spectral red-shifting of high power laser pulses propagating through underdense plasma can be a source of ultrashort mid-infrared (MIR) radiation. During propagation, a high power laser pulse drives large amplitude plasma waves, depleting the pulse energy. At the same time, the large amplitude plasma wave provides a dynamic dielectric response that leads to spectral shifting. The loss of laser pulse energy and the approximate conservation of laser pulse action imply that spectral red-shifts accompany the depletion. In this paper, we investigate, through simulation, the parametric dependence of MIR generation on pulse energy, initial pulse duration, and plasma density.

Zhu, W.; Palastro, J. P.; Antonsen, T. M. [IREAP, University of Maryland, College Park, Maryland 20740 (United States)] [IREAP, University of Maryland, College Park, Maryland 20740 (United States)

2013-07-15T23:59:59.000Z

210

Dielectric strength of parylene HT  

SciTech Connect (OSTI)

The dielectric strength of parylene HT (PA-HT) films was studied at room temperature in a wide thickness range from 500?nm to 50??m and was correlated with nano- and microstructure analyses. X-ray diffraction and polarized optical microscopy have revealed an enhancement of crystallization and spherulites development, respectively, with increasing the material thickness (d). Moreover, a critical thickness d{sub C} (between 5 and 10??m) is identified corresponding to the beginning of spherulite developments in the films. Two distinct behaviors of the dielectric strength (F{sub B}) appear in the thickness range. For d???d{sub C}, PA-HT films exhibit a decrease in the breakdown field following a negative slope (F{sub B}???d{sup ?0.4}), while for d?dielectric strength (F{sub B}???10 MV/cm) is obtained. A model of spherulite development in PA-HT films with increasing the thickness is proposed. The decrease in F{sub B} above d{sub C} is explained by the spherulites development, whereas its increase below d{sub C} is induced by the crystallites growth. An annealing of the material shows both an enhancement of F{sub B} and an increase of the crystallites and spherulites dimensions, whatever the thickness. The breakdown field becomes thickness-independent below d{sub C} showing a strong influence of the nano-scale structural parameters. On the contrary, both nano- and micro-scale structural parameters appear as influent on F{sub B} for d???d{sub C}.

Diaham, S., E-mail: sombel.diaham@laplace.univ-tlse.fr; Bechara, M.; Locatelli, M.-L.; Khazaka, R. [Université de Toulouse, UPS, INPT, LAPLACE, 118 route de Narbonne-Bât. 3R3, F-31062 Toulouse Cedex 9 (France); CNRS, LAPLACE, F-31062 Toulouse (France); Tenailleau, C. [Université de Toulouse, UPS, Laboratoire CIRIMAT/LCMIE, 118 route de Narbonne-Bât. 2R1, F-31062 Toulouse Cedex 9 (France); Kumar, R. [Speciality Coating Systems, Inc. (SCS), Cookson Electronics, 7645 Woodland Drive, Indianapolis, Indiana 46278 (United States)

2014-02-07T23:59:59.000Z

211

Multiorbit induction accelerators  

SciTech Connect (OSTI)

Large numbers of particles accelerated per cycle are made possible by accelerating simultaneously in several equilibrium orbits in a single betatron structure. (AIP)

Zvontsov, A.A.; Kas'yanov, V.A.; Chakhlov, V.L.

1985-09-01T23:59:59.000Z

212

Dielectric liquid ionization chambers for detecting fast neutrons  

E-Print Network [OSTI]

Three ionization chambers with different geometries have been constructed and filled with dielectric liquids for detection of fast neutrons. The three dielectric liquids studied were Tetramethylsilane (TMS), Tetramethylpentane ...

Boyd, Erin M

2008-01-01T23:59:59.000Z

213

High thermal conductivity lossy dielectric using a multi layer configuration  

DOE Patents [OSTI]

Systems and methods are described for loss dielectrics. A loss dielectric includes at least one high dielectric loss layer and at least one high thermal conductivity-electrically insulating layer adjacent the at least one high dielectric loss layer. A method of manufacturing a loss dielectric includes providing at least one high dielectric loss layer and providing at least one high thermal conductivity-electrically insulating layer adjacent the at least one high dielectric loss layer. The systems and methods provide advantages because the loss dielectrics are less costly and more environmentally friendly than the available alternatives.

Tiegs, Terry N. (Lenoir City, TN); Kiggans, Jr., James O. (Oak Ridge, TN)

2003-01-01T23:59:59.000Z

214

Dielectric properties and electronic applications of aerogels  

SciTech Connect (OSTI)

Among their other exceptional properties, aerogels also exhibits unusual dielectric properties due to their nano-sized structures and high porosities. For example, our measurements of the dielectric constants and loss tangents for several aerogel varieties at microwave frequencies show that they both vary linearly with the aerogel density, indicating that the dielectric behavior of aerogels is more gas-like than solid-like. We have also measured the dielectric strength of silica aerogels and find that they are better than ceramics for high voltage insulation. The low dielectric constants and loss tangents of aerogels, along with their controllable thermal expansion properties, make them desirable materials for use as thin films in high speed integrated digital and microwave circuitry.

Hrubesh, L.W.; Pekala, R.W.

1993-07-01T23:59:59.000Z

215

Dielectric  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth7-1D: Vegetation Proposed Newcatalyst phasesData FilesShape,Physics Diagnostics UWDiamondoidDianaDick

216

New initiatives for producing high current electron accelerators  

SciTech Connect (OSTI)

New classes of compact electron accelerators able to deliver multi-kiloamperes of pulsed 10-50 MeV electron beams are being studied. One class is based upon rf linac technology with dielectric-filled cavities. For materials with {epsilon}/{epsilon}{sub o}>>1, the greatly increased energy storage permits high current operation. The second type is a high energy injected betatron. Circulating current limits scale as {Beta}{sup 2}{gamma}{sup 3}.

Faehl, R.J.; Keinigs, R.K.; Pogue, E.W.

1996-11-01T23:59:59.000Z

217

Facility for Advanced Accelerator Experimental Tests at SLAC (FACET) Conceptual Design Report  

SciTech Connect (OSTI)

This Conceptual Design Report (CDR) describes the design of FACET. It will be updated to stay current with the developing design of the facility. This CDR begins as the baseline conceptual design and will evolve into an 'as-built' manual for the completed facility. The Executive Summary, Chapter 1, gives an introduction to the FACET project and describes the salient features of its design. Chapter 2 gives an overview of FACET. It describes the general parameters of the machine and the basic approaches to implementation. The FACET project does not include the implementation of specific scientific experiments either for plasma wake-field acceleration for other applications. Nonetheless, enough work has been done to define potential experiments to assure that the facility can meet the requirements of the experimental community. Chapter 3, Scientific Case, describes the planned plasma wakefield and other experiments. Chapter 4, Technical Description of FACET, describes the parameters and design of all technical systems of FACET. FACET uses the first two thirds of the existing SLAC linac to accelerate the beam to about 20GeV, and compress it with the aid of two chicanes, located in Sector 10 and Sector 20. The Sector 20 area will include a focusing system, the generic experimental area and the beam dump. Chapter 5, Management of Scientific Program, describes the management of the scientific program at FACET. Chapter 6, Environment, Safety and Health and Quality Assurance, describes the existing programs at SLAC and their application to the FACET project. It includes a preliminary analysis of safety hazards and the planned mitigation. Chapter 7, Work Breakdown Structure, describes the structure used for developing the cost estimates, which will also be used to manage the project. The chapter defines the scope of work of each element down to level 3.

Amann, J.; Bane, K.; /SLAC

2009-10-30T23:59:59.000Z

218

I. ACCELERATION A. Introduction  

E-Print Network [OSTI]

I. ACCELERATION A. Introduction Following cooling and initial bunch compression, the beams must be rapidly accelerated. The acceleration needed for a Higgs collider is probably the most conventional part undertaken. A sequence of linacs would work, but would be expensive. Some form of circulating acceleration

McDonald, Kirk

219

Superconducting Radiofrequency (SRF) Accelerator Cavities  

ScienceCinema (OSTI)

Charlie Reece, an accelerator technology scientist, explains how superconducting radiofrequency accelerator cavities work.

Reece, Charlie

2014-05-22T23:59:59.000Z

220

Method of and apparatus for accelerating a projectile  

DOE Patents [OSTI]

A projectile is accelerated along a confined path by supplying a pulsed high pressure, high velocity plasma jet to the rear of the projectile as the projectile traverses the path. The jet enters the confined path at a non-zero angle relative to the projectile path. The pulse is derived from a dielectric capillary tube having an interior wall from which plasma forming material is ablated in response to a discharge voltage. The projectile can be accelerated in response to the kinetic energy in the plasma jet or in response to a pressure increase of gases in the confined path resulting from the heat added to the gases by the plasma.

Goldstein, Yeshayahu S. A. (Gaithersburg, MD); Tidman, Derek A. (Silver Spring, MD)

1986-01-01T23:59:59.000Z

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


221

K. Baird, F.-J. Decker, M. J. Hogan* , R.H. Iverson, P. Raimondi, R.H. Siemann, D. Walz  

E-Print Network [OSTI]

a unique and timely opportunity for looking at, plasma focusing and wakefield acceleration of positron

222

Layered Binary-Dielectrics for Energy Applications: Limitations and Potentials  

SciTech Connect (OSTI)

In this Letter, an attempt is made to illustrate how performance of an electrically insulating material, a dielectric, can be improved by constructing a layered binary-dielectric structure that employs a weak insulator with high dielectric permittivity. It is shown that layered binary-dielectrics could have a signicant impact on energy storage and electrical insulation.

Tuncer, Enis [ORNL

2012-01-01T23:59:59.000Z

223

Epoxy Foam Encapsulants: Processing and Dielectric Characterization  

SciTech Connect (OSTI)

The dielectric performance of epoxy foams was investigated to determine if such materials might provide advantages over more standard polyurethane foams in the encapsulation of electronic assemblies. Comparisons of the dielectric characteristics of epoxy and urethane encapsulant foams found no significant differences between the two resin types and no significant difference between as-molded and machined foams. This study specifically evaluated the formulation and processing of epoxy foams using simple methylhydrosiloxanes as the flowing agent and compared the dielectric performance of those to urethane foams of similar density.

Linda Domeier; Marion Hunter

1999-01-01T23:59:59.000Z

224

Dielectric studies of water absorbed in epoxies  

E-Print Network [OSTI]

times. By using the Williams, l, andel, and Ferry (WLF) equation, all the dielectric constant and dielectric loss curves were successfully reduced to master plots at room tem- perature. From the WLF equation, activation energies for the processes... are assumed to be hydrogen bonded to each other, and to the active sites of the polymers, to form linear, one-dimensional water chains with a wide size distribution. All water molecules in a chain can, cooperatively, undergo dipolar reorientation along...

Pham, Ha Quoc

1987-01-01T23:59:59.000Z

225

Investigation of dielectric overlay microstrip circuits  

E-Print Network [OSTI]

INVESTIGATION OF DIELECTRIC OVERLAY MICROSTRIP CIRCUITS A Thesis by JAMES LOUIS KLEIN Submitted to the Graduate College of Texas ARM University in partial fulfillment of the requirement for the degree of MASTER OF SCIENCE August 1988 Major... Subject: Electrical Engineering INVESTIGATION OF DIELECTRIC OVERLAY MICRO STRIP CIRCUITS A Thesis by JAMES LOUIS KLEIN Approved as to style and content by: Kai Chang Robert D. Nevels (Member) Krzysztof A. Michalski (Member) Mark H. Weichold...

Klein, James Louis

1988-01-01T23:59:59.000Z

226

Method of casting patterned dielectric structures  

DOE Patents [OSTI]

A pattern of dielectric structures are formed directly on a substrate in a single step using sol-gel chemistry and molding procedures. The resulting dielectric structures are useful in vacuum applications for electronic devices. Porous, lightweight structures having a high aspect ratio that are suitable for use as spacers between the faceplate and baseplate of a field emission display can be manufactured using this method.

Poco, John F. (Livermore, CA); Hrubesh, Lawrence W. (Livermore, CA)

2001-01-01T23:59:59.000Z

227

Thin film dielectric composite materials  

DOE Patents [OSTI]

A dielectric composite material comprising at least two crystal phases of different components with TiO.sub.2 as a first component and a material selected from the group consisting of Ba.sub.1-x Sr.sub.x TiO.sub.3 where x is from 0.3 to 0.7, Pb.sub.1-x Ca.sub.x TiO.sub.3 where x is from 0.4 to 0.7, Sr.sub.1-x Pb.sub.x TiO.sub.3 where x is from 0.2 to 0.4, Ba.sub.1-x Cd.sub.x TiO.sub.3 where x is from 0.02 to 0.1, BaTi.sub.1-x Zr.sub.x O.sub.3 where x is from 0.2 to 0.3, BaTi.sub.1-x Sn.sub.x O.sub.3 where x is from 0.15 to 0.3, BaTi.sub.1-x Hf.sub.x O.sub.3 where x is from 0.24 to 0.3, Pb.sub.1-1.3x La.sub.x TiO.sub.3+0.2x where x is from 0.23 to 0.3, (BaTiO.sub.3).sub.x (PbFeo.sub.0.5 Nb.sub.0.5 O.sub.3).sub.1-x where x is from 0.75 to 0.9, (PbTiO.sub.3).sub.- (PbCo.sub.0.5 W.sub.0.5 O.sub.3).sub.1-x where x is from 0.1 to 0.45, (PbTiO.sub.3).sub.x (PbMg.sub.0.5 W.sub.0.5 O.sub.3).sub.1-x where x is from 0.2 to 0.4, and (PbTiO.sub.3).sub.x (PbFe.sub.0.5 Ta.sub.0.5 O.sub.3).sub.1-x where x is from 0 to 0.2, as the second component is described. The dielectric composite material can be formed as a thin film upon suitable substrates.

Jia, Quanxi (Los Alamos, NM); Gibbons, Brady J. (Los Alamos, NM); Findikoglu, Alp T. (Los Alamos, NM); Park, Bae Ho (Los Alamos, NM)

2002-01-01T23:59:59.000Z

228

E-Print Network 3.0 - all-dielectric optical elements Sample...  

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

demonstrated. - All dielectric feature provides front-end survivability - The use of optics provides unique... AllAll--Dielectric PhotonicDielectric Photonic--AssistedAssisted...

229

Accelerator R&D  

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

(505) 667-5657 Email Accelerator R&D R&D model Figure 1: Conceptual drawing of a superconducting radio-frequency accelerator with a PBG coupler cell. The ultimate goal of this...

230

History of Proton Linear Accelerators  

E-Print Network [OSTI]

much. References 1. Linear Accelerators, edited by P. M .at the 1986 Linear Accelerator Conference, SLAC, Stanford,HISTORY OF PROTON LINEAR ACCELERATORS Luis W. Alvarez TWO-

Alvarez, Luis W.

1987-01-01T23:59:59.000Z

231

LARGE-APERTURE D- ACCELERATORS  

E-Print Network [OSTI]

Vignetted current profile at accelerator entrance aperture 'LARGE-APERTURE D" ACCELERATORS* 0. A. Anderson" " Lawrencen i a 9-1720 Abstract Accelerator designs are described for

Anderson, O.A.

2010-01-01T23:59:59.000Z

232

Beam Dynamics for Induction Accelerators  

E-Print Network [OSTI]

Dynamics for Induction Accelerators Edward P. Lee Lawrencea natural candidate accelerator for a heavy ion fusion (HIF)words: Fusion, Induction, Accelerators, Dynamics This work

Lee, E.P.

2014-01-01T23:59:59.000Z

233

Application of Plasma Waveguides to High Energy Accelerators  

SciTech Connect (OSTI)

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

Milchberg, Howard M

2013-03-30T23:59:59.000Z

234

ULTRA-COMPACT ACCELERATOR TECHNOLOGIES FOR APPLICATION IN NUCLEAR TECHNIQUES  

SciTech Connect (OSTI)

We report on compact accelerator technology development for potential use as a pulsed neutron source quantitative post verifier. The technology is derived from our on-going compact accelerator technology development program for radiography under the US Department of Energy and for a clinic sized compact proton therapy systems under an industry sponsored Cooperative Research and Development Agreement. The accelerator technique relies on the synchronous discharge of a prompt pulse generating stacked transmission line structure with the beam transit. The goal of this technology is to achieve {approx}10 MV/m gradients for 10s of nanoseconds pulses and to {approx}100 MV/m gradients for {approx}1 ns systems. As a post verifier for supplementing existing x-ray equipment, this system can remain in a charged, stand-by state with little or no energy consumption. We detail the progress of our overall component development effort with the multilayer dielectric wall insulators (i.e., the accelerator wall), compact power supply technology, kHz repetition-rate surface flashover ion sources, and the prompt pulse generation system consisting of wide-bandgap switches and high performance dielectric materials.

Sampayan, S; Caporaso, G; Chen, Y; Carazo, V; Falabella, S; Guethlein, G; Guse, S; Harris, J R; Hawkins, S; Holmes, C; Krogh, M; Nelson, S; Paul, A C; Pearson, D; Poole, B; Schmidt, R; Sanders, D; Selenes, K; Sitaraman, S; Sullivan, J; Wang, L; Watson, J

2009-06-11T23:59:59.000Z

235

Application of SiO2 aerogel film with low dielectric constant to intermetal dielectrics  

E-Print Network [OSTI]

Application of SiO2 aerogel film with low dielectric constant to intermetal dielectrics Moon-Ho Jo aerogel film was characterized from its structural and chemical viewpoints. High porosity of material infrared spectroscopy (FT-IR) for their chemical states. The improved electrical properties of SiO2 aerogel

Jo, Moon-Ho

236

Novel Methods in the Particle-In-Cell Accelerator Code-Framework Warp  

SciTech Connect (OSTI)

The Particle-In-Cell (PIC) Code-Framework Warp is being developed by the Heavy Ion Fusion Science Virtual National Laboratory (HIFS-VNL) to guide the development of accelerators that can deliver beams suitable for high energy density experiments and implosion of inertial fusion capsules. It is also applied in various areas outside the Heavy Ion Fusion program to the study and design of existing and next-generation high-energy accelerators, including the study of electron cloud effects and laser wakefield acceleration for example. This paper presents an overview of Warp’s capabilities, summarizing recent original numerical methods that were developed by the HIFS-VNL (including Particle-In-Cell with Adaptive Mesh Refinement, a large-timestep “drift-Lorentz” mover for arbitrarily magnetized species, a relativistic Lorentz invariant leapfrog particle pusher, simulations in Lorentz boosted frames, an electromagnetic solver with tunable numerical dispersion and efficient stride20 based digital filtering), with great emphasis on the description of the mesh refinement capability. Selected examples of applications of the methods to the abovementioned fields are given.

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

2011-09-01T23:59:59.000Z

237

Automated detection and analysis of particle beams in laser-plasma accelerator simulations  

SciTech Connect (OSTI)

Numerical simulations of laser-plasma wakefield (particle) accelerators model the acceleration of electrons trapped in plasma oscillations (wakes) left behind when an intense laser pulse propagates through the plasma. The goal of these simulations is to better understand the process involved in plasma wake generation and how electrons are trapped and accelerated by the wake. Understanding of such accelerators, and their development, offer high accelerating gradients, potentially reducing size and cost of new accelerators. One operating regime of interest is where a trapped subset of electrons loads the wake and forms an isolated group of accelerated particles with low spread in momentum and position, desirable characteristics for many applications. The electrons trapped in the wake may be accelerated to high energies, the plasma gradient in the wake reaching up to a gigaelectronvolt per centimeter. High-energy electron accelerators power intense X-ray radiation to terahertz sources, and are used in many applications including medical radiotherapy and imaging. To extract information from the simulation about the quality of the beam, a typical approach is to examine plots of the entire dataset, visually determining the adequate parameters necessary to select a subset of particles, which is then further analyzed. This procedure requires laborious examination of massive data sets over many time steps using several plots, a routine that is unfeasible for large data collections. Demand for automated analysis is growing along with the volume and size of simulations. Current 2D LWFA simulation datasets are typically between 1GB and 100GB in size, but simulations in 3D are of the order of TBs. The increase in the number of datasets and dataset sizes leads to a need for automatic routines to recognize particle patterns as particle bunches (beam of electrons) for subsequent analysis. Because of the growth in dataset size, the application of machine learning techniques for scientific data mining is increasingly considered. In plasma simulations, Bagherjeiran et al. presented a comprehensive report on applying graph-based techniques for orbit classification. They used the KAM classifier to label points and components in single and multiple orbits. Love et al. conducted an image space analysis of coherent structures in plasma simulations. They used a number of segmentation and region-growing techniques to isolate regions of interest in orbit plots. Both approaches analyzed particle accelerator data, targeting the system dynamics in terms of particle orbits. However, they did not address particle dynamics as a function of time or inspected the behavior of bunches of particles. Ruebel et al. addressed the visual analysis of massive laser wakefield acceleration (LWFA) simulation data using interactive procedures to query the data. Sophisticated visualization tools were provided to inspect the data manually. Ruebel et al. have integrated these tools to the visualization and analysis system VisIt, in addition to utilizing efficient data management based on HDF5, H5Part, and the index/query tool FastBit. In Ruebel et al. proposed automatic beam path analysis using a suite of methods to classify particles in simulation data and to analyze their temporal evolution. To enable researchers to accurately define particle beams, the method computes a set of measures based on the path of particles relative to the distance of the particles to a beam. To achieve good performance, this framework uses an analysis pipeline designed to quickly reduce the amount of data that needs to be considered in the actual path distance computation. As part of this process, region-growing methods are utilized to detect particle bunches at single time steps. Efficient data reduction is essential to enable automated analysis of large data sets as described in the next section, where data reduction methods are steered to the particular requirements of our clustering analysis. Previously, we have described the application of a set of algorithms to automate the data analys

Ushizima, Daniela Mayumi; Geddes, C.G.; Cormier-Michel, E.; Bethel, E. Wes; Jacobsen, J.; Prabhat, ,; R.ubel, O.; Weber, G,; Hamann, B.

2010-05-21T23:59:59.000Z

238

RF properties of periodic accelerating structures for linear colliders  

SciTech Connect (OSTI)

With the advent of the SLAC electron-positron linear collider (SLC) in the 100 GeV center-of-mass energy range, research and development work on even higher energy machines of this type has started in several laboratories in the United States, Europe, the Soviet Union and Japan. These linear colliders appear to provide the only promising approach to studying e/sup /plus//e/sup /minus// physics at center-of-mass energies approaching 1 TeV. This thesis concerns itself with the study of radio frequency properties of periodic accelerating structures for linear colliders and their interaction with bunched beams. The topics that have been investigated are: experimental measurements of the energy loss of single bunches to longitudinal modes in two types of structures, using an equivalent signal on a coaxial wire to simulate the beam; a method of canceling the energy spread created within a single bunch by longitudinal wakefields, through appropriate shaping of the longitudinal charge distribution of the bunch; derivation of the complete transient beam-loading equation for a train of bunches passing through a constant-gradient accelerator section, with application to the calculation and minimization of multi-bunch energy spread; detailed study of field emission and radio frequency breakdown in disk-loaded structures at S-, C- and X-band frequencies under extremely high-gradient conditions, with special attention to thermal effects, radiation, sparking, emission of gases, surface damage through explosive emission and its possible control through RF-gas processing. 53 refs., 49 figs., 9 tabs.

Wang, J.W.

1989-07-01T23:59:59.000Z

239

Method of fabricating a solar cell with a tunnel dielectric layer  

DOE Patents [OSTI]

Methods of fabricating solar cells with tunnel dielectric layers are described. Solar cells with tunnel dielectric layers are also described.

Dennis, Tim; Harrington, Scott; Manning, Jane; Smith, David; Waldhauer, Ann

2012-12-18T23:59:59.000Z

240

Method of fabricating a solar cell with a tunnel dielectric layer  

DOE Patents [OSTI]

Methods of fabricating solar cells with tunnel dielectric layers are described. Solar cells with tunnel dielectric layers are also described.

Dennis, Tim; Harrington, Scott; Manning, Jane; Smith, David D; Waldhauer, Ann

2014-04-29T23:59:59.000Z

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


241

Tuneable dielectric films having low electrical losses  

DOE Patents [OSTI]

The present invention is directed to a method for forming dielectric thin films having substantially reduced electrical losses at microwave and millimeter wave frequencies relative to conventional dielectric thin films. The reduction in losses is realized by dramatically increasing the grain sizes of the dielectric films, thereby minimizing intergranular scattering of the microwave signal due to grain boundaries and point defects. The increase in grain size is realized by heating the film to a temperature at which the grains experience regrowth. The grain size of the films can be further increased by first depositing the films with an excess of one of the compoents, such that a highly mobile grain boundary phase is formed.

Dimos, Duane Brian (Albuquerque, NM); Schwartz, Robert William (Albuquerque, NM); Raymond, Mark Victor (Albuquerque, NM); Al-Shareef, Husam Niman (Boise, ID); Mueller, Carl (Lakewood, CO); Galt, David (Denver, CO)

2000-01-01T23:59:59.000Z

242

Method for fabrication of crack-free ceramic dielectric films  

DOE Patents [OSTI]

The invention provides a process for forming crack-free dielectric films on a substrate. The process comprise the application of a dielectric precursor layer of a thickness from about 0.3 .mu.m to about 1.0 .mu.m to a substrate. The deposition is followed by low temperature heat pretreatment, prepyrolysis, pyrolysis and crystallization step for each layer. The deposition, heat pretreatment, prepyrolysis, pyrolysis and crystallization are repeated until the dielectric film forms an overall thickness of from about 1.5 .mu.m to about 20.0 .mu.m and providing a final crystallization treatment to form a thick dielectric film. Also provided was a thick crack-free dielectric film on a substrate, the dielectric forming a dense thick crack-free dielectric having an overall dielectric thickness of from about 1.5 .mu.m to about 20.0 .mu.m.

Ma, Beihai; Balachandran, Uthamalingam; Chao, Sheng; Liu, Shanshan; Narayanan, Manoj

2014-02-11T23:59:59.000Z

243

PUBLISHED ONLINE: 12 APRIL 2009; CORRECTED ONLINE: 24 APRIL 2009 | DOI: 10.1038/NPHYS1248 Proton-driven plasma-wakefield acceleration  

E-Print Network [OSTI]

therefore be used for accel- erating particles to relativistic energies1­3 . Initially, laser-driven plasma to produce electric fields of 10­100 GV m-1 . This has opened up the possibility of building compact particle to the energy frontier of particle physics--the teraelectronvolt regime. Here, we introduce the possibility

Loss, Daniel

244

Method for producing high dielectric strength microvalves  

DOE Patents [OSTI]

A microvalve having a cast-in-place and lithographically shaped mobile, polymer monolith for fluid flow control in microfluidic devices and method of manufacture. The microvalve contains a porous fluorinated polymer monolithic element whose pores are filled with an electrically insulating, high dielectric strength fluid, typically a perfluorinated liquid. This combination provides a microvalve that combines high dielectric strength with extremely low electrical conductivity. These microvalves have been shown to have resistivities of at least 100 G.OMEGA. and are compatible with solvents such as water at a pH between 2.7 and 9.0, 1-1 propanol, acetonitrile, and acetone.

Kirby, Brian J. (San Francisco, CA); Reichmuth, David S. (Oakland, CA); Shepodd, Timothy J. (Livermore, CA)

2006-04-04T23:59:59.000Z

245

Nonlinear dielectric effect of dipolar fluids  

E-Print Network [OSTI]

The nonlinear dielectric effect for dipolar fluids is studied within the framework of the mean spherical approximation (MSA) of hard core dipolar Yukawa fluids. Based on earlier results for the electric field dependence of the polarization our analytical results show so-called normal saturation effects which are in good agreement with corresponding NVT ensemble Monte Carlo simulation data. The linear and the nonlinear dielectric permittivities obtained from MC simulations are determined from the fluctuations of the total dipole moment of the system in the absence of an applied electric field. We compare the MSA based theoretical results with the corresponding Langevin and Debye-Weiss behaviors.

I. Szalai; S. Nagy; S. Dietrich

2009-08-13T23:59:59.000Z

246

Optically pulsed electron accelerator  

DOE Patents [OSTI]

An optically pulsed electron accelerator can be used as an injector for a free electron laser and comprises a pulsed light source, such as a laser, for providing discrete incident light pulses. A photoemissive electron source emits electron bursts having the same duration as the incident light pulses when impinged upon by same. The photoemissive electron source is located on an inside wall of a radiofrequency-powered accelerator cell which accelerates the electron burst emitted by the photoemissive electron source.

Fraser, J.S.; Sheffield, R.L.

1985-05-20T23:59:59.000Z

247

Market Acceleration (Fact Sheet)  

SciTech Connect (OSTI)

The fact sheet summarizes the goals and activities of the DOE Solar Energy Technologies Program efforts within its market acceleration subprogram.

Not Available

2010-09-01T23:59:59.000Z

248

Norbornylene-based polymer systems for dielectric applications  

DOE Patents [OSTI]

A capacitor having at least one electrode pair being separated by a dielectric component, with the dielectric component being made of a polymer such as a norbornylene-containing polymer with a dielectric constant greater than 3 and a dissipation factor less than 0.1 where the capacitor has an operating temperature greater than 100.degree. C. and less than 170.degree. C.

Dirk, Shawn M. (Albuquerque, NM); Wheeler, David R. (Albuquerque, NM)

2012-07-17T23:59:59.000Z

249

Accelerators, Beams And Physical Review Special Topics - Accelerators And Beams  

SciTech Connect (OSTI)

Accelerator science and technology have evolved as accelerators became larger and important to a broad range of science. Physical Review Special Topics - Accelerators and Beams was established to serve the accelerator community as a timely, widely circulated, international journal covering the full breadth of accelerators and beams. The history of the journal and the innovations associated with it are reviewed.

Siemann, R.H.; /SLAC

2011-10-24T23:59:59.000Z

250

Acceleration Worksheet 8/24/2011 ACCELERATION WORKSHEET  

E-Print Network [OSTI]

Acceleration Worksheet 8/24/2011 ACCELERATION WORKSHEET College of Arts and Sciences Name _____________ TO _____________ month/year month/year II. I meet the requirements for acceleration under [fill out either a) or b;Acceleration Worksheet 8/24/2011 Acceleration 2011-2012 Courses of Study The faculty of the college desires

Davis, H. Floyd

251

Laser wakefield generated X-ray probe for femtosecond time-resolved measurements of ionization states of warm dense aluminum  

SciTech Connect (OSTI)

We have developed a laser wakefield generated X-ray probe to directly measure the temporal evolution of the ionization states in warm dense aluminum by means of absorption spectroscopy. As a promising alternative to the free electron excited X-ray sources, Betatron X-ray radiation, with femtosecond pulse duration, provides a new technique to diagnose femtosecond to picosecond transitions in the atomic structure. The X-ray probe system consists of an adjustable Kirkpatrick-Baez (KB) microscope for focusing the Betatron emission to a small probe spot on the sample being measured, and a flat Potassium Acid Phthalate Bragg crystal spectrometer to measure the transmitted X-ray spectrum in the region of the aluminum K-edge absorption lines. An X-ray focal spot size of around 50 ?m was achieved after reflection from the platinum-coated 10-cm-long KB microscope mirrors. Shot to shot positioning stability of the Betatron radiation was measured resulting in an rms shot to shot variation in spatial pointing on the sample of 16 ?m. The entire probe setup had a spectral resolution of ?1.5 eV, a detection bandwidth of ?24 eV, and an overall photon throughput efficiency of the order of 10{sup ?5}. Approximately 10 photons were detected by the X-ray CCD per laser shot within the spectrally resolved detection band. Thus, it is expected that hundreds of shots will be required per absorption spectrum to clearly observe the K-shell absorption features expected from the ionization states of the warm dense aluminum.

Mo, M. Z.; Chen, Z.; Tsui, Y. Y.; Fedosejevs, R. [Department of Electrical and Computer Engineering, University of Alberta, Edmonton, Alberta T6G 2V4 (Canada)] [Department of Electrical and Computer Engineering, University of Alberta, Edmonton, Alberta T6G 2V4 (Canada); Fourmaux, S.; Saraf, A.; Otani, K.; Kieffer, J. C. [INRS-EMT, Université du Québec, 1650 Lionel Boulet, Varennes, Québec J3X 1S2 (Canada)] [INRS-EMT, Université du Québec, 1650 Lionel Boulet, Varennes, Québec J3X 1S2 (Canada); Ng, A. [Department of Physics and Astronomy, University of British Columbia, British Columbia V6T 1Z1 (Canada)] [Department of Physics and Astronomy, University of British Columbia, British Columbia V6T 1Z1 (Canada)

2013-12-15T23:59:59.000Z

252

Ceramic-polymer nanocomposites with increased dielectric permittivity and low dielectric loss  

SciTech Connect (OSTI)

The use of lead free materials in device fabrication is very essential from environmental point of view. We have synthesized the lead free ferroelectric polymer nanocomposite films with increased dielectric properties. Lead free bismuth titanate has been used as active ceramic nanofillers having crystallite size 24nm and PVDF as the polymer matrix. Ferroelectric ?-phase of the polymer composite films was confirmed by X-ray diffraction pattern. Mapping data confirms the homogeneous dispersion of ceramic particles into the polymer matrix. Frequency dependent dielectric constant increases up to 43.4 at 100Hz, whereas dielectric loss decreases with 7 wt% bismuth titanate loading. This high dielectric constant lead free ferroelectric polymer films can be used for energy density applications.

Bhardwaj, Sumit, E-mail: sumit.bhardwaj4@gmail.com; Paul, Joginder, E-mail: sumit.bhardwaj4@gmail.com [Centre for Materials Science and Engineering, National Institute of Technology, Hamirpur -177 005 (India); Raina, K. K. [School of Physics and Materials Science, Thapar University, Patiala -147 004 (India); Thakur, N. S. [Centre for Energy and Environment, National Institute of Technology, Hamirpur -177005 (India); Kumar, Ravi [Centre for Materials Science and Engineering, National Institute of Technology, Hamirpur -177 005 (India); Beant College of Engineering and Technology, Gurdaspur -143521 (India)

2014-04-24T23:59:59.000Z

253

Electric field shielding in dielectric nanosolutions  

E-Print Network [OSTI]

To gain some insight into electrochemical activity of dielectric colloids of technical and biomedical interest we investigate a model of dielectric nanosolution whose micro-constitution is dominated by dipolarions -- positively and negatively charged spherically symmetric nano-structures composed of ionic charge surrounded by cloud of radially polarized dipoles of electrically neutral molecules of solvent. Combing the standard constitutive equations of an isotropic dielectric liquid with Maxwell equation of electrostatics and presuming the Boltzmann shape of the particle density of bound-charge we derive equation for the in-medium electrostatic field. Particular attention is given to numerical analysis of obtained analytic solutions of this equation describing the exterior fields of dipolarions with dipolar atmospheres of solvent molecules endowed with either permanent or field-induced dipole moments radially polarized by central symmetric field of counterions. The presented computations show that the electric field shielding of dipolarions in dielectric nanosolutions is quite different from that of counterionic nano-complexes of Debye-H\\"uckel theory of electrolytes.

Sergey Bastrukov; Pik-Yin Lai; Irina Molodtsova

2014-03-26T23:59:59.000Z

254

Electromagnetic Interrogation of Dielectric Materials 1  

E-Print Network [OSTI]

Electromagnetic Interrogation of Dielectric Materials 1 H.T. Banks M.W. Buksas Center for Research grant P200A40730. #12; Abstract We investigate time domain based electromagnetic inverse problems electromagnetic phenomenon. For our purposes, we categorize the materials and the models employed to describe them

255

Safety of Accelerator Facilities  

Broader source: Directives, Delegations, and Requirements [Office of Management (MA)]

To establish accelerator-specific safety requirements which, when supplemented by other applicable safety and health requirements, will serve to prevent injuries and illnesses associated with Department of Energy (DOE) or National Nuclear Security Administration (NNSA) accelerator operations. Cancels DOE O 420.2A. Certified 5-13-08. Canceled by DOE O 420.2C.

2004-07-23T23:59:59.000Z

256

Safety of Accelerator Facilities  

Broader source: Directives, Delegations, and Requirements [Office of Management (MA)]

To establish accelerator-specific safety requirements which, when supplemented by other applicable safety and health requirements, will serve to prevent injuries and illnesses associated with Department of Energy (DOE) or National Nuclear Security Administration (NNSA) accelerator operations. Cancels DOE O 420.2. Canceled by DOE O 420.2B.

2001-01-08T23:59:59.000Z

257

Microscale acceleration history discriminators  

DOE Patents [OSTI]

A new class of micromechanical acceleration history discriminators is claimed. These discriminators allow the precise differentiation of a wide range of acceleration-time histories, thereby allowing adaptive events to be triggered in response to the severity (or lack thereof) of an external environment. Such devices have applications in airbag activation, and other safety and surety applications.

Polosky, Marc A. (Albuquerque, NM); Plummer, David W. (Albuquerque, NM)

2002-01-01T23:59:59.000Z

258

Neutrino physics at accelerators  

E-Print Network [OSTI]

Present and future neutrino experiments at accelerators are mainly concerned with understanding the neutrino oscillation phenomenon and its implications. Here a brief account of neutrino oscillations is given together with a description of the supporting data. Some current and planned accelerator neutrino experiments are also explained.

Enrique Fernandez

2006-07-16T23:59:59.000Z

259

Accelerators (5/5)  

ScienceCinema (OSTI)

1a) Introduction and motivation 1b) History and accelerator types 2) Transverse beam dynamics 3a) Longitudinal beam dynamics 3b) Figure of merit of a synchrotron/collider 3c) Beam control 4) Main limiting factors 5) Technical challenges Prerequisite knowledge: Previous knowledge of accelerators is not required.

None

2011-10-06T23:59:59.000Z

260

Safety of Accelerator Facilities  

Broader source: Directives, Delegations, and Requirements [Office of Management (MA)]

The order defines accelerators and establishes accelerator specific safety requirements and approval authorities which, when supplemented by other applicable safety and health requirements, promote safe operations to ensure protection of workers, the public, and the environment. Cancels DOE O 420.2B.

2011-07-21T23:59:59.000Z

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


261

Accelerators (4/5)  

ScienceCinema (OSTI)

1a) Introduction and motivation 1b) History and accelerator types 2) Transverse beam dynamics 3a) Longitudinal beam dynamics 3b) Figure of merit of a synchrotron/collider 3c) Beam control 4) Main limiting factors 5) Technical challenges Prerequisite knowledge: Previous knowledge of accelerators is not required.

None

2011-10-06T23:59:59.000Z

262

Accelerators (3/5)  

ScienceCinema (OSTI)

1a) Introduction and motivation 1b) History and accelerator types 2) Transverse beam dynamics 3a) Longitudinal beam dynamics 3b) Figure of merit of a synchrotron/collider 3c) Beam control 4) Main limiting factors 5) Technical challenges Prerequisite knowledge: Previous knowledge of accelerators is not required.

None

2011-10-06T23:59:59.000Z

263

Surface charge in dielectric barrier discharge plasma actuators  

SciTech Connect (OSTI)

Direct measurements of the dielectric surface potential and its dynamics in asymmetric dielectric barrier discharge (DBD) plasma actuators show that the charge builds up at the dielectric surface and extends far downstream of the plasma. The surface charge persists for a long time (tens of minutes) after the driving voltage has been turned off. For a sinusoidal voltage waveform, the dielectric surface charges positively. With the voltage waveform consisting of nanosecond pulses superimposed on a dc bias, the sign of the dielectric surface charge is the same as the sign (polarity) of the bias voltage. The surface charging significantly affects DBD plasma actuator performance.

Opaits, D. F.; Shneider, M. N.; Miles, Richard B. [Department of Mechanical and Aerospace Engineering, Princeton University, Princeton, New Jersey 08544 (United States); Likhanskii, A. V. [Pennsylvania State University, University Park, Pennsylvania 16802 (United States); Macheret, S. O. [Lockheed Martin Aeronautics Company, Palmdale, California 93599 (United States)

2008-07-15T23:59:59.000Z

264

Accelerator Modeling with MATLAB Accelerator Toolbox  

SciTech Connect (OSTI)

This paper introduces Accelerator Toolbox (AT)--a collection of tools to model storage rings and beam transport lines in the MATLAB environment. The objective is to illustrate the flexibility and efficiency of the AT-MATLAB framework. The paper discusses three examples of problems that are analyzed frequently in connection with ring-based synchrotron light sources.

Terebilo, Andrei

2002-08-21T23:59:59.000Z

265

Compensation of wakefield-driven energy spread in energy recovery linacs Georg H. Hoffstaetter and Yang Hao Lau  

E-Print Network [OSTI]

and Yang Hao Lau Cornell University, Ithaca, New York 14853, USA (Received 16 May 2008; published 23 July, so that their energy is available for the acceleration of new particles. During this deceleration at a decelerating phase to recover the particles' energy. This energy is then used to accelerate new bunches

Hoffstaetter, Georg

266

Accelerated Quantum Dynamics  

E-Print Network [OSTI]

In this paper we establish a formalism for the computation of observables due to acceleration-induced particle physics processes. General expressions for the transition rate, multiplicity, power, spectra, and displacement law of particles undergoing time-dependent acceleration and transitioning into a final state of arbitrary particle number are obtained. The transition rate, power, and spectra are characterised by unique polynomials of multiplicity and thermal distributions of both bosonic and fermionic statistics. The acceleration dependent multiplicity is computed in terms of the branching fractions of the associated inertial processes. The displacement law of the spectra predicts the energy of the emitted particles are directly proportional to the accelerated temperature. These results extend our understanding of particle physics into the high acceleration sector.

Lynch, Morgan H

2015-01-01T23:59:59.000Z

267

Optimization of silver-dielectric-silver nanoshell for sensing applications  

SciTech Connect (OSTI)

In this paper, resonance light scattering (RLS) properties of a silver-dielectric-silver nanoshell, based on quasi-static approach and plasmon hybridization theory, are investigated. Scattering spectrum of silver-dielectric-silver nanoshell has two intense and clearly separated RLS peaks and provides a potential for biosensing based on surface plasmon resonance and surface-enhanced Raman scattering. The two RLS peaks in silver-dielectric-silver nanoshell are optimized by tuning the geometrical dimensions. In addition, the optimal geometry is discussed to obtain the high sensitivity of silver-dielectric-silver nanoshell. As the silver core radius increases, the sensitivity of silver-dielectric-silver nanoshell decreases whereas increasing the middle dielectric thickness increases the sensitivity of silver-dielectric-silver nanoshell.

Shirzaditabar, Farzad; Saliminasab, Maryam [Department of Physics, Razi University, Kermanshah 67144-15111 (Iran, Islamic Republic of)] [Department of Physics, Razi University, Kermanshah 67144-15111 (Iran, Islamic Republic of)

2013-08-15T23:59:59.000Z

268

DEDICATED HEAVY ION MEDICAL ACCELERATORS  

E-Print Network [OSTI]

Lancaster, R.B. Yourd, Pre~,Accelerator A w·ideroe~,Basedcarbon beam medical accelerator facility. N "' . ,;j "' ::lEat the MARIA Workshop III: Accelerator Systems for Relat ic

Gough, R.A.

2013-01-01T23:59:59.000Z

269

History of Proton Linear Accelerators  

E-Print Network [OSTI]

the board to show why the accelerator couldn't work. Then atmuch. References 1. Linear Accelerators, edited by P. M .at the 1986 Linear Accelerator Conference, SLAC, Stanford,

Alvarez, Luis W.

1986-01-01T23:59:59.000Z

270

Accelerated Least Squares Multidimensional Scaling  

E-Print Network [OSTI]

x(make_x(36,2)) xACCELERATED SCALING R EFERENCES I.ACCELERATED LEAST SQUARES MULTIDIMENSIONAL SCALING JAN DEare simpler to write. ACCELERATED SCALING It is shown in De

Leeuw, Jan de

2006-01-01T23:59:59.000Z

271

Accelerated Least Squares Multidimensional Scaling  

E-Print Network [OSTI]

x(make_x(36,2)) xACCELERATED SCALING R EFERENCES I.ACCELERATED LEAST SQUARES MULTIDIMENSIONAL SCALING JAN DEare simpler to write. ACCELERATED SCALING It is shown in De

Jan de Leeuw

2011-01-01T23:59:59.000Z

272

Accelerator on a Chip  

ScienceCinema (OSTI)

SLAC's Joel England explains how the same fabrication techniques used for silicon computer microchips allowed their team to create the new laser-driven particle accelerator chips. (SLAC Multimedia Communications)

England, Joel

2014-07-16T23:59:59.000Z

273

Charged particle accelerator grating  

DOE Patents [OSTI]

A readily disposable and replaceable accelerator grating for a relativistic particle accelerator is described. The grating is formed for a plurality of liquid droplets that are directed in precisely positioned jet streams to periodically dispose rows of droplets along the borders of a predetermined particle beam path. A plurality of lasers are used to direct laser beams onto the droplets, at predetermined angles, thereby to excite the droplets to support electromagnetic accelerating resonances on their surfaces. Those resonances operate to accelerate and focus particles moving along the beam path. As the droplets are distorted or destroyed by the incoming radiation, they are replaced at a predetermined frequency by other droplets supplied through the jet streams.

Palmer, R.B.

1985-09-09T23:59:59.000Z

274

Accelerator on a Chip  

SciTech Connect (OSTI)

SLAC's Joel England explains how the same fabrication techniques used for silicon computer microchips allowed their team to create the new laser-driven particle accelerator chips. (SLAC Multimedia Communications)

England, Joel

2014-06-30T23:59:59.000Z

275

Breakthrough: Fermilab Accelerator Technology  

SciTech Connect (OSTI)

There are more than 30,000 particle accelerators in operation around the world. At Fermilab, scientists are collaborating with other laboratories and industry to optimize the manufacturing processes for a new type of powerful accelerator that uses superconducting niobium cavities. Experimenting with unique polishing materials, a Fermilab team has now developed an efficient and environmentally friendly way of creating cavities that can propel particles with more than 30 million volts per meter.

None

2012-04-23T23:59:59.000Z

276

Breakthrough: Fermilab Accelerator Technology  

ScienceCinema (OSTI)

There are more than 30,000 particle accelerators in operation around the world. At Fermilab, scientists are collaborating with other laboratories and industry to optimize the manufacturing processes for a new type of powerful accelerator that uses superconducting niobium cavities. Experimenting with unique polishing materials, a Fermilab team has now developed an efficient and environmentally friendly way of creating cavities that can propel particles with more than 30 million volts per meter.

None

2014-08-12T23:59:59.000Z

277

CEBAF accelerator achievements  

SciTech Connect (OSTI)

In the past decade, nuclear physics users of Jefferson Lab's Continuous Electron Beam Accelerator Facility (CEBAF) have benefited from accelerator physics advances and machine improvements. As of early 2011, CEBAF operates routinely at 6 GeV, with a 12 GeV upgrade underway. This article reports highlights of CEBAF's scientific and technological evolution in the areas of cryomodule refurbishment, RF control, polarized source development, beam transport for parity experiments, magnets and hysteresis handling, beam breakup, and helium refrigerator operational optimization.

Y.C. Chao, M. Drury, C. Hovater, A. Hutton, G.A. Krafft, M. Poelker, C. Reece, M. Tiefenback

2011-06-01T23:59:59.000Z

278

Dielectric Boundary Force in Biomolecular Solvation  

E-Print Network [OSTI]

for Theoretical Biological Physics UC San Diego Funding: NIH and NSF Applied Mathematics and Analysis Seminar vs. Implicit Molecular dynamics simulations Statistical Mechanics P(X, Y ) = P0e-U(X,Y )/kBT U(X, Y dielectric x Qi i w m =80 =1 w m Free-energy functional Gtotal[] = P Vol (m) + 0 (1 - 2H) dS + w w UvdW d

Li, Bo

279

Advanced accelerator simulation research: miniaturizing accelerators from kilometers to meters  

E-Print Network [OSTI]

Advanced accelerator simulation research: miniaturizing accelerators from kilometers to meters W: Advanced accelerator research is aimed at finding new technologies that can dramatically reduce the size and cost of future high-energy accelerators. Supercomputing is already playing a dramatic and critical role

Geddes, Cameron Guy Robinson

280

Plasma processing of low-k dielectrics  

SciTech Connect (OSTI)

This paper presents an in-depth overview of the present status and novel developments in the field of plasma processing of low dielectric constant (low-k) materials developed for advanced interconnects in ULSI technology. The paper summarizes the major achievements accomplished during the last 10 years. It includes analysis of advanced experimental techniques that have been used, which are most appropriate for low-k patterning and resist strip, selection of chemistries, patterning strategies, masking materials, analytical techniques, and challenges appearing during the integration. Detailed discussions are devoted to the etch mechanisms of low-k materials and their degradation during the plasma processing. The problem of k-value degradation (plasma damage) is a key issue for the integration, and it is becoming more difficult and challenging as the dielectric constant of low-k materials scales down. Results obtained with new experimental methods, like the small gap technique and multi-beams systems with separated sources of ions, vacuum ultraviolet light, and radicals, are discussed in detail. The methods allowing reduction of plasma damage and restoration of dielectric properties of damaged low-k materials are also discussed.

Baklanov, Mikhail R.; Marneffe, Jean-Francois de [IMEC, Leuven (Belgium); Shamiryan, Denis; Urbanowicz, Adam M. [GLOBALFOUNDRIES, Dresden (Germany); Shi Hualiang [INTEL Corporation, Chandler, Arizona 85226 (United States); Rakhimova, Tatyana V. [Skobeltsyn Institute of Nuclear Physics, Moscow State University, Moscow (Russian Federation); Huang Huai; Ho, Paul S. [University of Texas at Austin, Texas 78758 (United States)

2013-01-28T23:59:59.000Z

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


281

ACCELERATED IMPROVEMENT A CONCENTRATED APPROACH  

E-Print Network [OSTI]

ACCELERATED IMPROVEMENT A CONCENTRATED APPROACH FOR CONTINUOUS IMPROVEMENT #12;Accelerated.quality.wisc.edu O F F I C E O F Q U A L I T Y I M P R O V E M E N T Accelerated Improvement This guide to improving resources. You will find helpful information needed to conduct an Accelerated Improvement project

Shapiro, Vadim

282

Plasma-based accelerator structures  

SciTech Connect (OSTI)

Plasma-based accelerators have the ability to sustain extremely large accelerating gradients, with possible high-energy physics applications. This dissertation further develops the theory of plasma-based accelerators by addressing three topics: the performance of a hollow plasma channel as an accelerating structure, the generation of ultrashort electron bunches, and the propagation of laser pulses is underdense plasmas.

Schroeder, Carl B.

1999-12-01T23:59:59.000Z

283

Fermilab | Science | Particle Accelerators | Fermilab's Accelerator Complex  

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

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

284

Fermilab | Science | Particle Accelerators | Leading Accelerator Technology  

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

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

285

Microelectromechanical acceleration-sensing apparatus  

DOE Patents [OSTI]

An acceleration-sensing apparatus is disclosed which includes a moveable shuttle (i.e. a suspended mass) and a latch for capturing and holding the shuttle when an acceleration event is sensed above a predetermined threshold level. The acceleration-sensing apparatus provides a switch closure upon sensing the acceleration event and remains latched in place thereafter. Examples of the acceleration-sensing apparatus are provided which are responsive to an acceleration component in a single direction (i.e. a single-sided device) or to two oppositely-directed acceleration components (i.e. a dual-sided device). A two-stage acceleration-sensing apparatus is also disclosed which can sense two acceleration events separated in time. The acceleration-sensing apparatus of the present invention has applications, for example, in an automotive airbag deployment system.

Lee, Robb M. (Albuquerque, NM); Shul, Randy J. (Albuquerque, NM); Polosky, Marc A. (Albuquerque, NM); Hoke, Darren A. (Albuquerque, NM); Vernon, George E. (Rio Rancho, NM)

2006-12-12T23:59:59.000Z

286

Light propagation around a relativistic vortex flow of dielectric medium  

E-Print Network [OSTI]

We determine the path of the light around a dielectric vortex described by the relativistic vortex flow of a perfect fluid.

B. Linet

2000-11-06T23:59:59.000Z

287

Electromagnetic field quantization in a linear dielectric medium  

E-Print Network [OSTI]

By modeling a dielectric medium with two independent reservoirs, i.e., electric and magnetic reservoirs, the electromagnetic field is quantized in a linear dielectric medium consistently. A Hamiltonian is proposed from which using the Heisenberg equations, not only the Maxwell equations but also the structural equations can be obtained. Using the Laplace transformation, the wave equation for the electromagnetic vector potential is solved in the case of a homogeneous dielectric medium. Some examples are considered showing the applicability of the model to both absorptive and nonabsorptive dielectrics.

F. Kheirandish; M. Amooshahi

2005-11-13T23:59:59.000Z

288

Accelerated molecular dynamics methods  

SciTech Connect (OSTI)

The molecular dynamics method, although extremely powerful for materials simulations, is limited to times scales of roughly one microsecond or less. On longer time scales, dynamical evolution typically consists of infrequent events, which are usually activated processes. This course is focused on understanding infrequent-event dynamics, on methods for characterizing infrequent-event mechanisms and rate constants, and on methods for simulating long time scales in infrequent-event systems, emphasizing the recently developed accelerated molecular dynamics methods (hyperdynamics, parallel replica dynamics, and temperature accelerated dynamics). Some familiarity with basic statistical mechanics and molecular dynamics methods will be assumed.

Perez, Danny [Los Alamos National Laboratory

2011-01-04T23:59:59.000Z

289

Accelerating Scientific Discovery  

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

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

290

Modeling of dielectric elastomer as electromechanical resonator  

SciTech Connect (OSTI)

Dielectric elastomers (DEs) feature nonlinear dynamics resulting from an electromechanical coupling. Under alternating voltage, the DE resonates with tunable performances. We present an analysis of the nonlinear dynamics of a DE as electromechanical resonator (DEER) configured as a pure shear actuator. A theoretical model is developed to characterize the complex performance under different boundary conditions. Physical mechanisms are presented and discussed. Chaotic behavior is also predicted, illustrating instabilities in the dynamics. The results provide a guide to the design and application of DEER in haptic devices.

Li, Bo, E-mail: liboxjtu@mail.xjtu.edu.cn; Liu, Lei; Chen, Hualing; Jia, Shuhai [School of Mechanical Engineering, Xi'an Jiaotong University, 28 Xianning West Road, Xi'an 710049 (China); State Key Laboratory for Strength and Vibration of Mechanical Structures, Xi'an Jiaotong University, 28 Xianning West Road, Xi'an 710049 (China); Zhang, Junshi [State Key Laboratory for Strength and Vibration of Mechanical Structures, Xi'an Jiaotong University, 28 Xianning West Road, Xi'an 710049 (China); School of Aerospace Engineering, Xi'an Jiaotong University, 28 Xianning West Road, Xi'an 710049 (China); Li, Dichen [School of Mechanical Engineering, Xi'an Jiaotong University, 28 Xianning West Road, Xi'an 710049 (China)

2014-09-28T23:59:59.000Z

291

Experimental demonstration of superdirective dielectric antenna  

SciTech Connect (OSTI)

We propose and demonstrate experimentally a simple approach for achieving superdirectivity of emitted radiation for electrically small antennas based on a spherical dielectric resonator with a notch excited by a dipole source. Superdirectivity is achieved without using complex antenna arrays and for a wide range of frequencies. We also demonstrate the steering effect for a subwavelength displacement of the source. Finally, unlike previously known superdirective antennas, our design has significantly smaller losses, at the operation frequency radiation efficiency attains 80%, and matching holds in the 3%-wide frequency band without any special matching technique.

Krasnok, Alexander E.; Filonov, Dmitry S.; Belov, Pavel A. [National Research University of Information Technologies, Mechanics and Optics (ITMO), St. Petersburg 197101 (Russian Federation); Simovski, Constantin R. [National Research University of Information Technologies, Mechanics and Optics (ITMO), St. Petersburg 197101 (Russian Federation); Aalto University, School of Electric and Electronic Engineering, Aalto FI76000 (Finland); Kivshar, Yuri S. [National Research University of Information Technologies, Mechanics and Optics (ITMO), St. Petersburg 197101 (Russian Federation); Nonlinear Physics Center, Research School of Physics and Engineering, Australian National University, Canberra ACT 0200 (Australia)

2014-03-31T23:59:59.000Z

292

E-Print Network 3.0 - anomalous dielectric absorption Sample...  

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

Sample search results for: anomalous dielectric absorption Page: << < 1 2 3 4 5 > >> 1 PHY 7097--Optical Effects in Solids 2011 Course Syllabus Summary: dielectric function, . 3....

293

E-Print Network 3.0 - altering dielectric structure Sample Search...  

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

of the liquid dielectric that is used in the system... breakdown in such transmission line configurations for a variety of dielectric materials and ... Source: New Mexico,...

294

Accelerating News Issue 5  

E-Print Network [OSTI]

In this spring issue, we look at developments towards higher luminosity and higher energy colliders. We report on the technology developed for the remote powering of the LHC magnets and studies of diagnostics based on higher order mode port signals. We also inform you about the main outcome of the TIARA survey on market needs for accelerator scientists.

Szeberenyi, A

2013-01-01T23:59:59.000Z

295

Dielectric function of diluted magnetic semiconductors in the infrared regime  

E-Print Network [OSTI]

We present a study of the dielectric function of metallic (III,Mn)V diluted magnetic semiconductors in the infrared regime. Our theoretical approach is based on the kinetic exchange model for carrier induced (III,Mn)V ferromagnetism. The dielectric...

Aguado, R.; Lopez-Sancho, MP; Sinova, Jairo; Brey, L.

2004-01-01T23:59:59.000Z

296

Basics of Measuring the Dielectric Properties of Materials  

E-Print Network [OSTI]

......................................................................................32 #12;Introduction Every material has a unique set of electrical characteristics that are dependent for more solid designs or to monitor a manufacturing process for improved quality control. A dielectric. For example, the loss of a cable insulator, the impedance of a substrate, or the frequency of a dielectric

Anlage, Steven

297

Modeling of Field Distribution and Energy Storage in Diphasic Dielectrics  

E-Print Network [OSTI]

Modeling of Field Distribution and Energy Storage in Diphasic Dielectrics S. K. Patil, M. Y, USA Modeling of electrostatic field distribution and energy storage in diphasic dielectrics containing to the increased energy storage density. For composites with lower volume fractions of high-permittivity inclusions

Koledintseva, Marina Y.

298

Longitudinal dielectric permettivity of quantum Maxwell collisional plasmas  

E-Print Network [OSTI]

The kinetic equation of Wigner -- Vlasov -- Boltzmann with collision integral in relaxation BGK (Bhatnagar, Gross and Krook) form in coordinate space for quantum non--degenerate (Maxwellian) collisional plasma is used. Exact expression (within the limits of considered model) is found. The analysis of longitudinal dielectric permeability is done. It is shown that in the limit when Planck's constant tends to zero of expression for dielectric permettivity transforms into the classical case of dielectric permettivity. At small values of wave number it has been received the solution of the dispersion equation. Damping of plasma oscillations has been analized. The analytical comparison with the dielectric Mermin' function received with the use of the kinetic equation in momentum space is done. Graphic comparison of the real and imaginary parts of dielectric permettivity of quantum and classical plasma is done also.

A. V. Latyshev; A. A. Yushkanov

2010-03-12T23:59:59.000Z

299

Nanostructure multilayer dielectric materials for capacitors and insulators  

DOE Patents [OSTI]

A capacitor is formed of at least two metal conductors having a multilayer dielectric and opposite dielectric-conductor interface layers in between. The multilayer dielectric includes many alternating layers of amorphous zirconium oxide (ZrO.sub.2) and alumina (Al.sub.2 O.sub.3). The dielectric-conductor interface layers are engineered for increased voltage breakdown and extended service life. The local interfacial work function is increased to reduce charge injection and thus increase breakdown voltage. Proper material choices can prevent electrochemical reactions and diffusion between the conductor and dielectric. Physical vapor deposition is used to deposit the zirconium oxide (ZrO.sub.2) and alumina (Al.sub.2 O.sub.3) in alternating layers to form a nano-laminate.

Barbee, Jr., Troy W. (Palo Alto, CA); Johnson, Gary W. (Livermore, CA)

1998-04-21T23:59:59.000Z

300

Nanostructure multilayer dielectric materials for capacitors and insulators  

DOE Patents [OSTI]

A capacitor is formed of at least two metal conductors having a multilayer dielectric and opposite dielectric-conductor interface layers in between. The multilayer dielectric includes many alternating layers of amorphous zirconium oxide (ZrO{sub 2}) and alumina (Al{sub 2}O{sub 3}). The dielectric-conductor interface layers are engineered for increased voltage breakdown and extended service life. The local interfacial work function is increased to reduce charge injection and thus increase breakdown voltage. Proper material choices can prevent electrochemical reactions and diffusion between the conductor and dielectric. Physical vapor deposition is used to deposit the zirconium oxide (ZrO{sub 2}) and alumina (Al{sub 2}O{sub 3}) in alternating layers to form a nano-laminate. 1 fig.

Barbee, T.W. Jr.; Johnson, G.W.

1998-04-21T23:59:59.000Z

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


301

"Z" Facility Dielectric Oil Clean-Up  

SciTech Connect (OSTI)

In August of 1998 the Z facility leaked approximately 150 gallons of deionized water into the dielectric oil of the Energy Storage Section (ESS). After processing the oil to remove existing particulate and free water the dielectric breakdown strength increased from the mid 20kV range to values in excess of 40 kV. 40 kV is above historical operating levels of about 35 kV. This, however, was not enough to allow 90 kV charging of the Marx Generators in the ESS. Further analysis of the oil showed dissolved water at a saturated level (70 - 80 ppm) and some residual particulate contamination smaller than 3 microns. The dissolved water and particulate combination was preventing the 90 kV charging of the Marx Generators in the ESS. After consulting with the oil industry it was determined that nitrogen sparging could be used to remove the dissolved water. Further particulate filtering was also conducted. After approximately 20 hours of sparging the water content in the ESS was reduced to 42 ppm which enabled Marx charging to 90 kV.

Alessandri, Daniel; Bloomquist, Doug; Donovan, Guy; Feltz, Greg; Grelle, Nibby; Guthrie, Doug; Harris, Mark; Horry, Mike; Lockas, Mike; Potter, Jimmy; Pritchard, Chuck; Steedly, Jim

1999-06-30T23:59:59.000Z

302

Electromagnetic Siegert states for periodic dielectric structures  

E-Print Network [OSTI]

The formalism of Siegert states to describe the resonant scattering in quantum theory is extended to the resonant scattering of electromagnetic waves on periodic dielectric arrays. The excitation of electromagnetic Siegert states by an incident wave packet and their decay is studied. The formalism is applied to develop a theory of coupled electromagnetic resonances arising in the electromagnetic scattering problem for two such arrays separated by a distance 2h (or, generally, when the physical properties of the scattering array depend on a real coupling parameter h). Analytic properties of Siegert states as functions of the coupling parameter h are established by the Regular Perturbation Theorem which is an extension the Kato-Rellich theorem to the present case. By means of this theorem, it is proved that if the scattering structure admits a bound state in the radiation continuum at a certain value of the coupling parameter h, then there always exist regions within the structure in which the near field can be amplified as much as desired by adjusting the value of h. This establishes a rather general mechanism to control and amplify optical nonlinear effects in periodically structured planar structures possessing a nonlinear dielectric susceptibility.

Friends R. Ndangali; Sergei V. Shabanov

2011-08-09T23:59:59.000Z

303

Acceleration and Classical Electromagnetic Radiation  

E-Print Network [OSTI]

Classical radiation from an accelerated charge is reviewed along with the reciprocal topic of accelerated observers detecting radiation from a static charge. This review commemerates Bahram Mashhoon's 60th birthday.

E. N. Glass

2008-01-09T23:59:59.000Z

304

Charge Diagnostics for Laser Plasma Accelerators  

E-Print Network [OSTI]

the 1989 Particle Accelerator Conference, IEEE, Piscataway,Diagnostics for Laser Plasma Accelerators K . Nakamura, A .ALS) synchrotron booster accelerator. The sensitivity of the

Nakamura, K.

2011-01-01T23:59:59.000Z

305

Acceleration in de Sitter spacetimes  

E-Print Network [OSTI]

We propose a definition of uniform accelerated frames in de Sitter spacetimes exploiting the Nachtmann group theoretical method of introducing coordinates on these manifolds. Requiring the transformation between the static frame and the accelerated one to depend continuously on acceleration in order to recover the well-known Rindler approach in the flat limit, we obtain a new metric with a reasonable physical meaning.

Ion I. Cotaescu

2014-07-09T23:59:59.000Z

306

Adaptive control for accelerators  

DOE Patents [OSTI]

An adaptive feedforward control loop is provided to stabilize accelerator beam loading of the radio frequency field in an accelerator cavity during successive pulses of the beam into the cavity. A digital signal processor enables an adaptive algorithm to generate a feedforward error correcting signal functionally determined by the feedback error obtained by a beam pulse loading the cavity after the previous correcting signal was applied to the cavity. Each cavity feedforward correcting signal is successively stored in the digital processor and modified by the feedback error resulting from its application to generate the next feedforward error correcting signal. A feedforward error correcting signal is generated by the digital processor in advance of the beam pulse to enable a composite correcting signal and the beam pulse to arrive concurrently at the cavity.

Eaton, Lawrie E. (Los Alamos, NM); Jachim, Stephen P. (Los Alamos, NM); Natter, Eckard F. (Santa Fe, NM)

1991-01-01T23:59:59.000Z

307

Review of ion accelerators  

SciTech Connect (OSTI)

The field of ion acceleration to higher energies has grown rapidly in the last years. Many new facilities as well as substantial upgrades of existing facilities have extended the mass and energy range of available beams. Perhaps more significant for the long-term development of the field has been the expansion in the applications of these beams, and the building of facilities dedicated to areas outside of nuclear physics. This review will cover many of these new developments. Emphasis will be placed on accelerators with final energies above 50 MeV/amu. Facilities such as superconducting cyclotrons and storage rings are adequately covered in other review papers, and so will not be covered here.

Alonso, J.

1990-06-01T23:59:59.000Z

308

Accelerator research studies  

SciTech Connect (OSTI)

The Accelerator Research Studies program at the University of Maryland, sponsored by the Department of Energy under grant number DE-FG05-91ER40642, is currently in the second year of a three-year funding cycle. The program consists of the following three tasks: TASK A, Study of Transport and Longitudinal Compression of Intense, High-Brightness Beams,'' (P.I., M. Reiser); TASK B, Study of Collective Ion Acceleration by Intense Electron Beams and Pseudospark Produced High Brightness Electron Beams,'' (Co-P.I.'s, W.W. Destler, M. Reiser, M.J. Rhee, and C.D. Striffler); TASK C, Study of a Gyroklystron High-Power Microwave Source for Linear Colliders,'' (Co-P.I.'s, V.L. Granatstein, W. Lawson, M. Reiser, and C.D. Striffler). In this report we document the progress that has been made during the past year for each of the three tasks.

Not Available

1993-01-01T23:59:59.000Z

309

Linear induction accelerator  

DOE Patents [OSTI]

A linear induction accelerator includes a plurality of adder cavities arranged in a series and provided in a structure which is evacuated so that a vacuum inductance is provided between each adder cavity and the structure. An energy storage system for the adder cavities includes a pulsed current source and a respective plurality of bipolar converting networks connected thereto. The bipolar high-voltage, high-repetition-rate square pulse train sets and resets the cavities. 4 figs.

Buttram, M.T.; Ginn, J.W.

1988-06-21T23:59:59.000Z

310

Accelerators AND Beams  

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

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311

Accelerating QDP++ using GPUs  

E-Print Network [OSTI]

Graphic Processing Units (GPUs) are getting increasingly important as target architectures in scientific High Performance Computing (HPC). NVIDIA established CUDA as a parallel computing architecture controlling and making use of the compute power of GPUs. CUDA provides sufficient support for C++ language elements to enable the Expression Template (ET) technique in the device memory domain. QDP++ is a C++ vector class library suited for quantum field theory which provides vector data types and expressions and forms the basis of the lattice QCD software suite Chroma. In this work accelerating QDP++ expression evaluation to a GPU was successfully implemented leveraging the ET technique and using Just-In-Time (JIT) compilation. The Portable Expression Template Engine (PETE) and the C API for CUDA kernel arguments were used to build the bridge between host and device memory domains. This provides the possibility to accelerate Chroma routines to a GPU which are typically not subject to special optimisation. As an application example a smearing routine was accelerated to execute on a GPU. A significant speed-up compared to normal CPU execution could be measured.

Frank Winter

2011-05-11T23:59:59.000Z

312

Parametric Study of Emerging High Power Accelerator Applications Using Accelerator Systems Model (ASM)  

E-Print Network [OSTI]

Parametric Study of Emerging High Power Accelerator Applications Using Accelerator Systems Model (ASM)

Berwald, D H; Myers, T J; Paulson, C C; Peacock, M A; Piaszczyk, C M; Rathke, J W; Piechowiak, E M

1996-01-01T23:59:59.000Z

313

Dielectric and magnetic properties of some gadolinium silica nanoceramics  

SciTech Connect (OSTI)

Some nanostructure gadolinium silica glass-ceramics were obtained undergoing a sol gel method and a heat-treatment at 1000°C about two hours. The magnetic and dielectric properties of these samples were studied. The magnetic properties were evidenced performing susceptibility measurements in the 80-300K temperature range. A Curie-Weiss behavior has acquired. The values estimated for paramagnetic Curie temperature being small and positive suggest the presence of weak ferromagnetic interactions between Gd{sup 3+} ions. The dielectric properties were evaluated from dielectric permittivity (?{sub r}) and dielectric loss (tan?) measurements at the frequency 1 kHz, 10 kHz and 100 kHz, in the 25-225°C temperature range and dielectric dispersion at room temperature for 79.5 kHz - 1GHz frequency area. The dielectric properties suggest that the main polarization mechanism corresponds to interfacial polarization, characteristic for polycrystalline-structured dielectrics. The polycrystalline structure of the samples is due to the polymorphous transformations of the nanostructure silica crystallites in the presence of gadolinium oxide. They were highlighted by SEM micrographs.

Coroiu, I., E-mail: coroiu@phys.utcluj.ro; Pascuta, P., E-mail: coroiu@phys.utcluj.ro; Bosca, M., E-mail: coroiu@phys.utcluj.ro; Culea, E., E-mail: coroiu@phys.utcluj.ro [Technical University, Chemical and Physics Department, 28, Memorandumului, 400114, Cluj-Napoca (Romania)

2013-11-13T23:59:59.000Z

314

Static dielectric properties of dense ionic fluids  

E-Print Network [OSTI]

The static dielectric properties of dense ionic fluids, e.g., room temperature ionic liquids (RTILs) and inorganic fused salts, are investigated on different length scales by means of grandcanonical Monte Carlo simulations. A generally applicable scheme is developed which allows one to approximately decompose the electric susceptibility of dense ionic fluids into the orientation and the distortion polarization contribution. It is shown that at long range the well-known plasma-like perfect screening behavior occurs, which corresponds to a diverging distortion susceptibility, whereas at short range orientation polarization dominates, which coincides with that of a dipolar fluid of attached cation-anion pairs. This observation suggests that the recently debated interpretation of RTILs as dilute electrolyte solutions might not be simply a yes-no-question but it might depend on the considered length scale.

Zarubin, Grigory

2015-01-01T23:59:59.000Z

315

Nonlinear dielectric response of periodic composite materials A. Kolpakov & A. K. Tagantsev & L. Berlyand &  

E-Print Network [OSTI]

periodic composite (a matrix of a large dielectric constant ferro- electric material with linear dielectric of ferroelectric/dielectric composites. A typical example is a (Ba,Sr)TiO3 ceramic fabricated with addition of MgNonlinear dielectric response of periodic composite materials A. Kolpakov & A. K. Tagantsev & L

Berlyand, Leonid

316

Magnetically coupled electromagnetically induced transparency analogy of dielectric metamaterial  

SciTech Connect (OSTI)

In this manuscript, we experimentally demonstrate magnetically coupled electromagnetically induced transparency (EIT) analogy effect inside dielectric metamaterial. In contrast to previous studies employed different metallic topological microstructures to introduce dissipation loss change, barium strontium titanate, and calcium titanate (CaTiO{sub 3}) are chosen as the bright and dark EIT resonators, respectively, due to their different intrinsic dielectric loss. Under incident magnetic field excitation, dielectric metamaterial exhibits an EIT-type transparency window around 8.9?GHz, which is accompanied by abrupt change of transmission phase. Numerical calculations show good agreement with experiment spectra and reveal remarkably increased group index, indicating potential application in slow light.

Zhang, Fuli, E-mail: fuli.zhang@nwpu.edu.cn; He, Xuan [Key Laboratory of Space Applied Physics and Chemistry, Ministry of Education and Department of Applied Physics, School of Science, Northwestern Polytechnical University, Xi'an 710072 (China); Zhao, Qian [State Key Laboratory of Tribology, Department of Mechanical Engineering, Tsinghua University, Beijing 100084 (China); Lan, Chuwen; Zhou, Ji [State Key Laboratory of New Ceramics and Fine Processing, Department of Materials Science and Engineering, Tsinghua University, Beijing 100084 (China); Zhang, Weihong, E-mail: zhangwh@nwpu.edu.cn; Qiu, Kepeng [School of Mechanical Engineering, P.O. Box 552, Northwestern Polytechnical University, Xi'an 710072 (China)

2014-03-31T23:59:59.000Z

317

Unusual dielectric response in cobalt doped reduced graphene oxide  

SciTech Connect (OSTI)

Intensive research on cobalt doped reduced graphene oxide (Co-RGO) to investigate the modification in graphene magnetism and spin polarization due to presence of transition metal atom has been carried out, however, its dielectric spectroscopy, particularly, how capacitance changes with impurity levels in graphene is relatively unexplored. In the present work, dielectric spectroscopy along with magneto-dielectric effect are investigated in Co-RGO. Contrary to other materials, here permittivity increases abruptly with frequency in the low frequency region and continues to increase till 10{sup 7}?Hz. This unusual behavior is explained on the basis of trap induced capacitance created due to impurity levels.

Akhtar, Abu Jahid; Gupta, Abhisek; Kumar Shaw, Bikash; Saha, Shyamal K., E-mail: cnssks@iacs.res.in [Department of Materials Science, Indian Association for the Cultivation of Science, Jadavpur, Kolkata 700032 (India)

2013-12-09T23:59:59.000Z

318

Spherical cloaking using multilayer shells of ordinary dielectrics  

SciTech Connect (OSTI)

An approach for spherical cloaking using multilayer ordinary dielectric materials has been developed. The total scattering cross section (TSCS) of the spherical multilayer shell with metallic core was derived based on the Mie theory. The dielectric profile of the shell was optimized to minimize the TSCS of the cloaked target. The specific directions, at which the scattering could be practically eliminated, were detected. The influence of the target size and the dielectric material loss on the cloaking efficiency was analyzed. It was shown that the cloaking efficiency for larger targets could be improved by employing lossy materials in the shell.

Wang, Xiaohui; Chen, Fang; Semouchkina, Elena, E-mail: esemouch@mtu.edu [Department of Electrical and Computer Engineering, Michigan Technological University, Houghton, MI, 49931 (United States)] [Department of Electrical and Computer Engineering, Michigan Technological University, Houghton, MI, 49931 (United States)

2013-11-15T23:59:59.000Z

319

Dielectric covered hairpin probe for its application in reactive plasmas  

SciTech Connect (OSTI)

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

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

2012-07-23T23:59:59.000Z

320

Millimeter wave analysis of the dielectric properties of oil shales  

E-Print Network [OSTI]

Natural sedimentation processes give rise to fine layers in shales. If these layers alternate between organic-rich and organic-poor sediments, then the contrast in dielectric properties gives rise to an effective birefringence as the presence of hydrocarbons suppresses the dielectric constant of the host rock. We have measured these effects with a quasioptical millimeter wave setup that is rapid and noncontacting. We find that the strength of this birefringence and the overall dielectric permittivity provide two useful diagnostic of the organic content of oil shales.

John A. Scales; Michael Batzle

2006-06-06T23:59:59.000Z

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


321

Accelerating Clean Energy Adoption (Fact Sheet), Weatherization...  

Broader source: Energy.gov (indexed) [DOE]

Accelerating Clean Energy Adoption (Fact Sheet), Weatherization and Intergovernmental Program (WIP) Accelerating Clean Energy Adoption (Fact Sheet), Weatherization and...

322

Accelerating Energy Savings Performance Contracting Through Model...  

Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

Accelerating Energy Savings Performance Contracting Through Model Statewide Programs Accelerating Energy Savings Performance Contracting Through Model Statewide Programs Provides...

323

Safety of Accelerator Facilities - DOE Directives, Delegations...  

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

Health, Environmental Protection, Facility Authorization, Safety The order defines accelerators and establishes accelerator specific safety requirements and approval authorities...

324

APT accelerator. Topical report  

SciTech Connect (OSTI)

The Accelerator Production of Tritium (APT) project, sponsored by Department of Energy Defense Programs (DOE/DP), involves the preconceptual design of an accelerator system to produce tritium for the nation`s stockpile of nuclear weapons. Tritium is an isotope of hydrogen used in nuclear weapons, and must be replenished because of radioactive decay (its half-life is approximately 12 years). Because the annual production requirements for tritium has greatly decreased since the end of the Cold War, an alternative approach to reactors for tritium production, based on a linear accelerator, is now being seriously considered. The annual tritium requirement at the time this study was undertaken (1992-1993) was 3/8 that of the 1988 goal, usually stated as 3/8-Goal. Continued reduction in the number of weapons in the stockpile has led to a revised (lower) production requirement today (March, 1995). The production requirement needed to maintain the reduced stockpile, as stated in the recent Nuclear Posture Review (summer 1994) is approximately 3/16-Goal, half the previous level. The Nuclear Posture Review also requires that the production plant be designed to accomodate a production increase (surge) to 3/8-Goal capability within five years, to allow recovery from a possible extended outage of the tritium plant. A multi-laboratory team, collaborating with several industrial partners, has developed a preconceptual APT design for the 3/8-Goal, operating at 75% capacity. The team has presented APT as a promising alternative to the reactor concepts proposed for Complex-21. Given the requirements of a reduced weapons stockpile, APT offers both significant safety, environmental, and production-fexibility advantages in comparison with reactor systems, and the prospect of successful development in time to meet the US defense requirements of the 21st Century.

Lawrence, G.; Rusthoi, D. [comp.] [ed.

1995-03-01T23:59:59.000Z

325

Black holes at accelerators.  

E-Print Network [OSTI]

ar X iv :h ep -p h/ 05 11 12 8v 3 6 A pr 2 00 6 Black Holes at Accelerators Bryan Webber Cavendish Laboratory, University of Cambridge, Cambridge CB3 0HE, UK In theories with large extra dimensions and TeV-scale gravity, black holes... 2000 3000 Missing ET (GeV) Ar bi tra ry S ca le p p ? QCD SUSY 5 TeV BH (n=6) 5 TeV BH (n=2) (PT > 600 GeV) (SUGRA point 5) Figure 10: Missing transverse energy for various processes at the LHC. 4.2. Event Characteristics Turning from single...

Webber, Bryan R

326

Laser plasma accelerators  

SciTech Connect (OSTI)

This review article highlights the tremendous evolution of the research on laser plasma accelerators which has, in record time, led to the production of high quality electron beams at the GeV level, using compact laser systems. I will describe the path we followed to explore different injection schemes and I will present the most significant breakthrough which allowed us to generate stable, high peak current and high quality electron beams, with control of the charge, of the relative energy spread and of the electron energy.

Malka, V. [Laboratoire d'Optique Appliquee, ENSTA-ParisTech, CNRS, Ecole Polytechnique, UMR 7639, 91761 Palaiseau (France)

2012-05-15T23:59:59.000Z

327

Accelerator Concepts Workshop  

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

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328

Fermilab | Tevatron | Accelerator  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsruc DocumentationP-Series toESnet4:EpitaxialtransatlanticUnified Forces | Do all theAccelerator

329

Materials for freeform fabrication of GHz tunable dielectric photonic crystals.  

SciTech Connect (OSTI)

Photonic crystals are of interest for GHz transmission applications, including rapid switching, GHz filters, and phased-array technology. 3D fabrication by Robocasting enables moldless printing of high solid loading slurries into structures such as the ''woodpile'' structures used to fabricate dielectric photonic band gap crystals. In this work, tunable dielectric materials were developed and printed into woodpile structures via solid freeform fabrication (SFF) toward demonstration of tunable photonic crystals. Barium strontium titanate ceramics possess interesting electrical properties including high permittivity, low loss, and high tunability. This paper discusses the processing route and dielectric characterization of (BaxSr1-XTiO3):MgO ceramic composites, toward fabrication of tunable dielectric photonic band gap crystals.

Niehaus, Michael Keith; Lewis, Jennifer A. (University of Illinois, Urbana, IL); Smay, James Earl; Clem, Paul Gilbert; Lin, Shawn-Yu; Cesarano, Joseph, III (,; ); Carroll, James F.

2003-01-01T23:59:59.000Z

330

Ferroelectric and dielectric properties of strontium bismuth niobate vanadates  

E-Print Network [OSTI]

Ferroelectric and dielectric properties of strontium bismuth niobate vanadates Yun Wu and Guozhong 19 November 1999; accepted 20 April 2000) Strontium bismuth niobate vanadates, SrBi2(VxNb1-x)2O9

Cao, Guozhong

331

affect dielectric membrane: Topics by E-print Network  

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

how relaxation dynamics of a poly-vinyl-acetate ultra-thin film is influenced by inorganic nano-inclusions of a layered silicate (montmorillonite). Dielectric loss spectra are...

332

Electromagnetic Inverse Problems Involving Distributions of Dielectric Mechanisms and Parameters  

E-Print Network [OSTI]

Electromagnetic Inverse Problems Involving Distributions of Dielectric Mechanisms and Parameters H University, Raleigh, NC 27695-8205 August 17, 2005 Abstract We consider electromagnetic interrogation, uniform, log-normal, and log-Bi-Gaussian distributions. Keywords: Electromagnetic interrogation

333

Keer electro-optic measurements in liquid dielectrics  

E-Print Network [OSTI]

Kerr electro-optic technique has been used to measure the electric field distribution in high voltage stressed dielectric liquids, where the difference between refractive indices for light polarized parallel and perpendicular ...

Zhang, Xuewei

2014-01-01T23:59:59.000Z

334

Dielectric based resonant guided wave networks Eyal Feigenbaum1,*  

E-Print Network [OSTI]

Dielectric based resonant guided wave networks Eyal Feigenbaum1,* and Harry A. Atwater1 1 Thomas J. 285(6), 46­55 (2001). 2. J. D. Joannopoulos, S. G. Johnson, J. N. Winn, and R. D. Meade, Photonic

Atwater, Harry

335

Evaluation of unsaturated fluorocarbons for dielectric Etch applications  

E-Print Network [OSTI]

The semiconductor industry is currently faced with the problem of the use and emissions of strong global warming compounds, known as perfluorocompounds (PFCs) for dielectric etch applications. The release of global warming ...

Chatterjee, Ritwik, 1974-

2003-01-01T23:59:59.000Z

336

Silica aerogel: An intrinsically low dielectric constant material  

SciTech Connect (OSTI)

Silica aerogels are highly porous solids having unique morphologies in wavelength of visible which both the pores and particles have sizes less than the wavelength of visible light. This fine nanostructure modifies the normal transport mechanisms within aerogels and endows them with a variety of exceptional physical properties. For example, aerogels have the lowest measured thermal conductivity and dielectric constant for any solid material. The intrinsically low dielectric properties of silica aerogels are the direct result of the extremely high achievable porosities, which are controllable over a range from 75% to more than 99.8 %, and which result in measured dielectric constants from 2.0 to less than 1.01. This paper discusses the synthesis of silica aerogels, processing them as thin films, and characterizing their dielectric properties. Existing data and other physical characteristics of bulk aerogels (e.g., thermal stablity, thermal expansion, moisture adsorption, modulus, dielectric strength, etc.), which are useful for evaluating them as potential dielectrics for microelectronics, are also given.

Hrubesh, L.W.

1995-04-01T23:59:59.000Z

337

Accelerating and Retarding Anomalous Diffusion  

E-Print Network [OSTI]

In this paper Gaussian models of retarded and accelerated anomalous diffusion are considered. Stochastic differential equations of fractional order driven by single or multiple fractional Gaussian noise terms are introduced to describe retarding and accelerating subdiffusion and superdiffusion. Short and long time asymptotic limits of the mean squared displacement of the stochastic processes associated with the solutions of these equations are studied. Specific cases of these equations are shown to provide possible descriptions of retarding or accelerating anomalous diffusion.

Chai Hok Eab; S. C. Lim

2012-01-14T23:59:59.000Z

338

Modern electron accelerators for radiography  

SciTech Connect (OSTI)

Over the past dozen years or so there have been significant advances in electron accelerators designed specifically for radiography of hydrodynamic experiments. Accelerator technology has evolved to accomodate the radiographers' contitiuing quest for multiple images in t h e and space:, improvements in electron beam quality have resulted in smaller radiographic spot sizes for better resolution, while higher radiation do% now provides imprcwed penetration of large, dense objects. Inductive isolation and acceleration techniques have played a ley rob in these advances.

Ekdahl, C. A. (Carl A.)

2001-01-01T23:59:59.000Z

339

Accelerating Combined Heat & Power Deployment  

Broader source: Energy.gov (indexed) [DOE]

ACCELERATING COMBINED HEAT & POWER DEPLOYMENT An Industry Consultation by the United States Energy Association August 31, 2011 Cover Photograph: CHP Plant at the Mueller Energy...

340

High field gradient particle accelerator  

DOE Patents [OSTI]

A high electric field gradient electron accelerator utilizing short duration, microwave radiation, and capable of operating at high field gradients for high energy physics applications or at reduced electric field gradients for high average current intermediate energy accelerator applications is disclosed. Particles are accelerated in a smooth bore, periodic undulating waveguide, wherein the period is so selected that the particles slip an integral number of cycles of the r.f. wave every period of the structure. This phase step of the particles produces substantially continuous acceleration in a traveling wave without transverse magnetic or other guide means for the particle. 10 figs.

Nation, J.A.; Greenwald, S.

1989-05-30T23:59:59.000Z

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


341

High field gradient particle accelerator  

DOE Patents [OSTI]

A high electric field gradient electron accelerator utilizing short duration, microwave radiation, and capable of operating at high field gradients for high energy physics applications or at reduced electric field gradients for high average current intermediate energy accelerator applications. Particles are accelerated in a smooth bore, periodic undulating waveguide, wherein the period is so selected that the particles slip an integral number of cycles of the r.f. wave every period of the structure. This phase step of the particles produces substantially continuous acceleration in a traveling wave without transverse magnetic or other guide means for the particle.

Nation, John A. (Ithaca, NY); Greenwald, Shlomo (Haifa, IL)

1989-01-01T23:59:59.000Z

342

Lab Breakthrough: Fermilab Accelerator Technology  

Broader source: Energy.gov [DOE]

Fermilab scientists developed techniques to retrofit some of the 30,000 particle accelerators in use around the world to make them more efficient and powerful.

343

Non-Paraxial Accelerating Beams  

E-Print Network [OSTI]

We present the spatially accelerating solutions of the Maxwell equations. Such non-paraxial beams accelerate in a circular trajectory, thus generalizing the concept of Airy beams. For both TE and TM polarizations, the beams exhibit shape-preserving bending with sub-wavelength features, and the Poynting vector of the main lobe displays a turn of more than 90 degrees. We show that these accelerating beams are self-healing, analyze their properties, and compare to the paraxial Airy beams. Finally, we present the new family of periodic accelerating beams which can be constructed from our solutions.

Ido Kaminer; Rivka Bekenstein; Jonathan Nemirovsky; Mordechai Segev

2012-02-03T23:59:59.000Z

344

Compact accelerator for medical therapy  

DOE Patents [OSTI]

A compact accelerator system having an integrated particle generator-linear accelerator with a compact, small-scale construction capable of producing an energetic (.about.70-250 MeV) proton beam or other nuclei and transporting the beam direction to a medical therapy patient without the need for bending magnets or other hardware often required for remote beam transport. The integrated particle generator-accelerator is actuable as a unitary body on a support structure to enable scanning of a particle beam by direction actuation of the particle generator-accelerator.

Caporaso, George J.; Chen, Yu-Jiuan; Hawkins, Steven A.; Sampayan, Stephen E.; Paul, Arthur C.

2010-05-04T23:59:59.000Z

345

Muon Collider Progress: Accelerators  

E-Print Network [OSTI]

A muon collider would be a powerful tool for exploring the energy-frontier with leptons, and would complement the studies now under way at the LHC. Such a device would offer several important benefits. Muons, like electrons, are point particles so the full center-of-mass energy is available for particle production. Moreover, on account of their higher mass, muons give rise to very little synchrotron radiation and produce very little beamstrahlung. The first feature permits the use of a circular collider that can make efficient use of the expensive rf system and whose footprint is compatible with an existing laboratory site. The second feature leads to a relatively narrow energy spread at the collision point. Designing an accelerator complex for a muon collider is a challenging task. Firstly, the muons are produced as a tertiary beam, so a high-power proton beam and a target that can withstand it are needed to provide the required luminosity of ~1 \\times 10^34 cm^-2s^-1. Secondly, the beam is initially produced with a large 6D phase space, which necessitates a scheme for reducing the muon beam emittance ("cooling"). Finally, the muon has a short lifetime so all beam manipulations must be done very rapidly. The Muon Accelerator Program, led by Fermilab and including a number of U.S. national laboratories and universities, has undertaken design and R&D activities aimed toward the eventual construction of a muon collider. Design features of such a facility and the supporting R&D program are described.

Michael S. Zisman

2011-09-14T23:59:59.000Z

346

Laser acceleration of ion beams  

E-Print Network [OSTI]

We consider methods of charged particle acceleration by means of high-intensity lasers. As an application we discuss a laser booster for heavy ion beams provided, e.g. by the Dubna nuclotron. Simple estimates show that a cascade of crossed laser beams would be necessary to provide additional acceleration to gold ions of the order of GeV/nucleon.

I. A. Egorova; A. V. Filatov; A. V. Prozorkevich; S. A. Smolyansky; D. B. Blaschke; M. Chubaryan

2007-02-01T23:59:59.000Z

347

Particle Acceleration in Astrophysical Sources  

E-Print Network [OSTI]

Astrophysical sources are extremely efficient accelerators. Some sources emit photons up to multi-TeV energies, a signature of the presence, within them, of particles with energies much higher than those achievable with the largest accelerators on Earth. Even more compelling evidence comes from the study of Cosmic Rays, charged relativistic particles that reach the Earth with incredibly high energies: at the highest energy end of their spectrum, these subatomic particles are carrying a macroscopic energy, up to a few Joules. Here I will address the best candidate sources and mechanisms as cosmic particle accelerators. I will mainly focus on Galactic sources such as Supernova Remnants and Pulsar Wind Nebulae, which being close and bright, are the best studied among astrophysical accelerators. These sources are held responsible for most of the energy that is put in relativistic particles in the Universe, but they are not thought to accelerate particles up to the highest individual energies, $\\approx 10^{20}$ eV...

Amato, Elena

2015-01-01T23:59:59.000Z

348

Bayesian Optimum Planning for Accelerated Life Tests  

E-Print Network [OSTI]

Bayesian Optimum Planning for Accelerated Life Tests Yao Zhang and William Q. Meeker Dept for optimum accelerated life test planning with one accelerating variable, when the acceleration model design; Preposterior; Reliability. 1 #12;2 1 Introduction 1.1 Background and Motivation Accelerated life

349

Community petascale project for accelerator science and simulation: Advancing computational science for future accelerators and accelerator technologies  

E-Print Network [OSTI]

al. 2005 Impact of SciDAC on accelerator projects across the171; Spentzouris P 2006 Accelerator modeling under SciDAC:of next-generation accelerator design, analysis, and

Spentzouris, Panagiotis

2008-01-01T23:59:59.000Z

350

Velocity bunching in travelling wave accelerator with low acceleration gradient  

E-Print Network [OSTI]

We present the analytical and simulated results concerning the influences of the acceleration gradient in the velocity bunching process, which is a bunch compression scheme that uses a traveling wave accelerating structure as a compressor. Our study shows that the bunch compression application with low acceleration gradient is more tolerant to phase jitter and more successful to obtain compressed electron beam with symmetrical longitudinal distribution and low energy spread. We also present a transverse emittance compensation scheme to compensate the emittance growth caused by the increasing of the space charge force in the compressing process that is easy to be adjusted for different compressing factors.

Huang, Rui-Xuan; Li, Wei-Wei; Jia, Qi-Ka

2013-01-01T23:59:59.000Z

351

Electron beam accelerator with magnetic pulse compression and accelerator switching  

DOE Patents [OSTI]

An electron beam accelerator is described comprising an electron beam generator-injector to produce a focused beam of greater than or equal to .1 MeV energy electrons; a plurality of substantially identical, aligned accelerator modules to sequentially receive and increase the kinetic energies of the beam electron by about .1-1 MeV per module. Each accelerator module includes a pulse-forming network that delivers a voltage pulse to the module of substantially .1-1 MeV maximum energy over a time duration of less than or equal to 1 ..mu..sec.

Birx, D.L.; Reginato, L.L.

1984-03-22T23:59:59.000Z

352

RFQ accelerator tuning system  

DOE Patents [OSTI]

A cooling system is provided for maintaining a preselected operating temperature in a device, which may be an RFQ accelerator, having a variable heat removal requirement, by circulating a cooling fluid through a cooling system remote from the device. Internal sensors in the device enable an estimated error signal to be generated from parameters which are indicative of the heat removal requirement from the device. Sensors are provided at predetermined locations in the cooling system for outputting operational temperature signals. Analog and digital computers define a control signal functionally related to the temperature signals and the estimated error signal, where the control signal is defined effective to return the device to the preselected operating temperature in a stable manner. The cooling system includes a first heat sink responsive to a first portion of the control signal to remove heat from a major portion of the circulating fluid. A second heat sink is responsive to a second portion of the control signal to remove heat from a minor portion of the circulating fluid. The cooled major and minor portions of the circulating fluid are mixed in response to a mixing portion of the control signal, which is effective to proportion the major and minor portions of the circulating fluid to establish a mixed fluid temperature which is effective to define the preselected operating temperature for the remote device. In an RFQ environment the stable temperature control enables the resonant frequency of the device to be maintained at substantially a predetermined value during transient operations.

Bolie, Victor W. (Albuquerque, NM)

1990-01-01T23:59:59.000Z

353

RFQ accelerator tuning system  

DOE Patents [OSTI]

A cooling system is provided for maintaining a preselected operating temperature in a device, which may be an RFQ accelerator, having a variable heat removal requirement, by circulating a cooling fluid through a cooling system remote from the device. Internal sensors in the device enable an estimated error signal to be generated from parameters which are indicative of the heat removal requirement from the device. Sensors are provided at predetermined locations in the cooling system for outputting operational temperature signals. Analog and digital computers define a control signal functionally related to the temperature signals and the estimated error signal, where the control signal is defined effective to return the device to the preselected operating temperature in a stable manner. The cooling system includes a first heat sink responsive to a first portion of the control signal to remove heat from a major portion of the circulating fluid. A second heat sink is responsive to a second portion of the control signal to remove heat from a minor portion of the circulating fluid. The cooled major and minor portions of the circulating fluid are mixed in response to a mixing portion of the control signal, which is effective to proportion the major and minor portions of the circulating fluid to establish a mixed fluid temperature which is effective to define the preselected operating temperature for the remote device. In an RFQ environment the stable temperature control enables the resonant frequency of the device to be maintained at substantially a predetermined value during transient operations. 3 figs.

Bolie, V.W.

1990-07-03T23:59:59.000Z

354

RESEARCH ON HIGH BEAM-CURRENT ACCELERATORS  

E-Print Network [OSTI]

and M. Wilson, Particle Accelerators 10, 223 13. A. I.Proc. 1976 Proton Linear Accelerator Conf. , Chalk River,and D. Keefe, Particle Accelerators~' 23. S. Humphries, J.

Keefe, Denis

2014-01-01T23:59:59.000Z

355

CALCIUM SULFATE-INDUCED ACCELERATED CORROSION  

E-Print Network [OSTI]

10286 CALCIUM SULFATE-INDUCED ACCELERATED CORROSION HilaryCT Calcium Sulf(1te··induced Accelerated Corrosion By Hilaryof the Caso - induced accelerated attack on pure iron and

Akuezue, Hilary Chikezie

2013-01-01T23:59:59.000Z

356

PROTON ACCELERATION AT OBLIQUE SHOCKS  

SciTech Connect (OSTI)

Acceleration at the shock waves propagating oblique to the magnetic field is studied using a recently developed theoretical/numerical model. The model assumes that resonant hydromagnetic wave-particle interaction is the most important physical mechanism relevant to motion and acceleration of particles as well as to excitation and damping of waves. The treatment of plasma and waves is self-consistent and time dependent. The model uses conservation laws and resonance conditions to find where waves will be generated or damped, and hence particles will be pitch-angle-scattered. The total distribution is included in the model and neither introduction of separate population of seed particles nor some ad hoc escape rate of accelerated particles is needed. Results of the study show agreement with diffusive shock acceleration models in the prediction of power spectra for accelerated particles in the upstream region. However, they also reveal the presence of spectral break in the high-energy part of the spectra. The role of the second-order Fermi-like acceleration at the initial stage of the acceleration is discussed. The test case used in the paper is based on ISEE-3 data collected for the shock of 1978 November 12.

Galinsky, V. L.; Shevchenko, V. I., E-mail: vit@ucsd.edu [ECE Department, UC San Diego, MC 407, La Jolla, CA 92093-0407 (United States)

2011-06-20T23:59:59.000Z

357

Dielectric supported radio-frequency cavities  

DOE Patents [OSTI]

A device which improves the electrical and thermomechanical performance of an RF cavity, for example, in a disk-loaded accelerating structure. A washer made of polycrystalline diamond is brazed in the middle to a copper disk washer and at the outer edge to the plane wave transformer tank wall, thus dissipating heat from the copper disk to the outer tank wall while at the same time providing strong mechanical support to the metal disk. The washer structure eliminates the longitudinal connecting rods and cooling channels used in the currently available cavities, and as a result minimizes problems such as shunt impedance degradation and field distortion in the plane wave transformer, and mechanical deflection and uneven cooling of the disk assembly.

Yu, David U. L. (Rancho Palos Verdes, CA); Lee, Terry G. (Cupertino, CA)

2000-01-01T23:59:59.000Z

358

Effect of Dielectric Selection on Sintering Behavior of LTCC  

SciTech Connect (OSTI)

Low Temperature Cofired Ceramic (LTCC) is a versatile ceramic packaging technology. LTCC’s functionality and performance can be enhanced with the incorporation of passive devices such as resistors, capacitors, and inductors into the structure of the substrate. This incorporation, which eliminates surface mount solder joints is desirable for improving system reliability and allows for increased package density. Commercially available dielectrics for embedding capacitors into LTCC are limited and the incorporation of such systems into LTCC substrates poses processing challenges related to material compatibility. This paper will review multiple dielectric systems and techniques for embedding capacitors into LTCC as well as present new data related to the cofiring behavior of LTCC and custom dielectrics.

Krueger, Daniel S.; Agee, Laura; Fadner, Cristie; Duncan, J. Brent

2010-11-02T23:59:59.000Z

359

Modeling of dielectric elastomers: Design of actuators and energy harvesting devices  

E-Print Network [OSTI]

Modeling of dielectric elastomers: Design of actuators and energy harvesting devices David L Keywords: Dielectric elastomers Large deformations Actuators Energy harvesting devices Finite and energy harvesting devices that convert mechanical energy into electrical energy. Numerically based design

360

EFFECT OF SALINITY ON THE DIELECTRIC PROPERTIES OF GEOLOGICAL MATERIALS : IMPLICATION FOR SOIL  

E-Print Network [OSTI]

. Dielectric mixing models were first calibrated by means of experimental measurements before being used of SAR data (AIRSAR, PALSAR). Keywords- Earth, evaporites, dielectric mixing model, IEM, Mars, polarimetry, radar backscattering, salinity, SAR, soil moisture. I. INTRODUCTION The measurement of soil

Paris-Sud XI, Université de

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


361

Parameter Identification for a Dispersive Dielectric in 2D Electromagnetics: Forward and Inverse  

E-Print Network [OSTI]

Parameter Identification for a Dispersive Dielectric in 2D Electromagnetics: Forward and Inverse with a Debye dielectric slab and PML absorbing boundaries. This system assumes that the electric #12;Parameter

362

Cosmic Particle Acceleration: Basic Issues  

E-Print Network [OSTI]

Cosmic-rays are ubiquitous, but their origins are surprisingly difficult to understand. A review is presented of some of the basic issues common to cosmic particle accelerators and arguments leading to the likely importance of diffusive shock acceleration as a general explanation. The basic theory of diffusive shock acceleration is outlined, followed by a discussion of some of the key issues that still prevent us from a full understanding of its outcomes. Some recent insights are mentioned at the end that may help direct ultimate resolution of our uncertainties.

T. W. Jones

2000-12-22T23:59:59.000Z

363

Cascaded target normal sheath acceleration  

SciTech Connect (OSTI)

A cascaded target normal sheath acceleration (TNSA) scheme is proposed to simultaneously increase energy and improve energy spread of a laser-produced mono-energetic proton beam. An optimum condition that uses the maximum sheath field to accelerate the center of the proton beam is theoretically found and verified by two-dimensional particle-in-cell simulations. An initial 10 MeV proton beam is accelerated to 21 MeV with energy spread decreased from 5% to 2% under the optimum condition during the process of the cascaded TNSA. The scheme opens a way to scale proton energy lineally with laser energy.

Wang, W. P.; Shen, B. F.; Zhang, X. M.; Wang, X. F.; Xu, J. C.; Zhao, X. Y.; Yu, Y. H.; Yi, L. Q.; Shi, Y.; Zhang, L. G.; Xu, T. J.; Xu, Z. Z. [State Key Laboratory of High Field Laser Physics, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800 (China)] [State Key Laboratory of High Field Laser Physics, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800 (China)

2013-11-15T23:59:59.000Z

364

Charge Diagnostics for Laser Plasma Accelerators  

E-Print Network [OSTI]

Laser plasma accelerator, charge diagnostics, Lanex, ICT,Charge Diagnostics for Laser Plasma Accelerators K .CHARGE DIAGNOSTICS CROSS-CALIBRATIONS WITH LASER PLASMA

Nakamura, K.

2011-01-01T23:59:59.000Z

365

CRAD, Criticality Safety - Idaho Accelerated Retrieval Project...  

Broader source: Energy.gov (indexed) [DOE]

Criticality Safety - Idaho Accelerated Retrieval Project Phase II CRAD, Criticality Safety - Idaho Accelerated Retrieval Project Phase II February 2006 A section of Appendix C to...

366

Hyundai Sonata HEV Accelerated Testing - March 2013  

Broader source: Energy.gov (indexed) [DOE]

Hyundai Sonata HEV Accelerated Testing - March 2013 Two model year 2011 Hyundai Sonata hybrid electric vehicles (HEVs) entered Accelerated testing during June 2011 in a fleet in...

367

CRAD, Occupational Safety & Health - Idaho Accelerated Retrieval...  

Broader source: Energy.gov (indexed) [DOE]

Occupational Safety & Health - Idaho Accelerated Retrieval Project Phase II CRAD, Occupational Safety & Health - Idaho Accelerated Retrieval Project Phase II February 2006 A...

368

Accelerated Laboratory Tests Using Simultaneous UV, Temperature...  

Broader source: Energy.gov (indexed) [DOE]

Accelerated Laboratory Tests Using Simultaneous UV, Temperature, and Moisture for PV Encapsulants, Frontsheets, and Backsheets Accelerated Laboratory Tests Using Simultaneous UV,...

369

Comparing Accelerated Testing and Outdoor Exposure | Department...  

Broader source: Energy.gov (indexed) [DOE]

Comparing Accelerated Testing and Outdoor Exposure Comparing Accelerated Testing and Outdoor Exposure Presented at the PV Module Reliability Workshop, February 26 - 27 2013,...

370

ACCELERATED SCHEMES FOR A CLASS OF VARIATIONAL ...  

E-Print Network [OSTI]

We propose a novel method, namely the accelerated mirror-prox (AMP) method, ... the rate of convergence of the AMP method can be accelerated in terms of.

2014-03-17T23:59:59.000Z

371

Chevrolet Malibu HEV Accelerated Testing - June 2013  

Broader source: Energy.gov (indexed) [DOE]

Malibu HEV Accelerated Testing - June 2013 Four model year 2013 Chevrolet Malibu hybrid electric vehicles (HEVs) entered Accelerated testing during November 2012 in a fleet in...

372

ASTA at Fermilab: Accelerator Physics and Accelerator Education Programs at the Modern Accelerator R&D Users Facility for HEP and Accelerator Applications  

E-Print Network [OSTI]

We present the current and planned beam physics research program and accelerator education program at Advanced Superconducting Test Accelerator (ASTA) at Fermilab.

Shiltsev, V

2014-01-01T23:59:59.000Z

373

ASTA at Fermilab: Accelerator Physics and Accelerator Education Programs at the Modern Accelerator R&D Users Facility for HEP and Accelerator Applications.  

SciTech Connect (OSTI)

We present the current and planned beam physics research program and accelerator education program at Advanced Superconducting Test Accelerator (ASTA) at Fermilab.

Shiltsev, V.; Piot, P.

2013-09-01T23:59:59.000Z

374

Accelerating DSMC data extraction.  

SciTech Connect (OSTI)

In many direct simulation Monte Carlo (DSMC) simulations, the majority of computation time is consumed after the flowfield reaches a steady state. This situation occurs when the desired output quantities are small compared to the background fluctuations. For example, gas flows in many microelectromechanical systems (MEMS) have mean speeds more than two orders of magnitude smaller than the thermal speeds of the molecules themselves. The current solution to this problem is to collect sufficient samples to achieve the desired resolution. This can be an arduous process because the error is inversely proportional to the square root of the number of samples so we must, for example, quadruple the samples to cut the error in half. This work is intended to improve this situation by employing more advanced techniques, from fields other than solely statistics, for determining the output quantities. Our strategy centers on exploiting information neglected by current techniques, which collect moments in each cell without regard to one another, values in neighboring cells, nor their evolution in time. Unlike many previous acceleration techniques that modify the method itself, the techniques examined in this work strictly post-process so they may be applied to any DSMC code without affecting its fidelity or generality. Many potential methods are drawn from successful applications in a diverse range of areas, from ultrasound imaging to financial market analysis. The most promising methods exploit relationships between variables in space, which always exist in DSMC due to the absence of shocks. Disparate techniques were shown to produce similar error reductions, suggesting that the results shown in this report may be typical of what is possible using these methods. Sample count reduction factors of approximately three to five were found to be typical, although factors exceeding ten were shown on some variables under some techniques.

Gallis, Michail A.; Piekos, Edward Stanley

2006-10-01T23:59:59.000Z

375

E-Print Network 3.0 - active dielectric microstructures Sample...  

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

Plasma Actuators for Active Aerodynamic Flow Control," AIAA... Results Using Aerogels and Ferroelectrics for Dielectric Barrier Discharge Actuators Ryan Durscher......

376

E-Print Network 3.0 - atmospheric dielectric barrier Sample Search...  

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

Force Measurement Techniques and Preliminary Results Summary: Results Using Aerogels and Ferroelectrics for Dielectric Barrier Discharge Actuators Ryan Durscher......

377

Dielectric behavior of barium modified strontium bismuth titanate ceramic  

SciTech Connect (OSTI)

Barium Modified Strontium Bismuth Titanate(SBT) ceramic with general formula Sr1?xBaxBi4Ti4O15 is prepared by solid state reaction route. The structural analysis of the ceramics was done by X-ray diffraction technique. The X-ray patterns show that all the compositions are of single phase with orthorhombic structure. The temperature dependent dielectric behavior shows that the transition temperature decreases with Ba content but the maximum dielectric constant increases. The decreases of the transition with increase in Ba{sup 2+} ion, may be due to the decrease of orthorhombicity by the incorporation of Ba{sup 2+} ion in SBT lattice.

Nayak, P., E-mail: priyambada.pce@gmail.com [Department of Physics, National Institute of Technology, Rourkela, Odisha-769008 (India); Badapanda, T. [Department of Physics, C.V. Raman College of Engineering, Bhubaneswar, Odisha-752054 (India); Anwar, S.; Panigrahi, S. [Colloids and Materials Chemistry, Institute of Minerals and Materials Technology, Bhubaneswar, Odisha-751013 (India)

2014-04-24T23:59:59.000Z

378

Probing the membrane potential of living cells by dielectric spectroscopy  

E-Print Network [OSTI]

In this paper we demonstrate a quantitative way to measure the membrane potential of live cells by dielectric spectroscopy. We also show that the values of the membrane potential obtained using our technique are in good agreement with those obtained using traditional methods-voltage sensitive dyes. The membrane potential is determined by fitting the experimental dielectric dispersion curves with the dispersion curves obtain from a theoretical model. Variations in the membrane potential were induced by modifying the concentration of potassium chloride in the solution of the cell suspension in the presence of valinomycin. For exemplification of the method, E. coli were chosen for our experiments.

Corina Bot; Camelia Prodan

2008-12-17T23:59:59.000Z

379

Alternative Gate Dielectrics on Semiconductors for MOSFET Device Applications  

SciTech Connect (OSTI)

We have investigated the synthesis and properties of deposited oxides on Si and Ge for use as alternative gate dielectrics in MOSFET applications. The capacitance and leakage current behavior of polycrystalline Y{sub 2}O{sub 3} films synthesized by pulsed-laser deposition is reported. In addition, we also discuss the growth of epitaxial oxide structures. In particular, we have investigated the use of silicide termination for oxide growth on (001) Si using laser-molecular beam epitaxy. In addition, we discuss a novel approach involving the use of hydrogen to eliminate native oxide during initial dielectric oxide nucleation on (001) Ge.

Norton, D.P.; Budai, J.D.; Chisholm, M.F.; Pennycook, S.J.; McKee, R.; Walker, F.; Lee, Y.; Park, C.

1999-12-06T23:59:59.000Z

380

Electromagnetic Field Quantization in Time-Dependent Dielectric Media  

E-Print Network [OSTI]

We present a Gupta-Bleuler quantization scheme for the electromagnetic field in time-dependent dielectric media. Starting from the Maxwell equations, a generalization of the Lorentz gauge condition adapted to time varying dielectrics is derived. Using this gauge, a Gupta-Bleuler approach to quantize all polarizations of the radiation field and the corresponding constraint condition are introduced. This new approach is different from the quantized electromagnetic field in vacuum in the sense that here the contributions of unphysical photons cannot be thoroughly eliminated, which further lead to a surface charge density. Finally, a discussion of potential experimental tests and possible implication is also made.

Xiao-Min Bei; Zhong-Zhu Liu

2011-04-18T23:59:59.000Z

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


381

Tunable subwavelength strong absorption by graphene wrapped dielectric particles  

E-Print Network [OSTI]

The optical absorption properties of graphene wrapped dielectric particles have been investigated by using Mie scattering theory and exact multi-scattering method. It is shown that subwavelength strong absorption in infrared spectra can take place in such systems due to the excitation of plasmon resonance in graphene. The absorption characteristics and efficiency are tunable by varying Fermi level and damping constant of graphene, or by changing size and dielectric constant of small particles. For a cluster of these particles, the absorption characteristics are also affected by the separation distance between them. These extreme light resonances and absorptions in graphene wrapped nanostructures have great potential for opto-electronic devices.

Yang, Bing; Yang, Yue; Zhang, Xiangdong

2015-01-01T23:59:59.000Z

382

Accelerating and rotating black holes  

E-Print Network [OSTI]

An exact solution of Einstein's equations which represents a pair of accelerating and rotating black holes (a generalised form of the spinning C-metric) is presented. The starting point is a form of the Plebanski-Demianski metric which, in addition to the usual parameters, explicitly includes parameters which describe the acceleration and angular velocity of the sources. This is transformed to a form which explicitly contains the known special cases for either rotating or accelerating black holes. Electromagnetic charges and a NUT parameter are included, the relation between the NUT parameter $l$ and the Plebanski-Demianski parameter $n$ is given, and the physical meaning of all parameters is clarified. The possibility of finding an accelerating NUT solution is also discussed.

J. B. Griffiths; J. Podolsky

2005-07-06T23:59:59.000Z

383

Dielectric nonlinearity and stochastic effects in strontium titanate Alp T. Findikoglua)  

E-Print Network [OSTI]

Dielectric nonlinearity and stochastic effects in strontium titanate Alp T. Findikoglua) Materials-film superconducting YBa2Cu3O7 electrodes. The substrate is strontium titanate, whose nonlinear dielectric properties American Institute of Physics. DOI: 10.1063/1.1477278 Nonlinear dielectrics such as strontium titanate STO

Lythe, Grant

384

Rectification of evanescent heat transfer between dielectric-coated and uncoated silicon carbide plates  

E-Print Network [OSTI]

Rectification of evanescent heat transfer between dielectric-coated and uncoated silicon carbide://jap.aip.org/authors #12;Rectification of evanescent heat transfer between dielectric-coated and uncoated silicon carbide-infinite bodies of the dielectric-coated silicon carbide and uncoated silicon carbide. The permittivity

Fan, Shanhui

385

Dependence of exciton transition energy of single-walled carbon nanotubes on surrounding dielectric materials  

E-Print Network [OSTI]

Dependence of exciton transition energy of single-walled carbon nanotubes on surrounding dielectric 11, 2007) We theoretically investigate the dependence of exciton transition energies on dielectric transition energy dependence on dielectric constant of various surrounding materials. PACS numbers: 78.67.Ch

Maruyama, Shigeo

386

HIGH-THROUGHPUT CELL AND PARTICLE CHARACTERIZATION USING ISO-DIELECTRIC  

E-Print Network [OSTI]

HIGH-THROUGHPUT CELL AND PARTICLE CHARACTERIZATION USING ISO-DIELECTRIC SEPARATION Michael D. Vahey conductivity. Using a re- cently developed separation method - iso-dielectric separation (IDS) - we character for developing new screens. THEORY We recently developed a separa- tion method, called iso-dielectric sepa

Voldman, Joel

387

Sequentially pulsed traveling wave accelerator  

DOE Patents [OSTI]

A sequentially pulsed traveling wave compact accelerator having two or more pulse forming lines each with a switch for producing a short acceleration pulse along a short length of a beam tube, and a trigger mechanism for sequentially triggering the switches so that a traveling axial electric field is produced along the beam tube in synchronism with an axially traversing pulsed beam of charged particles to serially impart energy to the particle beam.

Caporaso, George J. (Livermore, CA); Nelson, Scott D. (Patterson, CA); Poole, Brian R. (Tracy, CA)

2009-08-18T23:59:59.000Z

388

8 IEEE TRANSACTIONS ON PLASMA SCIENCE, VOL. 33, NO. 1, FEBRUARY 2005 Radiation From Laser Accelerated Electron Bunches  

E-Print Network [OSTI]

. The short-pulse nature of the acceler- ated bunches and high particle energy offer the possibility of gen mod- ulation (wakefield) that can trap background electrons and accel- erate them to high energies

Geddes, Cameron Guy Robinson

389

Teleportation with Multiple Accelerated Partners  

E-Print Network [OSTI]

As the current revolution in communication is underway, quantum teleportation can increase the level of security in quantum communication applications. In this paper, we present a quantum teleportation procedure that capable to teleport either accelerated or non-accelerated information through different quantum channels. These quantum chan- nels are based on accelerated multi-qubit states, where each qubit of each of these channels represent a partner. Namely, these states are the the W state, Greenberger-Horne-Zeilinger (GHZ) state, and the GHZ-like state. Here, we show that the fidelity of teleporting acceler- ated information is higher than the fidelity of teleporting non-accelerated information, both through a quantum channel that is based on accelerated state. Also, the comparison among the performance of these three channels shows that the degree of fidelity depends on type of the used channel, type of the measurement, and value of the acceleration. The result of comparison concludes that teleporting information through channel that is based on the GHZ state is more robust than teleporting information through channels that are based on the other two states. For future work, the proposed procedure can be generalized later to achieve communication through a wider quantum network.

Alaa Sagheer; Hala Hamdoun

2014-01-31T23:59:59.000Z

390

Generation and Characterization of Electron Bunches with Ramped Current Profiles in a Dual-Frequency Superconducting Linear Accelerator  

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

We report on the successful experimental generation of electron bunches with ramped current profiles. The technique relies on impressing nonlinear correlations in the longitudinal phase space using a superconducing radiofrequency linear accelerator operating at two frequencies and a current-enhancing dispersive section. The produced {approx} 700-MeV bunches have peak currents of the order of a kilo-Ampere. Data taken for various accelerator settings demonstrate the versatility of the method and in particular its ability to produce current profiles that have a quasi-linear dependency on the longitudinal (temporal) coordinate. The measured bunch parameters are shown, via numerical simulations, to produce gigavolt-per-meter peak accelerating electric fields with transformer ratios larger than 2 in dielectric-lined waveguides.

Piot, P [Northern Illinois U.; Fermilab; Behrens, C; Gerth, C; Dohlus, M [DESY; Lemery, F; Mihalcea, D [Northern Illinois U.; Stoltz, P [Tech-X, Boulder; Vogt, M [DESY

2011-09-07T23:59:59.000Z

391

Effect of mechanical parameters on dielectric elastomer minimum energy structures  

E-Print Network [OSTI]

Effect of mechanical parameters on dielectric elastomer minimum energy structures Jun Shintake energy structures Jun Shintake*a,b , Samuel Rosseta , Dario Floreanob , Herbert R. Sheaa a Microsystems for Space Technologies Laboratory, Ecole Polytechnique Fédérale de Lausanne (EPFL), Neuchâtel, Switzerland b

Floreano, Dario

392

Temperature and moisture dependence of dielectric constant for silica aerogels  

SciTech Connect (OSTI)

The dielectric constants of silica aerogels are among the lowest measured for any solid material. The silica aerogels also exhibit low thermal expansion and are thermally stable to temperatures exceeding 500{degrees}C. However, due to the open porosity and large surface areas for aerogels, their dielectric constants are strongly affected by moisture and temperature. This paper presents data for the dielectric constants of silica aerogels as a function of moisture content at 25{degrees}C, and as a function of temperature, for temperatures in the range from 25{degrees}C to 450{degrees}C. Dielectric constant data are also given for silica aerogels that are heat treated in dry nitrogen at 500{degrees}C, then cooled to 25{degrees}C for measurements in dry air. All measurements are made on bulk aerogel spheres at 22GHz microwave frequency, using a cavity perturbation method. The results of the dependence found here for bulk materials can be inferred to apply also to thin films of silica aerogels having similar nano-structures and densities.

Hrubesh, L.H., LLNL

1997-03-01T23:59:59.000Z

393

Dielectric nanostructures for broadband light trapping in organic solar cells  

E-Print Network [OSTI]

Dielectric nanostructures for broadband light trapping in organic solar cells Aaswath Raman, Zongfu light trapping configuration for thin-film solar cells," Appl. Phys. Lett. 91, 243501 (2007). 8. M@stanford.edu Abstract: Organic bulk heterojunction solar cells are a promising candidate for low-cost next

Fan, Shanhui

394

ACCELERATED DESTRUCTIVE DEGRADATION TESTS: DATA, MODELS,  

E-Print Network [OSTI]

ACCELERATED DESTRUCTIVE DEGRADATION TESTS: DATA, MODELS, AND ANALYSIS Luis A. Escobar Dept are often accelerated by testing at higher than usual levels of accelerating variables like temperature. This chapter describes an important class of models for accelerated destructive degradation data. We use

395

Accelerators: powering cutting-edge research  

E-Print Network [OSTI]

Accelerators: powering cutting-edge research #12;What is a particle accelerator? Booster ourselves. Particle accelerators are our attempt to turn back the clock and see into the early stages of the Universe. They accelerate everyday charged particles (electrons or protons) to close to the speed of light

Crowther, Paul

396

Accelerator and electrodynamics capability review  

SciTech Connect (OSTI)

Los Alamos National Laboratory (LANL) uses capability reviews to assess the science, technology and engineering (STE) quality and institutional integration and to advise Laboratory Management on the current and future health of the STE. Capability reviews address the STE integration that LANL uses to meet mission requirements. The Capability Review Committees serve a dual role of providing assessment of the Laboratory's technical contributions and integration towards its missions and providing advice to Laboratory Management. The assessments and advice are documented in reports prepared by the Capability Review Committees that are delivered to the Director and to the Principal Associate Director for Science, Technology and Engineering (PADSTE). Laboratory Management will use this report for STE assessment and planning. LANL has defined fifteen STE capabilities. Electrodynamics and Accelerators is one of the seven STE capabilities that LANL Management (Director, PADSTE, technical Associate Directors) has identified for review in Fiscal Year (FY) 2010. Accelerators and electrodynamics at LANL comprise a blend of large-scale facilities and innovative small-scale research with a growing focus on national security applications. This review is organized into five topical areas: (1) Free Electron Lasers; (2) Linear Accelerator Science and Technology; (3) Advanced Electromagnetics; (4) Next Generation Accelerator Concepts; and (5) National Security Accelerator Applications. The focus is on innovative technology with an emphasis on applications relevant to Laboratory mission. The role of Laboratory Directed Research and Development (LDRD) in support of accelerators/electrodynamics will be discussed. The review provides an opportunity for interaction with early career staff. Program sponsors and customers will provide their input on the value of the accelerator and electrodynamics capability to the Laboratory mission.

Jones, Kevin W [Los Alamos National Laboratory

2010-01-01T23:59:59.000Z

397

Ultra-high vacuum photoelectron linear accelerator  

DOE Patents [OSTI]

An rf linear accelerator for producing an electron beam. The outer wall of the rf cavity of said linear accelerator being perforated to allow gas inside said rf cavity to flow to a pressure chamber surrounding said rf cavity and having means of ultra high vacuum pumping of the cathode of said rf linear accelerator. Said rf linear accelerator is used to accelerate polarized or unpolarized electrons produced by a photocathode, or to accelerate thermally heated electrons produced by a thermionic cathode, or to accelerate rf heated field emission electrons produced by a field emission cathode.

Yu, David U.L.; Luo, Yan

2013-07-16T23:59:59.000Z

398

Substrate dielectric effects on graphene field effect transistors  

SciTech Connect (OSTI)

Graphene is emerging as a promising material for future electronics and optoelectronics applications due to its unique electronic structure. Understanding the graphene-dielectric interaction is of vital importance for the development of graphene field effect transistors (FETs) and other novel graphene devices. Here, we extend the exploration of substrate dielectrics from conventionally used thermally grown SiO{sub 2} and hexagonal boron nitride films to technologically relevant deposited dielectrics used in semiconductor industry. A systematic analysis of morphology and optical and electrical properties was performed to study the effects of different substrates (SiO{sub 2}, HfO{sub 2}, Al{sub 2}O{sub 3}, tetraethyl orthosilicate (TEOS)-oxide, and Si{sub 3}N{sub 4}) on the carrier transport of chemical vapor deposition-derived graphene FET devices. As baseline, we use graphene FETs fabricated on thermal SiO{sub 2} with a relatively high carrier mobility of 10?000 cm{sup 2}/(V s). Among the deposited dielectrics studied, silicon nitride showed the highest mobility, comparable to the properties of graphene fabricated on thermal SiO{sub 2}. We conclude that this result comes from lower long range scattering and short range scattering rates in the nitride compared those in the other deposited films. The carrier fluctuation caused by substrates, however, seems to be the main contributing factor for mobility degradation, as a universal mobility-disorder density product is observed for all the dielectrics examined. The extrinsic doping trend is further confirmed by Raman spectra. We also provide, for the first time, correlation between the intensity ratio of G peak and 2D peak in the Raman spectra to the carrier mobility of graphene for different substrates.

Hu, Zhaoying; Prasad Sinha, Dhiraj; Ung Lee, Ji, E-mail: jlee1@albany.edu; Liehr, Michael [College of Nanoscale Science and Engineering, The State University of New York at Albany, Albany, New York 12203 (United States)

2014-05-21T23:59:59.000Z

399

Theory of factors limiting high gradient operation of warm accelerating structures  

SciTech Connect (OSTI)

This final report summarizes the research performed during the time period from 8/1/2010 to 7/31/2013. It consists of two parts describing our studies in two directions: (a) analysis of factors limiting operation of dielectric-loaded accelerating (DLA) structures where the main problem is the occurrence of multipactor on dielectric surfaces, and (b) studies of effects associated with either RF magnetic or RF electric fields which may cause the RF breakdown in high-gradient metallic accelerating structures. In the studies of DLA structures, at least, two accomplishments should be mentioned: the development of a 3D non-stationary, self-consistent code describing the multipactor phenomena and yielding very good agreement with some experimental data obtained in joint ANL/NRL experiments. In the metallic structures, such phenomena as the heating and melting of micro-particles (metallic dust) by RF electric and magnetic fields in single-shot and rep-rate regimes is analyzed. Also, such processes in micro-protrusions on the structure surfaces as heating and melting due to the field emitted current and the Nottingham effect are thoroughly investigated with the account for space charge of emitted current on the field emission from the tip.

Nusinovich, Gregory S. [University of Maryland; Antonsen, Thomas M. [University of Maryland; Kishek, Rami [University of Maryland

2014-07-25T23:59:59.000Z

400

Dielectric Torque and Orientation Dynamics of Liquid Crystals with Dielectric Dispersion S. V. Shiyanovskii,1,2  

E-Print Network [OSTI]

, and reorientation of the permanent molecular dipoles. The characteristic relaxation times of the first two processes field causes director reorientation, which in its turn changes the dielectric coupling between the field in the classical electro- magnetic theory results in the following dependence [6]: D t "0Et "0 Z t ÿ1 t; t0 Et0

Lavrentovich, Oleg D.

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


401

Derivation of Hamiltonians for accelerators  

SciTech Connect (OSTI)

In this report various forms of the Hamiltonian for particle motion in an accelerator will be derived. Except where noted, the treatment will apply generally to linear and circular accelerators, storage rings, and beamlines. The generic term accelerator will be used to refer to any of these devices. The author will use the usual accelerator coordinate system, which will be introduced first, along with a list of handy formulas. He then starts from the general Hamiltonian for a particle in an electromagnetic field, using the accelerator coordinate system, with time t as independent variable. He switches to a form more convenient for most purposes using the distance s along the reference orbit as independent variable. In section 2, formulas will be derived for the vector potentials that describe the various lattice components. In sections 3, 4, and 5, special forms of the Hamiltonian will be derived for transverse horizontal and vertical motion, for longitudinal motion, and for synchrobetatron coupling of horizontal and longitudinal motions. Hamiltonians will be expanded to fourth order in the variables.

Symon, K.R.

1997-09-12T23:59:59.000Z

402

Accelerator Physics Accelerators form the backbone of SLAC's on-site experimental program. Research at SLAC  

E-Print Network [OSTI]

#12;Accelerator Physics Accelerators form the backbone of SLAC's on-site experimental program. Research at SLAC is continually improving accelerators, both here and at other laboratories, and paving the way for a new generation of particle acceleration technology. SLAC's famous linear accelerator

Wechsler, Risa H.

403

Symposium on accelerator mass spectrometry  

SciTech Connect (OSTI)

The area of accelerator mass spectrometry has expanded considerably over the past few years and established itself as an independent and interdisciplinary research field. Three years have passed since the first meeting was held at Rochester. A Symposium on Accelerator Mass Spectrometry was held at Argonne on May 11-13, 1981. In attendance were 96 scientists of whom 26 were from outside the United States. The present proceedings document the program and excitement of the field. Papers are arranged according to the original program. A few papers not presented at the meeting have been added to complete the information on the status of accelerator mass spectrometry. Individual papers were prepared separately for the data base.

None

1981-01-01T23:59:59.000Z

404

Superconducting Magnets for Particle Accelerators  

E-Print Network [OSTI]

Superconductivity has been the most influential technology in the field of accelerators in the last 30 years. Since the commissioning of the Tevatron, which demonstrated the use and operability of superconductivity on a large scale, superconducting magnets and rf cavities have been at the heart of all new large accelerators. Superconducting magnets have been the invariable choice for large colliders, as well as cyclotrons and large synchrotrons. In spite of the long history of success, superconductivity remains a difficult technology, requires adequate R&D and suitable preparation, and has a relatively high cost. Hence, it is not surprising that the development has also been marked by a few setbacks. This article is a review of the main superconducting accelerator magnet projects; it highlights the main characteristics and main achievements, and gives a perspective on the development of superconducting magnets for the future generation of very high energy colliders.

Rossi, L

2012-01-01T23:59:59.000Z

405

Pre-breakdown cavitation development in the dielectric fluid in the inhomogeneous, pulsed electric fields  

E-Print Network [OSTI]

We consider the development of pre-breakdown cavitation nanopores appearing in the dielectric fluid under the influence of the electrostrictive stresses in the inhomogeneous pulsed electric field. It is shown that three characteristic regions can be distinguished near the needle electrode. In the first region, where the electric field gradient is greatest, the cavitation nanopores, occurring during the voltage nanosecond pulse, may grow to the size at which an electron accelerated by the field inside the pores can acquire enough energy for excitation and ionization of the liquid on the opposite pore wall, i.e., the breakdown conditions are satisfied. In the second region, the negative pressure caused by the electrostriction is large enough for the cavitation initiation (which can be registered by optical methods), but, during the voltage pulse, the pores do not reach the size at which the potential difference across their borders becomes sufficient for ionization or excitation of water molecules. And, in the third, the development of cavitation is impossible, due to an insufficient level of the negative pressure: in this area, the spontaneously occurring micropores do not grow and collapse under the influence of surface tension forces. This paper discusses the expansion dynamics of the cavitation pores and their most probable shape.

Mikhail N. Shneider; Mikhail Pekker

2014-12-01T23:59:59.000Z

406

X-ray driven channeling acceleration in crystals and carbon nanotubes  

SciTech Connect (OSTI)

Acceleration of particles channeling in a crystal by means of diffracted x-rays via Bormann anomalous transmission was conceived for heavy ions and muons by Tajima and Cavenago [Phys. Rev. Lett. 59, 1440 (1987)], which potentially offers an appreciably high field gradient on the order of GV/cm. The theoretical model of the high gradient acceleration has been studied in two kinds of atomic structure, crystals and carbon nanotubes (CNTs), with analytic calculations and electromagnetic eigenmode simulations. A range of acceleration gradients and cutoffs of the x-ray power (the lowest power limit to overcome the Bremsstrahlung radiation losses) are characterized in terms of the lattice constants, unit cell sizes, and photon energies. The parametric analysis indicates that the required x-ray power can be reduced to an order of megawatt by replacing crystals with CNTs. Eventually, the equivalent dielectric approximation of a multi-wall nanotube shows that 250–810 MeV muons can be synchronously coupled with x-rays of 0.65–1.32 keV in the accelerating structure.

Shin, Young-Min [Department of Physics, Northern Illinois Center for Accelerator and Detector Development (NICADD), Northern Illinois University, Dekalb, Illinois 60115 (United States) [Department of Physics, Northern Illinois Center for Accelerator and Detector Development (NICADD), Northern Illinois University, Dekalb, Illinois 60115 (United States); Fermi National Accelerator Laboratory, Batavia, Illinois 60510 (United States); Still, Dean A.; Shiltsev, Vladimir [Fermi National Accelerator Laboratory, Batavia, Illinois 60510 (United States)] [Fermi National Accelerator Laboratory, Batavia, Illinois 60510 (United States)

2013-12-15T23:59:59.000Z

407

Weak-Chaos Ratchet Accelerator  

E-Print Network [OSTI]

Classical Hamiltonian systems with a mixed phase space and some asymmetry may exhibit chaotic ratchet effects. The most significant such effect is a directed momentum current or acceleration. In known model systems, this effect may arise only for sufficiently strong chaos. In this paper, a Hamiltonian ratchet accelerator is introduced, featuring a momentum current for arbitrarily weak chaos. The system is a realistic, generalized kicked rotor and is exactly solvable to some extent, leading to analytical expressions for the momentum current. While this current arises also for relatively strong chaos, the maximal current is shown to occur, at least in one case, precisely in a limit of arbitrarily weak chaos.

Itzhack Dana; Vladislav B. Roitberg

2012-05-28T23:59:59.000Z

408

Centralized digital control of accelerators  

SciTech Connect (OSTI)

In contrasting the title of this paper with a second paper to be presented at this conference entitled Distributed Digital Control of Accelerators, a potential reader might be led to believe that this paper will focus on systems whose computing intelligence is centered in one or more computers in a centralized location. Instead, this paper will describe the architectural evolution of SLAC's computer based accelerator control systems with respect to the distribution of their intelligence. However, the use of the word centralized in the title is appropriate because these systems are based on the use of centralized large and computationally powerful processors that are typically supported by networks of smaller distributed processors.

Melen, R.E.

1983-09-01T23:59:59.000Z

409

OpenMP for Accelerators  

SciTech Connect (OSTI)

OpenMP [13] is the dominant programming model for shared-memory parallelism in C, C++ and Fortran due to its easy-to-use directive-based style, portability and broad support by compiler vendors. Similar characteristics are needed for a programming model for devices such as GPUs and DSPs that are gaining popularity to accelerate compute-intensive application regions. This paper presents extensions to OpenMP that provide that programming model. Our results demonstrate that a high-level programming model can provide accelerated performance comparable to hand-coded implementations in CUDA.

Beyer, J C; Stotzer, E J; Hart, A; de Supinski, B R

2011-03-15T23:59:59.000Z

410

Electron Cloud Effects in Accelerators  

SciTech Connect (OSTI)

Abstract We present a brief summary of various aspects of the electron-cloud effect (ECE) in accelerators. For further details, the reader is encouraged to refer to the proceedings of many prior workshops, either dedicated to EC or with significant EC contents, including the entire ?ECLOUD? series [1?22]. In addition, the proceedings of the various flavors of Particle Accelerator Conferences [23] contain a large number of EC-related publications. The ICFA Beam Dynamics Newsletter series [24] contains one dedicated issue, and several occasional articles, on EC. An extensive reference database is the LHC website on EC [25].

Furman, M.A.

2012-11-30T23:59:59.000Z

411

Relativistic tunneling and accelerated transmission  

E-Print Network [OSTI]

We obtain the solutions for the tunneling zone of a one-dimensional electrostatic potential in the relativistic (Dirac to Klein-Gordon) wave equation regime when the incoming wave packet exhibits the possibility of being almost totally transmitted through the potential barrier. The conditions for the occurrence of accelerated and, eventually, superluminal tunneling transmission probabilities are all quantified and the problematic superluminal interpretation originated from the study based on non-relativistic dynamics of tunneling is overcome. The treatment of the problem suggests revealing insights into condensed-matter experiments using electrostatic barriers in single- and bi-layer graphene, for which the accelerated tunneling effect deserves a more careful investigation.

Alex E. Bernardini

2007-06-26T23:59:59.000Z

412

Accelerated BS/DPT Program Academic Policy and Procedure Manual 1 ACCELERATED HEALTH STUDIES /  

E-Print Network [OSTI]

_____________________________________________________________________________________ Accelerated BS/DPT Program Academic Policy and Procedure Manual 1 ACCELERATED HEALTH STUDIES / DOCTOR OF PHYSICAL;_____________________________________________________________________________________ Accelerated BS/DPT Program Academic Policy and Procedure Manual 2 TABLE OF CONTENTS Department Personnel

Guenther, Frank

413

Tapered plasma channels to phase-lock accelerating and focusing forces in laser-plasma accelerators  

E-Print Network [OSTI]

elds in laser plasma accelerators using higher order modes”,collider, in Advanced Accelerator Concepts, edited by C. B.forces in laser-plasma accelerators W. Rittershofer, 1, a)

Rittershofer, W.

2010-01-01T23:59:59.000Z

414

Repair of overheating linear accelerator  

SciTech Connect (OSTI)

Los Alamos Neutron Science Center (LANSCE) is a proton accelerator that produces high energy particle beams for experiments. These beams include neutrons and protons for diverse uses including radiography, isotope production, small feature study, lattice vibrations and material science. The Drift Tube Linear Accelerator (DTL) is the first portion of a half mile long linear section of accelerator that raises the beam energy from 750 keV to 100 MeV. In its 31st year of operation (2003), the DTL experienced serious issues. The first problem was the inability to maintain resonant frequency at full power. The second problem was increased occurrences of over-temperature failure of cooling hoses. These shortcomings led to an investigation during the 2003 yearly preventative maintenance shutdown that showed evidence of excessive heating: discolored interior tank walls and coper oxide deposition in the cooling circuits. Since overheating was suspected to be caused by compromised heat transfer, improving that was the focus of the repair effort. Investigations revealed copper oxide flow inhibition and iron oxide scale build up. Acid cleaning was implemented with careful attention to protection of the base metal, selection of components to clean and minimization of exposure times. The effort has been very successful in bringing the accelerator through a complete eight month run cycle allowing an incredible array of scientific experiments to be completed this year (2003-2004). This paper will describe the systems, investigation analysis, repair, return to production and conclusion.

Barkley, Walter; Baldwin, William; Bennett, Gloria; Bitteker, Leo; Borden, Michael; Casados, Jeff; Fitzgerald, Daniel; Gorman, Fred; Johnson, Kenneth; Kurennoy, Sergey; Martinez, Alberto; O’Hara, James; Perez, Edward; Roller, Brandon; Rybarcyk, Lawrence; Stark, Peter; Stockton, Jerry

2004-01-01T23:59:59.000Z

415

Physics Needs for Future Accelerators  

E-Print Network [OSTI]

Contents: 1. Prologomena to any meta future physics 1.1 Physics needs for building future accelerators 1.2 Physics needs for funding future accelerators 2. Physics questions for future accelerators 2.1 Crimes and misapprehensions 2.1.1 Organized religion 2.1.2 Feudalism 2.1.3 Trotsky was right 2.2 The Standard Model as an effective field theory 2.3 What is the scale of new physics? 2.4 What could be out there? 2.5 Model-independent conclusions 3. Future accelerators 3.1 What is the physics driving the LHC? 3.2 What is the physics driving the LC? 3.2.1 Higgs physics is golden 3.2.2 LHC won't be sufficient to unravel the new physics as the TeV scale 3.2.3 LC precision measurements can pin down new physics scales 3.3 Why a Neutrino Factory? 3.4 Pushing the energy frontier

Joseph D. Lykken

2000-01-30T23:59:59.000Z

416

Thomas Jefferson National Accelerator Facility  

SciTech Connect (OSTI)

The Thomas Jefferson National Accelerator Facility (Jefferson Lab) in Newport News, Virginia, USA, is one of ten national laboratories under the aegis of the Office of Science of the U.S. Department of Energy (DOE). It is managed and operated by Jefferson Science Associates, LLC. The primary facility at Jefferson Lab is the Continuous Electron Beam Accelerator Facility (CEBAF) as shown in an aerial photograph in Figure 1. Jefferson Lab was created in 1984 as CEBAF and started operations for physics in 1995. The accelerator uses superconducting radio-frequency (srf) techniques to generate high-quality beams of electrons with high-intensity, well-controlled polarization. The technology has enabled ancillary facilities to be created. The CEBAF facility is used by an international user community of more than 1200 physicists for a program of exploration and study of nuclear, hadronic matter, the strong interaction and quantum chromodynamics. Additionally, the exceptional quality of the beams facilitates studies of the fundamental symmetries of nature, which complement those of atomic physics on the one hand and of high-energy particle physics on the other. The facility is in the midst of a project to double the energy of the facility and to enhance and expand its experimental facilities. Studies are also pursued with a Free-Electron Laser produced by an energy-recovering linear accelerator.

Joseph Grames, Douglas Higinbotham, Hugh Montgomery

2010-09-01T23:59:59.000Z

417

Physics Needs for Future Accelerators  

E-Print Network [OSTI]

Contents: 1. Prologomena to any meta future physics 1.1 Physics needs for building future accelerators 1.2 Physics needs for funding future accelerators 2. Physics questions for future accelerators 2.1 Crimes and misapprehensions 2.1.1 Organized religion 2.1.2 Feudalism 2.1.3 Trotsky was right 2.2 The Standard Model as an effective field theory 2.3 What is the scale of new physics? 2.4 What could be out there? 2.5 Model-independent conclusions 3. Future accelerators 3.1 What is the physics driving the LHC? 3.2 What is the physics driving the LC? 3.2.1 Higgs physics is golden 3.2.2 LHC won't be sufficient to unravel the new physics as the TeV scale 3.2.3 LC precision measurements can pin down new physics scales 3.3 Why a Neutrino Factory? 3.4 Pushing the energy frontier

Lykken, J D

2000-01-01T23:59:59.000Z

418

High Performance Outdoor Lighting Accelerator  

Broader source: Energy.gov [DOE]

Hosted by the U.S. Department of Energy (DOE)’s Weatherization and Intergovernmental Programs Office (WIPO), this webinar covered the expansion of the Better Buildings platform to include the newest initiative for the public sector: the High Performance Outdoor Lighting Accelerator (HPOLA).

419

Accelerators for Intensity Frontier Research  

SciTech Connect (OSTI)

In 2008, the Particle Physics Project Prioritization Panel identified three frontiers for research in high energy physics, the Energy Frontier, the Intensity Frontier, and the Cosmic Frontier. In this paper, I will describe how Fermilab is configuring and upgrading the accelerator complex, prior to the development of Project X, in support of the Intensity Frontier.

Derwent, Paul; /Fermilab

2012-05-11T23:59:59.000Z

420

Accelerating Development in the Americas  

E-Print Network [OSTI]

for governments and as a strategic tool for development strategies; · Creating reference cases and best practices by making them feel useful, but also that of their families. OAS & MICROSOFT Accelerating Sustainable for the economic development of our countries as it is part of the process of globalisation and therefore

Narasayya, Vivek

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


421

Petawatt pulsed-power accelerator  

DOE Patents [OSTI]

A petawatt pulsed-power accelerator can be driven by various types of electrical-pulse generators, including conventional Marx generators and linear-transformer drivers. The pulsed-power accelerator can be configured to drive an electrical load from one- or two-sides. Various types of loads can be driven; for example, the accelerator can be used to drive a high-current z-pinch load. When driven by slow-pulse generators (e.g., conventional Marx generators), the accelerator comprises an oil section comprising at least one pulse-generator level having a plurality of pulse generators; a water section comprising a pulse-forming circuit for each pulse generator and a level of monolithic triplate radial-transmission-line impedance transformers, that have variable impedance profiles, for each pulse-generator level; and a vacuum section comprising triplate magnetically insulated transmission lines that feed an electrical load. When driven by LTD generators or other fast-pulse generators, the need for the pulse-forming circuits in the water section can be eliminated.

Stygar, William A. (Albuquerque, NM); Cuneo, Michael E. (Albuquerque, NM); Headley, Daniel I. (Albuquerque, NM); Ives, Harry C. (Albuquerque, NM); Ives, legal representative; Berry Cottrell (Albuquerque, NM); Leeper, Ramon J. (Albuquerque, NM); Mazarakis, Michael G. (Albuquerque, NM); Olson, Craig L. (Albuquerque, NM); Porter, John L. (Sandia Park, NM); Wagoner; Tim C. (Albuquerque, NM)

2010-03-16T23:59:59.000Z

422

E-Print Network 3.0 - accelerator system accelerator Sample Search...  

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

systems Michael J... - based systems that emphasize computation on accelerators (rather than on general purpose cores) should... in these accelerator-based...

423

Phase Stable Net Acceleration of Electrons From a Two-Stage Optical Accelerator  

SciTech Connect (OSTI)

In this article we demonstrate the net acceleration of relativistic electrons using a direct, in-vacuum interaction with a laser. In the experiment, an electron beam from a conventional accelerator is first energy modulated at optical frequencies in an inverse-free-electron-laser and bunched in a chicane. This is followed by a second stage optical accelerator to obtain net acceleration. The optical phase between accelerator stages is monitored and controlled in order to scan the accelerating phase and observe net acceleration and deceleration. Phase jitter measurements indicate control of the phase to {approx}13{sup o} allowing for stable net acceleration of electrons with lasers.

Sears, Christopher M.S.; /SLAC /Munich, Max Planck Inst. Quantenopt.; Colby, Eric; England, R.J.; Ischebeck, Rasmus; McGuinness, Christopher; Nelson, Janice; Noble, Robert; Siemann, Robert H.; Spencer, James; Walz, Dieter; /SLAC; Plettner, Tomas; Byer, Robert L.; /Stanford U., Phys. Dept.

2011-11-11T23:59:59.000Z

424

The momentum of an electromagnetic wave inside a dielectric  

SciTech Connect (OSTI)

The problem of assigning a momentum to an electromagnetic wave packet propagating inside an insulator has become known under the name of the Abraham–Minkowski controversy. In the present paper we re-examine this issue making the hypothesis that the forces exerted on an insulator by an electromagnetic field do not distinguish between polarization and free charges. Under this assumption we show that the Abraham expression for the radiation mechanical momentum is highly favored. -- Highlights: •We discuss an approximation to treat electrodynamics of a dielectric material. •We support the Abraham form for the electromagnetic momentum. •We deduce Snell’s law from the conservation of the Abraham momentum. •We show how to deal with the electric field discontinuity at the dielectric boundary.

Testa, Massimo, E-mail: massimo.testa@roma1.infn.it

2013-09-15T23:59:59.000Z

425

Dielectric waveguide gas-filled stark shift modulator  

DOE Patents [OSTI]

An optical modulator includes a dielectric waveguide for receiving an optical beam and coupling energy of the optical beam into the waveguide. At least one Stark material is provided in the waveguide. A bias circuit generates a bias signal to produce an electrical field across the Stark material to shift at least one of the Stark absorption frequencies towards the frequency of the optical beam. A circuit for producing a time varying electric field across the Stark material modulates the optical beam. At least a portion of the bias field can be generated by an alternating bias signal, such as a square wave. A method of modulating optical signals includes the steps of providing a dielectric waveguide for receiving an optical beam and coupling energy of the optical beam into the waveguide, the waveguide having at least one Stark material disposed therein, and varying an electric field imposed across the Stark material.

Hutchinson, Donald P.; Richards, Roger K.

2003-07-22T23:59:59.000Z

426

THE DEVELOPMENT OF HEAVY-ION ACCELERATORS AS DRIVERS FOR INERTIALLY CONFINED FUSION  

E-Print Network [OSTI]

HEAVY ION ACCELERATORS Principal Components . . . . .Ion Sources Pre-accelerators Low-beta Accelerators Sain Accelerators Rf Linacs . . .

Herrmannsfeldt, W.b.

2010-01-01T23:59:59.000Z

427

Double dielectric passivation layer on InAs  

E-Print Network [OSTI]

) August 1985 ABSTRACT Double Dielectric Passivation Layer on InAs. (August 1985) James Lee Egley, B. S. , Lewis University Chairman of Advisory Committee: Yellapu Anjaneyulu This thesis investigates the characteristics of the substrate surface... as the lubricant. The wafers were polished to a mirror-like finish. An alumina slurry was also tried for this step, but it was found that the chemicals contained in the slurry etched the surface. After the above mechanical polishing the samples were removed...

Egley, James Lee

1985-01-01T23:59:59.000Z

428

Sign reversal in optical nonlinearity: Impact of dielectric fied enhancement  

E-Print Network [OSTI]

Sign reversal in optical nonlinearity: Impact of dielectric fied enhancement Summary and Outlook Z(mm) T -10 -5 0 5 10 0.8 0.9 1.0 Irradiation from particle layer Irradiation from glass side T/T0 I0= 150 GWcm-2 Z(mm) -10 0 10 0,9 1,0 1,1 T/T0 =0 >0 Z(mm) optical

Mosegaard, Klaus

429

Ferroelectric and dielectric properties of ferrite-ferroelectric ceramic composites  

SciTech Connect (OSTI)

Particulate composites of ferrite and ferroelectric phases with xNiFe{sub 2}O{sub 4} (NF) and (1 - x)Pb{sub 0.988}(Zr{sub 0.52}Ti{sub 0.48}){sub 0.976}Nb{sub 0.024}O{sub 3} (where x = 2, 10, 20, 30, 50, 70, and 100 wt. %) were prepared in situ by sol-gel method. The presence of a diphase composition was confirmed by X-ray diffraction while the microstructure of the composites was studied by scanning electron microscopy revealing a good mixing of the two phases and a good densification of the bulk ceramics. The dielectric permittivity shows usual dielectric dispersion behavior with increasing frequency due to Maxwell-Wagner interfacial polarization. AC conductivity measurements made in frequency range 1 Hz-1 MHz suggest that the conduction process is due to mixed polaron hopping. The effect of NF phase concentration on the P-E and M-H hysteresis behavior and dielectric properties of the composites was investigated. At low NF concentration a sharp ferro-paraelectric transition peak can be observed at around 360 Degree-Sign C while for higher NF concentrations a trend to a diffuse phase transition occurs. All the composite samples exhibit typical ferromagnetic hysteresis loops, indicating the presence of ordered magnetic structure.

Elena Ciomaga, Cristina; Maria Neagu, Alexandra; Valentin Pop, Mihai; Mitoseriu, Liliana [Faculty of Physics, 'Al. I. Cuza' University of Iasi 700506, Iasi (Romania); Airimioaei, Mirela [Faculty of Chemistry, 'Al. I. Cuza' University of Iasi 700506, Iasi, Romania and Dept. Chemistry and Process Engineering, University of Genoa, P-le Kennedy no. 1, I-16129, Genoa (Italy); Tascu, Sorin [RAMTECH Faculty of Physics, 'Al. I. Cuza' University of Iasi 700506 (Romania); Schileo, Giorgio [Christian Doppler Laboratory for Advanced Ferroic Oxides, Sheffield Hallam University, Howard Street, Sheffield S1 1WB (United Kingdom); Galassi, Carmen [CNR-ISTEC, Via Granarolo no. 64, I-48018 Faenza (Italy)

2013-02-21T23:59:59.000Z

430

Vapor etching of nuclear tracks in dielectric materials  

DOE Patents [OSTI]

A process involving vapor etching of nuclear tracks in dielectric materials for creating high aspect ratio (i.e., length much greater than diameter), isolated cylindrical holes in dielectric materials that have been exposed to high-energy atomic particles. The process includes cleaning the surface of the tracked material and exposing the cleaned surface to a vapor of a suitable etchant. Independent control of the temperatures of the vapor and the tracked materials provide the means to vary separately the etch rates for the latent track region and the non-tracked material. As a rule, the tracked regions etch at a greater rate than the non-tracked regions. In addition, the vapor-etched holes can be enlarged and smoothed by subsequent dipping in a liquid etchant. The 20-1000 nm diameter holes resulting from the vapor etching process can be useful as molds for electroplating nanometer-sized filaments, etching gate cavities for deposition of nano-cones, developing high-aspect ratio holes in trackable resists, and as filters for a variety of molecular-sized particles in virtually any liquid or gas by selecting the dielectric material that is compatible with the liquid or gas of interest.

Musket, Ronald G. (Danville, CA); Porter, John D. (Berkeley, CA); Yoshiyama, James M. (Fremont, CA); Contolini, Robert J. (Lake Oswego, OR)

2000-01-01T23:59:59.000Z

431

Microwave Dielectric Heating of Drops in Microfluidic Devices  

E-Print Network [OSTI]

We present a technique to locally and rapidly heat water drops in microfluidic devices with microwave dielectric heating. Water absorbs microwave power more efficiently than polymers, glass, and oils due to its permanent molecular dipole moment that has a large dielectric loss at GHz frequencies. The relevant heat capacity of the system is a single thermally isolated picoliter drop of water and this enables very fast thermal cycling. We demonstrate microwave dielectric heating in a microfluidic device that integrates a flow-focusing drop maker, drop splitters, and metal electrodes to locally deliver microwave power from an inexpensive, commercially available 3.0 GHz source and amplifier. The temperature of the drops is measured by observing the temperature dependent fluorescence intensity of cadmium selenide nanocrystals suspended in the water drops. We demonstrate characteristic heating times as short as 15 ms to steady-state temperatures as large as 30 degrees C above the base temperature of the microfluidic device. Many common biological and chemical applications require rapid and local control of temperature, such as PCR amplification of DNA, and can benefit from this new technique.

David Issadore; Katherine J. Humphry; Keith A. Brown; Lori Sandberg; David Weitz; Robert M. Westervelt

2009-01-09T23:59:59.000Z

432

Reactor accelerator coupling experiments: a feasability study  

E-Print Network [OSTI]

The Reactor Accelerator Coupling Experiments (RACE) are a set of neutron source driven subcritical experiments under temperature feedback conditions. These experiments will involve coupling an accelerator driven neutron source to a TRIGA reactor...

Woddi Venkat Krishna, Taraknath

2006-08-16T23:59:59.000Z

433

Accelerator on a Chip: How It Works  

SciTech Connect (OSTI)

In an advance that could dramatically shrink particle accelerators for science and medicine, researchers used a laser to accelerate electrons at a rate 10 times higher than conventional technology in a nanostructured glass chip smaller than a grain of rice.

None

2014-06-30T23:59:59.000Z

434

MANUFACTURING ACCELERATING THE INCORPORATION OF MATERIALS  

E-Print Network [OSTI]

MANUFACTURING ACCELERATING THE INCORPORATION OF MATERIALS ADVANCES INTO MANUFACTURING PROCESSES NATIONAL NEED The proposed topic "Accelerating the Incorporation of Materials Advances into Manufacturing organizations, leading researchers from academic institutions, and others. Materials performance is often

Magee, Joseph W.

435

CRAD, Engineering - Idaho Accelerated Retrieval Project Phase...  

Broader source: Energy.gov (indexed) [DOE]

Engineering - Idaho Accelerated Retrieval Project Phase II CRAD, Engineering - Idaho Accelerated Retrieval Project Phase II February 2006 A section of Appendix C to DOE G 226.1-2...

436

CRAD, Management - Idaho Accelerated Retrieval Project Phase...  

Broader source: Energy.gov (indexed) [DOE]

Management - Idaho Accelerated Retrieval Project Phase II CRAD, Management - Idaho Accelerated Retrieval Project Phase II February 2006 A section of Appendix C to DOE G 226.1-2...

437

CRAD, Radiological Controls - Idaho Accelerated Retrieval Project...  

Broader source: Energy.gov (indexed) [DOE]

Accelerated Retrieval Project Phase II CRAD, Radiological Controls - Idaho Accelerated Retrieval Project Phase II February 2006 A section of Appendix C to DOE G 226.1-2 "Federal...

438

CRAD, Emergency Management - Idaho Accelerated Retrieval Project...  

Broader source: Energy.gov (indexed) [DOE]

Idaho Accelerated Retrieval Project Phase II CRAD, Emergency Management - Idaho Accelerated Retrieval Project Phase II February 2006 A section of Appendix C to DOE G 226.1-2...

439

HIGH-FIELD SUPERCONDUCTING ACCELERATOR MAGNETS  

E-Print Network [OSTI]

D. C. 'Niobium-Titanium Superconducting Material s ', in S.14, 1982 HIGH-FIELD SUPERCONDUCTING ACCELERATOR MAGNETS C.SUMAG-68 HIGH-FIELD SUPERCONDUCTING ACCELERATOR MAGNETS* C.

Taylor, C.

2011-01-01T23:59:59.000Z

440

ACCELERATORS: ENGINES FOR TRAVERSING A LARGE AND OFTEN DIFFICULT LANDSCAPE  

E-Print Network [OSTI]

of California. ACCELERATORS: ENGINES FOR TRAVERSING A LARGEand Andre Lebedev Abstract TYPES OF ACCELERATORS The manyapplications of accelerators are presented, with pictures

Sessler, Andrew M.

2014-01-01T23:59:59.000Z

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


441

Staging laser plasma accelerators for increased beam energy  

E-Print Network [OSTI]

Staging Laser Plasma Accelerators for Increased Beam EnergyStaging laser plasma accelerators is an efficient way ofcompact laser-plasma accelerators to generate particle

Panasenko, Dmitriy

2010-01-01T23:59:59.000Z

442

Electron Beam Charge Diagnostics for Laser Plasma Accelerators  

E-Print Network [OSTI]

the 1989 Particle Accelerator Conference (IEEE, Piscataway,the 1993 Particle Accelerator Conference (IEEE, Piscataway,Diagnostics for Laser Plasma Accelerators K. Nakamura, 1 A.

Nakamura, Kei

2012-01-01T23:59:59.000Z

443

Laser Plasma Particle Accelerators: Large Fields for Smaller Facility Sources  

E-Print Network [OSTI]

essential understanding of accelerator physics to advanceof high- gradient, laser plasma particle accelerators.to conventional particle accelerators, plasmas can sustain

Geddes, Cameron G.R.

2010-01-01T23:59:59.000Z

444

accelerate positional cloning: Topics by E-print Network  

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

of velocity is acceleration (i DeTurck, Dennis 2 LTB universes as alternatives to dark energy: does positive averaged acceleration imply positive cosmic acceleration?...

445

Accelerated Evolution of Conserved Noncoding Sequences in the Human Genome  

E-Print Network [OSTI]

associated with CNSs accelerated in chimpanzee. (F)associated with CNSs accelerated in mouse. (G) CNScomponent associations of accelerated CNSs (adjustment for

Prambhakar, Shyam; Noonan, James P.; Paabo, Svante; Rubin, Edward M.

2006-01-01T23:59:59.000Z

446

Effects of an Accelerated Diesel Engine Replacement/Retrofit Program  

E-Print Network [OSTI]

No. 894 Effects of an Accelerated Diesel Engine Replacement/2009 Effects of an Accelerated Diesel Engine Replacement/reductions occurring on an accelerated schedule compared to

Millstein, Dev E.; Harley, Robert A

2009-01-01T23:59:59.000Z

447

Accelerated maximum likelihood parameter estimation for stochastic biochemical systems  

E-Print Network [OSTI]

as: Daigle et al. : Accelerated maximum likelihood parame-Gillespie DT: Approximate accelerated stochastic simulationARTICLE Open Access Accelerated maximum likelihood parameter

Daigle, Bernie J; Roh, Min K; Petzold, Linda R; Niemi, Jarad

2012-01-01T23:59:59.000Z

448

Accelerated New Product Development in Credit Card Industry  

E-Print Network [OSTI]

CALIFORNIA Los Angeles Accelerated New Product DevelopmentABSTRACT OF THE THESIS Accelerated New Product Developmentmodels to provide accelerated new product development

Gupta, Ravi Kumar

2012-01-01T23:59:59.000Z

449

Cell Component Accelerated Stress Test Protocols for PEM Fuel...  

Broader source: Energy.gov (indexed) [DOE]

Cell Component Accelerated Stress Test Protocols for PEM Fuel Cells Cell Component Accelerated Stress Test Protocols for PEM Fuel Cells Accelerated Stress Test Protocols for PEM...

450

LASER-PLASMA-ACCELERATOR-BASED GAMMA GAMMA COLLIDERS  

E-Print Network [OSTI]

LASER-PLASMA-ACCELERATOR-BASED ?? COLLIDERS ? C. B.linear col- lider based on laser-plasma-accelerators arediscussed, and a laser-plasma-accelerator-based gamma-

Schroeder, C. B.

2010-01-01T23:59:59.000Z

451

Comments on Backreaction and Cosmic Acceleration  

E-Print Network [OSTI]

In this brief WEB note we comment on recent papers related to our paper "On Acceleration Without Dark Energy".

E. W. Kolb; S. Matarrese; A. Riotto

2005-11-02T23:59:59.000Z

452

Comments on backreaction and cosmic acceleration  

SciTech Connect (OSTI)

In this brief WEB note we comment on recent papers related to our paper ''On Acceleration Without Dark Energy''.

Kolb, Edward W.; /Fermilab /Chicago U., Astron. Astrophys. Ctr. /Chicago U., EFI; Matarrese, Sabinio; /Padua U. /INFN, Padua; Riotto, Antonion; /CERN

2005-11-01T23:59:59.000Z

453

Technical Report No. 2006510 ACCELERATING MACHINES \\Lambda  

E-Print Network [OSTI]

Technical Report No. 2006­510 ACCELERATING MACHINES \\Lambda Robert Fraser and Selim G. Akl School Abstract This paper presents an overview of accelerating machines. We begin by exploring the history of the accelerating machine model and the potential power that it provides. We look at some of the problems that could

Graham, Nick

454

Voltage regulation in linear induction accelerators  

DOE Patents [OSTI]

Improvement in voltage regulation in a Linear Induction Accelerator wherein a varistor, such as a metal oxide varistor, is placed in parallel with the beam accelerating cavity and the magnetic core. The non-linear properties of the varistor result in a more stable voltage across the beam accelerating cavity than with a conventional compensating resistance.

Parsons, William M. (Santa Fe, NM)

1992-01-01T23:59:59.000Z

455

RESOLVING BEAM TRANSPORT PROBLEMS IN ELECTROSTATIC ACCELERATORS  

E-Print Network [OSTI]

RESOLVING BEAM TRANSPORT PROBLEMS IN ELECTROSTATIC ACCELERATORS J. D. LARSON (*) Oak Ridge National are frequently encounte- red during the design, operation and upgrading of electrostatic accelerators. Examples are provided of analytic procedures that clarify accelerator ion optics and lead to more effective beam

Boyer, Edmond

456

Voltage regulation in linear induction accelerators  

DOE Patents [OSTI]

Improvement in voltage regulation in a linear induction accelerator wherein a varistor, such as a metal oxide varistor, is placed in parallel with the beam accelerating cavity and the magnetic core is disclosed. The non-linear properties of the varistor result in a more stable voltage across the beam accelerating cavity than with a conventional compensating resistance. 4 figs.

Parsons, W.M.

1992-12-29T23:59:59.000Z

457

Accelerating the transformation of power systems  

E-Print Network [OSTI]

Accelerating the transformation of power systems Ancillary Services Peer Exchange with India- to-peer consultation. The 21st Century Power Partnership aims to accelerate the global transformation consultative support Accelerating the transformation of power systems NREL/FS-6A20-61811 · May 2014 15013

458

Accelerated immunosenescence in preindustrial twin mothers  

E-Print Network [OSTI]

Accelerated immunosenescence in preindustrial twin mothers Samuli Helle* , Virpi Lummaa , and Jukka that this tradeoff is a result of reproductive costs accelerating senescence of the immune system, leading to earlier accelerated immunosenescence. immune function cost of reproduction longevity reproductive effort tuberculosis

Lummaa, Virpi

459

HASKELL ARRAYS, ACCELERATED Manuel M. T. Chakravarty  

E-Print Network [OSTI]

HASKELL ARRAYS, ACCELERATED USING GPUS Manuel M. T. Chakravarty University of New South Wales JOINT, memory-access patterns, etc. Portability... Monday, 7 September 2009 #12;OTHER COMPUTE ACCELERATOR ACCELERATOR ARCHITECTURES Goal: portable data parallelism Tesla T10 GPU Monday, 7 September 2009 #12;OTHER

Chakravarty, Manuel

460

Accelerated expansion from cosmological holography  

E-Print Network [OSTI]

It is shown that holographic cosmology implies an evolving Hubble radius $c^{-1}\\dot{R}_H = -1 + 3\\Omega_m$ in the presence of a dimensionless matter density $\\Omega_m$ scaled to the closure density $3H^2/8\\pi G$, where $c$ denotes the velocity of light and $H$ and $G$ denote the Hubble parameter and Newton's constant. It reveals a dynamical dark energy and a sixfold increase in gravitational attraction to matter on the scale of the Hubble acceleration. It reproduces the transition redshift $z_t\\simeq 0.4$ to the present epoch of accelerated expansion and is consistent with $(q_0,(dq/dz)_0)$ of the deceleration parameter $q(z)=q_0+(dq/dz)_0z$ observed in Type Ia supernovae.

van Putten, Maurice H P M

2015-01-01T23:59:59.000Z

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


461

Accelerated leach test development program  

SciTech Connect (OSTI)

In FY 1989, a draft accelerated leach test for solidified waste was written. Combined test conditions that accelerate leaching were validated through experimental and modeling efforts. A computer program was developed that calculates test results and models leaching mechanisms. This program allows the user to determine if diffusion controls leaching and, if this is the case, to make projections of releases. Leaching mechanisms other than diffusion (diffusion plus source term partitioning and solubility limited leaching) are included in the program is indicators of other processes that may control leaching. Leach test data are presented and modeling results are discussed for laboratory scale waste forms composed of portland cement containing sodium sulfate salt, portland cement containing incinerator ash, and vinyl ester-styrene containing sodium sulfate. 16 refs., 38 figs., 5 tabs.

Fuhrmann, M.; Pietrzak, R.F.; Heiser, J.; Franz, E.M.; Colombo, P.

1990-11-01T23:59:59.000Z

462

Transplanckian collisions at future accelerators  

E-Print Network [OSTI]

Scattering at transplanckian energies offers model independent tests of TeV scale gravity. Black-hole production is one spectacular signal, though a full calculation of the cross section is not yet available. Another signal is given by gravitational elastic scattering, which is maybe less spectacular but which can be nicely computed in the forward region using the eikonal approximation. In this talk I discuss the distinctive signatures of eikonalized scattering at future accelerators.

Riccardo Rattazzi

2002-05-23T23:59:59.000Z

463

The US muon accelerator program  

E-Print Network [OSTI]

A directed R&D program is presently underway in the U.S. to evaluate the designs and technologies required to provide muon-based high energy physics (HEP) accelerator capabilities. Such capabilities have the potential to provide unique physics reach for the HEP community. An overview of the status of the designs for the neutrino factory and muon collider applications is provided. Recent progress in the technology R&D program is summarized.

Palmer, M A

2015-01-01T23:59:59.000Z

464

Accelerating Solutions | ornl.gov  

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

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

465

The development of microstrip to dielectric waveguide transitions and beam steering techniques  

E-Print Network [OSTI]

Dielectric waveguide tapered in y dimension. . 8 Dielectric waveguide tapered in x and y dimensions. 20 9 Transition loss for 521 mm of dielectric waveguide and two standard horn transitions. 22 10 Two new transitions connected simultaneously. 11 Time.... 56 GHz for one transition, one horn, and 521 mm of dielectric waveguide 25 14 Diamond shaped 1'oil. 26 15 Foil shapes derived from narrowing width D. 27 16 Transition loss for two transitions and 521 mm of waveguide with foil widths: a) 15. 88 mm...

Miller, Jeffrey Allen

1989-01-01T23:59:59.000Z

466

E-Print Network 3.0 - acid gate dielectric Sample Search Results  

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

circuitryand the growthof n... distinct halves of the chip, one large dielectric growth window was wet etched after circuit fabrication... and fabrication of LED's grown in...

467

E-Print Network 3.0 - anode dielectric coating Sample Search...  

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

10-5 Table 1. Dielectric parameters for anodic oxide, shunt capacitance... Josephson junction geometry with minimal volume of lossy isolation ... Source: Martinis, John M. -...

468

Relationship between orientation factor of lead zirconate titanate nanowires and dielectric permittivity of nanocomposites  

SciTech Connect (OSTI)

The relationship between the orientation of lead zirconate titanate (PZT) nanowires dispersed in nanocomposites and the resulting dielectric constants are quantified. The orientation of the PZT nanowires embedded in a polymer matrix is controlled by varying the draw ratio and subsequently quantified using Herman's Orientation Factor. Consequently, it is demonstrated that the dielectric constants of nanocomposites are improved by increasing the orientation factor of the PZT nanowires. This technique is proposed to improve the dielectric constant of the nanocomposites without the need for additional filler volume fraction since the nanocomposites are utilized in a wide range of high dielectric permittivity electronic components.

Tang, Haixiong, E-mail: htang15@ufl.edu, E-mail: hsodano@ufl.edu [Department of Materials Science and Engineering, University of Florida, Gainesville, Florida 32611 (United States)] [Department of Materials Science and Engineering, University of Florida, Gainesville, Florida 32611 (United States); Malakooti, Mohammad H. [Department of Mechanical and Aerospace Engineering, University of Florida, Gainesville, Florida 32611 (United States)] [Department of Mechanical and Aerospace Engineering, University of Florida, Gainesville, Florida 32611 (United States); Sodano, Henry A., E-mail: htang15@ufl.edu, E-mail: hsodano@ufl.edu [Department of Materials Science and Engineering, University of Florida, Gainesville, Florida 32611 (United States); Department of Mechanical and Aerospace Engineering, University of Florida, Gainesville, Florida 32611 (United States)

2013-11-25T23:59:59.000Z

469

Chemical vapor deposition of organosilicon composite thin films for porous low-k dielectrics  

E-Print Network [OSTI]

Pulsed plasma enhanced chemical vapor deposition has produced organosilicon thin films with the potential use as low dielectric constant interconnect materials in microelectronic circuits. Both diethylsilane and ...

Ross, April Denise, 1977-

2005-01-01T23:59:59.000Z

470

Time-dependent dielectric breakdown measurements of porous organosilicate glass using mercury and solid metal probes  

SciTech Connect (OSTI)

Time-dependent dielectric breakdown (TDDB) is one of the major concerns for low-k dielectric materials. During plasma processing, low-k dielectrics are subjected to vacuum ultraviolet photon radiation and charged-particle bombardment. To examine the change of TDDB properties, time-to-breakdown measurements are made to porous SiCOH before and after plasma exposure. Significant discrepancies between mercury and solid-metal probes are observed and have been shown to be attributed to mercury diffusion into the dielectric porosities.

Pei, Dongfei; Nichols, Michael T.; Shohet, J. Leon, E-mail: shohet@engr.wisc.edu [Plasma Processing and Technology Laboratory, Department of Electrical and Computer Engineering, University of Wisconsin-Madison, Madison, Wisconsin 53706 (United States); King, Sean W.; Clarke, James S. [Intel Corporation, Hillsboro, Oregon 97124 (United States); Nishi, Yoshio [Department of Electrical Engineering, Stanford University, Stanford, California 94305 (United States)

2014-09-01T23:59:59.000Z

471

E-Print Network 3.0 - anomalous dielectric response Sample Search...  

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

spherical cavities... When a polar liquid becomes a dielectric? Center for Biological ... Source: Matyushov, Dmitry - Department of Chemistry and Biochemistry, Arizona State...

472

Automated analysis for detecting beams in laser wakefield simulations Daniela M. Ushizima, Oliver Rubel, Prabhat, Gunther H. Weber, E. Wes Bethel, Cecilia R. Aragon  

E-Print Network [OSTI]

to generate electric fields thousands of times higher than those of conventional accelerators. The resulting as nodes in a minimum spanning tree. Second, we partition the multivariate data using fuzzy clustering are then con- centrated near a single energy [8], when a high quality beam can form. PIC codes model

Geddes, Cameron Guy Robinson

473

Accelerator Research Department BAccelerator Research Department B E163: Laser Acceleration  

E-Print Network [OSTI]

1 Accelerator Research Department BAccelerator Research Department B E163: Laser Acceleration, D. R. Walz Stanford Linear Accelerator Center R. L. Byer, T. Plettner Stanford University * Spokesman. #12;2 Accelerator Research Department B Outline · Introduction ­­ Future requirements for high

Wechsler, Risa H.

474

Acceleration-field calculation for a structure-based laser-driven linear accelerator  

E-Print Network [OSTI]

Acceleration-field calculation for a structure-based laser-driven linear accelerator Y. C. Huanga for publication 16 April 1998 A laser-driven particle accelerator, scaled to optical wavelengths, has a feature size many orders of magnitude smaller than a radio-frequency accelerator. However, similar to a radio

Byer, Robert L.

475

Accelerator and new accelerating schemes B. Heusch (1) and G. Matthieussent (2)  

E-Print Network [OSTI]

1420 Accelerator and new accelerating schemes B. Heusch (1) and G. Matthieussent (2) (1) Centre de and high energy physics, astrophysics and plasma physics had the opportunity to discuss accelerators under con- struction as well as the novel acceleration techniques which have appeared during the past few

Paris-Sud XI, Université de

476

Accelerated_Program_Application_10_31.doc | Revised: 11/4/13 Accelerated Program Application  

E-Print Network [OSTI]

Accelerated_Program_Application_10_31.doc | Revised: 11/4/13 Accelerated Program Application OFFICE://www.grad.usf.edu/ STUDENT AGREEMENT Please initial, indicating agreement: I have reviewed the Accelerated Program Requirements and information (http://www.grad.usf.edu/accelerated.php) I have met with my undergraduate

Meyers, Steven D.

477

Compensation Techniques in Accelerator Physics  

SciTech Connect (OSTI)

Accelerator physics is one of the most diverse multidisciplinary fields of physics, wherein the dynamics of particle beams is studied. It takes more than the understanding of basic electromagnetic interactions to be able to predict the beam dynamics, and to be able to develop new techniques to produce, maintain, and deliver high quality beams for different applications. In this work, some basic theory regarding particle beam dynamics in accelerators will be presented. This basic theory, along with applying state of the art techniques in beam dynamics will be used in this dissertation to study and solve accelerator physics problems. Two problems involving compensation are studied in the context of the MEIC (Medium Energy Electron Ion Collider) project at Jefferson Laboratory. Several chromaticity (the energy dependence of the particle tune) compensation methods are evaluated numerically and deployed in a figure eight ring designed for the electrons in the collider. Furthermore, transverse coupling optics have been developed to compensate the coupling introduced by the spin rotators in the MEIC electron ring design.

Hisham Kamal Sayed

2011-05-31T23:59:59.000Z

478

Acceleration  

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

on the Cray XE6 platform Kirsten M. Fagnan, Michael Lijewski, George Pau, Nicholas J. Wright Lawrence Berkeley National Laboratory 1 Cyclotron Road Berkeley, CA 94720 May 18, 2011...

479

Accelerator Technology Division progress report, FY 1992  

SciTech Connect (OSTI)

This report briefly discusses the following topics: The Ground Test Accelerator Program; Defense Free-Electron Lasers; AXY Programs; A Next Generation High-Power Neutron-Scattering Facility; JAERI OMEGA Project and Intense Neutron Sources for Materials Testing; Advanced Free-Electron Laser Initiative; Superconducting Supercollider; The High-Power Microwave (HPM) Program; Neutral Particle Beam (NPB) Power Systems Highlights; Industrial Partnering; Accelerator Physics and Special Projects; Magnetic Optics and Beam Diagnostics; Accelerator Design and Engineering; Radio-Frequency Technology; Accelerator Theory and Free-Electron Laser Technology; Accelerator Controls and Automation; Very High-Power Microwave Sources and Effects; and GTA Installation, Commissioning, and Operations.

Schriber, S.O.; Hardekopf, R.A.; Heighway, E.A.

1993-07-01T23:59:59.000Z

480

On Dark Energy and Accelerated Reference Frames  

E-Print Network [OSTI]

The paper is devoted to an explanation of the accelerated rate of expansion of the Universe. Usually the acceleration of the Universe, which is described by FRW metric, is due to dark energy. It is shown that this effect may be considered as a manifestation of torsion tensor for a flat Universe in the realm of Teleparallel gravity. An observer with radial field velocity obey Hubble's Law. As a consequence it is established that this is radial acceleration in a flat Universe. In Eq. (\\ref{24}) the acceleration is written in terms of the deceleration parameter, the Hubble's constant and the proper distance. This may be interpreted as an acceleration of the Universe.

S. C. Ulhoa

2011-12-10T23:59:59.000Z

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481

ACCELERATOR DIVISION ANNUAL REPORT, JAN-DEC. 1975  

E-Print Network [OSTI]

F. Voelker H. W. Vogel ACCELERATOR THEORY A. A. Garren L. J.marked a turning point for the Accelerator Division. A majorbright indeed. VII ACCELERATOR DIVISION Contents ACCELERATOR

Lofgren, E.J.

2008-01-01T23:59:59.000Z

482

Laser Guiding for GeV Laser-Plasma Accelerators  

E-Print Network [OSTI]

Overview of plasma-based accelerator concepts. IEEE Trans.using laser wake?eld accelerators. Meas. Sci. Technol. 12,for GeV laser-plasma accelerators. In Advanced Accelerator

Leemans, Wim; Esarey, Eric; Geddes, Cameron; Schroeder, C.B.; Toth, Csaba

2005-01-01T23:59:59.000Z

483

Fermilab | Science | Particle Accelerators | LHC and Future Accelerators  

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

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484

Community Petascale Project for Accelerator Science and Simulation: Advancing Computational Science for Future Accelerators and Accelerator Technologies  

SciTech Connect (OSTI)

The design and performance optimization of particle accelerators are essential for the success of the DOE scientific program in the next decade. Particle accelerators are very complex systems whose accurate description involves a large number of degrees of freedom and requires the inclusion of many physics processes. Building on the success of the SciDAC-1 Accelerator Science and Technology project, the SciDAC-2 Community Petascale Project for Accelerator Science and Simulation (ComPASS) is developing a comprehensive set of interoperable components for beam dynamics, electromagnetics, electron cooling, and laser/plasma acceleration modelling. ComPASS is providing accelerator scientists the tools required to enable the necessary accelerator simulation paradigm shift from high-fidelity single physics process modeling (covered under SciDAC1) to high-fidelity multiphysics modeling. Our computational frameworks have been used to model the behavior of a large number of accelerators and accelerator R&D experiments, assisting both their design and performance optimization. As parallel computational applications, the ComPASS codes have been shown to make effective use of thousands of processors. ComPASS is in the first year of executing its plan to develop the next-generation HPC accelerator modeling tools. ComPASS aims to develop an integrated simulation environment that will utilize existing and new accelerator physics modules with petascale capabilities, by employing modern computing and solver technologies. The ComPASS vision is to deliver to accelerator scientists a virtual accelerator and virtual prototyping modeling environment, with the necessary multiphysics, multiscale capabilities. The plan for this development includes delivering accelerator modeling applications appropriate for each stage of the ComPASS software evolution. Such applications are already being used to address challenging problems in accelerator design and optimization. The ComPASS organization for software development and applications accounts for the natural domain areas (beam dynamics, electromagnetics, and advanced acceleration), and all areas depend on the enabling technologies activities, such as solvers and component technology, to deliver the desired performance and integrated simulation environment. The ComPASS applications focus on computationally challenging problems important for design or performance optimization to all major HEP, NP, and BES accelerator facilities. With the cost and complexity of particle accelerators rising, the use of computation to optimize their designs and find improved operating regimes becomes essential, potentially leading to significant cost savings with modest investment.

Spentzouris, P.; /Fermilab; Cary, J.; /Tech-X, Boulder; McInnes, L.C.; /Argonne; Mori, W.; /UCLA; Ng, C.; /SLAC; Ng, E.; Ryne, R.; /LBL, Berkeley

2011-11-14T23:59:59.000Z

485

High Performance Computing in Accelerator Science: Past Successes. Future Challenges  

E-Print Network [OSTI]

High Performance Computing in Accelerator Science: PastAC02- 05CH11231. High Performance Computing in Accelerator

Ryne, R.

2013-01-01T23:59:59.000Z

486

Accelerated stem cell labeling with ferucarbotran and protamine  

E-Print Network [OSTI]

Heike E. Daldrup-Link Accelerated stem cell labeling withferu- carbotran can be accelerated in MSCs with protamine,

2010-01-01T23:59:59.000Z

487

Dielectric relaxation of thin films of polyamide random copolymers  

E-Print Network [OSTI]

We investigate the relaxation behavior of thin films of a polyamide random copolymer, PA66/6I, with various film thicknesses using dielectric relaxation spectroscopy. Two dielectric signals are observed at high temperatures, the $\\alpha$-process and the relaxation process due to electrode polarization (the EP-process), in addition to the conductivity component. The relaxation time of the EP-process has a Vogel-Fulcher-Tammann type of temperature dependence, and the glass transition temperature, $T_{\\rm g}$, evaluated from the EP-process agrees very well with the $T_{\\rm g}$ determined from the thermal measurements. The fragility index derived from the EP-process increases with decreasing film thickness. The relaxation time and the dielectric relaxation strength of the EP-process are described by a linear function of the film thickness $d$ for large values of $d$, which can be regarded as experimental evidence for the validity of attributing the observed signal to the EP-process. Furthermore, there is distinct deviation from this linear law for thicknesses smaller than a critical value. This deviation observed in thinner films is associated with an increase in the mobility and/or diffusion constant of the charge carriers responsible for the EP-process. The $\\alpha$-process is located in a high frequency region than the EP-process at high temperatures, but merges with the EP-process at lower temperatures near the glass transition region. The thickness dependence of the relaxation time of the $\\alpha$-process is different from that of the EP-process. This suggests that there is decoupling between the segmental motion of the polymers and the translational motion of the charge carriers in confinement.

Natsumi Taniguchi; Koji Fukao; Paul Sotta; Didier R. Long

2015-02-13T23:59:59.000Z

488

Deuterium accelerator experiments for APT.  

SciTech Connect (OSTI)

Sandia National Laboratories in California initiated an experimental program to determine whether tritium retention in the tube walls and permeation through the tubes into the surrounding coolant water would be a problem for the Accelerator Production of Tritium (APT), and to find ways to mitigate the problem, if it existed. Significant holdup in the tube walls would limit the ability of APT to meet its production goals, and high levels of permeation would require a costly cleanup system for the cooling water. To simulate tritium implantation, a 200 keV accelerator was used to implant deuterium into Al 6061-T and SS3 16L samples at temperatures and particle fluxes appropriate for APT, for times varying between one week and five months. The implanted samples were characterized to determine the deuterium retention and Permeation. During the implantation, the D(d,p)T nuclear reaction was used to monitor the build-up of deuterium in the implant region of the samples. These experiments increased in sophistication, from mono-energetic deuteron implants to multi-energetic deuteron and proton implants, to more accurately reproduce the conditions expected in APT. Micron-thick copper, nickel, and anodized aluminum coatings were applied to the front surface of the samples (inside of the APT walls) in an attempt to lower retention and permeation. The reduction in both retention and permeation produced by the nickel coatings, and the ability to apply them to the inside of the APT tubes, indicate that both nickel-coated Al 6061-T6 and nickel-coated SS3 16L tubes would be effective for use in APT. The results of this work were submitted to the Accelerator Production of Tritium project in document number TPO-E29-Z-TNS-X-00050, APT-MP-01-17.

Causey, Rion A. (Sandia National Laboratories, Livermore, CA); Hertz, Kristin L. (Sandia National Laboratories, Livermore, CA); Cowgill, Donald F. (Sandia National Laboratories, Livermore, CA)

2005-08-01T23:59:59.000Z

489

Soft coincidence in late acceleration  

SciTech Connect (OSTI)

We study the coincidence problem of late cosmic acceleration by assuming that the present ratio between dark matter and dark energy is a slowly varying function of the scale factor. As the dark energy component we consider two different candidates, first a quintessence scalar field, and then a tachyon field. In either case analytical solutions for the scale factor, the field, and the potential are derived. Both models show a good fit to the recent magnitude-redshift supernovae data. However, the likelihood contours disfavor the tachyon field model as it seems to prefer a excessively high value for the matter component.

Campo, Sergio del [Instituto de Fisica, Pontificia Universidad Catolica de Valparaiso, Avenida Brasil 2950, Casilla 4059, Valparaiso (Chile); Herrera, Ramon [Departamento de Ciencias Fisicas, Universidad Andres Bello, Avenida Republica 273, Santiago (Chile); Pavon, Diego [Departamento de Fisica, Facultad de Ciencias, Universidad Autonoma de Barcelona, 08193 Bellaterra, Barcelona (Spain)

2005-06-15T23:59:59.000Z

490

Domain Walls, Triples and Acceleration  

E-Print Network [OSTI]

We present a construction of domain walls in string theory. The domain walls can bridge both Minkowski and AdS string vacua. A key ingredient in the construction are novel classical Yang-Mills configurations, including instantons, which interpolate between toroidal Yang-Mills vacua. Our construction provides a concrete framework for the study of inflating metrics in string theory. In some cases, the accelerating space-time comes with a holographic description. The general form of the holographic dual is a field theory with parameters that vary over space-time.

Travis Maxfield; Savdeep Sethi

2014-04-09T23:59:59.000Z

491

Accelerator experiments contradicting general relativity  

E-Print Network [OSTI]

The deflection of gamma-rays in Earth's gravitational field is tested in laser Compton scattering at high energy accelerators. Within a formalism connecting the bending angle to the photon's momentum it follows that detected gamma-ray spectra are inconsistent with a deflection magnitude of 2.78 nrad, predicted by Einstein's gravity theory. Moreover, preliminary results for 13-28 GeV photons from two different laboratories show opposite - away from the Earth - deflection, amounting to 33.8-0.8 prad. I conclude that general relativity, which describes gravity at low energies precisely, break down at high energies.

Vahagn Gharibyan

2014-07-12T23:59:59.000Z

492

Muon Accelerator Program (MAP) | Homepage  

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

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493

Accelerated Aging of Roofing Surfaces  

Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

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494

Thickness-modulated optical dielectric constants and band alignments of HfO{sub x}N{sub y} gate dielectrics  

SciTech Connect (OSTI)

Thickness-modulated optical dielectric constants and band alignments of HfO{sub x}N{sub y} films grown by sputtering have been investigated by spectroscopic ellipsometry (SE) and x-ray photoelectron spectroscopy. Based on SE measurements, it has been noted that an increase in optical dielectric constant and band gap has been observed as a function of the film thickness. Analyses of thickness-dependent band alignment of the HfO{sub x}N{sub y}/Si system indicate that the valence band offset increases, but only slight change in the conduction band offset, resulting from the thickness-induced change in the structure. The suitable optical dielectric constants and band offsets relative to Si make sputtering-derived HfO{sub x}N{sub y} film a promising candidate for high-k gate dielectrics.

He, G.; Zhang, L. D.; Liu, M.; Zhang, J. P.; Wang, X. J. [Key Laboratory of Materials Physics, Anhui Key Laboratory of Nanomaterials and Nanostructure, Institute of Solid State Physics, Chinese Academy of Sciences, Hefei 230031 (China); Zhen, C. M. [Department of Physics, Hebei Advanced Thin Films Laboratory, Hebei Normal University, Shijiazhuang 050016 (China)

2009-01-01T23:59:59.000Z

495

Towards a deployable satellite gripper based on multisegment dielectric elastomer minimum energy  

E-Print Network [OSTI]

Towards a deployable satellite gripper based on multisegment dielectric elastomer minimum energy dielectric elastomer minimum energy structures O. A. Araromi*a , I. Gavrilovichb , J. Shintakea , S. Rosseta , H. R. Sheaa a Microsystems For Space Technologies Laboratory, �cole Polytechnique Fédérale de

Floreano, Dario

496

Zirconium-doped tantalum oxide high-k gate dielectric films  

E-Print Network [OSTI]

A new high-k dielectric material, i.e., zirconium-doped tantalum oxide (Zr-doped TaOx), in the form of a sputter-deposited thin film with a thickness range of 5-100 nm, has been studied. Important applications of this new dielectric material include...

Tewg, Jun-Yen

2005-02-17T23:59:59.000Z

497

Leakage current and dielectric breakdown behavior in annealed SiO2 aerogel films  

E-Print Network [OSTI]

Leakage current and dielectric breakdown behavior in annealed SiO2 aerogel films Moon-Ho Jo behavior in annealed SiO2 aerogel films for intermetal dielectric applications was investigated in a metal­insulator­semiconductor structure. SiO2 aerogel films with porosities of 70% exhibited Poole­Frenkel conduction both before

Jo, Moon-Ho

498

Dielectric properties of liquid ethanol. A computer simulation study Leonor Saiz  

E-Print Network [OSTI]

Dielectric properties of liquid ethanol. A computer simulation study Leonor Saiz Departament de Fi Static and dynamic dielectric properties of liquid ethanol have been studied as a function of the wave, but in the case of ethanol, the latter are restricted to the microwave region of the spectra6 and to the infrared

Saiz, Leonor

499

Graphene field-effect transistors based on boron nitride gate dielectrics Inanc Meric1  

E-Print Network [OSTI]

Graphene field-effect transistors based on boron nitride gate dielectrics Inanc Meric1 , Cory Dean1, 10027 Tel: (212) 854-2529, Fax: (212) 932-9421, Email: shepard@ee.columbia.edu Abstract Graphene field of graphene, as the gate dielectric. The devices ex- hibit mobility values exceeding 10,000 cm2 /V

Shepard, Kenneth

500

Environmental Effects on Subcritical Delamination of Dielectric and Metal Films from Organosilicate Glass (OSG) Thin Films  

E-Print Network [OSTI]

Environmental Effects on Subcritical Delamination of Dielectric and Metal Films from Organosilicate., Dallas, TX 75243, USA ABSTRACT Subcritical delamination of dielectric and metal films from organosilicate/SiNx. For both sets of experiments, subcritical crack growth in OSG is found to be described by a model