Sample records for intensity laser science

  1. 1738 IEEE TRANSACTIONS ON PLASMA SCIENCE, VOL. 36, NO. 4, AUGUST 2008 Propagation of a Short Intense Laser Pulse

    E-Print Network [OSTI]

    Strathclyde, University of

    , the propagation of a short intense laser pulse in a curved plasma channel is considered. The effects of the shape1738 IEEE TRANSACTIONS ON PLASMA SCIENCE, VOL. 36, NO. 4, AUGUST 2008 Propagation of a Short Intense Laser Pulse in a Curved Plasma Channel Albert Reitsma and Dino Jaroszynski Abstract--In this paper

  2. New photon science and extreme field physics: volumetric interaction of ultra-intense laser pulses with over-dense targets

    SciTech Connect (OSTI)

    Hegelich, Bjorn M [Los Alamos National Laboratory

    2010-11-24T23:59:59.000Z

    The constantly improving capabilities of ultra-high power lasers are enabling interactions of matter with ever extremer fields. As both the on target intensity and the laser contrast are increasing, new physics regimes are becoming accessible and new effects materialize, which in turn enable a host of applications. A first example is the realization of interactions in the transparent-overdense regime (TOR), which is reached by interacting a highly relativistic (a{sub 0} > 10), ultra high contrast laser pulse with a solid density, nanometer target. Here, a still overdense target is turned transparent to the laser by the relativistic mass increase of the electrons, increasing the skin depth beyond the target thickness and thus enabling volumetric interaction of the laser with the entire target instead of only a small interaction region at the critical density surface. This increases the energy coupling, enabling a range of effects, including relativistic optics and pulse shaping, mono-energetic electron acceleration, highly efficient ion acceleration in the break-out afterburner regime, the generation of relativistic and forward directed surface harmonics. In this talk we will show the theoretical framework for this regime, explored by multi-D, high resolution and high density PIC simulations as well as analytic theory and present measurements and experimental demonstrations of direct relativistic optics, relativistic HHG, electron acceleration, and BOA ion acceleration in the transparent overdense regime. These effects can in turn be used in a host of applications including laser pulse shaping, ICF diagnostics, coherent x-ray sources, and ion sources for fast ignition (IFI), homeland security applications and medical therapy. This host of applications already makes transparent-overdense regime one of general interest, a situation reinforced by the fact that the TOR target undergoes an extremely wide HEDP parameter space during interaction ranging from WDM conditions (e.g . brown dwarfs) early in the interaction to extremely high energy densities of {approx}10{sup 11} J/cm{sup 3} at peak, dropping back to the underdense but extremely hot parameter range of gamma-ray bursts. Furthermore, whereas today this regime can only be accessed on very few dedicated facilities, employing special targets and pulse cleaning technology, the next generation of laser facilities like RAL-10PW, ELI, or Gekko-Exa will operate in this regime by default, turning its understanding in a necessity rather than a curiosity.

  3. Intense Femtosecond Laser Interactions with Ions in

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    ), ultra-short laser light with atoms and molecules has led to the discovery of new phenomena such as bondIntense Femtosecond Laser Interactions with Ions in Beams and Traps A thesis presented through a re-scattering process where an electron is ionized, propagated in the laser field and is driven

  4. Semiconductor lasers with uniform longitudinal intensity distribution

    SciTech Connect (OSTI)

    Schrans, T.; Yariv, A. (Department of Applied Physics 128-95, California Institute of Technology, Pasadena, California 91125 (USA))

    1990-04-16T23:59:59.000Z

    Power-dependent nonuniform longitudinal intensity distribution leading to spectral and spatial instabilities is a major problem in semiconductor lasers. It is shown theoretically that a proper choice of the longitudinal distribution of the gain as well as that of the magnitude of the grating coupling coefficient will lead to a uniform intensity distribution in distributed feedback lasers. We also show that the widely used phase, rather than magnitude, control of the coupling coefficient cannot lead to a uniform intensity distribution when the facet reflectivities are zero.

  5. Compton Process in Intense Short Laser Pulses

    E-Print Network [OSTI]

    K. Krajewska; J. Z. Kaminski

    2012-06-05T23:59:59.000Z

    The spectra of Compton radiation emitted during electron scattering off an intense laser beam are calculated using the framework of strong-field quantum electrodynamics. We model these intense laser beams as finite length plane-wave-fronted pulses, similar to Neville and Rohrlich [Phys. Rev. D {\\bf 3}, 1692 (1971)], or as trains of such pulses. Expressions for energy and angular distributions of Compton photons are derived such that a comparison of both situations becomes meaningful. Comparing frequency distributions for both an isolated laser pulse and a laser pulse train, we find a very good agreement between the results for long pulse durations which breaks down however for ultrashort laser pulses. The dependence of angular distributions of emitted radiation on a pulse duration is also investigated. Pronounced asymmetries of angular distributions are found for very short laser pulses, which gradually disappear with increasing the number of laser field oscillations. Those asymmetries are attributed to asymmetries of the vector potential describing an incident laser beam.

  6. Laser intensity effects in noncommutative QED

    E-Print Network [OSTI]

    Thomas Heinzl; Anton Ilderton; Mattias Marklund

    2010-02-17T23:59:59.000Z

    We discuss a two-fold extension of QED assuming the presence of strong external fields provided by an ultra-intense laser and noncommutativity of spacetime. While noncommutative effects leave the electron's intensity induced mass shift unchanged, the photons change significantly in character: they acquire a quasi-momentum that is no longer light-like. We study the consequences of this combined noncommutative strong-field effect for basic lepton-photon interactions.

  7. Investigation of laser-driven proton acceleration using ultra-short, ultra-intense laser pulses

    E-Print Network [OSTI]

    Marjoribanks, Robin S.

    Investigation of laser-driven proton acceleration using ultra-short, ultra- intense laser pulses S;Investigation of laser-driven proton acceleration using ultra-short, ultra-intense laser pulses S. Fourmaux,1,a metallic foils irradiated by ultra-intense ultra-short laser pulses.8­10 Laser-driven ion beams take

  8. Fundamental Physics Explored with High Intensity Laser

    E-Print Network [OSTI]

    T. Tajima; K. Homma

    2012-09-13T23:59:59.000Z

    Over the last Century the method of particle acceleration to high energies has become the prime approach to explore the fundamental nature of matter in laboratory. It appears that the latest search of the contemporary accelerator based on the colliders shows a sign of saturation (or at least a slow-down) in increasing its energy and other necessary parameters to extend this frontier. We suggest two pronged approach enabled by the recent progress in high intensity lasers.

  9. Laser intensity effects in noncommutative QED

    SciTech Connect (OSTI)

    Heinzl, Thomas [School of Computing and Mathematics, University of Plymouth, Plymouth PL4 8AA (United Kingdom); Ilderton, Anton; Marklund, Mattias [Department of Physics, Umeaa University, SE-901 87 Umeaa (Sweden)

    2010-03-01T23:59:59.000Z

    We discuss a twofold extension of QED assuming the presence of strong external fields provided by an ultraintense laser and noncommutativity of spacetime. While noncommutative effects leave the electron's intensity induced mass shift unchanged, photons change significantly in character: they acquire a quasimomentum that is no longer lightlike. We study the consequences of this combined noncommutative strong-field effect for the basic lepton-photon interactions.

  10. Laser Guiding at Relativistic Intensities and Wakefield Particle Acceleration

    E-Print Network [OSTI]

    Geddes, Cameron Guy Robinson

    Laser Guiding at Relativistic Intensities and Wakefield Particle Acceleration in Plasma Channels C for the first time in a high gradient laser wakefield accelerator by guiding the drive laser pulse. Channels formed by hydrodynamic shock were used to guide acceleration relevant laser intensities of at least 1E18

  11. ?-Decay in Ultra-Intense Laser Fields

    E-Print Network [OSTI]

    Serban Misicu; Margarit Rizea

    2013-07-05T23:59:59.000Z

    We investigate the \\alpha-decay of a spherical nucleus under the influence of an ultra-intense laser field for the case when the radius vector joining the center-of-masses of the \\alpha-particle and the daughter is aligned with the direction of the external field. The time-independent part of the \\alpha-daughter interaction is taken from elastic scattering compilations whereas the time-varying part describes the interaction between the decaying system with the laser field. The time-dependent Schr\\"odinger equation is solved numerically by appealing to a modified scheme of the Crank-Nicolson type where an additional first-order time derivative appears compared to the field-free case. The tunneling probability of the \\alpha-cluster, and derived quantities (decay rate, total flux) is determined for various laser intensities and frequencies for either continous waves or few-cycle pulses of envelope function F(t)=1. We show that in the latter case pulse sequences containing an odd number of half-cycles determine an enhancement of the tunneling probability compared to the field-free case and the continuous wave case. The present study is carried out taking as example the alpha decaying nucleus $^{106}$Te.

  12. Probing the quantum vacuum with ultra intense laser pulses

    E-Print Network [OSTI]

    B. Manuel Hegelich; Gerard Mourou; Johann Rafelski

    2014-12-28T23:59:59.000Z

    This article presents: 1) The theoretical background of strong field physics and vacuum structure and stability; 2) The instrumental developments in the area of pulse lasers and considers the physics case for ultra intense laser facilities; and 3) Discussion of the applied and fundamental uses of ultra-intense lasers.

  13. Probing the quantum vacuum with ultra intense laser pulses

    E-Print Network [OSTI]

    Hegelich, B Manuel; Rafelski, Johann

    2014-01-01T23:59:59.000Z

    This article presents: 1) The theoretical background of strong field physics and vacuum structure and stability; 2) The instrumental developments in the area of pulse lasers and considers the physics case for ultra intense laser facilities; and 3) Discussion of the applied and fundamental uses of ultra-intense lasers.

  14. High-power, high-intensity laser propagation and interactions

    SciTech Connect (OSTI)

    Sprangle, Phillip [Plasma Physics Division, Naval Research Laboratory, Washington, DC 20375 (United States); Electrical and Computer Engineering and Physics, University of Maryland, College Park, Maryland 20740 (United States); Hafizi, Bahman [Plasma Physics Division, Naval Research Laboratory, Washington, DC 20375 (United States)

    2014-05-15T23:59:59.000Z

    This paper presents overviews of a number of processes and applications associated with high-power, high-intensity lasers, and their interactions. These processes and applications include: free electron lasers, backward Raman amplification, atmospheric propagation of laser pulses, laser driven acceleration, atmospheric lasing, and remote detection of radioactivity. The interrelated physical mechanisms in the various processes are discussed.

  15. Electron generation and transport in intense relativistic laser-plasma interactions relevant to fast ignition ICF

    E-Print Network [OSTI]

    Ma, Tammy Yee Wing

    2010-01-01T23:59:59.000Z

    Transport of Energy by Ultra-Intense Laser-Generated tronsof Energy by Ultra-Intense Laser-Generated Electrons inUltra-High In- tensity Lasers . . . . . . . . . . . . . . . . . . . . . . . .

  16. The investigation of high intensity laser driven micro neutron sources

    E-Print Network [OSTI]

    Ghoniem, Nasr M.

    , access to high temperature states of mat- ter capable of thermonuclear fusion and/or the effi- cientThe investigation of high intensity laser driven micro neutron sources for fusion materials. The application of fast pulse, high intensity lasers to drive low cost DT point neutron sources for fusion

  17. What is Data-Intensive Science?

    SciTech Connect (OSTI)

    Critchlow, Terence J.; Kleese van Dam, Kerstin

    2013-06-03T23:59:59.000Z

    What is Data Intensive Science? Today we are living in a digital world, where scientists often no longer interact directly with the physical object of their research, but do so via digitally captured, reduced, calibrated, analyzed, synthesized and, at times, visualized data. Advances in experimental and computational technologies have lead to an exponential growth in the volumes, variety and complexity of this data and while the deluge is not happening everywhere in an absolute sense, it is in a relative one. Science today is data intensive. Data intensive science has the potential to transform not only how we do science, but how quickly we can translate scientific progress into complete solutions, policies, decisions and ultimately economic success. Critically, data intensive science touches some of the most important challenges we are facing. Consider a few of the grand challenges outlined by the U.S. National Academy of Engineering: make solar energy economical, provide energy from fusion, develop carbon sequestration methods, advance health informatics, engineer better medicines, secure cyberspace, and engineer the tools of scientific discovery. Arguably, meeting any of these challenges requires the collaborative effort of trans-disciplinary teams, but also significant contributions from enabling data intensive technologies. Indeed for many of them, advances in data intensive research will be the single most important factor in developing successful and timely solutions. Simple extrapolations of how we currently interact with and utilize data and knowledge are not sufficient to meet this need. Given the importance of these challenges, a new, bold vision for the role of data in science, and indeed how research will be conducted in a data intensive environment is evolving.

  18. The interaction of intense subpicosecond laser pulses with underdense plasmas

    SciTech Connect (OSTI)

    Coverdale, C.A.

    1995-05-11T23:59:59.000Z

    Laser-plasma interactions have been of interest for many years not only from a basic physics standpoint, but also for their relevance to numerous applications. Advances in laser technology in recent years have resulted in compact laser systems capable of generating (psec), 10{sup 16} W/cm{sup 2} laser pulses. These lasers have provided a new regime in which to study laser-plasma interactions, a regime characterized by L{sub plasma} {ge} 2L{sub Rayleigh} > c{tau}. The goal of this dissertation is to experimentally characterize the interaction of a short pulse, high intensity laser with an underdense plasma (n{sub o} {le} 0.05n{sub cr}). Specifically, the parametric instability known as stimulated Raman scatter (SRS) is investigated to determine its behavior when driven by a short, intense laser pulse. Both the forward Raman scatter instability and backscattered Raman instability are studied. The coupled partial differential equations which describe the growth of SRS are reviewed and solved for typical experimental laser and plasma parameters. This solution shows the growth of the waves (electron plasma and scattered light) generated via stimulated Raman scatter. The dispersion relation is also derived and solved for experimentally accessible parameters. The solution of the dispersion relation is used to predict where (in k-space) and at what frequency (in {omega}-space) the instability will grow. Both the nonrelativistic and relativistic regimes of the instability are considered.

  19. Electron generation and transport in intense relativistic laser-plasma interactions relevant to fast ignition ICF

    E-Print Network [OSTI]

    Ma, Tammy Yee Wing

    2010-01-01T23:59:59.000Z

    Ultra-Short Pulse, Ultra-High In- tensity Lasers . . . . . . . . . . . . . . . . . . . . . . . .ignition), an ultra-intense short pulse laser is brought inof the ultra-high intensity, short-pulse laser has opened up

  20. Sideband Mixing in Intense Laser Backgrounds

    E-Print Network [OSTI]

    Martin Lavelle; David McMullan

    2014-07-04T23:59:59.000Z

    The electron propagator in a laser background has been shown to be made up of a series of sideband poles. In this paper we study this decomposition by analysing the impact of the residual gauge freedom in the Volkov solution on the sidebands. We show that the gauge transformations do not alter the location of the poles. The identification of the propagator from the two-point function is maintained but we show that the sideband structures mix under residual gauge transformations.

  1. Signatures of Radiation Reaction in Ultra-Intense Laser Fields

    E-Print Network [OSTI]

    C. Harvey; T. Heinzl; M. Marklund

    2011-10-04T23:59:59.000Z

    We discuss radiation reaction effects on charges propagating in ultra-intense laser fields. Our analysis is based on an analytic solution of the Landau-Lifshitz equation. We suggest to measure radiation reaction in terms of a symmetry breaking parameter associated with the violation of null translation invariance in the direction opposite to the laser beam. As the Landau-Lifshitz equation is nonlinear the energy transfer within the pulse is rather sensitive to initial conditions. This is elucidated by comparing colliding and fixed target modes in electron laser collisions.

  2. Bragg cell laser intensity modulation: effect on laser Doppler velocimetry measurements

    SciTech Connect (OSTI)

    Mychkovsky, Alexander G.; Chang, Natasha A.; Ceccio, Steven L.

    2009-06-20T23:59:59.000Z

    In most laser Doppler velocimetry (LDV) systems, the frequency of one of the two laser beams that intersect to create the probe volume is shifted with an acousto-optic element. It is shown here that Bragg shifting can impose a problematic fluctuation in intensity on the frequency-shifted beam, producing spurious velocity measurements. This fluctuation occurs at twice the Bragg cell frequency, and its relative amplitude to the time average intensity is a function of the ratio of the laser beam diameter to the Bragg cell acoustic wavelength. A physical model and a configuration procedure to minimize adverse effects of the intensity modulations are presented.

  3. Investigation of laser-driven proton acceleration using ultra-short, ultra-intense laser pulses

    SciTech Connect (OSTI)

    Fourmaux, S.; Gnedyuk, S.; Lassonde, P.; Payeur, S.; Pepin, H.; Kieffer, J. C. [INRS-EMT, Universite du Quebec, 1650 Lionel Boulet, Varennes, Quebec J3X 1S2 (Canada); Buffechoux, S.; Albertazzi, B. [INRS-EMT, Universite du Quebec, 1650 Lionel Boulet, Varennes, Quebec J3X 1S2 (Canada); LULI, UMR 7605, CNRS - CEA - Universite Paris 6 - Ecole Polytechnique, 91128 Palaiseau (France); Capelli, D.; Antici, P. [LULI, UMR 7605, CNRS - CEA - Universite Paris 6 - Ecole Polytechnique, 91128 Palaiseau (France); Dipartimento SBAI, Sapienza, Universita di Roma, Via Scarpa 16, 00161 Roma (Italy); Levy, A.; Fuchs, J. [LULI, UMR 7605, CNRS - CEA - Universite Paris 6 - Ecole Polytechnique, 91128 Palaiseau (France); Lecherbourg, L.; Marjoribanks, R. S. [Department of Physics and Institute for Optical Sciences, University of Toronto, Toronto, Ontario M5S 1A7 (Canada)

    2013-01-15T23:59:59.000Z

    We report optimization of laser-driven proton acceleration, for a range of experimental parameters available from a single ultrafast Ti:sapphire laser system. We have characterized laser-generated protons produced at the rear and front target surfaces of thin solid targets (15 nm to 90 {mu}m thicknesses) irradiated with an ultra-intense laser pulse (up to 10{sup 20} W Dot-Operator cm{sup -2}, pulse duration 30 to 500 fs, and pulse energy 0.1 to 1.8 J). We find an almost symmetric behaviour for protons accelerated from rear and front sides, and a linear scaling of proton energy cut-off with increasing pulse energy. At constant laser intensity, we observe that the proton cut-off energy increases with increasing laser pulse duration, then roughly constant for pulses longer than 300 fs. Finally, we demonstrate that there is an optimum target thickness and pulse duration.

  4. Making Relativistic Positrons Using Ultra-Intense Short Pulse Lasers

    SciTech Connect (OSTI)

    Chen, H; Wilks, S; Bonlie, J; Chen, C; Chen, S; Cone, K; Elberson, L; Gregori, G; Liang, E; Price, D; Van Maren, R; Meyerhofer, D D; Mithen, J; Murphy, C V; Myatt, J; Schneider, M; Shepherd, R; Stafford, D; Tommasini, R; Beiersdorfer, P

    2009-08-24T23:59:59.000Z

    This paper describes a new positron source produced using ultra-intense short pulse lasers. Although it has been studied in theory since as early as the 1970s, the use of lasers as a valuable new positron source was not demonstrated experimentally until recent years, when the petawatt-class short pulse lasers were developed. In 2008 and 2009, in a series of experiments performed at Lawrence Livermore National Laboratory, a large number of positrons were observed after shooting a millimeter thick solid gold target. Up to 2 x 10{sup 10} positrons per steradian ejected out the back of {approx}mm thick gold targets were detected. The targets were illuminated with short ({approx}1 ps) ultra-intense ({approx}1 x 10{sup 20} W/cm{sup 2}) laser pulses. These positrons are produced predominantly by the Bethe-Heitler process, and have an effective temperature of 2-4 MeV, with the distribution peaking at 4-7 MeV. The angular distribution of the positrons is anisotropic. For a wide range of applications, this new laser based positron source with its unique characteristics may complements the existing sources using radioactive isotopes and accelerators.

  5. Relativistic Positron Creation Using Ultra-Intense Short Pulse Lasers

    SciTech Connect (OSTI)

    Chen, H; Wilks, S; Bonlie, J; Liang, E; Myatt, J; Price, D; Meyerhofer, D; Beiersdorfer, P

    2008-08-25T23:59:59.000Z

    We measure up to 2 x 10{sup 10} positrons per steradian ejected out the back of {approx}mm thick gold targets when illuminated with short ({approx} 1 ps) ultra-intense ({approx} 1 x 10{sup 20} W/cm{sup 2}) laser pulses. Positrons produced predominately by the Bethe-Heitler process and have an effective temperature of 2-4 MeV, with the distribution peaking at 4-7 MeV. The angular distribution of the positrons is anisotropic. The measurements indicate the laser produced, relativistic positron densities ({approx} 10{sup 16} positrons/cm{sup 3}) are the highest ever created in the laboratory.

  6. Optimum laser intensity for the production of energetic deuterium ions from laser-cluster interaction

    SciTech Connect (OSTI)

    Bang, W.; Dyer, G.; Quevedo, H. J.; Bernstein, A. C.; Gaul, E.; Rougk, J.; Aymond, F.; Donovan, M. E.; Ditmire, T. [Department of Physics, Center for High Energy Density Science, C1510, University of Texas at Austin, Austin, Texas 78712 (United States)] [Department of Physics, Center for High Energy Density Science, C1510, University of Texas at Austin, Austin, Texas 78712 (United States)

    2013-09-15T23:59:59.000Z

    We measured, using Petawatt-level pulses, the average ion energy and neutron yield in high-intensity laser interactions with molecular clusters as a function of laser intensity. The interaction volume over which fusion occurred (1–10 mm{sup 3}) was larger than previous investigations, owing to the high laser power. Possible effects of prepulses were examined by implementing a pair of plasma mirrors. Our results show an optimum laser intensity for the production of energetic deuterium ions both with and without the use of the plasma mirrors. We measured deuterium plasmas with 14 keV average ion energies, which produced 7.2 × 10{sup 6} and 1.6 × 10{sup 7} neutrons in a single shot with and without plasma mirrors, respectively. The measured neutron yields qualitatively matched the expected yields calculated using a cylindrical plasma model.

  7. Response of GaAs to fast intense laser pulses

    E-Print Network [OSTI]

    Graves, JS; Allen, Roland E.

    1998-01-01T23:59:59.000Z

    . The Hamiltonian is H ~ r !5 S ?1 V~r ! V ~ r ! ?2 D , ~1.1! so the bonding and antibonding states have energies ? 6 5 1 2 ~?11?2!6 1 2 @~?12?2! 2 14V ~ r !2#1/2. ~1.2! PRB 580163-1829/98/58~20!/13627~7!/$15.00 t intense laser pulses R. E... to TABLE II. Repulsive potential parameters for GaAs and Si. These values are appropriate when distances are measured in ? and energies in eV. a b g GaAs 263.7 -1227.5 3653.1 Si 263.2 -1027.0 2631.8 PRB 58D R. E. ALLEN an intense laser pulse...

  8. Title of Document: INTERACTION OF INTENSE SHORT LASER PULSES WITH GASES OF NANOSCALE

    E-Print Network [OSTI]

    Anlage, Steven

    ABSTRACT Title of Document: INTERACTION OF INTENSE SHORT LASER PULSES WITH GASES OF NANOSCALE-cluster interaction. #12;INTERACTION OF INTENSE SHORT LASER PULSES WITH GASES OF NANOSCALE ATOMIC AND MOLECULAR., Department of Electrical and Computer Engineering We study the interaction of intense laser pulses with gases

  9. Extracting mode components in laser intensity distribution by independent component analysis

    E-Print Network [OSTI]

    Hefei Institute of Intelligent Machines

    Extracting mode components in laser intensity distribution by independent component analysis Hai, a reliable method to charac- terize the intensity distribution of the laser beam has become a more and more important task. However, traditional optic and electronic methods can offer only a laser beam intensity

  10. Resonant high-order harmonic generation from plasma ablation: Laser intensity dependence of the harmonic intensity and phase

    SciTech Connect (OSTI)

    Milosevic, D. B. [Faculty of Science, University of Sarajevo, Zmaja od Bosne 35, 71000 Sarajevo (Bosnia and Herzegowina); Max-Born-Institut, Max-Born-Str. 2a, D-12489 Berlin (Germany)

    2010-02-15T23:59:59.000Z

    Experimentally observed strong enhancement of a single high-order harmonic in harmonic generation from low-ionized laser plasma ablation is explained as resonant harmonic generation. The resonant harmonic intensity increases regularly with the increase of the laser intensity, while the phase of the resonant harmonic is almost independent of the laser intensity. This is in sharp contrast with the usual plateau and cutoff harmonics, the intensity of which exhibits wild oscillations while its phase changes rapidly with the laser intensity. The temporal profile of a group of harmonics, which includes the resonant harmonic, has the form of a broad peak in each laser-field half cycle. These characteristics of resonant harmonics can have an important application in attoscience. We illustrate our results using examples of Sn and Sb plasmas.

  11. Laser-based proton acceleration on ultra-thin foil with a 100 TW class high intensity laser system

    E-Print Network [OSTI]

    Marjoribanks, Robin S.

    of electromagnetic fields in plasma, isotopes production or hadron therapy. The 100 TW class laser systemLaser-based proton acceleration on ultra-thin foil with a 100 TW class high intensity laser system. To characterize the plasma expansion, we monitor it with an imaging technique using a femtosecond laser probe

  12. Generation of mega-electron-volt electron beams by an ultrafast intense laser pulse

    E-Print Network [OSTI]

    Umstadter, Donald

    Generation of mega-electron-volt electron beams by an ultrafast intense laser pulse Xiaofang Wang emission from the interaction of an ultrafast ( 29 fs), intense ( 1018 W/cm2 ) laser pulse with underdense of such an ultrafast laser pulse with matter and possible new approaches to MeV electron generation. In this paper we

  13. Molecular Dynamics of Methylamine, Methanol, and Methyl Fluoride Cations in Intense 7 Micron Laser Fields

    E-Print Network [OSTI]

    Schlegel, H. Bernhard

    Molecular Dynamics of Methylamine, Methanol, and Methyl Fluoride Cations in Intense 7 Micron Laser of methylamine (CH3NH2 + ), methanol (CH3OH+ ), and methyl fluoride (CH3F+ ) cations by short, intense laser 7 m laser pulses. This work is motivated by recent studies of methanol cations by Yamanouchi and co

  14. Measurement of laser intensities approaching 1015 with an accuracy of 1%

    E-Print Network [OSTI]

    Kheifets, Anatoli

    , 2013) Accurate knowledge of the intensity of focused ultra-short laser pulses is crucial to the correctMeasurement of laser intensities approaching 1015 W/cm2 with an accuracy of 1% M. G. Pullen1,2 , W interpretation of experimental results in strong-field physics. We have developed a technique to measure laser

  15. Injection of harmonics generated in gas in a free-electron laser providing intense and

    E-Print Network [OSTI]

    Loss, Daniel

    LETTERS Injection of harmonics generated in gas in a free-electron laser providing intense lasers promise to extend this down to femtosecond timescales. The process by which free-electron lasers of the free-electron laser saturation length, and the generation of nonlinear harmonics13 at 54 nm and 32 nm

  16. Intensity-resolved Above Threshold Ionization Yields of Atoms with Ultrashort Laser Pulses

    E-Print Network [OSTI]

    Hart, Nathan Andrew

    2012-10-19T23:59:59.000Z

    The above threshold ionization (ATI) spectra provide a diversity of information about a laser-atom ionization process such as laser intensity, pulse duration, carrier envelope phase, and atomic energy level spacing. However, the spatial distribution...

  17. Photonuclear Reactions induced by Intense Short Laser Pulses

    E-Print Network [OSTI]

    B. Dietz; H. A. Weidenmueller

    2010-03-26T23:59:59.000Z

    A measurement of the decay in time of nuclei excited by an intense short laser pulse of energy E(0) yields the Fourier transform of the autocorrelation function of the associated scattering matrix. We determine the optimal length (in time) of the pulse and evaluate the time-decay function using random-matrix theory. That function is shown to contain information not otherwise available. We approximate that function in a manner that is useful for the analysis of data. For E(0) below the threshold energy E(n) of the first neutron channel, the time-decay function is exponential in time t while it is the product of an exponential and a power in t for E(0) > E(n). The comparison of the measured decay functions in both energy domains yields an unambiguous and novel test of random-matrix theory in nuclei.

  18. System for obtaining smooth laser beams where intensity variations are reduced by spectral dispersion of the laser light (SSD)

    DOE Patents [OSTI]

    Skupsky, Stanley (Rochester, NY); Kessler, Terrance J. (Rochester, NY); Short, Robert W. (Rochester, NY); Craxton, Stephen (Rochester, NY); Letzring, Samuel A. (Honeoye Falls, NY); Soures, John (Pittsford, NY)

    1991-01-01T23:59:59.000Z

    In an SSD (smoothing by spectral dispersion) system which reduces the time-averaged spatial variations in intensity of the laser light to provide uniform illumination of a laser fusion target, an electro-optic phase modulator through which a laser beam passes produces a broadband output beam by imposing a frequency modulated bandwidth on the laser beam. A grating provides spatial and angular spectral dispersion of the beam. Due to the phase modulation, the frequencies ("colors") cycle across the beam. The dispersed beam may be amplified and frequency converted (e.g., tripled) in a plurality of beam lines. A distributed phase plate (DPP) in each line is irradiated by the spectrally dispersed beam and the beam is focused on the target where a smooth (uniform intensity) pattern is produced. The color cycling enhances smoothing and the use of a frequency modulated laser pulse prevents the formation of high intensity spikes which could damage the laser medium in the power amplifiers.

  19. High-intensity double-pulse X-ray free-electron laser

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

    Marinelli, A.; Ratner, D.; Lutman, A. A.; Turner, J.; Welch, J.; Decker, F. -J.; Loos, H.; Behrens, C.; Gilevich, S.; Miahnahri, A. A.; et al

    2015-03-06T23:59:59.000Z

    The X-ray free-electron laser has opened a new era for photon science, improving the X-ray brightness by ten orders of magnitude over previously available sources. Similar to an optical laser, the spectral and temporal structure of the radiation pulses can be tailored to the specific needs of many experiments by accurately manipulating the lasing medium, that is, the electron beam. Here we report the generation of mJ-level two-colour hard X-ray pulses of few femtoseconds duration with an XFEL driven by twin electron bunches at the Linac Coherent Light Source. This performance represents an improvement of over an order of magnitudemore »in peak power over state-of-the-art two-colour XFELs. The unprecedented intensity and temporal coherence of this new two-colour X-ray free-electron laser enable an entirely new set of scientific applications, ranging from X-ray pump/X-ray probe experiments to the imaging of complex biological samples with multiple wavelength anomalous dispersion.« less

  20. PHYSICAL REVIEW A 83, 013405 (2011) Precision calculation of above-threshold multiphoton ionization in intense short-wavelength laser

    E-Print Network [OSTI]

    Chu, Shih-I

    2011-01-01T23:59:59.000Z

    in intense short-wavelength laser fields: The momentum-space approach and time-dependent generalized to the advance of the intense and short pulse laser technology, the study of ATI phenomenon continues to attract) dynamics of atomic systems driven by intense laser fields. In this approach, the electron wave function

  1. Hollow screw like drill in plasma using an intense Laguerre Gaussian laser

    E-Print Network [OSTI]

    Wang, Wenpeng; Zhang, Xiaomei; Zhang, Lingang; Shi, Yin; Xu, Zhizhan

    2014-01-01T23:59:59.000Z

    With the development of ultra intense laser technology, MeV ions from the laser foil interaction have been obtained by different mechanisms, such as target normal sheath acceleration, radiation pressure acceleration, collisionless shock acceleration, breakout afterburner, and a combination of different mechanisms. These energetic ion beams can be applied in fast ignition for inertial confinement fusion, medical therapy, and proton imaging. However, these ions are mainly accelerated in the laser propagation direction, and the ion acceleration in an azimuthal orientation is scarcely mentioned. Here, a doughnut Laguerre Gaussian LG laser is used for the first time to study the laser plasma interaction in the relativistic intensity regime in three dimensional particle in cell simulations. Studies have shown that a novel rotation of the plasma is produced from the hollow screw like drill of a LG mode laser. The angular momentum of the protons in the longitudinal direction produced by the LG laser is remarkably enh...

  2. Narrowband inverse Compton scattering x-ray sources at high laser intensities

    E-Print Network [OSTI]

    Seipt, D; Surzhykov, A; Fritzsche, S

    2014-01-01T23:59:59.000Z

    Narrowband x- and gamma-ray sources based on the inverse Compton scattering of laser pulses suffer from a limitation of the allowed laser intensity due to the onset of nonlinear effects that increase their bandwidth. It has been suggested that laser pulses with a suitable frequency modulation could compensate this ponderomotive broadening and reduce the bandwidth of the spectral lines, which would allow to operate narrowband Compton sources in the high-intensity regime. In this paper we, therefore, present the theory of nonlinear Compton scattering in a frequency modulated intense laser pulse. We systematically derive the optimal frequency modulation of the laser pulse from the scattering matrix element of nonlinear Compton scattering, taking into account the electron spin and recoil. We show that, for some particular scattering angle, an optimized frequency modulation completely cancels the ponderomotive broadening for all harmonics of the backscattered light. We also explore how sensitive this compensation ...

  3. Nonlinear dynamics of ionization stabilization of atoms in intense laser fields

    E-Print Network [OSTI]

    Michael Norman; C. Chandre; T. Uzer; Peijie Wang

    2014-12-06T23:59:59.000Z

    We revisit the stabilization of ionization of atoms subjected to a superintense laser pulse using nonlinear dynamics. We provide an explanation for the lack of complete ionization at high intensity and for the decrease of the ionization probability as intensity is increased. We investigate the role of each part of the laser pulse (ramp-up, plateau, ramp-down) in this process. We emphasize the role of the choice for the ionization criterion, energy versus distance criterion.

  4. Control of Laser Plasma Based Accelerators up to 1 GeV

    E-Print Network [OSTI]

    Nakamura, Kei

    2008-01-01T23:59:59.000Z

    phenomena generated by ultra-intense lasers. Science, 300:interaction of an intense ultra-short laser pulse with a gasbe needed for such ultra-intense laser pulses to propagate a

  5. Fiber Bragg grating inscription by high-intensity femtosecond UV laser light: comparison

    E-Print Network [OSTI]

    Nikogosyan, David N.

    Fiber Bragg grating inscription by high-intensity femtosecond UV laser light: comparison with other 264-nm laser light and a phase mask technique, Bragg grating inscription in a range of different, that result in a significant photosensitivity enhancement of the in- vestigated fibers in comparison

  6. Request for Support for the Conference on Super Intense Laser Atom Physics

    SciTech Connect (OSTI)

    Todd Ditmire

    2004-10-21T23:59:59.000Z

    The Conference on Super Intense Laser Atom Physics (SILAP) was held in November 2003 in Dallas, Texas. The venue for the meeting was South Fork Ranch in the outskirts of Dallas. The topics of the meeting included high harmonic generation and attosecond pulse generation, strong field interactions with molecules and clusters, particle acceleration, and relativistic laser atom interactions.

  7. Investigation of long-period fiber gratings induced by high-intensity femtosecond UV laser pulses

    E-Print Network [OSTI]

    Nikogosyan, David N.

    efficiency with that for other existing meth- ods of recording. We studied the temperature sensing properties changes in the fiber core induced by thermal heating, were developed. They include the use of a CO2 laserInvestigation of long-period fiber gratings induced by high-intensity femtosecond UV laser pulses

  8. Unveiling temporal correlations characteristic to phase transition in the intensity of a fibre laser radiation

    E-Print Network [OSTI]

    Andres Aragoneses; Laura Carpi; Nikita Tarasov; Dmitry V. Churkin; M. C. Torrent; Cristina Masoller; Sergei K. Turitsyn

    2015-06-09T23:59:59.000Z

    We use advanced statistical tools of time-series analysis to characterize the dynamical complexity of the transition to optical wave turbulence in a fibre laser. Ordinal analysis and the horizontal visibility graph applied to the experimentally measured laser output intensity reveal the presence of temporal correlations during the transition from the laminar to the turbulent lasing regimes. Both methods unveil coherent structures with well defined time-scales and strong correlations both, in the timing of the laser pulses and in their peak intensities. Our approach is generic and may be used in other complex systems that undergo similar transitions involving the generation of extreme fluctuations.

  9. Breit-Wheeler Process in Intense Short Laser Pulses

    E-Print Network [OSTI]

    K. Krajewska; J. Z. Kaminski

    2012-09-11T23:59:59.000Z

    Energy-angular distributions of electron-positron pair creation in collisions of a laser beam and a nonlaser photon are calculated using the $S$-matrix formalism. The laser field is modeled as a finite pulse, similar to the formulation introduced in our recent paper in the context of Compton scattering [Phys. Rev. A {\\bf 85}, 062102 (2012)]. The nonperturbative regime of pair creation is considered here. The energy spectra of created particles are compared with the corresponding spectra obtained using the modulated plane wave approximation for the driving laser field. A very good agreement in these two cases is observed, provided that the laser pulse is sufficiently long. For short pulse durations, this agreement breaks down. The sensitivity of pair production to the polarization of a driving pulse is also investigated. We show that in the nonperturbative regime, the pair creation yields depend on the polarization of the pulse, reaching their maximal values for the linear polarization. Therefore, we focus on this case. Specifically, we analyze the dependence of pair creation on the relative configuration of linear polarizations of the laser pulse and the nonlaser photon. Lastly, we investigate the carrier-envelope phase effect on angular distributions of created particles, suggesting the possibility of phase control in relation to the pair creation processes.

  10. Proton radiography of magnetic field produced by ultra-intense laser irradiating capacity-coil target

    E-Print Network [OSTI]

    Wang, W W; Chen, J; Cai, H B; He, S K; Zhou, W M; Shan, L Q; Lu, F; Wu, Y C; Hong, W; Liu, D X; Bi, B; Zhang, F; Xue, F B; Li, B Y; Zhang, B; He, Y L; He, W; Jiao, J L; Dong, K G; Zhang, F Q; Deng, Z G; Zhang, Z M; Cui, B; Han, D; Zhou, K N; Wang, X D; Zhao, Z Q; Cao, L F; Zhang, B H; He, X T; Gu, Y Q

    2014-01-01T23:59:59.000Z

    Ultra-intense ultra-short laser is firstly used to irradiate the capacity-coil target to generate magnetic field. The spatial structure and temporal evolution of huge magnetic fields were studied with time-gated proton radiography method. A magnetic flux density of 40T was measured by comparing the proton deflection and particle track simulations. Although the laser pulse duration is only 30fs, the generated magnetic field can last for over 100 picoseconds. The energy conversion efficiency from laser to magnetic field can reach as high as ~20%. The results indicate that tens of tesla (T) magnetic field could be produced in many ultra intense laser facilities around the world, and higher magnetic field could be produced by picosecond lasers.

  11. Resonant absorption and not-so-resonant absorption in short, intense laser irradiated plasma

    SciTech Connect (OSTI)

    Ge, Z. Y.; Zhuo, H. B.; Ma, Y. Y.; Yang, X. H.; Yu, T. P.; Zou, D. B.; Yin, Y.; Shao, F. Q. [College of Science, National University of Defense Technology, Changsha 410073 (China)] [College of Science, National University of Defense Technology, Changsha 410073 (China); Yu, W.; Luan, S. X. [Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800 (China)] [Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800 (China); Zhou, C. T. [College of Science, National University of Defense Technology, Changsha 410073 (China) [College of Science, National University of Defense Technology, Changsha 410073 (China); Institute of Applied Physics and Computational Mathematics, Beijing 100088 (China); Peng, X. J. [Institute of Applied Physics and Computational Mathematics, Beijing 100088 (China)] [Institute of Applied Physics and Computational Mathematics, Beijing 100088 (China)

    2013-07-15T23:59:59.000Z

    An analytical model for laser-plasma interaction during the oblique incidence by an ultrashort ultraintense p-polarized laser on a solid-density plasma is proposed. Both the resonant absorption and not-so-resonant absorption are self-consistently included. Different from the previous theoretical works, the physics of resonant absorption is found to be valid in more general conditions as the steepening of the electron density profile is considered. Even for a relativistic intensity laser, resonant absorption can still exist under certain plasma scale length. For shorter plasma scale length or higher laser intensity, the not-so-resonant absorption tends to be dominant, since the electron density is steepened to a critical level by the ponderomotive force. The laser energy absorption rates for both mechanisms are discussed in detail, and the difference and transition between these two mechanisms are presented.

  12. Electron acceleration by an intense short pulse laser in a static magnetic field in vacuum K. P. Singh*

    E-Print Network [OSTI]

    Roy, Subrata

    Electron acceleration by an intense short pulse laser in a static magnetic field in vacuum K. P by a laser pulse having Gaussian radial and temporal profiles of intensity has been studied in a static to be the same as that of the magnetic field of the laser pulse. The electron gains considerable energy

  13. Ultra hard x rays from krypton clusters heated by intense laser fields R. C. Issac,a)

    E-Print Network [OSTI]

    Strathclyde, University of

    Ultra hard x rays from krypton clusters heated by intense laser fields R. C. Issac,a) G. Vieux, B of ultrashort laser pulses with krypton clusters at intensity up to 1.3 1018 Wcm 2 has been investigated. This is ascribed to the presence of a hot electron population, similar to that found in laser­solid interactions

  14. Asymmetric explosion of clusters in intense laser fields

    SciTech Connect (OSTI)

    Kundu, M. [Institute for Plasma Research, Bhat, Gandhinagar 382 428, Gujarat (India)

    2012-08-15T23:59:59.000Z

    We examine asymmetric expansion of argon clusters illuminated by 800 nm laser pulses of duration Almost-Equal-To 23fs, using three-dimensional particle-in-cell (PIC) simulation. For this short pulse duration, laser energy absorption by cluster electrons is dominated by the nonlinear resonance (NLR) absorption process [Phys. Rev. Lett. 96, 123401 (2006)]. In this work, we concentrate, particularly, on the ionic outcome in the NLR regime and show that higher charge states of argon ions are produced along the laser polarization than in the transverse directions leading to the anisotropy (asymmetry) in the ion energy distribution. This anisotropy already established during the short pulse duration (or in the early duration of a long pulse) may contribute to the anisotropic ion emission reported in cluster experiments with pulse duration longer than 100 fs. Our PIC results are compared with a charged-sphere model showing that cluster explosion is mainly due to Coulomb repulsion between the cluster ions.

  15. Femtosecond-scale Synchronisation of Ultra-Intense Focused Laser Beams

    E-Print Network [OSTI]

    Corvan, D J; Cole, J; Ahmed, H; Krushelnick, K; Mangles, S P D; Najmudin, Z; Symes, D; Thomas, A G R; Yeung, M; Zepf, M; Zhao, Z; Sarri, G

    2014-01-01T23:59:59.000Z

    Synchronising ultra-short (~fs) and focussed laser pulses is a particularly difficult task, as this timescale lies orders of magnitude below the typical range of fast electronic devices. Here we present an optical technique that allows for femtosecond-scale synchronisation of the focal planes of two focussed laser pulses. This technique is virtually applicable to any focussing geometry and relative intensity of the two lasers. Experimental implementation of this technique provides excellent quantitative agreement with theoretical expectations. The proposed technique will prove highly beneficial for the next generation of multiple, petawatt class laser systems.

  16. System for obtaining smooth laser beams where intensity variations are reduced by spectral dispersion of the laser light (SSD)

    DOE Patents [OSTI]

    Skupsky, S.; Kessler, T.J.; Short, R.W.; Craxton, S.; Letzring, S.A.; Soures, J.

    1991-09-10T23:59:59.000Z

    In an SSD (smoothing by spectral dispersion) system which reduces the time-averaged spatial variations in intensity of the laser light to provide uniform illumination of a laser fusion target, an electro-optic phase modulator through which a laser beam passes produces a broadband output beam by imposing a frequency modulated bandwidth on the laser beam. A grating provides spatial and angular spectral dispersion of the beam. Due to the phase modulation, the frequencies (''colors'') cycle across the beam. The dispersed beam may be amplified and frequency converted (e.g., tripled) in a plurality of beam lines. A distributed phase plate (DPP) in each line is irradiated by the spectrally dispersed beam and the beam is focused on the target where a smooth (uniform intensity) pattern is produced. The color cycling enhances smoothing and the use of a frequency modulated laser pulse prevents the formation of high intensity spikes which could damage the laser medium in the power amplifiers. 8 figures.

  17. Title of dissertation: NOVEL APPLICATIONS OF HIGH INTENSITY FEMTOSECOND LASERS

    E-Print Network [OSTI]

    Anlage, Steven

    -cycle seed pulse of terahertz radiation: a short, intense optical pulse (or sequence of pulses) aligns for amplification of few-cycle, high energy pulses of terahertz radiation. We report the development of corrugated the limitations of diffraction, phase matching, and material damage thresholds and promise to allow high

  18. Production of neutrons up to 18 MeV in high-intensity, short-pulse laser matter interactions

    E-Print Network [OSTI]

    Production of neutrons up to 18 MeV in high-intensity, short-pulse laser matter interactions D. P of neutrons up to 18 MeV in high-intensity, short-pulse laser matter interactions D. P. Higginson,1,2 J. M. Mc of laser energy in a 9 ps pulse. In this technique, a short-pulse, high-energy laser accelerates deuterons

  19. HOT ELECTRON ENERGY DISTRIBUTIONS FROM ULTRA-INTENSE LASER SOLID INTERACTIONS

    SciTech Connect (OSTI)

    Chen, H; Wilks, S C; Kruer, W; Patel, P; Shepherd, R

    2008-10-08T23:59:59.000Z

    Measurements of electron energy distributions from ultra-intense (>10{sup 19} W/cm{sup 2}) laser-solid interactions using an electron spectrometer are presented. These measurements were performed on the Vulcan petawatt laser at Rutherford Appleton Laboratory and the Callisto laser at Lawrence Livermore National Laboratory. The effective hot electron temperatures (T{sub hot}) have been measured for laser intensities (I{lambda}{sup 2}) from 10{sup 18} W/cm{sup 2} {micro}m{sup 2} to 10{sup 21} W/cm{sup 2} {micro}m{sup 2} for the first time, and T{sub hot} is found to increase as (I{lambda}{sup 2}){sup 0.34} {+-} 0.4. This scaling agrees well with the empirical scaling published by Beg et al. (1997), and is explained by a simple physical model that gives good agreement with experimental results and particle-in-cell simulations.

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

    SciTech Connect (OSTI)

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

    2012-10-15T23:59:59.000Z

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

  1. Systems for controlling the intensity variations in a laser beam and for frequency conversion thereof

    DOE Patents [OSTI]

    Skupsky, Stanley (Rochester, NY); Craxton, R. Stephen (Rochester, NY); Soures, John (Pittsford, NY)

    1990-01-01T23:59:59.000Z

    In order to control the intensity of a laser beam so that its intensity varies uniformly and provides uniform illumination of a target, such as a laser fusion target, a broad bandwidth laser pulse is spectrally dispersed spatially so that the frequency components thereof are spread apart. A disperser (grating) provides an output beam which varies spatially in wavelength in at least one direction transverse to the direction of propagation of the beam. Temporal spread (time delay) across the beam is corrected by using a phase delay device (a time delay compensation echelon). The dispersed beam may be amplified with laser amplifiers and frequency converted (doubled, tripled or quadrupled in frequency) with nonlinear optical elements (birefringent crystals). The spectral variation across the beam is compensated by varying the angle of incidence on one of the crystals with respect to the crystal optical axis utilizing a lens which diverges the beam. Another lens after the frequency converter may be used to recollimate the beam. The frequency converted beam is recombined so that portions of different frequency interfere and, unlike interference between waves of the same wavelength, there results an intensity pattern with rapid temoral oscillations which average out rapidly in time thereby producing uniform illumination on target. A distributed phase plate (also known as a random phase mask), through which the spectrally dispersed beam is passed and then focused on a target, is used to provide the interference pattern which becomes nearly modulation free and uniform in intensity in the direction of the spectral variation.

  2. Probing the spectral and temporal structures of high-order harmonic generation in intense laser pulses

    E-Print Network [OSTI]

    Chu, Shih-I

    understanding of the origin of the har- monics with energies much in excess of the ionization po- tential Ip of the electronic wave packet with the parent ionic core. Based on this model, the cutoff energy is predicted in intense pulsed laser fields. Accurate time-dependent wave functions are obtained by means of the time

  3. Systems for controlling the intensity variations in a laser beam and for frequency conversion thereof

    DOE Patents [OSTI]

    Skupsky, S.; Craxton, R.S.; Soures, J.

    1990-10-02T23:59:59.000Z

    In order to control the intensity of a laser beam so that its intensity varies uniformly and provides uniform illumination of a target, such as a laser fusion target, a broad bandwidth laser pulse is spectrally dispersed spatially so that the frequency components thereof are spread apart. A disperser (grating) provides an output beam which varies spatially in wavelength in at least one direction transverse to the direction of propagation of the beam. Temporal spread (time delay) across the beam is corrected by using a phase delay device (a time delay compensation echelon). The dispersed beam may be amplified with laser amplifiers and frequency converted (doubled, tripled or quadrupled in frequency) with nonlinear optical elements (birefringent crystals). The spectral variation across the beam is compensated by varying the angle of incidence on one of the crystals with respect to the crystal optical axis utilizing a lens which diverges the beam. Another lens after the frequency converter may be used to recollimate the beam. The frequency converted beam is recombined so that portions of different frequency interfere and, unlike interference between waves of the same wavelength, there results an intensity pattern with rapid temporal oscillations which average out rapidly in time thereby producing uniform illumination on target. A distributed phase plate (also known as a random phase mask), through which the spectrally dispersed beam is passed and then focused on a target, is used to provide the interference pattern which becomes nearly modulation free and uniform in intensity in the direction of the spectral variation. 16 figs.

  4. Infrared Two-Color Multicycle Laser Field Synthesis for Generating an Intense Attosecond Pulse

    SciTech Connect (OSTI)

    Takahashi, Eiji J.; Lan Pengfei; Nabekawa, Yasuo; Midorikawa, Katsumi [Extreme Photonics Research Group, RIKEN Advanced Science Institute, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); Muecke, Oliver D. [Photonics Institute, Vienna University of Technology, Gusshausstrasse 27-387, A-1040 Vienna (Austria)

    2010-06-11T23:59:59.000Z

    We propose and demonstrate the generation of a continuum high-order harmonic spectrum by mixing multicycle two-color (TC) laser fields with the aim of obtaining an intense isolated attosecond pulse. By optimizing the wavelength of a supplementary infrared pulse in a TC field, a continuum harmonic spectrum was created around the cutoff region without carrier-envelope phase stabilization. The obtained harmonic spectra clearly show the possibility of generating isolated attosecond pulses from a multicycle TC laser field, which is generated by an 800 nm, 30 fs pulse mixed with a 1300 nm, 40 fs pulse. Our proposed method enables us not only to relax the requirements for the pump pulse duration but also to reduce ionization of the harmonic medium. This concept opens the door to create an intense isolated attosecond pulse using a conventional femtosecond laser system.

  5. Isochoric heating of reduced mass targets by ultra-intense laser produced relativistic electrons

    SciTech Connect (OSTI)

    Neumayer, P; Lee, H J; Offerman, D; Shipton, E; Kemp, A; Kritcher, A L; Doppner, T; Back, C A; Glenzer, S H

    2009-02-04T23:59:59.000Z

    We present measurements of the chlorine K-alpha emission from reduced mass targets, irradiated with ultra-high intensity laser pulses. Chlorinated plastic targets with diameters down to 50 micrometers and mass of a few 10{sup -8} g were irradiated with up to 7 J of laser energy focused to intensities of several 10{sup 19} W/cm{sup 2}. The conversion of laser energy to K-alpha radiation is measured, as well as high resolution spectra that allow observation of line shifts, indicating isochoric heating of the target up to 18 eV. A zero-dimensional 2-temperature equilibration model, combined with electron impact K-shell ionization and post processed spectra from collisional radiative calculations reproduces the observed K-alpha yields and line shifts, and shows the importance of target expansion due to the hot electron pressure.

  6. Nonlinear relativistic single-electron Thomson scattering power spectrum for incoming laser of arbitrary intensity

    SciTech Connect (OSTI)

    Alvarez-Estrada, R. F. [Departamento de Fisica Teorica I, Facultad de Ciencias Fisicas, Universidad Complutense, 28040 Madrid (Spain); Pastor, I.; Guasp, J.; Castejon, F. [Asociacion Euratom/Ciemat para Fusion, Avenida Complutense 22, 28040 Madrid (Spain)

    2012-06-15T23:59:59.000Z

    The classical nonlinear incoherent Thomson scattering power spectrum from a single relativistic electron with incoming laser radiation of any intensity, investigated numerically by the present authors in a previous publication, displayed both an approximate quadratic behavior in frequency and a redshift of the power spectrum for high intensity incoming radiation. The present work is devoted to justify, in a more general setup, those numerical findings. Those justifications are reinforced by extending suitably analytical approaches, as developed by other authors. Moreover, our analytical treatment exhibits differences between the Doppler-like frequencies for linear and circular polarization of the incoming radiation. Those differences depend nonlinearly on the laser intensity and on the electron initial velocity and do not appear to have been displayed by previous authors. Those Doppler-like frequencies and their differences are validated by new Monte Carlo computations beyond our previuos ones and reported here.

  7. Asymmetries of azimuthal photon distributions in non-linear Compton scattering in ultra-short intense laser pulses

    E-Print Network [OSTI]

    Seipt, D

    2013-01-01T23:59:59.000Z

    Non-linear Compton scattering in ultra-short intense laser pulses is discussed with the focus on angular distributions of the emitted photon energy. This is an observable which is accessible easily experimentally. Asymmetries of the azimuthal distributions are predicted for both linear and circular polarization. We present a systematic survey of the influence of the laser intensity, the carrier envelope phase and the laser polarization on the emission spectra for single-cycle and few-cycle laser pulses. For linear polarization, the dominant direction of the emission changes from a perpendicular pattern with respect to the laser polarization at low-intensity to a dominantly parallel emission for high-intensity laser pulses.

  8. Asymmetries of azimuthal photon distributions in non-linear Compton scattering in ultra-short intense laser pulses

    E-Print Network [OSTI]

    D. Seipt; B. Kampfer

    2013-05-16T23:59:59.000Z

    Non-linear Compton scattering in ultra-short intense laser pulses is discussed with the focus on angular distributions of the emitted photon energy. This is an observable which is accessible easily experimentally. Asymmetries of the azimuthal distributions are predicted for both linear and circular polarization. We present a systematic survey of the influence of the laser intensity, the carrier envelope phase and the laser polarization on the emission spectra for single-cycle and few-cycle laser pulses. For linear polarization, the dominant direction of the emission changes from a perpendicular pattern with respect to the laser polarization at low-intensity to a dominantly parallel emission for high-intensity laser pulses.

  9. Enhancement of x-ray line emission from plasmas produced by short high-intensity laser double pulses

    E-Print Network [OSTI]

    Limpouch, Jiri

    Enhancement of x-ray line emission from plasmas produced by short high-intensity laser double.25.Os, 52.65. y I. INTRODUCTION The advanced technology of short pulse lasers now pro- vides on experimental conditions. The enhancement of x-ray yield by short laser prepulses has been reported in several

  10. Ultrafast dynamics and fragmentation of C60 in intense laser pulses

    E-Print Network [OSTI]

    Lin, Zheng-Zhe

    2014-01-01T23:59:59.000Z

    The radiation-induced fragmentation of the C60 fullerene was investigated by the tight-binding electron-ion dynamics simulations. In intense laser field, the breathing vibrational mode is much more strongly excited than the pentagonal-pinch mode. The fragmentation effect was found more remarkable at long wavelength lambda>800 nm rather than the resonant wavelengths due to the internal laser-induced dipole force, and the production ratio of C and C2 rapidly grows with increasing wavelength. By such fragmentation law, C atoms, C2 dimers or large Cn fragments could be selectively obtained by changing the laser wavelength. And the fragmentation of C60 by two laser pulses like the multi-step atomic photoionization was investigated.

  11. Shock Wave Acceleration of Monoenergetic Protons using a Multi-Terawatt CO2 Laser

    E-Print Network [OSTI]

    Haberberger, Dan

    2012-01-01T23:59:59.000Z

    fusion implosions at ultra-high laser energies,” Science,of ultrashort, ultra-intense laser light by solids andby an ultra intense and short- pulsed laser in under-dense

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

    SciTech Connect (OSTI)

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

    2010-12-01T23:59:59.000Z

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

  13. Ionization heating in rare-gas clusters under intense XUV laser pulses

    SciTech Connect (OSTI)

    Arbeiter, Mathias; Fennel, Thomas [Institute of Physics, University of Rostock, D-18051 Rostock (Germany)

    2010-07-15T23:59:59.000Z

    The interaction of intense extreme ultraviolet (XUV) laser pulses ({lambda}=32 nm, I=10{sup 11}-10{sup 14} W/cm{sup 2}) with small rare-gas clusters (Ar{sub 147}) is studied by quasiclassical molecular dynamics simulations. Our analysis supports a very general picture of the charging and heating dynamics in finite samples under short-wavelength radiation that is of relevance for several applications of free-electron lasers. First, up to a certain photon flux, ionization proceeds as a series of direct photoemission events producing a jellium-like cluster potential and a characteristic plateau in the photoelectron spectrum as observed in Bostedt et al. [Phys. Rev. Lett. 100, 133401 (2008)]. Second, beyond the onset of photoelectron trapping, nanoplasma formation leads to evaporative electron emission with a characteristic thermal tail in the electron spectrum. A detailed analysis of this transition is presented. Third, in contrast to the behavior in the infrared or low vacuum ultraviolet range, the nanoplasma energy capture proceeds via ionization heating, i.e., inner photoionization of localized electrons, whereas collisional heating of conduction electrons is negligible up to high laser intensities. A direct consequence of the latter is a surprising evolution of the mean energy of emitted electrons as function of laser intensity.

  14. High-intensity laser-driven proton acceleration enhancement from hydrogen containing ultrathin targets

    SciTech Connect (OSTI)

    Dollar, F.; Reed, S. A.; Matsuoka, T.; Bulanov, S. S.; Chvykov, V.; Kalintchenko, G.; McGuffey, C.; Rousseau, P.; Thomas, A. G. R.; Willingale, L.; Yanovsky, V.; Krushelnick, K.; Maksimchuk, A. [Center for Ultrafast Optical Science, University of Michigan, Ann Arbor, Michigan 48109 (United States)] [Center for Ultrafast Optical Science, University of Michigan, Ann Arbor, Michigan 48109 (United States); Litzenberg, D. W. [Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan 48109 (United States)] [Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan 48109 (United States)

    2013-09-30T23:59:59.000Z

    Laser driven proton acceleration experiments from micron and submicron thick targets using high intensity (2 × 10{sup 21} W/cm{sup 2}), high contrast (10{sup ?15}) laser pulses show an enhancement of maximum energy when hydrogen containing targets were used instead of non-hydrogen containing. In our experiments, using thin (<1?m) plastic foil targets resulted in maximum proton energies that were consistently 20%–100% higher than when equivalent thickness inorganic targets, including Si{sub 3}N{sub 4} and Al, were used. Proton energies up to 20 MeV were measured with a flux of 10{sup 7} protons/MeV/sr.

  15. Electronic and intraband optical properties of single quantum rings under intense laser field radiation

    SciTech Connect (OSTI)

    Radu, A. [Department of Physics, Politehnica University of Bucharest, 313 Splaiul Independentei, Bucharest RO-060042 (Romania); Kirakosyan, A. A.; Baghramyan, H. M.; Barseghyan, M. G., E-mail: mbarsegh@ysu.am [Department of Solid State Physics, Yerevan State University, Alex Manoogian 1, 0025 Yerevan (Armenia); Laroze, D. [Instituto de Alta Investigación, Universidad de Tarapacá, Casilla 7D, Arica (Chile)

    2014-09-07T23:59:59.000Z

    The influence of an intense laser field on one-electron states and intraband optical absorption coefficients is investigated in two-dimensional GaAs/Ga{sub 0.7}Al{sub 0.3}As quantum rings. An analytical expression of the effective lateral confining potential induced by the laser field is obtained. The one-electron energy spectrum and wave functions are found using the effective mass approximation and exact diagonalization technique. We have shown that changes in the incident light polarization lead to blue- or redshifts in the intraband optical absorption spectrum. Moreover, we found that only blueshift is obtained with increasing outer radius of the quantum ring.

  16. Enhancing the energy of terahertz radiation from plasma produced by intense femtosecond laser pulses

    SciTech Connect (OSTI)

    Jahangiri, Fazel [Advanced Research Center for Beam Science, ICR, Kyoto University, Kyoto (Japan) [Advanced Research Center for Beam Science, ICR, Kyoto University, Kyoto (Japan); Laser and Plasma Research Institute, Shahid Beheshti University, Tehran (Iran, Islamic Republic of); Hashida, Masaki; Tokita, Shigeki; Sakabe, Shuji [Advanced Research Center for Beam Science, ICR, Kyoto University, Kyoto (Japan) [Advanced Research Center for Beam Science, ICR, Kyoto University, Kyoto (Japan); Department of Physics, GSS, Kyoto University, Kyoto (Japan); Nagashima, Takeshi; Hangyo, Masanori [Department of Physics, GSS, Kyoto University, Kyoto (Japan) [Department of Physics, GSS, Kyoto University, Kyoto (Japan); Institute of Laser Engineering, Osaka University, Osaka (Japan)

    2013-05-13T23:59:59.000Z

    Terahertz (THz) radiation from atomic clusters illuminated by intense femtosecond laser pulses is investigated. By studying the angular distribution, polarization properties and energy dependence of THz waves, we aim to obtain a proper understanding of the mechanism of THz generation. The properties of THz waves measured in this study differ from those predicted by previously proposed mechanisms. To interpret these properties qualitatively, we propose that the radiation is generated by time-varying quadrupoles, which are produced by the ponderomotive force of the laser pulse.

  17. Dimensional scaling treatment with relativistic corrections for stable multiply charged atomic ions in high-frequency super-intense laser fields

    E-Print Network [OSTI]

    Kais, Sabre

    in high-frequency super-intense laser fields Ross D. Hoehn, Jiaxiang Wang, and Sabre Kais Citation-intense laser fields Ross D. Hoehn,1 Jiaxiang Wang,2 and Sabre Kais1,a) 1 Departments of Chemistry and Physics

  18. Intensity-resolved ionization yields of aniline with femtosecond laser pulses

    SciTech Connect (OSTI)

    Strohaber, J.; Hart, N.; Zhu, F.; Nava, R.; Pham, F.; Kolomenskii, A. A.; Paulus, G. G.; Schuessler, H. A. [Texas A and M University, Department of Physics, College Station, Texas 77843-4242 (United States); Mohamed, T. [Physics Department, Faculty of Science, BeniSuef University (Egypt); Schroeder, H. [Max-Planck-Institut fuer Quantenoptik, Hans-Kopfermann-Strasse 1, DE-85748 Garching (Germany)

    2011-12-15T23:59:59.000Z

    We present experimental results for the ionization of aniline and benzene molecules subjected to intense ultrashort laser pulses. Measured parent molecular ions yields were obtained using a recently developed technique capable of three-dimensional imaging of ion distributions within the focus of a laser beam. By selecting ions originating from the central region of the focus, where the spatial intensity distribution is nearly uniform, volumetric-free intensity-dependent ionization yields were obtained. The measured data revealed a previously unseen resonance-enhanced multiphoton ionization (REMPI)-like process. Comparison of benzene, aniline, and Xe ion yields demonstrates that the observed intensity-dependent structures are not due to geometric artifacts in the focus. Finally for intensities greater than {approx}3x10{sup 13} W/cm{sup 2}, we attribute the ionization of aniline to a stepwise process going through the {pi}{sigma}{sup *} state which sits three photons above the ground state and two photons below the continuum.

  19. Hole boring in a DT pellet and fast ion ignition with ultra-intense laser pulses

    E-Print Network [OSTI]

    Naumova, N; Tikhonchuk, V T; Labaune, C; Sokolov, I V; Mourou, G; 10.1103/PhysRevLett.102.025002

    2009-01-01T23:59:59.000Z

    Recently achieved high intensities of short laser pulses open new prospects in their application to hole boring in inhomogeneous overdense plasmas and for ignition in precompressed DT fusion targets. A simple analytical model and numerical simulations demonstrate that pulses with intensities exceeding 1022 W/cm2 may penetrate deeply into the plasma as a result of efficient ponderomotive acceleration of ions in the forward direction. The penetration depth as big as hundreds of microns depends on the laser fluence, which has to exceed a few tens of GJ/cm2. The fast ions, accelerated at the bottom of the channel with an efficiency of more than 20%, show a high directionality and may heat the precompressed target core to fusion conditions.

  20. Standoff detection of hidden objects using backscattered ultra-intense laser-produced x-rays

    SciTech Connect (OSTI)

    Kuwabara, H. [IHI Corporation, 1, Shin-Nakahara-cho, Isogo-ku, Yokohama 235-8501 (Japan)] [IHI Corporation, 1, Shin-Nakahara-cho, Isogo-ku, Yokohama 235-8501 (Japan); Mori, Y.; Kitagawa, Y. [The Graduate School for the Creation of New Photonics Industries, 1955-1 Kurematsucho, Nishiku, Hamamatsu, Shizuoka 431-1202 (Japan)] [The Graduate School for the Creation of New Photonics Industries, 1955-1 Kurematsucho, Nishiku, Hamamatsu, Shizuoka 431-1202 (Japan)

    2013-08-28T23:59:59.000Z

    Ultra-intense laser-produced sub-ps X-ray pulses can detect backscattered signals from objects hidden in aluminium containers. Coincident measurements using primary X-rays enable differentiation among acrylic, copper, and lead blocks inside the container. Backscattering reveals the shapes of the objects, while their material composition can be identified from the modification methods of the energy spectra of backscattered X-ray beams. This achievement is an important step toward more effective homeland security.

  1. Electron-Positron Plasma Drop Formed by Ultra-Intense Laser Pulses

    E-Print Network [OSTI]

    Inga Kuznetsova; Johann Rafelski

    2012-04-25T23:59:59.000Z

    We study the initial properties and positron annihilation within a small electron-positron plasma drop formed by intense laser pulse. Such QED cascade initiated plasma is, in general, far below the chemical (particle yield) equilibrium. We find that the available electrons and positrons equilibrate kinetically, yet despite relatively high particle density, the electron-positron annihilation is very slow, suggesting a rather long lifespan of the plasma drop.

  2. Longitudinal and transverse cooling of relativistic electron beams in intense laser pulses

    E-Print Network [OSTI]

    Yoffe, Samuel R; Noble, Adam; Jaroszynski, Dino A

    2015-01-01T23:59:59.000Z

    With the emergence in the next few years of a new breed of high power laser facilities, it is becoming increasingly important to understand how interacting with intense laser pulses affects the bulk properties of a relativistic electron beam. A detailed analysis of the radiative cooling of electrons indicates that, classically, equal contributions to the phase space contraction occur in the transverse and longitudinal directions. In the weakly quantum regime, in addition to an overall reduction in beam cooling, this symmetry is broken, leading to significantly less cooling in the longitudinal than the transverse directions. By introducing an efficient new technique for studying the evolution of a particle distribution, we demonstrate the quantum reduction in beam cooling, and find that it depends on the distribution of energy in the laser pulse, rather than just the total energy as in the classical case.

  3. Epithermal Neutron Source for Neutron Resonance Spectroscopy (NRS) using High Intensity, Short Pulse Lasers

    SciTech Connect (OSTI)

    Higginson, D P; McNaney, J M; Swift, D C; Bartal, T; Hey, D S; Pape, S L; Mackinnon, A; Mariscal, D; Nakamura, H; Nakanii, N; Beg, F N

    2010-04-22T23:59:59.000Z

    A neutron source for neutron resonance spectroscopy (NRS) has been developed using high intensity, short pulse lasers. This measurement technique will allow for robust measurements of interior ion temperature of laser-shocked materials and provide insight into equation of state (EOS) measurements. The neutron generation technique uses protons accelerated by lasers off of Cu foils to create neutrons in LiF, through (p,n) reactions with {sup 7}Li and {sup 19}F. The distribution of the incident proton beam has been diagnosed using radiochromic film (RCF). This distribution is used as the input for a (p,n) neturon prediction code which is compared to experimentally measured neutron yields. From this calculation, a total fluence of 1.8 x 10{sup 9} neutrons is infered, which is shown to be a reasonable amount for NRS temperature measurement.

  4. Electromagnetic cascade in high energy electron, positron, and photon interactions with intense laser pulses

    E-Print Network [OSTI]

    S. S. Bulanov; C. B. Schroeder; E. Esarey; W. P. Leemans

    2013-06-05T23:59:59.000Z

    The interaction of high energy electrons, positrons, and photons with intense laser pulses is studied in head-on collision geometry. It is shown that electrons and/or positrons undergo a cascade-type process involving multiple emissions of photons. These photons can consequently convert into electron-positron pairs. As a result charged particles quickly lose their energy developing an exponentially decaying energy distribution, which suppresses the emission of high energy photons, thus reducing the number of electron-positron pairs being generated. Therefore, this type of interaction suppresses the development of the electromagnetic avalanche-type discharge, i.e., the exponential growth of the number of electrons, positrons, and photons does not occur in the course of interaction. The suppression will occur when 3D effects can be neglected in the transverse particle orbits, i.e., for sufficiently broad laser pulses with intensities that are not too extreme. The final distributions of electrons, positrons, and photons are calculated for the case of a high energy e-beam interacting with a counter-streaming, short intense laser pulse. The energy loss of the e-beam, which requires a self-consistent quantum description, plays an important role in this process, as well as provides a clear experimental observable for the transition from the classical to quantum regime of interaction.

  5. Multiple hot images from an obscuration in an intense laser beam through cascaded Kerr medium disks

    SciTech Connect (OSTI)

    Wang Youwen; Wen Shuangchun; You Kaiming; Tang Zhixiang; Deng Jianqin; Zhang Lifu; Fan Dianyuan

    2008-10-20T23:59:59.000Z

    We present a theoretical investigation on the formation of hot images in an intense laser beam through cascaded Kerr medium disks, to disclose the distribution and intensity of hot images in high-power disk amplifiers. It is shown that multiple hot images from an obscuration may be formed, instead of one hot image as reported previously in the literature. This gives a clear explanation for the curious damage pattern of hot images, namely, damage sites appearing on alternating optics in periodic trains. Further analysis demonstrates that the distribution and intensity of hot images depend closely on the number of Kerr medium disks, the distance from the obscuration to the front of the first disk downstream, the space between two neighboring disks, and the thickness and B integral of each disk. Moreover, we take two cascaded Kerr medium disks for example to detail multiple hot images from an obscuration and confirm the theoretical results by numerical simulations.

  6. Self-focusing, channel formation, and high-energy ion generation in interaction of an intense short laser pulse with a He jet

    E-Print Network [OSTI]

    Umstadter, Donald

    A number of proposed applications of ultrahigh intensity short laser pulses require laser guiding-focusing related to plasma motion during the laser pulse. Although the self-focusing of a short laser pulse motion induced by a short relativistic laser pulse was studied in hydrodynamic simula

  7. Electronic and structural response of InSb to ultra-short and ultra-intense laser pulses

    E-Print Network [OSTI]

    Burzo, Andrea Mihaela

    2001-01-01T23:59:59.000Z

    of the behavior of InSb following application of ultra-short and ultra-intense laser pulses. Motivated directly by these experiments, we have performed simulations of the electron-ion dynamics of InSb subjected to femtosecond-scale laser pulses. These simulations...

  8. Collapse and revival of electromagnetic cascades in focused intense laser pulses

    E-Print Network [OSTI]

    A. A. Mironov; N. B. Narozhny; A. M. Fedotov

    2014-07-24T23:59:59.000Z

    We consider interaction of a high-energy electron beam with two counterpropagating femtosecond laser pulses. Nonlinear Compton scattering and electron-positron pair production by the emitted photons result in development of an electromagnetic "shower-type" cascade, which however collapses rather quickly due to energy losses by secondary particles. Nevertheless, the laser field accelerates the low-energy electrons and positrons trapped in the focal region, thus giving rise to development of electromagnetic cascade of another type ("avalanche-type"). This effect of cascade collapse and revival can be observed at the electron beam energy of the order of several GeV and intensity of the colliding laser pulses of the level of $10^{24}$W/cm$^2$. This means that it can be readily observed at the novel laser facilities which are either planned for the nearest future, or are already under construction. The proposed experimental setup provides the most realistic and promissory way to observe the "avalanche-type" cascades.

  9. Collapse and revival of electromagnetic cascades in focused intense laser pulses

    E-Print Network [OSTI]

    Mironov, A A; Fedotov, A M

    2014-01-01T23:59:59.000Z

    We consider interaction of a high-energy electron beam with two counterpropagating femtosecond laser pulses. Nonlinear Compton scattering and electron-positron pair production by the emitted photons result in development of an electromagnetic "shower-type" cascade, which however collapses rather quickly due to energy losses by secondary particles. Nevertheless, the laser field accelerates the low-energy electrons and positrons trapped in the focal region, thus giving rise to development of electromagnetic cascade of another type ("avalanche-type"). This effect of cascade collapse and revival can be observed at the electron beam energy of the order of several GeV and intensity of the colliding laser pulses of the level of $10^{24}$W/cm$^2$. This means that it can be readily observed at the novel laser facilities which are either planned for the nearest future, or are already under construction. The proposed experimental setup provides the most realistic and promissory way to observe the "avalanche-type" cascad...

  10. Ion heating dynamics in solid buried layer targets irradiated by ultra-short intense laser pulses

    E-Print Network [OSTI]

    Huang, Lingen; Kluge, Thomas; Lei, Anle; Yu, Wei; Cowan, Thomas E

    2013-01-01T23:59:59.000Z

    We investigate bulk ion heating in solid buried layer targets irradiated by ultra-short laser pulses of relativistic intensities using particle-in-cell simulations. Our study focuses on a CD2-Al-CD2 sandwich target geometry. We find enhanced deuteron ion heating in a layer compressed by the expanding aluminium layer. A pressure gradient created at the Al-CD2 interface pushes this layer of deuteron ions towards the outer regions of the target. During its passage through the target, deuteron ions are constantly injected into this layer. Our simulations suggest that the directed collective outward motion of the layer is converted into thermal motion inside the layer, leading to deuteron temperatures higher than those found in the rest of the target. This enhanced heating can already be observed at laser pulse durations as low as 100 femtoseconds. Thus, detailed experimental surveys at repetition rates of several ten laser shots per minute are in reach at current high-power laser systems, which would allow for pr...

  11. Double-slit vacuum polarisation effects in ultra-intense laser fields

    E-Print Network [OSTI]

    B. King; A. Di Piazza; C. H. Keitel

    2013-01-29T23:59:59.000Z

    The influence of the strong laser-driven vacuum on a propagating electromagnetic probe wave has been studied in detail. We investigate two scenarios comprising a focused probe laser beam passing through a region of vacuum polarised by an ultra-intense laser field. By splitting this strong field into two, separated, monochromatic Gaussian pulses counter-propagating in a plane perpendicular to the probe field axis, we demonstrate a leading order light-by-light diffraction effect that generates an interference pattern reminiscent of the classic double-slit experiment. We calculate the total number of probe photons diffracted as well as the number diffracted into regions where the vacuum polarisation signal is higher than the probe background. In addition, we calculate the induced ellipticity and polarisation rotation in the probe beam and show how, in the realistic situation in which the centres of the two strong fields are not exactly aligned, certain ranges of beam separation and observation distance may actually lead to an increase over the idealised case of a single strong laser beam.

  12. Photoionization dynamics and angular squeezing phenomenon in intense long-wavelength laser fields

    E-Print Network [OSTI]

    Chu, Shih-I; Zhou, Zhongyuan

    2011-03-11T23:59:59.000Z

    distribution (PAD) of H2 in laser fields are also explored in order to have a further insight into the tunneling photoionization. We find that the PAD is squeezed with the increase of laser wavelength and/or intensity, and thus the photoelectrons focus... direction, and (e)–(h) PADs for different photoelectron energy. 033406-6 PHOTOIONIZATION DYNAMICS AND ANGULAR . . . PHYSICAL REVIEW A 83, 033406 (2011) 0 20 40 60 80 100 0.0 0.2 0.4 0.6 0.8 1.0 (a) ? = 660 nm d2 P/ dE d? E (eV) 0 20 40 60 80 100 0.0 0.2 0...

  13. Dynamics of an electron in a relativistically intense laser field including radiaion reaction

    SciTech Connect (OSTI)

    Galkin, A. L., E-mail: galkin@kapella.gpi.ru [Prokhorov General Physics Institute of the Russian Academy of Science (Russian Federation)

    2012-08-15T23:59:59.000Z

    The dynamics of an electron in a relativistically intense laser pulse field is described with the radiation reaction being taken into account. The study is based on solving the Newton equation with the Lorentz and the radiation reaction forces. Validation is provided for an iteration technique which makes it possible to remove the discrepancies found in the theoretical models of radiation reaction. It is demonstrated that an electron having a high initial velocity and colliding head-on with a laser pulse sheds a considerable part of its kinetic energy due to the radiation reaction. A broadening of the electromagnetic pulse emitted by the electron occurs as a result of the same effect. The findings obtained can be used to experimentally verify the effect of radiation reaction.

  14. A focusable, convergent fast-electron beam from ultra-high-intensity laser-solid interactions

    E-Print Network [OSTI]

    Scott, R H H

    2015-01-01T23:59:59.000Z

    A novel scheme for the creation of a convergent, or focussing, fast-electron beam generated from ultra-high-intensity laser-solid interactions is described. Self-consistent particle-in-cell simulations are used to demonstrate the efficacy of this scheme in two dimensions. It is shown that a beam of fast-electrons of energy 500 keV - 3 MeV propagates within a solid-density plasma, focussing at depth. The depth of focus of the fast-electron beam is controlled via the target dimensions and focussing optics.

  15. Surfaces in the interaction of intense long wavelength laser light with plasmas

    SciTech Connect (OSTI)

    Jones, R.D.

    1985-01-01T23:59:59.000Z

    The role of surface in the interaction of intense CO/sub 2/ laser light with plasmas is reviewed. The collisionless absorption of long wavelength light is discussed. Specific comments on the role of ponderomotive forces and profile steepening on resonant absorption are made. It is shown that at intensities above 10/sup 15/W/cm/sup 2/ the absorption is determined by ion acoustic-like surface modes. It is demonstrated experimentally that harmonics up to the forty-sixth can be generated in steep density profiles. Computer simulations and theoretical mechanisms for this phenomena are presented. The self generation of magnetic fields on surfaces is discussed. The role these fields play in the lateral transport of energy, the insulation of the target from hot electrons, and the acceleration of fast ions is discussed.

  16. Observation of a Long-Wavelength Hosing Modulation of a High-Intensity Laser Pulse in Underdense Plasma

    E-Print Network [OSTI]

    Kaluza, M C; Thomas, A G R; Najmudin, Z; Dangor, A E; Murphy, C D; Collier, J L; Divall, E J; Foster, P S; Hooker, C J; Langley, A J; Smith, J; Krushelnick, K

    2010-01-01T23:59:59.000Z

    We report the first experimental observation of a long-wavelength hosing modulation of a high-intensity laser pulse. Side-view images of the scattered optical radiation at the fundamental wave-length of the laser reveal a transverse oscillation of the laser pulse during its propagation through underdense plasma. The wavelength of the oscillation \\lambda_hosing depends on the background plasma density n_e and scales as \\lambda_hosing~n_e^-3/2. Comparisons with an analytical model and 2-dimensional particle-in-cell simulations reveal that this laser hosing can be induced by a spatio-temporal asymmetry of the intensity distribution in the laser focus which can be caused by a misalignment of the parabolic focussing mirror or of the diffraction gratings in the pulse compressor.

  17. Ultra-Intense Gamma-Rays Created Using the Texas Petawatt Laser

    E-Print Network [OSTI]

    Alexander Henderson; Edison Liang; Nathan Riley; Pablo Yepes; Gillis Dyer; Kristina Serratto; Petr Shagin

    2014-03-28T23:59:59.000Z

    In a series of experiments at the Texas Petawatt Laser (TPW) in Austin, TX, we have used attenuation spectrometers, dosimeters, and a new Forward Compton Electron Spectrometer (FCES) to measure and characterize the angular distribution, fluence, and energy spectrum of the X-rays and gamma rays produced by the TPW striking multi-millimeter thick gold targets. Our results represent the first such measurements at laser intensities > 10 21 W*cm-2 and pulse durations laser energy of 4% and a mean yield of 2%. We futher obtain a Full Width Half Maximum (FWHM) of the gamma distribution of 37{\\deg}. We were able to characterize the gamma-ray spectrum from 3 MeV to 90 MeV using a Forward Compton Electron Spectrometer, with an energy resolution of 0.5 MeV and mean kT of ~ 6 MeV.. We were able to characterize the spectrum from 1 to 7 MeV using a Filter Stack Spectrometer, measuring a mean gamma-ray temperature for the spectrum from 3 to 7 MeV of 2.1 MeV.

  18. Accelerating Protons to Therapeutic Energies with Ultra-Intense Ultra-Clean and Ultra-Short Laser Pulses

    E-Print Network [OSTI]

    Bulanov, Stepan S; Bychenkov, Valery Yu; Chvykov, Vladimir; Kalinchenko, Galina; Matsuoka, Takeshi; Rousseau, Pascal; Reed, Stephen; Yanovsky, Victor; Krushelnick, Karl; Litzenberg, Dale William; Maksimchuk, Anatoly

    2008-01-01T23:59:59.000Z

    Proton acceleration by high-intensity laser pulses from ultra-thin foils for hadron therapy is discussed. With the improvement of the laser intensity contrast ratio to 10-11 achieved on Hercules laser at the University of Michigan, it became possible to attain laser-solid interactions at intensities up to 1022 W/cm2 that allows an efficient regime of laser-driven ion acceleration from submicron foils. Particle-In-Cell (PIC) computer simulations of proton acceleration in the Directed Coulomb explosion regime from ultra-thin double-layer (heavy ions / light ions) foils of different thicknesses were performed under the anticipated experimental conditions for Hercules laser with pulse energies from 3 to 15 J, pulse duration of 30 fs at full width half maximum (FWHM), focused to a spot size of 0.8 microns (FWHM). In this regime heavy ions expand predominantly in the direction of laser pulse propagation enhancing the longitudinal charge separation electric field that accelerates light ions. The dependence of the ma...

  19. Fermilab | Science at Fermilab | Experiments & Projects | Intensity

    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: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOEThe Bonneville Power AdministrationField8,Dist.New Mexico Feb. 13, 2013Focusreceives .1Grid IntensityFermilab

  20. Loss of spatial coherence and limiting of focal plane intensity by small-scale laser-beam filamentation

    SciTech Connect (OSTI)

    Schweinsberg, Aaron; Kuper, Jerry [The Institute of Optics, University of Rochester, Rochester, New York 14627 (United States); Boyd, Robert W. [The Institute of Optics, University of Rochester, Rochester, New York 14627 (United States); Department of Physics and Astronomy, University of Rochester, Rochester, New York 14627 (United States); Department of Physics and School of Electrical Engineering and Computer Science, University of Ottawa, Ottawa, Ontario, Canda K1N 6N5 (Canada)

    2011-11-15T23:59:59.000Z

    We describe a nonlinear optical mechanism that leads to a decrease of the degree of (transverse) spatial coherence of a laser beam as a function of propagation distance. This prediction is in direct contrast with those of the van Cittert-Zernike theorem, which applies to propagation through a linear, homogeneous material. The mechanism by which coherence is lost is the growth of small phase irregularities initially present on the laser wave front. We develop a detailed theoretical model of this effect and present experimental results that validate this model. The practical importance of this result is that by being able to controllably decrease the spatial coherence of a laser beam, one can limit the maximum intensity that is produced in its focal region. By limiting the intensity, one can prevent laser damage to bulk optical components or to sensitive photodetectors. This mechanism thus provides an alternative to current approaches of sensor protection based on optical power limiting.

  1. NERSC Launches Data-intensive Science Pilot Program

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOE Office of Science (SC)Integrated Codes |IsLove Your1AllocationsNOVA Portal:Ott2006.jpg A

  2. Evidence for ultra-fast heating in intense-laser irradiated reduced-mass targets

    SciTech Connect (OSTI)

    Neumayer, P.; Gumberidze, A.; Hochhaus, D. C. [ExtreMe Matter Institute EMMI and Research Division, GSI Helmholtzzentrum fuer Schwerionenforschung, 64291 Darmstadt (Germany); Frankfurt Institute for Advanced Studies FIAS, 60438 Frankfurt am Main (Germany); Aurand, B.; Stoehlker, T. [Helmholtzzentrum fuer Schwerionenforschung GSI, 64291 Darmstadt (Germany); Helmholtz Institute Jena, 07743 Jena (Germany); Costa Fraga, R. A.; Kalinin, A. [Institut fuer Kernphysik, J. W. Goethe University Frankfurt, 60438 Frankfurt am Main (Germany); Ecker, B. [Johannes Gutenberg University Mainz, 55099 Mainz (Germany); Helmholtz Institute Jena, 07743 Jena (Germany); Grisenti, R. E. [Institut fuer Kernphysik, J. W. Goethe University Frankfurt, 60438 Frankfurt am Main (Germany); Helmholtzzentrum fuer Schwerionenforschung GSI, 64291 Darmstadt (Germany); Kaluza, M. C. [Helmholtz Institute Jena, 07743 Jena (Germany); IOQ Institute of Optics and Quantum Electronics, University of Jena (Germany); Kuehl, T. [Johannes Gutenberg University Mainz, 55099 Mainz (Germany); Helmholtzzentrum fuer Schwerionenforschung GSI, 64291 Darmstadt (Germany); Helmholtz Institute Jena, 07743 Jena (Germany); Polz, J. [IOQ Institute of Optics and Quantum Electronics, University of Jena (Germany); Reuschl, R. [ExtreMe Matter Institute EMMI and Research Division, GSI Helmholtzzentrum fuer Schwerionenforschung, 64291 Darmstadt (Germany); Winters, D.; Winters, N.; Yin, Z. [Helmholtzzentrum fuer Schwerionenforschung GSI, 64291 Darmstadt (Germany)

    2012-12-15T23:59:59.000Z

    We report on an experiment irradiating individual argon droplets of 20 {mu}m diameter with laser pulses of several Joule energy at intensities of 10{sup 19} W/cm{sup 2}. K-shell emission spectroscopy was employed to determine the hot electron energy fraction and the time-integrated charge-state distribution. Spectral fitting indicates that bulk temperatures up to 160 eV are reached. Modelling of the hot-electron relaxation and generation of K-shell emission with collisional hot-electron stopping only is incompatible with the experimental results, and the data suggest an additional ultra-fast (sub-ps) heating contribution. For example, including resistive heating in the modelling yields a much better agreement with the observed final bulk temperature and qualitatively reproduces the observed charge state distribution.

  3. Dominant deuteron acceleration with a high-intensity laser for isotope production and neutron generation

    SciTech Connect (OSTI)

    Maksimchuk, A.; Raymond, A.; Yu, F.; Dollar, F.; Willingale, L.; Zulick, C.; Krushelnick, K. [Center for Ultrafast Optical Science, University of Michigan, Ann Arbor, Michigan 48109 (United States)] [Center for Ultrafast Optical Science, University of Michigan, Ann Arbor, Michigan 48109 (United States); Petrov, G. M.; Davis, J. [Naval Research Laboratory, Plasma Physics Division, Washington, DC 20375 (United States)] [Naval Research Laboratory, Plasma Physics Division, Washington, DC 20375 (United States)

    2013-05-13T23:59:59.000Z

    Experiments on the interaction of an ultra-short pulse laser with heavy-water, ice-covered copper targets, at an intensity of 2 Multiplication-Sign 10{sup 19} W/cm{sup 2}, were performed demonstrating the generation of a 'pure' deuteron beam with a divergence of 20 Degree-Sign , maximum energy of 8 MeV, and a total of 3 Multiplication-Sign 10{sup 11} deuterons with energy above 1 MeV-equivalent to a conversion efficiency of 1.5%{+-} 0.2%. Subsequent experiments on irradiation of a {sup 10}B sample with deuterons and neutron generation from d-d reactions in a pitcher-catcher geometry, resulted in the production of {approx}10{sup 6} atoms of the positron emitter {sup 11}C and a neutron flux of (4{+-}1) Multiplication-Sign 10{sup 5} neutrons/sterad, respectively.

  4. Characterization of Molecular Breakup by Super-Intense, Femtosecond XUV Laser Pulses

    E-Print Network [OSTI]

    Yue, Lun

    2015-01-01T23:59:59.000Z

    We study the breakup of $\\text{H}_2^+$ exposed to super-intense, femtosecond laser pulses with frequencies greater than that corresponding to the ionization potential. By solving the time-dependent Schr\\"{o}dinger equation in an extensive field parameter range, it is revealed that highly nonresonant dissociation channels can dominate over ionization. By considering field-dressed Born-Oppenheimer potential energy curves in the reference frame following a free electron in the field, we propose a simple physical model that characterizes this dissociation mechanism. The model is used to predict control of vibrational excitation, magnitude of the dissociation yields, and nuclear kinetic energy release spectra. Finally, the joint energy spectrum for the ionization process illustrates the energy sharing between the electron and the nuclei and the correlation between ionization and dissociation processes.

  5. The Laser Astrometric Test of Relativity: Science, Technology, and Mission Design

    E-Print Network [OSTI]

    Slava G. Turyshev; Michael Shao

    2007-01-18T23:59:59.000Z

    The Laser Astrometric Test of Relativity (LATOR) experiment is designed to explore general theory of relativity in the close proximity to the Sun -- the most intense gravitational environment in the solar system. Using independent time-series of highly accurate measurements of the Shapiro time-delay (interplanetary laser ranging accurate to 3 mm at 2 AU) and interferometric astrometry (accurate to 0.01 picoradian), LATOR will measure gravitational deflection of light by the solar gravity with accuracy of 1 part in a billion -- a factor ~30,000 better than currently available. LATOR will perform series of highly-accurate tests in its search for cosmological remnants of scalar field in the solar system. We present science, technology and mission design for the LATOR mission.

  6. Ultrafast laser ablation ICP-MS: role of spot size, laser fluence, and repetition rate in signal intensity

    E-Print Network [OSTI]

    Harilal, S. S.

    Ultrafast laser ablation ICP-MS: role of spot size, laser fluence, and repetition rate in signal,a Richard E. Russob and Ahmed Hassaneina Ultrafast laser ablation inductively coupled plasma mass system. Though ultrafast laser ablation sample introduction provides better accuracy and precision

  7. HILL: The High-Intensity Laser Laboratory Core Team's Reply to Questions from the NNSA Experimental Facilities Panel

    SciTech Connect (OSTI)

    Albright, B J [Los Alamos National Laboratory

    2012-08-02T23:59:59.000Z

    Question 1 - The type of physics regimes that HILL can access for weapons studies is quite interesting. The question that arises for the proposal team is what priority does this type of experimental data have versus data that can be obtained with NIF, and Z. How does HILL rank in priority compared to MARIE 1.0 in terms of the experimental data it will provide? We reiterate that isochoric heating experiments to be conducted with HILL are complementary to the high energy density physics experiments at NIF and Z and uniquely access states of matter that neither other facility can access. It is our belief that HILL will enable several important questions, e.g., as related to mix morphology, radiation transfer from corrugated surfaces, and equations of state, to be run to ground through carefully diagnosed, 'unit-physics' experiments. Such experiments will substantially improve confidence in our computer models and provide a rigorous science basis for certification. Question 2 - A secondary question relates to the interests of LLNL and SNL in the physics that HILL can address. This should be spelled out clearly. I would like to see the other labs be part of the discussion regarding how important this capability would be if built. Both sister Labs have a keen interest in the physics enabled by high-intensity, high-energy lasers, as evinced by the Z Petawatt and NIF ARC upgrades to their signature facilities. LANL scientists have teamed with scientists from both Laboratories in high-intensity laser 'first experiments' envisioned for HILL and we fully intend to continue these profitable discussions going forward. In the preparation of the HILL proposal, feedback was solicited from the broader HEDP and weapons science communities. The consensus view was that HILL filled a critical gap and that there was a need for a facility like HILL to address outstanding questions in weapons science. It was recognized that co-location of HILL with a facility such as MaRIE 1.0, Z, NIF, or Omega may offer additional advantages and we would expect these to be explored and evaluated during the CD process. Question 3 - A laser/optics experts group should review this proposal to ensure the level of R&D is reasonable to provide a sufficient chance of success (>50%). In the preparation of the HILL proposal, we sent our proposal and cost estimates to laser designers/scientists across the complex. Though risks were identified with our design, the prevailing view of those we engaged was that the risks were appropriately represented by the TRL levels assigned and that the enabling R&D planned in our proposal was adequate for risk mitigation. Question 4 - More data and peer review is needed from its sister facilities around the world. It is our specific intent to conduct both scientific and technical workshops with the user community if the High Intensity Science field is further encouraged as part of the NNSA Roadmap. Question 5 - Does HILL have to be co-located with MARIE 1.0? Is that feasible from the point of view of TA-53 real estate? Multiple siting options were considered for HILL, including co-location with MaRIE 1.0 (the most cost-effective and flexible option), as well as in a separate, stand-alone building and in a retro-fitted existing building. The cost estimate included these contingencies and candidate locations for HILL in TA-53 were identified. There is actually significant space at TA-53 on the hill in the northeast end of the mesa. Question 6 - What would be the impact on the weapons program if this facility were NOT built? An inability to elucidate aspects of weapons science in the dense plasma regime and validate computer models for same. This will lead to reduced confidence in the computer tools used for certification. Question 7 - Will HILL allow some of the x-ray vulnerability studies proposed by SPARC? If so what does Sandia's vulnerability group think of this method versus SPARC. It is possible that some of the scope envisioned for SPARC could be achieved on HILL, although likely that the energy produced at HILL not bei

  8. Laser Ranging for Gravitational, Lunar, and Planetary Science

    E-Print Network [OSTI]

    Stephen M. Merkowitz; Philip W. Dabney; Jeffrey C. Livas; Jan F. McGarry; Gregory A. Neumann; Thomas W. Zagwodzki

    2007-12-20T23:59:59.000Z

    More precise lunar and Martian ranging will enable unprecedented tests of Einstein's theory of General Relativity and well as lunar and planetary science. NASA is currently planning several missions to return to the Moon, and it is natural to consider if precision laser ranging instruments should be included. New advanced retroreflector arrays at carefully chosen landing sites would have an immediate positive impact on lunar and gravitational studies. Laser transponders are currently being developed that may offer an advantage over passive ranging, and could be adapted for use on Mars and other distant objects. Precision ranging capability can also be combined with optical communications for an extremely versatile instrument. In this paper we discuss the science that can be gained by improved lunar and Martian ranging along with several technologies that can be used for this purpose.

  9. Selective emission and luminescence of Er{sub 2}O{sub 3} under intense laser excitation

    SciTech Connect (OSTI)

    Marchenko, V M; Studenikin, M I [A M Prokhorov General Physics Institute, Russian Academy of Sciences, Moscow (Russian Federation); Iskhakova, L D [Fiber Optics Research Center, Russian Academy of Sciences, Moscow (Russian Federation)

    2013-09-30T23:59:59.000Z

    The microstructure of Er{sub 2}O{sub 3} polycrystals synthesised by laser heating is studied. The synthesis of erbium silicate (Er{sub 2}SiO{sub 5}) layers was observed upon interaction of Er{sub 2}O{sub 3} and SiO{sub 2} melts. The dependences of the selective emission (SE) and luminescence spectra of Er{sub 2}O{sub 3} polycrystals in the range 200 – 1700 nm on the intensity of laser-thermal (at the wavelength ? = 10.6 ?m) and resonant laser (? ? 975 nm) excitation are investigated. The emission of heated Er{sub 2}O{sub 3} polycrystals arises as a result of multiphonon relaxation of absorbed energy and is a superposition of the SE at the electronic-vibrational transitions of Er{sup 3+} ions and the thermal radiation of the crystal lattice. The shape of the SE spectra of Er{sub 2}O{sub 3} polycrystals in the range 400 – 1700 nm almost does not change upon laser-thermal heating from 300 to 1500 K and subsequent cooling and corresponds to the absorption spectra of Er{sup 3+} ions. With increasing temperature, the thermal radiation intensity increases faster than the SE intensity, and the shape of the Er{sub 2}O{sub 3} spectrum becomes closer to the calculated spectrum of a blackbody. The anti-Stokes luminescence spectra of Er{sup 3+} ions formed under intense laser excitation of the {sup 4}I{sub 11/2} level are explained by additional SE caused by heating of the crystal matrix due to the Stokes losses. A difference between the SE and luminescence spectra is observed at low intensities of resonant laser excitation and low temperatures, when only the Stokes luminescence occurs. The temperature dependences of the SE and luminescence spectra of Er{sub 2}O{sub 3} upon laser excitation testify to the fundamental role played by the interaction of the electronic f-shell of Er{sup 3+} ions with crystal lattice vibrations in the processes of multiphonon radiative and nonradiative relaxation. The laser-thermal synthesis is promising for inprocess variation of the chemical composition of rare-earth samples. (interaction of laser radiation with matter)

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

    SciTech Connect (OSTI)

    Racz, E.; Foeldes, I. B. [KFKI RMKI, EURATOM Association, P.O.Box 49, H-1525 Budapest (Hungary); Ryc, L. [Institute of Plasma Physics and Laser Microfusion, Hery 23, 00-908 Warsaw (Poland)

    2006-01-15T23:59:59.000Z

    Experiments were carried out using a prepulse-free hybrid KrF excimer-dye laser system (700fs pulse duration, 248nm wavelength, 15mJ pulse energy). The intensity of the p-polarized, focused laser beam was 1.5{center_dot}1017 W/cm2. Vacuum ultraviolet (VUV) and x-rays from solid state laser plasmas were generated in the laser-plasma interaction of subpicosecond laser pulses of nonrelativistic laser intensities. An x-ray sensitive FLM photodiode (ITE, Warsaw) was used to detect x-rays between 1-19 keV in front of the targets. The diode was filtered by a 4{mu}m Al foil. The dependence of the x-ray flux on laser intensity and the angular distribution of x-rays for aluminum and copper targets in the half space of the front side of the targets were investigated.

  11. The Science DMZ: A Network Design Pattern for Data-Intensive Science

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

    Dart, Eli; Rotman, Lauren; Tierney, Brian; Hester, Mary; Zurawski, Jason

    2014-01-01T23:59:59.000Z

    The ever-increasing scale of scientific data has become a significant challenge for researchers that rely on networks to interact with remote computing systems and transfer results to collaborators worldwide. Despite the availability of high-capacity connections, scientists struggle with inadequate cyberinfrastructure that cripples data transfer performance, and impedes scientific progress. The ScienceDMZparadigm comprises a proven set of network design patterns that collectively address these problems for scientists. We explain the Science DMZ model, including network architecture, system configuration, cybersecurity, and performance tools, that creates an optimized network environment for science. We describe use cases from universities, supercomputing centers and research laboratories,more »highlighting the effectiveness of the Science DMZ model in diverse operational settings. In all, the Science DMZ model is a solid platform that supports any science workflow, and flexibly accommodates emerging network technologies. As a result, the Science DMZ vastly improves collaboration, accelerating scientific discovery.« less

  12. The Science DMZ: A Network Design Pattern for Data-Intensive Science

    SciTech Connect (OSTI)

    Dart, Eli; Rotman, Lauren; Tierney, Brian; Hester, Mary; Zurawski, Jason

    2013-08-13T23:59:59.000Z

    The ever-increasing scale of scientific data has become a significant challenge for researchers that rely on networks to interact with remote computing systems and transfer results to collaborators worldwide. Despite the availability of high-capacity connections, scientists struggle with inadequate cyberinfrastructure that cripples data transfer performance, and impedes scientific progress. The Science DMZ paradigm comprises a proven set of network design patterns that collectively address these problems for scientists. We explain the Science DMZ model, including network architecture, system configuration, cybersecurity, and performance tools, that creates an optimized network environment for science. We describe use cases from universities, supercomputing centers and research laboratories, highlighting the effectiveness of the Science DMZ model in diverse operational settings. In all, the Science DMZ model is a solid platform that supports any science workflow, and flexibly accommodates emerging network technologies. As a result, the Science DMZ vastly improves collaboration, accelerating scientific discovery.

  13. Relativistic effects in the interaction of high intensity ultra-short laser pulse with collisional underdense plasma

    SciTech Connect (OSTI)

    Abedi, Samira [Physics Department, North Tehran Branch, Islamic Azad University, Tehran (Iran, Islamic Republic of); Dorranian, Davoud [Laser Lab., Plasma Physics Research Center, Science and Research Branch, Islamic Azad University, Tehran (Iran, Islamic Republic of); Abari, Mehdi Etehadi [Physics Department, Science Faculty, Shahid Beheshti University, G.C., Evin, Tehran 19839 (Iran, Islamic Republic of); Shokri, Babak [Physics Department, Science Faculty, Shahid Beheshti University, G.C., Evin, Tehran 19839 (Iran, Islamic Republic of); Laser-Plasma Research Institute, Shahid Beheshti University, G.C., Evin, Tehran 19839 (Iran, Islamic Republic of)

    2011-09-15T23:59:59.000Z

    In this paper, the effect of weakly relativistic ponderomotive force in the interaction of intense laser pulse with nonisothermal, underdense, collisional plasma is studied. Ponderomotive force modifies the electron density and temperature distribution. By considering the weakly relativistic effect and ohmic heating of plasma electrons, the nonlinear dielectric permittivity of plasma medium is obtained and the equation of electromagnetic wave propagation in plasma is solved. It is shown that with considering the ohmic heating of electrons and collisions, the effect of ponderomotive force in weakly relativistic regime leads to steepening the electron density profile and increases the temperature of plasma electrons noticeably. Bunches of electrons in plasma become narrower. By increasing the laser pulse strength, the wavelength of density oscillations decreases. In this regime of laser-plasma interaction, electron temperature increases sharply by increasing the intensity of laser pulse. The amplitude of electric and magnetic fields increases by increasing the laser pulse energy while their wavelength decreases and they lost their sinusoidal form.

  14. Continuation of full-scale three-dimensional numerical experiments on high-intensity particle and laser beam-matter interactions

    SciTech Connect (OSTI)

    Mori, Warren, B.

    2012-12-01T23:59:59.000Z

    We present results from the grant entitled, ���¢��������Continuation of full-scale three-dimensional numerical experiments on high-intensity particle and laser beam-matter interactions.���¢������� The research significantly advanced the understanding of basic high-energy density science (HEDS) on ultra intense laser and particle beam plasma interactions. This advancement in understanding was then used to to aid in the quest to make 1 GeV to 500 GeV plasma based accelerator stages. The work blended basic research with three-dimensions fully nonlinear and fully kinetic simulations including full-scale modeling of ongoing or planned experiments. The primary tool was three-dimensional particle-in-cell simulations. The simulations provided a test bed for theoretical ideas and models as well as a method to guide experiments. The research also included careful benchmarking of codes against experiment. High-fidelity full-scale modeling provided a means to extrapolate parameters into regimes that were not accessible to current or near term experiments, thereby allowing concepts to be tested with confidence before tens to hundreds of millions of dollars were spent building facilities. The research allowed the development of a hierarchy of PIC codes and diagnostics that is one of the most advanced in the world.

  15. Laser enhanced high-intensity focused ultrasound thrombolysis: An in vitro study

    E-Print Network [OSTI]

    Cui, Huizhong; Yang, Xinmai

    2013-01-17T23:59:59.000Z

    radiation, and ultrasound and laser parameters were optimized to achieve better thrombolysis efficiency. The results indicated that the thrombolysis efficiency increased when pulse length of HIFU wave, HIFU pressure, or laser fluence increases. Also...

  16. Backward-Propagating MeV Electrons in Ultra-Intense Laser Interactions: Standing Wave Acceleration and Coupling to the Reflected Laser Pulse

    E-Print Network [OSTI]

    Orban, Chris; Chowdhury, Enam D; Nees, John A; Frische, Kyle; Roquemore, W Melvyn

    2014-01-01T23:59:59.000Z

    Laser-accelerated electron beams have been created at a kHz repetition rate from the reflection of intense ($\\sim10^{18}$ W/cm$^2$), 30 fs laser pulses focused on a continuous water-jet in an experiment at the Air Force Research Laboratory. This paper investigates Particle-In-Cell (PIC) simulations of the laser-target interaction to identify the physical mechanisms of electron acceleration in this experiment. We find that the standing-wave pattern created by the overlap of the incident and reflected laser is particularly important because this standing wave "injects" electrons into the reflected laser pulse where the electrons are further accelerated. We identify two regimes of standing wave acceleration: a highly relativistic case ($a_0~\\geq~1$), and a moderately relativistic case ($a_0~\\sim~0.5$) which operates over a larger fraction of the laser period. Previous work by other groups investigated the highly relativistic case for its usefulness in launching electrons in the forward direction. We extend this ...

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

    SciTech Connect (OSTI)

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

    2014-03-15T23:59:59.000Z

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

  18. Electrons in a relativistic-intensity laser field: generation of zeptosecond electromagnetic pulses and energy spectrum of the accelerated electrons

    SciTech Connect (OSTI)

    Andreev, A A; Galkin, A L; Kalashnikov, M P; Korobkin, V V; Romanovsky, Mikhail Yu; Shiryaev, O B [A M Prokhorov General Physics Institute, Russian Academy of Sciences, Moscow (Russian Federation)

    2011-08-31T23:59:59.000Z

    We study the motion of an electron and emission of electromagnetic waves by an electron in the field of a relativistically intense laser pulse. The dynamics of the electron is described by the Newton equation with the Lorentz force in the right-hand side. It is shown that the electrons may be ejected from the interaction region with high energy. The energy spectrum of these electrons and the technique of using the spectrum to assess the maximal intensity in the focus are analysed. It is found that electromagnetic radiation of an electron moving in an intense laser field occurs within a small angle around the direction of the electron trajectory tangent. The tangent quickly changes its direction in space; therefore, electromagnetic radiation of the electron in the far-field zone in a certain direction in the vicinity of the tangent is a short pulse with a duration as short as zeptoseconds. The calculation of the temporary and spectral distribution of the radiation field is carried out. (superintense laser fields)

  19. Laser AblationICPMS in the Earth Sciences CURRENT PRACTICES AND OUTSTANDING ISSUES

    E-Print Network [OSTI]

    Bodnar, Robert J.

    #12;Laser Ablation­ICP­MS in the Earth Sciences CURRENT PRACTICES AND OUTSTANDING ISSUES recently been developed to facilitate the reduction of data from laser ablation inductively coupled plasma.R. MUTCHLER, L. FEDELE & R.J. BODNAR 318 APPENDIX A5: ANALYSIS MANAGEMENT SYSTEM (AMS) FOR REDUCTION OF LASER

  20. Experimental nonlinear laser systems: Bigger data for better science?

    SciTech Connect (OSTI)

    Kane, D. M.; Toomey, J. P.; McMahon, C.; Noblet, Y. [MQ Photonics Research Centre, Department of Physics and Astronomy, Macquarie University ~ Sydney, NSW 2109 (Australia); Argyris, A.; Syvridis, D. [Department of Informatics and Telecommunications, National and Kapodistrian University of Athens, Panepistimiopolis, Ilisia, 15784 (Greece)

    2014-10-06T23:59:59.000Z

    Bigger data is supporting knowledge discovery in nonlinear laser systems as will be demonstrated with examples from three semiconductor laser based systems – one with optical feedback, a photonic integrated circuit (PIC) chaotic laser and a frequency shifted feedback laser system.

  1. Characteristic x-ray emission from undermines plasmas irradiated by ultra-intense lasers

    SciTech Connect (OSTI)

    Niemann, Christoph

    2012-05-05T23:59:59.000Z

    Between FY09 and FY11 we have conducted more than a dozen three-week experimental campaigns at high-power laser facilities around the world to investigate laser-channeling through x-ray and optical imaging and the conversion from laser-energy to xrays. We have performed simultaneous two-wavelength x-ray imaging (K-alpha and He-alpha) to distinguish the hot-plasma region (hot-spot) from the laser-produced electrons (K-alpha). In addition, we have initiated a new collaboration with SNL and have performed first shots on the 100 TW beamlet chamber to commission a fast x-ray streak camera to be used to investigate the temporal evolution of our K-alpha sources. We also collaborated on campaigns at the Rutherford Appleton Laboratory (UK) and the LANL Trident laser to employ laser produced x-ray sources for Thomson scattering off dense matter.

  2. ChemCam Rock Laser for the Mars Science Laboratory

    ScienceCinema (OSTI)

    LANL

    2009-09-01T23:59:59.000Z

    Los Alamos has a long history of space-related instr... Los Alamos has a long history of space-related instruments, tied primarily to its role in defense-related treaty verification. Space-based detectors have helped determine the differences between signals from lightning bolts and potential nuclear explosions. LANL-developed gamma-ray detection instruments first revealed the existence of what we now know as gamma-ray bursts, an exciting area of astrophysical research. And the use of LANL instruments on varied space missions continues with such products as the ChemCam rock laser for NASA, shown here. The Engineering Model of the ChemCam Mars Science Laboratory rover instrument arrived at NASA's Jet Propulsion Laboratory on February 6, 2008. ChemCam will use imaging and laser-induced breakdown spectroscopy (LIBS) to determine rock and soil compositions on Mars, up to 9 meters from the rover. The engineering model is being integrated into the rover test bed for the development and testing of the rover software. The actual flight model components are concurrently being assembled at Los Alamos and in Toulouse, France, and will be delivered to JPL in July. The Mars Science Laboratory is scheduled to launch in 2009. Animations courtesy of JPL/NASA.

  3. ChemCam rock laser for Mars Science Laboratory "Curiosity"

    ScienceCinema (OSTI)

    Wiens, Roger

    2014-08-12T23:59:59.000Z

    Los Alamos has a long history of space-related instruments, tied primarily to its role in defense-related treaty verification. Space-based detectors have helped determine the differences between signals from lightning bolts and potential nuclear explosions. LANL-developed gamma-ray detection instruments first revealed the existence of what we now know as gamma-ray bursts, an exciting area of astrophysical research. And the use of LANL instruments on varied space missions continues with such products as the ChemCam rock laser for NASA, shown here. The Engineering Model of the ChemCam Mars Science Laboratory rover instrument arrived at NASA's Jet Propulsion Laboratory on February 6, 2008. The Flight Model was shipped in August, 2010 for installation on the rover at JPL. ChemCam will use imaging and laser-induced breakdown spectroscopy (LIBS) to determine rock and soil compositions on Mars, up to 9 meters from the rover. The engineering model is being integrated into the rover test bed for the development and testing of the rover software. The actual flight model components were concurrently assembled at Los Alamos and in Toulouse, France. The Mars Science Laboratory is scheduled to launch in 2011. Animations courtesy of JPL/NASA.

  4. Proceedings of the workshop on the science of intense radioactive ion beams

    SciTech Connect (OSTI)

    McClelland, J.B.; Vieira, D.J. (comps.)

    1990-10-01T23:59:59.000Z

    This report contains the proceedings of a 2-1/2 day workshop on the Science of Intense Radioactive Ion Beams which was held at the Los Alamos National Laboratory on April 10--12, 1990. The workshop was attended by 105 people, representing 30 institutions from 10 countries. The thrust of the workshop was to develop the scientific opportunities which become possible with a new generation intense Radioactive Ion Beam (RIB) facility, currently being discussed within North America. The workshop was organized around five primary topics: (1) reaction physics; (2) nuclei far from stability/nuclear structure; (3) nuclear astrophysics; (4) atomic physics, material science, and applied research; and (5) facilities. Overview talks were presented on each of these topics, followed by 1-1/2 days of intense parallel working group sessions. The final half day of the workshop was devoted to the presentation and discussion of the working group summary reports, closing remarks and a discussion of future plans for this effort.

  5. Hydrodynamic Scaling Analysis of Nuclear Fusion driven by ultra-intense laser-plasma interactions

    E-Print Network [OSTI]

    Sachie Kimura; Aldo Bonasera

    2012-07-24T23:59:59.000Z

    We discuss scaling laws of fusion yields generated by laser-plasma interactions. The yields are found to scale as a function of the laser power. The origin of the scaling law in the laser driven fusion yield is derived in terms of hydrodynamic scaling. We point out that the scaling properties can be attributed to the laser power dependence of three terms: the reaction rate, the density of the plasma and the projected range of the plasma particle in the target medium. The resulting scaling relations have a predictive power that enables estimating the fusion yield for a nuclear reaction which has not been investigated by means of the laser accelerated ion beams.

  6. Using X-ray free-electron lasers for probing of complex interaction dynamics of ultra-intense lasers with solid matter

    SciTech Connect (OSTI)

    Kluge, T., E-mail: t.kluge@hzdr.de; Huang, L. G.; Metzkes, J.; Bussmann, M. [Helmholtz-Zentrum Dresden-Rossendorf e.V., D-01328 Dresden (Germany)] [Helmholtz-Zentrum Dresden-Rossendorf e.V., D-01328 Dresden (Germany); Gutt, C. [Universität Siegen, D-57068 Siegen (Germany)] [Universität Siegen, D-57068 Siegen (Germany); Schramm, U.; Cowan, T. E. [Helmholtz-Zentrum Dresden-Rossendorf e.V., D-01328 Dresden (Germany) [Helmholtz-Zentrum Dresden-Rossendorf e.V., D-01328 Dresden (Germany); Technische Universität Dresden, D-01062 Dresden (Germany)

    2014-03-15T23:59:59.000Z

    We demonstrate the potential of X-ray free-electron lasers (XFEL) to advance the understanding of complex plasma dynamics by allowing for the first time nanometer and femtosecond resolution at the same time in plasma diagnostics. Plasma phenomena on such short timescales are of high relevance for many fields of physics, in particular in the ultra-intense ultra-short laser interaction with matter. Highly relevant yet only partially understood phenomena become directly accessible in experiment. These include relativistic laser absorption at solid targets, creation of energetic electrons and electron transport in warm dense matter, including the seeding and development of surface and beam instabilities, ambipolar expansion, shock formation, and dynamics at the surfaces or at buried layers. In this paper, we focus on XFEL plasma probing for high power laser matter interactions based on quantitative calculations using synthesized data and evaluate the feasibility of various imaging and scattering techniques with special focus on the small angle X-ray scattering technique.

  7. Laser sustained discharge nozzle apparatus for the production of an intense beam of high kinetic energy atomic species

    DOE Patents [OSTI]

    Cross, J.B.; Cremers, D.A.

    1986-01-10T23:59:59.000Z

    Laser sustained discharge apparatus for the production of intense beams of high kinetic energy atomic species is described. A portion of the plasma resulting from a laser sustained continuous optical discharge which generates energetic atomic species from a gaseous source thereof is expanded through a nozzle into a region of low pressure. The expanded plasma contains a significant concentration of the high kinetic energy atomic species which may be used to investigate the interaction of surfaces therewith. In particular, O-atoms having velocities in excess of 3.5 km/s can be generated for the purpose of studying their interaction with materials in order to develop protective materials for spacecraft which are exposed to such energetic O-atoms during operation in low earth orbit.

  8. Electron Generation and Transport in Intense Relativistic Laser-Plasma Interactions Relevant to Fast Ignition ICF

    SciTech Connect (OSTI)

    Ma, T

    2010-04-21T23:59:59.000Z

    The reentrant cone approach to Fast Ignition, an advanced Inertial Confinement Fusion scheme, remains one of the most attractive because of the potential to efficiently collect and guide the laser light into the cone tip and direct energetic electrons into the high density core of the fuel. However, in the presence of a preformed plasma, the laser energy is largely absorbed before it can reach the cone tip. Full scale fast ignition laser systems are envisioned to have prepulses ranging between 100 mJ to 1 J. A few of the imperative issues facing fast ignition, then, are the conversion efficiency with which the laser light is converted to hot electrons, the subsequent transport characteristics of those electrons, and requirements for maximum allowable prepulse this may put on the laser system. This dissertation examines the laser-to-fast electron conversion efficiency scaling with prepulse for cone-guided fast ignition. Work in developing an extreme ultraviolet imager diagnostic for the temperature measurements of electron-heated targets, as well as the validation of the use of a thin wire for simultaneous determination of electron number density and electron temperature will be discussed.

  9. Absolute infrared vibrational band intensities of molecular ions determined by direct laser absorption spectroscopy in fast ion beams

    SciTech Connect (OSTI)

    Keim, E.R.; Polak, M.L.; Owrutsky, J.C.; Coe, J.V.; Saykally, R.J. (Department of Chemistry, University of California, Berkeley, CA (USA))

    1990-09-01T23:59:59.000Z

    The technique of direct laser absorption spectroscopy in fast ion beams has been employed for the determination of absolute integrated band intensities ({ital S}{sup 0}{sub {ital v}}) for the {nu}{sub 3} fundamental bands of H{sub 3}O{sup +} and NH{sup +}{sub 4}. In addition, the absolute band intensities for the {nu}{sub 1} fundamental bands of HN{sup +}{sub 2} and HCO{sup +} have been remeasured. The values obtained in units of cm{sup {minus}2} atm{sup {minus}1} at STP are 1880(290) and 580(90) for the {nu}{sub 1} fundamentals of HN{sup +}{sub 2} and HCO{sup +}, respectively; and 4000(800) and 1220(190) for the {nu}{sub 3} fundamentals of H{sub 3}O{sup +} and NH{sup +}{sub 4}, respectively. Comparisons with {ital ab} {ital initio} results are presented.

  10. Physical phenomena induced by passage of intense electromagnetic pulses (including CO/sub 2/ lasers) through the atmosphere

    SciTech Connect (OSTI)

    Yee, J.H.; Mayhall, D.J.; Alvarez, R.

    1985-10-23T23:59:59.000Z

    The electron fluid equations are combined with Maxwell's equations to investigate the physical phenomena that occurs when short, intense electromagnetic pulses (including the CO/sub 2/ laser pulse) interact with the atmosphere. The phenomena of ''tailed erosion'' occurs when the pulse intensity exceeds the air-breakdown threshold. In some cases, the erosion of the pulse occurs first in the middle of the pulse and then occurs in the tail of the pulse. In addition, we discovered that the amount of the energy that a pulse carries through the atmosphere is independent of whether it is propagating vertically upward from the Earth's surface or vertically downward toward the Earth's surface, provided the distance the pulse travels is the same for both directions of the propagation. 20 refs., 9 figs.

  11. Ultrahigh intensity laser-plasma interaction: A Lagrangian approach* J.-M. Flax+

    E-Print Network [OSTI]

    instability leading to collisionless heating. Second, in the generation of plasma wakes using ultrahigh of the wake amplitude occurs. Third, in the generation of third-harmonic waves using ultrahigh intensity, long should also consider a fourth regime, (iv) SW

  12. Extreme intensity pulses in a semiconductor laser with a short external cavity

    E-Print Network [OSTI]

    Jose A. Reinoso; Jordi Zamora-Munt; Cristina Masoller

    2013-05-30T23:59:59.000Z

    We present a numerical study of the pulses displayed by a semiconductor laser with optical feedback in the short cavity regime, such that the external cavity round trip time is smaller than the laser relaxation oscillation period. For certain parameters there are occasional pulses, which are high enough to be considered extreme events. We characterize the bifurcation scenario that gives rise to such extreme pulses and study the influence of noise. We demonstrate intermittency when the extreme pulses appear and hysteresis when the attractor that sustains these pulses is destroyed. We also show that this scenario is robust under the inclusion of noise.

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

    SciTech Connect (OSTI)

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

    2014-06-15T23:59:59.000Z

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

  14. LASER WELDING -Literature Review Materials Science and Metallurgy Department, University of Cambridge, England. July 2002.

    E-Print Network [OSTI]

    Cambridge, University of

    LASER WELDING - Literature Review C.A. Walsh Materials Science and Metallurgy Department industry to produce seam or stitch welds, as alternatives to conventional resistance spot welding, which are used extensively for attaching auto-body panels to sub- assemblies. The advantages of laser welding

  15. Laser Telecommunication timeLaser beam

    E-Print Network [OSTI]

    La Rosa, Andres H.

    Laser Telecommunication Experiment Laser time Laser beam intensity timeLaser beam Laser battery Laser connected to a circuit without a modulator. Bottom graph illustrates what happen when a modulating signal is superimposed to the DC voltage driving the laser Laser beam intensity DC Input voltage DC

  16. Light dark matter candidates in intense laser pulses I: paraphotons and fermionic minicharged particles

    E-Print Network [OSTI]

    Selym Villalba-Chávez; Carsten Müller

    2014-12-15T23:59:59.000Z

    Polarimetric experiments driven by the strong field of a circularly polarized laser wave can become a powerful tool to limit the parameter space of not yet detected hidden-photons and minicharged particles associated with extra U(1) gauge symmetries. We show how the absorption and dispersion of probe electromagnetic waves in the vacuum polarized by such a background are modified due to the coupling between the visible U(1)-gauge sector and these hypothetical degrees of freedom. The results of this analysis reveal that the regime close to the two-photon reaction threshold can be a sensititive probe of these hidden particles. Parameters of modern laser systems are used to estimate the constraints on the corresponding coupling constants in regions where experiments driven by dipole magnets are less constricted. The role played by a paraphoton field is analyzed via a comparison with a model in which the existence of minicharges is assumed only. For both scenarios is found that the most stringent exclusion limit occurs at the lowest threshold mass; this one being determined by a certain combination of the field frequencies and dictated by energy momentum balance of the photo-production of a pair of minicharged particles. The dependencies of the observables on the laser attributes as well as on the unknown particle parameters are also analyzed.

  17. Relative intensity noise and frequency noise of a compact Brillouin laser made

    E-Print Network [OSTI]

    Boyer, Edmond

    made of 4.9 m long bulk As2Se3 (AsSe) chalcogenide fiber, which has a Brillouin gain coefficient g]. The purpose of this Letter is twofold: first to demonstrate the possibility of making compact BFLs made of AsSe performances in terms of intensity and frequency noise of a BFL made of chalco- genide MOF. The AsSe MOF [inset

  18. Time-Resolved Imaging and Manipulation of H{sub 2} Fragmentation in Intense Laser Fields

    SciTech Connect (OSTI)

    Ergler, Th.; Rudenko, A.; Feuerstein, B.; Zrost, K.; Schroeter, C.D.; Moshammer, R.; Ullrich, J. [Max-Planck-Institut fuer Kernphysik, D-69029 Heidelberg (Germany)

    2005-08-26T23:59:59.000Z

    We report on the experimental realization of time-resolved coincident Coulomb explosion imaging of H{sub 2} fragmentation in 10{sup 14} W/cm{sup 2} laser fields. Combining a high-resolution 'reaction microscope' and a fs pump-probe setup, we map the motion of wave packets dissociating via one- or two-photon channels, respectively, and observe a new region of enhanced ionization. The long-term interferometric stability of our system allows us to extend pump-probe experiments into the region of overlapping pulses, which offers new possibilities for the manipulation of ultrafast molecular fragmentation dynamics.

  19. Coherent control and giant enhancement of multiphoton ionization and high-order-harmonic generation driven by intense frequency-comb laser fields: An ab initio theoretical investigation

    E-Print Network [OSTI]

    Chu, Shih-I; Zhao, Di; Li, Fu-li

    2013-04-11T23:59:59.000Z

    the intensity of the driving frequency-comb laser fields. However, the two-level model does not take into account the effects of multilevel structure and ionization, which are inherent in real atomic and/or molecular systems driven by intense laser fields... function. In general, the carrier frequency ?c is not necessarily one of the comb frequencies nor does it equal ?0. Due to the incommensuration between the time period (=2?/?c) of the carrier wave and the time interval ? of the pulse envelope, there is a...

  20. Laser conditioning study of KDP on the optical sciences laser using large area beams

    SciTech Connect (OSTI)

    Runkel, M.; DeYoreo, J.; Sell, W.; Milam, D.

    1997-12-20T23:59:59.000Z

    Considerable attention has been paid over the years to the problem of growing high purity KDP and KD*P to meet threshold requirements on succeeding generations of inertial confinement fusion lasers at LLNL. While damage thresholds for these materials have increased over time, the current National Ignition Facility (NIF) maximum fluence requirement (redline) for KD*P frequency triplers of 14.3 J/cm{sup 2} at 351 nm, 3 ns has not been reached without laser (pre)conditioning. It is reasonable to assume that, despite the rapid increase in damage thresholds for rapidly grown crystals, -a program of large scale conditioning of the 192 NIF triplers will be required. Small area ramp (R/1) tests on single sites indicate that KDP damage thresholds can be raised on average up to 1.5X the unconditioned values. Unpublished LLNL 3{omega} raster conditioning studies on KDP, however, have not conclusively shown that off-line conditioning is feasible for KD*P. Consequently, investigating the feasibility of on-line conditioning of NIF triplers at 3{omega} has become a high priority for the KDP damage group at LLNL. To investigate the feasibility of on-line conditioning we performed a series of experiments using the Optical Sciences Laser (OSL) on numerous samples of conventional and rapid growth KDP and KD*P. The experiment entailed exposing sites on each sample to a range of ramped shot (N/l) sequences starting at average fluences of -2 J/cm{sup 2} (in a 7 mm ``top hat`` beam @ 351 nm, 3 ns) up to peak fluences of approximately 13 J/cm{sup 2}. Test results indicated that the most effective conditioning procedure entailed a 7-8 shot ramp starting at 2 J/cm{sup 2} and ending at 12-13 J/cm{sup 2}. The pinpoint onset fluence for the 8/1 tests was 1.4 times that of the unconditioned site. Damage evolution appears to be exponential as a function of increasing fluence. When damage occurs after conditioning however, pinpoint density evolution exhibits a greater slope than less conditioned sites. The overall reduction in the total pinpoint number can be as high as 30OX. Despite laser conditioning , the pinpoint onset for the samples considered is below the NIF redline fluence of 14.3 J/cm{sup 2}. In addition, the exponential pinpoint evolution curves indicate that damage levels at NIF redline fluences will be on the order of 10{sup 4} pinpoints/mm{sup 2}. This suggests that there will be significant damage in NIP triplers, however, substantial damage has not been observed in the large Beamlet tripler (conventionally grown KD*P) under similar exposure conditions. By applying the OSL damage evolution curves to model NIF THG output spatial profiles it is possible to show damage in NIF triplers will be slight, consisting of isolated clusters with a few pinpoints at high fluence portions of the beam. This prediction has been verified by scatter mapping the 37 cm Beamlet tripler crystal. These results will be discussed in a future memo. These results indicate the feasibility of on-line conditioning for the NIF laser.

  1. Modelling gamma-ray photon emission and pair production in high-intensity laser–matter interactions

    SciTech Connect (OSTI)

    Ridgers, C.P. [Clarendon Laboratory, University of Oxford, Parks Road, Oxford, OX1 3PU (United Kingdom) [Clarendon Laboratory, University of Oxford, Parks Road, Oxford, OX1 3PU (United Kingdom); Central Laser Facility, STFC Rutherford-Appleton Laboratory, Chilton, Didcot, Oxfordshire, OX11 0QX (United Kingdom); Kirk, J.G. [Max-Planck-Institut für Kernphysik, Postfach 10 39 80, 69029 Heidelberg (Germany)] [Max-Planck-Institut für Kernphysik, Postfach 10 39 80, 69029 Heidelberg (Germany); Duclous, R. [Commissariat à l'Energie Atomique, DAM DIF, F-91297 Arpajon (France)] [Commissariat à l'Energie Atomique, DAM DIF, F-91297 Arpajon (France); Blackburn, T.G. [Clarendon Laboratory, University of Oxford, Parks Road, Oxford, OX1 3PU (United Kingdom)] [Clarendon Laboratory, University of Oxford, Parks Road, Oxford, OX1 3PU (United Kingdom); Brady, C.S.; Bennett, K.; Arber, T.D. [Centre for Fusion, Space and Astrophysics, University of Warwick, Coventry, CV4 7AL (United Kingdom)] [Centre for Fusion, Space and Astrophysics, University of Warwick, Coventry, CV4 7AL (United Kingdom); Bell, A.R. [Clarendon Laboratory, University of Oxford, Parks Road, Oxford, OX1 3PU (United Kingdom) [Clarendon Laboratory, University of Oxford, Parks Road, Oxford, OX1 3PU (United Kingdom); Central Laser Facility, STFC Rutherford-Appleton Laboratory, Chilton, Didcot, Oxfordshire, OX11 0QX (United Kingdom)

    2014-03-01T23:59:59.000Z

    In high-intensity (>10{sup 21} Wcm{sup ?2}) laser–matter interactions gamma-ray photon emission by the electrons can strongly affect the electron's dynamics and copious numbers of electron–positron pairs can be produced by the emitted photons. We show how these processes can be included in simulations by coupling a Monte Carlo algorithm describing the emission to a particle-in-cell code. The Monte Carlo algorithm includes quantum corrections to the photon emission, which we show must be included if the pair production rate is to be correctly determined. The accuracy, convergence and energy conservation properties of the Monte Carlo algorithm are analysed in simple test problems.

  2. Liquid crystal films as on-demand, variable thickness (50–5000?nm) targets for intense lasers

    SciTech Connect (OSTI)

    Poole, P. L., E-mail: poole.134@osu.edu; Andereck, C. D.; Schumacher, D. W.; Daskalova, R. L.; Feister, S.; George, K. M.; Willis, C.; Akli, K. U.; Chowdhury, E. A. [Physics Department, The Ohio State University, Columbus, Ohio 43210 (United States)

    2014-06-15T23:59:59.000Z

    We have developed a new type of target for intense laser-matter experiments that offers significant advantages over those currently in use. The targets consist of a liquid crystal film freely suspended within a metal frame. They can be formed rapidly on-demand with thicknesses ranging from nanometers to micrometers, where the particular value is determined by the liquid crystal temperature and initial volume as well as by the frame geometry. The liquid crystal used for this work, 8CB (4?-octyl-4-cyanobiphenyl), has a vapor pressure below 10{sup ?6}?Torr, so films made at atmospheric pressure maintain their initial thickness after pumping to high vacuum. Additionally, the volume per film is such that each target costs significantly less than one cent to produce. The mechanism of film formation and relevant physics of liquid crystals are described, as well as ion acceleration data from the first shots on liquid crystal film targets at the Ohio State University Scarlet laser facility.

  3. X-ray spectroscopy of buried layer foils irradiated with an ultra high intensity short pulse laser

    E-Print Network [OSTI]

    Chen, Sophia Nan

    2009-01-01T23:59:59.000Z

    of hot dense matter in short-pulse laser-plasma interactionof hot dense matter in short-pulse laser-plasma interactiona better picture of short pulse laser produced plasmas can

  4. X-ray spectroscopy of buried layer foils irradiated with an ultra high intensity short pulse laser

    E-Print Network [OSTI]

    Chen, Sophia Nan

    2009-01-01T23:59:59.000Z

    manufacturing, while the latter, also known as then CPA technique, has been instrumental in pushing laser

  5. Searching for minicharged particles via birefringence, dichroism and Raman spectroscopy of the vacuum polarized by a high-intensity laser wave

    SciTech Connect (OSTI)

    Villalba-Chávez, S., E-mail: selymv@gmail.com; Müller, C., E-mail: c.mueller@tp1.uni-duesseldorf.de

    2013-12-15T23:59:59.000Z

    Absorption and dispersion of probe photons in the field of a high-intensity circularly polarized laser wave are investigated. The optical theorem is applied for determining the absorption coefficients in terms of the imaginary part of the vacuum polarization tensor. Compact expressions for the vacuum refraction indices and the photon absorption coefficients are obtained in various asymptotic regimes of interest. The outcomes of this analysis reveal that, far from the region relatively close to the threshold of the two-photon reaction, the birefringence and dichroism of the vacuum are small and, in some cases, strongly suppressed. On the contrary, in a vicinity of the region in which the photo-production of a pair occurs, these optical properties are manifest with lasers of moderate intensities. We take advantage of such a property in the search of minicharged particles by considering high-precision polarimetric experiments. In addition, Raman-like electromagnetic waves resulting from the inelastic part of the vacuum polarization tensor are suggested as an alternative form for finding exclusion limits on these hypothetical charge carriers. The envisaged parameters of upcoming high-intensity laser facilities are used for establishing upper bounds on the minicharged particles. -- Highlights: •Via dichroism and birefringence of the vacuum by a strong laser wave, minicharged particles can be probed. •The discovery potential is the highest in a vicinity of the first pair production threshold. •As alternative observable, Raman scattered waves are put forward.

  6. Toward a self-consistent model of the interaction between an ultra-intense, normally incident laser pulse with an overdense plasma

    SciTech Connect (OSTI)

    Debayle, A. [CEA, DAM, DIF, F-91297 Arpajon (France) [CEA, DAM, DIF, F-91297 Arpajon (France); ETSI Aeronáuticos. Universidad Politécnica de Madrid, Madrid 28040 (Spain); Sanz, J. [ETSI Aeronáuticos. Universidad Politécnica de Madrid, Madrid 28040 (Spain)] [ETSI Aeronáuticos. Universidad Politécnica de Madrid, Madrid 28040 (Spain); Gremillet, L. [CEA, DAM, DIF, F-91297 Arpajon (France)] [CEA, DAM, DIF, F-91297 Arpajon (France); Mima, K. [School for the Creation of Photonic Industries, Shizuoka 431-1202 (Japan)] [School for the Creation of Photonic Industries, Shizuoka 431-1202 (Japan)

    2013-05-15T23:59:59.000Z

    Following a recent work by Sanz et al. [Phys. Rev. E 85, 046411 (2012)], we elaborate upon a one-dimensional model describing the interaction between an ultra-intense, normally incident laser pulse and an overdense plasma. The analytical solutions of the reflected laser field, the electrostatic field, and the plasma surface oscillation are obtained within the cold-fluid approximation. The high-order harmonic spectrum is calculated from the exact solution of the plasma surface oscillations. In agreement with particle-in-cell simulations, two regimes of harmonic generation are predicted: for moderately relativistic laser intensities, or high plasma densities, the harmonic spectrum is determined by the discontinuity in the derivative of the reflected field when the electron plasma boundary oscillates across the fixed ion boundary. For higher intensities, the electron plasma boundary is confined inside the ion region and oscillates at relativistic velocities, giving rise to a train of reflected attosecond pulses. In both cases, the harmonic spectrum obeys an asymptotic ?{sup ?4} scaling. The acceleration of electrons and the related laser absorption efficiency are computed by a test particle method. The model self-consistently reproduces the transition between the “anomalous skin effect” and the “J × B” heating predicted by particle-in-cell simulations. Analytical estimates of the different scalings are presented.

  7. Many-mode Floquet theoretical approach for coherent control of multiphoton dynamics driven by intense frequency-comb laser fields

    E-Print Network [OSTI]

    Son, Sang-Kil; Chu, Shih-I

    2008-06-05T23:59:59.000Z

    .07#3;?8#4; 2.92 2.41#3;?3#4; 2.92 1.33#3;?6#4; 2.92 2.01#3;?3#4; 5.00 4.53#3;?20#4; 4.91 3.42#3;?12#4; 5.00 6.62#3;?15#4; 4.93 3.39#3;?10#4; 5.00 1.28#3;?12#4; 4.94 2.07#3;?9#4; 7.02 1.99#3;?28#4; 6.92 1.83#3;?20#4; 7.00 3.10#3;?21#4; 6.93 1.82#3;?16#4; 7.00 4...Many-mode Floquet theoretical approach for coherent control of multiphoton dynamics driven by intense frequency-comb laser fields Sang-Kil Son (???#1;1,* and Shih-I Chu (???#1;1,2,† 1Department of Chemistry, University of Kansas, Lawrence, Kansas...

  8. Laser Twinkles in Rare Color (Science Daily) | Jefferson Lab

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOEThe Bonneville PowerCherries 82981-1cnHigh SchoolIn12electron 9 5 - -/e),,sandLaserLaser

  9. Potential Science for the OASIS Integral Field Spectrograph with Laser Guide Star Adaptive Optics

    E-Print Network [OSTI]

    Morris, S L; Swinbank, M; Wilman, R

    2006-01-01T23:59:59.000Z

    We review the science case for the Laser Guide Star system being built for the William Herschel Telescope (WHT) on La Palma. When used in combination with the NAOMI Adaptive Optics system and the OASIS visible-wavelength Integral Field Spectrograph, we demonstrate that there are substantial, exciting areas of astrophysical research in which the WHT can contribute.

  10. Potential Science for the OASIS Integral Field Spectrograph with Laser Guide Star Adaptive Optics

    E-Print Network [OSTI]

    S. L. Morris; J. Gerssen; M. Swinbank; R. Wilman

    2005-09-15T23:59:59.000Z

    We review the science case for the Laser Guide Star system being built for the William Herschel Telescope (WHT) on La Palma. When used in combination with the NAOMI Adaptive Optics system and the OASIS visible-wavelength Integral Field Spectrograph, we demonstrate that there are substantial, exciting areas of astrophysical research in which the WHT can contribute.

  11. Frontiers in Laser Cooling, Single-Molecule Biophysics, and Enrgy Science: A Talk by Carl Wieman

    SciTech Connect (OSTI)

    Wieman, Carl

    2008-08-30T23:59:59.000Z

    Carl Wieman presents a talk at Frontiers in Laser Cooling, Single-Molecule Biophysics and Energy Science, a scientific symposium honoring Steve Chu, director of Lawrence Berkeley National Laboratory and recipient of the 1997 Nobel Prize in Physics. The symposium was held August 30, 2008 in Berkeley.

  12. Frontiers in Laser Cooling, Single-Molecule Biophysics, and Enrgy Science: A Talk by Carl Wieman

    ScienceCinema (OSTI)

    Wieman, Carl

    2011-04-13T23:59:59.000Z

    Carl Wieman presents a talk at Frontiers in Laser Cooling, Single-Molecule Biophysics and Energy Science, a scientific symposium honoring Steve Chu, director of Lawrence Berkeley National Laboratory and recipient of the 1997 Nobel Prize in Physics. The symposium was held August 30, 2008 in Berkeley.

  13. Propagation In Matter Of Currents Of Relativistic Electrons Beyond The Alfven Limit, Produced In Ultra-High-Intensity Short-Pulse Laser-Matter Interactions

    SciTech Connect (OSTI)

    Batani, D.; Manclossi, M. [Dipartimento di Fisica 'G.Occhialini', Universita di Milano-Bicocca (Italy); INFM, Universita di Milano-Bicocca (Italy); Laboratoire d'Optique Appliquee, UMR ENSTA-CNRS-Ecole Polytechnique, Palaiseau (France); Baton, S.D.; Amiranoff, F.; Koenig, M.; Gremillet, L.; Popescu, H. [Laboratoire pour l'Utilisation des Lasers Intenses, UMR 7605 CNRS-CEA-X-Paris VI, Ecole Polytechnique, Palaiseau (France); Santos, J.J. [Laboratoire d'Optique Appliquee, UMR ENSTA-CNRS-Ecole Polytechnique, Palaiseau (France); Laboratoire pour l'Utilisation des Lasers Intenses, UMR 7605 CNRS-CEA-X-Paris VI, Ecole Polytechnique, Palaiseau (France); Martinolli, E. [Dipartimento di Fisica 'G.Occhialini', Universita di Milano-Bicocca (Italy); INFM, Universita di Milano-Bicocca (Italy); Laboratoire pour l'Utilisation des Lasers Intenses, UMR 7605 CNRS-CEA-X-Paris VI, Ecole Polytechnique, Palaiseau (France); Antonicci, A. [Dipartimento di Fisica 'G.Occhialini', Universita di Milano-Bicocca (Italy); INFM, Universita di Milano-Bicocca (Italy); Rousseaux, C.; Rabec Le Gloahec, M. [Commissariat a l'Energie Atomique, Bruyeres-le-Chatel (France); Hall, T. [University of Essex, Wivenhoe Park, Colchester, Essex, CO4 3SQ (United Kingdom); Malka, V. [Laboratoire d'Optique Appliquee, UMR ENSTA-CNRS-Ecole Polytechnique, Palaiseau (France); Cowan, T.E.; Stephens, R. [Inertial Fusion Technology Division, Fusion Group, General Atomics, San Diego, CA (United States); Key, M. [Lawrence Livermore National Laboratory, Livermore CA (United States); King, J.; Freeman, R. [Department of Applied Sciences, University of California Davis, CA 95616 (United States)

    2004-12-01T23:59:59.000Z

    This paper reports the results of several experiments performed at the LULI laboratory (Palaiseau, France) concerning the propagation of large relativistic currents in matter from ultra-high-intensity laser pulse interaction with target. We present our results according to the type of diagnostics used in the experiments: 1) K{alpha} emission and K{alpha} imaging, 2) study of target rear side emission in the visible region, 3) time resolved optical shadowgraphy.

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

    E-Print Network [OSTI]

    Scharer, John E.

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

  15. Extension of high-order harmonic generation cutoff via coherent control of intense few-cycle chirped laser pulses

    E-Print Network [OSTI]

    Carrera, Juan J.; Chu, Shih-I

    2007-03-16T23:59:59.000Z

    for larger dis- tances. #1;b#2; A second-order split-operator technique in the en- ergy representation, which allows the explicit elimination of undesirable fast-oscillating high-energy components, is used for the efficient time propagation of the wave... potential and the laser field. It then oscil- lates quasifreely driven by the Lorenz force and acquires kinetic energy from the laser field. Lastly, after the laser reverses its direction, the returning electron will emit har- monic photons by radiative...

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

    SciTech Connect (OSTI)

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

    2014-05-15T23:59:59.000Z

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

  17. X-ray spectroscopy of buried layer foils irradiated with an ultra high intensity short pulse laser

    E-Print Network [OSTI]

    Chen, Sophia Nan

    2009-01-01T23:59:59.000Z

    Short Pulse Laser by Sophia Nan Chen Doctor of Philosophy inEngineering Physics) by Sophia Nan Chen Committee in charge:Tynan The dissertation of Sophia Nan Chen is approved, and

  18. Nonlinear laser energy depletion in laser-plasma accelerators

    E-Print Network [OSTI]

    Shadwick, B.A.

    2009-01-01T23:59:59.000Z

    Nonlinear laser energydepletion in laser-plasma accelerators ? B. A. Shadwick,of intense, short-pulse lasers via excitation of plasma

  19. Lasers, Photonics, and Fusion Science: Bringing Star Power to Earth

    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: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625 1,006 492 742EnergyOnItem NotEnergy, science,SpeedingWu,IntelligenceYou are hereNews item slideshow

  20. Enhanced water window x-ray emission from in situ formed carbon clusters irradiated by intense ultra-short laser pulses

    SciTech Connect (OSTI)

    Chakravarty, U.; Rao, B. S.; Arora, V.; Upadhyay, A.; Singhal, H.; Naik, P. A.; Chakera, J. A.; Mukherjee, C.; Gupta, P. D. [Raja Ramanna Centre for Advanced Technology, Indore, 452 013 Madhya Pradesh (India)] [Raja Ramanna Centre for Advanced Technology, Indore, 452 013 Madhya Pradesh (India)

    2013-07-29T23:59:59.000Z

    Enhanced water window x-ray emission (23–44 Å) from carbon clusters, formed in situ using a pre-pulse, irradiated by intense (I > 10{sup 17} W/cm{sup 2}) ultra-short laser pulse, is demonstrated. An order of magnitude x-ray enhancement over planar graphite target is observed in carbon clusters, formed by a sub-ns pre-pulse, interacting with intense main pulse after a delay. The effect of the delay and the duration of the main pulse is studied for optimizing the x-ray emission in the water window region. This x-ray source has added advantages of being an efficient, high repetition rate, and low debris x-ray source.

  1. PanDA Beyond ATLAS: Workload Management for Data Intensive Science

    E-Print Network [OSTI]

    Schovancova, J; The ATLAS collaboration; Klimentov, A; Maeno, T; Nilsson, P; Oleynik, D; Panitkin, S; Petrosyan, A; Vaniachine, A; Wenaus, T; Yu, D

    2013-01-01T23:59:59.000Z

    The PanDA Production ANd Distributed Analysis system has been developed by ATLAS to meet the experiment's requirements for a data-driven workload management system for production and distributed analysis processing capable of operating at LHC data processing scale. After 7 years of impressively successful PanDA operation in ATLAS there are also other experiments which can benefit from PanDA in the Big Data challenge, with several at various stages of evaluation and adoption. The new project "Next Generation Workload Management and Analysis System for Big Data" is extending PanDA to meet the needs of other data intensive scientific applications in HEP, astro-particle and astrophysics communities, bio-informatics and other fields as a general solution to large scale workload management. PanDA can utilize dedicated or opportunistic computing resources such as grids, clouds, and High Performance Computing facilities, and is being extended to leverage next generation intelligent networks in automated workflow mana...

  2. Fundamental science investigations to develop a 6-MV laser triggered gas switch for ZR: first annual report.

    SciTech Connect (OSTI)

    Warne, Larry Kevin; Van Den Avyle, James A.; Lehr, Jane Marie; Rose, David (Voss Scientific, Albuquerque, NM); Krompholz, Hermann G. (Texas Tech University, Lubbock, TX); Vela, Russell (Texas Tech University, Lubbock, TX); Jorgenson, Roy Eberhardt; Timoshkin, Igor (University of Strathclyde, Glasgow, Scotland); Woodworth, Joseph Ray; Prestwich, Kenneth Randel (Voss Scientific, Albuquerque, NM); Krile, John (Texas Tech University, Lubbock, TX); Given, Martin (University of Strathclyde, Glasgow, Scotland); McKee, G. Randall; Rosenthal, Stephen Edgar; Struve, Kenneth William; Welch, Dale Robert (Voss Scientific, Albuquerque, NM); Benwell, Andrew L. (University of Missouri-Columbia, Columbia, Missouri); Kovaleski, Scott (University of Missouri-Columbia, Columbia, Missouri); LeChien, Keith, R.; Johnson, David (Titan Pulse Sciences Division); Fouracre, R.A. (University of Strathclyde, Glasgow, Scotland); Yeckel, Chris (University of Missouri-Columbia, Columbia, Missouri); Wakeland, Peter Eric (Ktech Corporation, Albuquerque, NM); Miller, A. R. (Titan Pulse Sciences Division); Hodge, Keith Conquest (Ktech Corporation, Albuquerque, NM); Pasik, Michael Francis; Savage, Mark Edward; Maenchen, John Eric; Curry, Randy D. (University of Missouri-Columbia, Columbia, Missouri); Feltz, Greg (Ktech Corporation, Albuquerque, NM); Bliss, David Emery; MacGregor, Scott (University of Strathclyde, Glasgow, Scotland); Corley, J. P. (Ktech Corporation, Albuquerque, NM); Anaya, Victor (Ktech Corporation, Albuquerque, NM); Wallace, Zachariah (Ktech Corporation, Albuquerque, NM); Thoma, Carsten (Voss Scientific, Albuquerque, NM); Neuber, Andreas. (Texas Tech University, Lubbock, TX)

    2007-03-01T23:59:59.000Z

    In October 2005, an intensive three-year Laser Triggered Gas Switch (LTGS) development program was initiated to investigate and solve observed performance and reliability issues with the LTGS for ZR. The approach taken has been one of mission-focused research: to revisit and reassess the design, to establish a fundamental understanding of LTGS operation and failure modes, and to test evolving operational hypotheses. This effort is aimed toward deploying an initial switch for ZR in 2007, on supporting rolling upgrades to ZR as the technology can be developed, and to prepare with scientific understanding for the even higher voltage switches anticipated needed for future high-yield accelerators. The ZR LTGS was identified as a potential area of concern quite early, but since initial assessments performed on a simplified Switch Test Bed (STB) at 5 MV showed 300-shot lifetimes on multiple switch builds, this component was judged acceptable. When the Z{sub 20} engineering module was brought online in October 2003 frequent flashovers of the plastic switch envelope were observed at the increased stresses required to compensate for the programmatically increased ZR load inductance. As of October 2006, there have been 1423 Z{sub 20} shots assessing a variety of LTGS designs. Numerous incremental and fundamental switch design modifications have been investigated. As we continue to investigate the LTGS, the basic science of plastic surface tracking, laser triggering, cascade breakdown, and optics degradation remain high-priority mission-focused research topics. Significant progress has been made and, while the switch does not yet achieve design requirements, we are on the path to develop successively better switches for rolling upgrade improvements to ZR. This report summarizes the work performed in FY 2006 by the large team. A high-level summary is followed by detailed individual topical reports.

  3. Laser-induced fluorescence measurements on plasma science experiments at PPPL

    SciTech Connect (OSTI)

    Koepke, Mark

    2011-12-20T23:59:59.000Z

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

  4. The associate of applied science degree in dental hygiene is an intensive, full-time endeavor that prepares you to take the American

    E-Print Network [OSTI]

    Hartman, Chris

    DENTAL HYGIENE The associate of applied science degree in dental hygiene is an intensive, full-time endeavor that prepares you to take the American Dental Association National Board Dental Hygiene exam-CTC@ALASKA.EDU WWW.CTC.UAF.EDU DENTAL HYGIENE Visit the Dental Hygiene Website: WWW.CTC.UAF.EDU/DH SAMPLE COURSES

  5. Fast magnetic field annihilation in the relativistic collisionless regime driven by two ultra-short high-intensity laser pulses

    E-Print Network [OSTI]

    Gu, Y J; Kumar, D; Liu, Y; Singh, S K; Esirkepov, T Zh; Bulanov, S V; Weber, S; Korn, G

    2015-01-01T23:59:59.000Z

    The magnetic quadrupole structure formation during the interaction of two ultra-short high power laser pulses with a collisionless plasma is demonstrated with 2.5-dimensional particle-in-cell simulations. The subsequent expansion of the quadrupole is accompanied by magnetic field annihilation in the ultrarelativistic regime, when the magnetic field can not be sustained by the plasma current. This results in a dominant contribution of the displacement current exciting a strong large scale electric?field. This field leads to the conversion of magnetic energy into kinetic energy of accelerated electrons inside the thin current sheet.

  6. Self-focusing and stimulated Brillouin back-scattering of a long intense laser pulse in a finite temperature relativistic plasma

    SciTech Connect (OSTI)

    Niknam, A. R.; Barzegar, S. [Laser and Plasma Research Institute, Shahid Beheshti University, G.C., Evin, Tehran (Iran, Islamic Republic of)] [Laser and Plasma Research Institute, Shahid Beheshti University, G.C., Evin, Tehran (Iran, Islamic Republic of); Hashemzadeh, M. [Faculty of Physics, Shahrood University, Shahrood (Iran, Islamic Republic of)] [Faculty of Physics, Shahrood University, Shahrood (Iran, Islamic Republic of)

    2013-12-15T23:59:59.000Z

    The nonlinear dynamics of electromagnetic waves propagating through a plasma considering the effects of relativistic mass and ponderomotive nonlinearities is investigated. The modified electron density distribution, the dispersion relation, and the spatial profiles of electromagnetic wave amplitude in the plasma are obtained. It is shown that the cut-off frequency decreases, and there is an intensity range in which the ponderomotive self-focusing takes place. In the upper limit of this range, the laser beam is defocused due to the relativistic ponderomotive force. In addition, the stability of electromagnetic waves to stimulated Brillouin scattering is studied, and the backscattered wave resulting from decay of high power electromagnetic beam is resolved in relativistic regime. The study of effects of electron density and temperature on the growth rate of backscattered wave has been shown that by increasing these effects, the growth rate of instability increases.

  7. Characterisation of a MeV Bremsstrahlung x-ray source produced from a high intensity laser for high areal density object radiography

    SciTech Connect (OSTI)

    Courtois, C.; Compant La Fontaine, A.; Bazzoli, S.; Bourgade, J. L.; Gazave, J.; Lagrange, J. M.; Landoas, O.; Dain, L. Le; Pichoff, N. [CEA, DAM, DIF, F-91297 Arpajon (France)] [CEA, DAM, DIF, F-91297 Arpajon (France); Edwards, R.; Aedy, C. [AWE Plc., Aldermaston, Reading RG7 4PR (United Kingdom)] [AWE Plc., Aldermaston, Reading RG7 4PR (United Kingdom); Mastrosimone, D.; Pien, G.; Stoeckl, C. [Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623 (United States)] [Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623 (United States)

    2013-08-15T23:59:59.000Z

    Results of an experiment to characterise a MeV Bremsstrahlung x-ray emission created by a short (<10 ps) pulse, high intensity (1.4 × 10{sup 19} W/cm{sup 2}) laser are presented. X-ray emission is characterized using several diagnostics; nuclear activation measurements, a calibrated hard x-ray spectrometer, and dosimeters. Results from the reconstructed x-ray energy spectra are consistent with numerical simulations using the PIC and Monte Carlo codes between 0.3 and 30 MeV. The intense Bremsstrahlung x-ray source is used to radiograph an image quality indicator (IQI) heavily filtered with thick tungsten absorbers. Observations suggest that internal features of the IQI can be resolved up to an external areal density of 85 g/cm{sup 2}. The x-ray source size, inferred by the radiography of a thick resolution grid, is estimated to be approximately 400 ?m (full width half maximum of the x-ray source Point Spread Function)

  8. Frontiers in Laser Cooling, Single-Molecule Biophysics, and Enrgy Science: A Talk from Leo Holberg and Allen Mills

    ScienceCinema (OSTI)

    Holberg, Leo; Mills, Allen [NIST

    2011-04-28T23:59:59.000Z

    Leo Holberg and Allen Mills present a talk at Frontiers in Laser Cooling, Single-Molecule Biophysics and Energy Science, a scientific symposium honoring Steve Chu, director of Lawrence Berkeley National Laboratory and recipient of the 1997 Nobel Prize in Physics. The symposium was held August 30, 2008 in Berkeley.

  9. Multiphoton ionization and high-order harmonic generation of He, Ne, and Ar atoms in intense pulsed laser fields: Self-interaction-free time-dependent density-functional theoretical approach

    E-Print Network [OSTI]

    Chu, Shih-I; Tong, Xiao-Min

    2001-06-12T23:59:59.000Z

    We present a detailed study of the multiphoton ionization and high-order harmonic generation (HHG) processes of rare-gas atoms (He, Ne, and Ar) in intense pulsed laser fields by means of a self-interaction-free time-dependent density...

  10. The effects of pre-formed plasma on the generation and transport of fast electrons in relativistic laser-solid interactions

    E-Print Network [OSTI]

    Paradkar, Bhooshan S.

    2012-01-01T23:59:59.000Z

    Langdon. Absorption of ultra-intense laser pulses. Physicalproton generation in ultra-intense laser–solid interactions.heating in ultra high intensity laser-plasma interaction.

  11. Ultra-high-contrast laser acceleration of relativistic electrons in solid targets

    E-Print Network [OSTI]

    Higginson, Drew Pitney

    2013-01-01T23:59:59.000Z

    Intensities with Short-Pulse Lasers 1.2 Inertial Confinementhigh-power, short laser pulse, D. . . . . . . . . . Figurea high-intensity short-pulse laser to produce relativistic

  12. Biomaterials Design for Control of Cell Behavior by Femtosecond Laser Processing

    E-Print Network [OSTI]

    Jeon, Hojeong

    2011-01-01T23:59:59.000Z

    polymers with ultra-short laser pulses. Physica Statushighly intense ultra-short laser pulses are focused intohighly intense ultra-short laser pulses are focused into

  13. Science, Technology and Mission Design for the Laser Astrometric Test Of Relativity

    E-Print Network [OSTI]

    Slava G. Turyshev; Michael Shao; Kenneth L. Nordtvedt Jr

    2006-02-09T23:59:59.000Z

    The Laser Astrometric Test Of Relativity (LATOR) is a Michelson-Morley-type experiment designed to achieve a major improvement in the accuracy of the tests of relativistic gravity in the solar system. By using a combination of independent time-series of gravitational deflection of light in the immediate proximity to the Sun, along with measurements of the relativistic time delay on interplanetary scales (to a precision respectively better than 0.1 picoradians and 1 cm), LATOR will measure the key post-Newtonian Eddington parameter \\gamma with accuracy of one part in a billion - a factor of 30,000 improvement compared to the present best result, Cassini's 2003 test. LATOR's primary measurement pushes to unprecedented accuracy the search for cosmologically relevant scalar-tensor modifications of gravity by looking for a remnant scalar field in today's solar system. We present a comprehensive discussion of the science objectives, proposed technology, mission and optical designs, as well as the expected performance of this fundamental physics experiment in space.

  14. Chirped pulse inverse free-electron laser vacuum accelerator

    DOE Patents [OSTI]

    Hartemann, Frederic V. (Dublin, CA); Baldis, Hector A. (Pleasanton, CA); Landahl, Eric C. (Walnut Creek, CA)

    2002-01-01T23:59:59.000Z

    A chirped pulse inverse free-electron laser (IFEL) vacuum accelerator for high gradient laser acceleration in vacuum. By the use of an ultrashort (femtosecond), ultrahigh intensity chirped laser pulse both the IFEL interaction bandwidth and accelerating gradient are increased, thus yielding large gains in a compact system. In addition, the IFEL resonance condition can be maintained throughout the interaction region by using a chirped drive laser wave. In addition, diffraction can be alleviated by taking advantage of the laser optical bandwidth with negative dispersion focusing optics to produce a chromatic line focus. The combination of these features results in a compact, efficient vacuum laser accelerator which finds many applications including high energy physics, compact table-top laser accelerator for medical imaging and therapy, material science, and basic physics.

  15. Direct laser acceleration of electrons in free-space

    E-Print Network [OSTI]

    Carbajo, Sergio; Wong, Liang Jie; Miller, R J Dwayne; Kärtner, Franz X

    2015-01-01T23:59:59.000Z

    Compact laser-driven accelerators are versatile and powerful tools of unarguable relevance on societal grounds for the diverse purposes of science, health, security, and technology because they bring enormous practicality to state-of-the-art achievements of conventional radio-frequency accelerators. Current benchmarking laser-based technologies rely on a medium to assist the light-matter interaction, which impose material limitations or strongly inhomogeneous fields. The advent of few cycle ultra-intense radially polarized lasers has materialized an extensively studied novel accelerator that adopts the simplest form of laser acceleration and is unique in requiring no medium to achieve strong longitudinal energy transfer directly from laser to particle. Here we present the first observation of direct longitudinal laser acceleration of non-relativistic electrons that undergo highly-directional multi-GeV/m accelerating gradients. This demonstration opens a new frontier for direct laser-driven particle accelerati...

  16. 40 IEEE TRANSACTIONS ON PLASMA SCIENCE, VOL. 30, NO. 1, FEBRUARY 2002 Simulation of Laser Pulse Amplification in a

    E-Print Network [OSTI]

    Wurtele, Jonathan

    . Index Terms--Lasers, optical pulse compression, Raman scattering. SHORT LASER pulses with high energy

  17. aluminium laser ablation: Topics by E-print Network

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

    radiation, FLASH (Free-electron LASer in Hamburg) provides ultra-intense femtosecond radiation and laser optics: UV, XUV, and X-ray lasers; (140.2600) Lasers and laser optics:...

  18. LANL | Physics | Trident Laser Facility

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

    Discovery science at Trident Laser Facility Several important discoveries and first observations have been made at the Trident Laser Facility, a unique three-beam neodymium-glass...

  19. Solar radiation intensity calculations

    E-Print Network [OSTI]

    Levine, Randolph Steven

    1978-01-01T23:59:59.000Z

    SOLAR RADIATION INTENSITY CALCULATIONS A Thesis by RANDOLPH STEVEN LEVINE Submitted to the Graduate College of Texas A&M University in partia'l fulfillment of the requirement for the degree of MASTER OF SCIENCE December 1978 Major Subject...: Physics SOLAR RADIATION INTENSITY CALCULATIONS A Thesis by RANDOLPH STEVEN LEVINE Approved as to style and content by: (Chairman of Committee) (Member) (Member) ( member) (Head of Department) December 1978 f219 037 ABSTRACT Solar Radiation...

  20. Laser Program annual report 1987

    SciTech Connect (OSTI)

    O'Neal, E.M.; Murphy, P.W.; Canada, J.A.; Kirvel, R.D.; Peck, T.; Price, M.E.; Prono, J.K.; Reid, S.G.; Wallerstein, L.; Wright, T.W. (eds.)

    1989-07-01T23:59:59.000Z

    This report discusses the following topics: target design and experiments; target materials development; laboratory x-ray lasers; laser science and technology; high-average-power solid state lasers; and ICF applications studies.

  1. Floquet-Liouville supermatrix approach: Time development of density-matrix operator and multiphoton resonance fluorescence spectra in intense laser fields

    E-Print Network [OSTI]

    Ho, Tak-San; Wang, Kwanghsi; Chu, Shih-I

    1986-03-01T23:59:59.000Z

    A Floquet-Liouville supermatrix (FLSM) approach is presented for nonperturbative treatment of the time development of the density-matrix operator of atoms and molecules exposed to intense polychromatic fields. By extending ...

  2. Correlated-Intensity velocimeter for Arbitrary Reflector

    DOE Patents [OSTI]

    Wang, Zhehui (Los Alamos, NM); Luo, Shengnian (Los Alamos, NM); Barnes, Cris W. (Arlington, VA); Paul, Stephen F. (West Orange, NJ)

    2008-11-11T23:59:59.000Z

    A velocimetry apparatus and method comprising splitting incoming reflected laser light and directing the laser light into first and second arms, filtering the laser light with passband filters in the first and second arms, one having a positive passband slope and the other having a negative passband slope, and detecting the filtered laser light via light intensity detectors following the passband filters in the first and second arms

  3. Control of Laser Plasma Based Accelerators up to 1 GeV

    E-Print Network [OSTI]

    Nakamura, Kei

    2008-01-01T23:59:59.000Z

    Ultrashort laser pulses and ultra- short electron bunchesinteraction of an intense ultra-short laser pulse with a gas

  4. Frontiers in Laser Cooling, Single-Molecule Biophysics, and Energy Science: Remarks from Steve Chu at the Scientific Symposium Held in his Honor

    SciTech Connect (OSTI)

    Chu, Steve

    2008-08-30T23:59:59.000Z

    Steve Chu, director of Lawrence Berkeley National Laboratory and recipient of the 1997 Nobel Prize, presents a talk at Frontiers in Laser Cooling, Single-Molecule Biophysics and Energy Science, a scientific symposium in his honor. The symposium was held August 30, 2008 in Berkeley.

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

    E-Print Network [OSTI]

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

    2013-01-01T23:59:59.000Z

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

  6. Kinetic-energy-angle differential distribution of photofragments in multiphoton above-threshold dissociation of D{sub 2}{sup +} by linearly polarized 400-nm intense laser fields: Effects of highly excited electronic states

    SciTech Connect (OSTI)

    Khan, Basir Ahamed; Saha, Samir; Bhattacharyya, S. S. [Atomic and Molecular Physics Section, Department of Materials Science, Indian Association for the Cultivation of Science, Jadavpur, Kolkata 700 032 (India)

    2006-02-15T23:59:59.000Z

    We have performed a detailed calculation of the double-differential angular-kinetic-energy distribution of photofragments in above threshold dissociation (ATD) of D{sub 2}{sup +} from initial vibrational-rotational levels v{sub i}=4,5 and J{sub i}=0,1 in an intense linearly polarized laser field of wavelength 400 nm and intensity 3x10{sup 13} W/cm{sup 2}. The calculation used a time-independent close-coupling (CC) formalism with eight (ten) electronic states included in the basis-set expansion of the molecular wave function. The molecular electronic states included, apart from the two lowest 1s{sigma}{sub g} and 2p{sigma}{sub u} states, were 2p{pi}{sub u}{sup {+-}}, 2s{sigma}{sub g}, 3p{sigma}{sub u}, 3d{sigma}{sub g}, 3d{pi}{sub g}{sup {+-}}, and 4f{sigma}{sub u}. All the higher electronic states dissociate to the atomic state D(2l). A sufficient number of photon absorption channels, n=0-7, and molecular rotational quantum numbers J=0-11 were taken into account to ensure the convergence of the multiphoton ATD probability. Altogether 198 coupled channels had to be considered in the calculation. The calculations reveal signatures of significant ejection of the photodissociation fragments away from the laser polarization direction due to the inclusion of the higher excited electronic states. The ratio of the photofragments perpendicular to and along the polarization axis shows good quantitative agreement with the experimental result. The angular distributions show considerable structures depending on the relative kinetic energies of the photofragments, and the fragments with different kinetic energies show peaks at different dissociation angles.

  7. A laser application to nuclear astrophysics

    SciTech Connect (OSTI)

    Barbui, M.; Hagel, K.; Schmidt, K.; Zheng, H.; Burch, R.; Barbarino, M.; Natowitz, J. B. [Cyclotron Institute, Texas A and M University, 3366 TAMU, College Station, TX (United States); Bang, W.; Dyer, G.; Quevedo, H. J.; Gaul, E.; Bernstein, A. C.; Donovan, M. [Center for High Energy Density Science, C1510, University of Texas at Austin, Austin, TX 78712 (United States); Bonasera, A. [Cyclotron Institute, Texas A and M University, 3366 TAMU, College Station, TX, U.S.A. and INFN- Laboratori Nazionali del Sud, via S.Sofia 62, 95125 Catania (Italy); Kimura, S. [Department of Physics, Università degli Studi di Milano, Via Celoria 16, 20133 Milano (Italy); Mazzocco, M. [Dipartimento di Fisica e Astronomia Università degli Studi di Padova and INFN Sezione di Padova, Via Marzolo 8, I-35131 Padova (Italy); Consoli, F.; De Angelis, R.; Andreoli, P. [Associazione Euratom-ENEA Sulla Fusione, Via Enrico Fermi 45, CP 65-00044 Frascati, Rome (Italy); Ditmire, T. [Center for High Energy Density Science, C1510, University of Texas at Austin, Austin, TX, 78712 (United States)

    2014-05-09T23:59:59.000Z

    In the last decade, the availability in high-intensity laser beams capable of producing plasmas with ion energies large enough to induce nuclear reactions has opened new research paths in nuclear physics. We studied the reactions {sup 3}He(d,p){sup 4}He and d(d,n){sup 3}He at temperatures of few keV in a plasma, generated by the interaction of intense ultrafast laser pulses with molecular deuterium or deuterated-methane clusters mixed with {sup 3}He atoms. The yield of 14.7 MeV protons from the {sup 3}He(d,p){sup 4}He reaction was used to extract the astrophysical S factor. Results of the experiment performed at the Center for High Energy Density Science at The University of Texas at Austin will be presented.

  8. Laser Safety Laser-emitting tools and equipment are common to many work situations. Lasers in printers, grocery store

    E-Print Network [OSTI]

    Burke, Peter

    Laser Safety Laser-emitting tools and equipment are common to many work situations. Lasers in printers, grocery store scanners, construction tools, and laser pointers are generally lower powered lasers emit high-intensity, directional light beams that vary in strength, they are a particular hazard

  9. Inner-Shell Multiple Ionization of Polyatomic Molecules With an Intense X-Ray Free-Electron Laser Studied By Coincident Ion Momentum Imaging

    SciTech Connect (OSTI)

    Erk, B. [Max Planck Advanced Study Group and Deutsches Elektronen-Synchrotron, Hamburg (Germany); Max Planck Inst. for Nuclear Physics, Heidelberg (Germany); Rolles, D. [Max Planck Advanced Study Group and Deutsches Elektronen-Synchrotron, Hamburg (Germany); Max Planck Inst. for Medical Rearch, Heidelburg (Germany); Foucar, L. [Max Planck Society, Hamburg (Germany); Max Planck Inst. for Medical Rearch, Heidelburg (Germany); Rudek, B. [Max Planck Advanced Study Group and Deutsches Elektronen-Synchrotron, Hamburg (Germany); Max Planck Inst. for Nuclear Physics, Heidelberg (Germany); Epp, S. W. [Max Planck Society, Hamburg (Germany). Max Planck Inst. for Nuclear Physics; Max Planck Inst. for Nuclear Physics, Heidelberg (Germany); Cryle, M. [Max Planck Inst. for Medical Rearch, Heidelburg (Germany); Bostedt, C. [SLAC National Accelerator Lab., Menlo Park, CA (United States). Linac Coherent Light Source; Schorb, S. [SLAC National Accelerator Lab., Menlo Park, CA (United States). Linac Coherent Light Source; Technical Univ. Berlin (Germany). Inst. for Optic and Atomic Physics; Bozek, J. [SLAC National Accelerator Lab., Menlo Park, CA (United States). Linac Coherent Light Source; Rouzee, A. [Max Born Inst., Berlin (Germany); Hundertmark, A. [Max Born Inst., Berlin (Germany); Marchenko, T. [Laboratory of Chemical Physics, Paris (France); Simon, M. [Laboratory of Chemical Physics, Paris (France); Filsinger, F. [Fritz Haber Inst. for Max Planck Gesellschaft, Berlin (Germany); Christensen, L. [Aarhus Univ. (Denmark). Dept. of Physics and Astronomy; De, S. [Aarhus Univ. (Denmark). Dept. of Chemistry; Saha Inst. of Nuclear Physics, Kolkata (India); Trippel, S. [Center for Free-Electron Laser Science (CFEL), Hamburg (Germany); Küpper, J. [Center for Free-Electron Laser Science (CFEL) and Univ. of Hamburg, Hamburg (Germany). Dept. of Physics, Center for Ultrafast Imaging; Stapelfeldt, H. [Aarhus Univ. (Denmark). Dept. of Chemistry; Wada, S. [SLAC National Accelerator Lab., Menlo Park, CA (United States). Linac Coherent Light Source; Hiroshima Univ., Higashi-Hiroshima (Japan), Dept. of Physical Science; Ueda, K. [Tohoku Univ., Sendai (Japan). IMRAM; Swiggers, M. [SLAC National Accelerator Lab., Menlo Park, CA (United States). Linac Coherent Light Source; Messerschmidt, M. [SLAC National Accelerator Lab., Menlo Park, CA (United States). Linac Coherent Light Source; Schröter, C. D. [Max Planck Inst. for Nuclear Physics, Heidelberg (Germany); Moshammer, R. [Max Planck Society, Hamburg (Germany). Max Planck Inst. for Nuclear Physics; Max Planck Inst. for Nuclear Physics, Heidelberg (Germany); Schlichting, I. [Max Planck Society, Hamburg (Germany); Max Planck Inst. for Medical Rearch, Heidelburg (Germany); Ullrich, J. [Max Planck Society, Hamburg (Germany). Max Planck Inst. for Nuclear Physics; Max Planck Inst. for Nuclear Physics, Heidelberg (Germany); National Institute for Physics and Technology, Braunschweig (Germany); Rudenko, A. [Max Planck Society, Hamburg (Germany). Max Planck Inst. for Nuclear Physics; Max Planck Inst. for Nuclear Physics, Heidelberg (Germany); Kansas State Univ., Manhattan, KS (United States). Dept. of Physics

    2013-08-28T23:59:59.000Z

    The ionization and fragmentation of two selenium containing hydrocarbon molecules, methylselenol (CH3SeH) and ethylselenol (C2H5SeH), by intense (>1017 W cm-2 ) 5 fs x-ray pulses with photon energies of 1.7 and 2 keV has been studied by means of coincident ion momentum spectroscopy. Measuring charge states and ion kinetic energies, we find signatures of charge redistribution within the molecular environment. Furthermore, by analyzing fragment ion angular correlations, we can determine the laboratory-frame orientation of individual molecules and thus investigate the fragmentation dynamics in the molecular frame. This allows distinguishing protons originating from different molecular sites along with identifying the reaction channels that lead to their emission.

  10. Inner-Shell Multiple Ionization of Polyatomic Molecules With an Intense X-Ray Free-Electron Laser Studied By Coincident Ion Momentum Imaging

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

    Erk, B.; Rolles, D.; Foucar, L.; Rudek, B.; Epp, S. W.; Cryle, M.; Bostedt, C.; Schorb, S.; Bozek, J.; Rouzee, A.; et al

    2013-08-28T23:59:59.000Z

    The ionization and fragmentation of two selenium containing hydrocarbon molecules, methylselenol (CH3SeH) and ethylselenol (C2H5SeH), by intense (>1017 W cm-2 ) 5 fs x-ray pulses with photon energies of 1.7 and 2 keV has been studied by means of coincident ion momentum spectroscopy. Measuring charge states and ion kinetic energies, we find signatures of charge redistribution within the molecular environment. Furthermore, by analyzing fragment ion angular correlations, we can determine the laboratory-frame orientation of individual molecules and thus investigate the fragmentation dynamics in the molecular frame. This allows distinguishing protons originating from different molecular sites along with identifying the reactionmore »channels that lead to their emission.« less

  11. Mechanism and computational model for Lyman-{alpha}-radiation generation by high-intensity-laser four-wave mixing in Kr-Ar gas

    SciTech Connect (OSTI)

    Louchev, Oleg A.; Saito, Norihito; Wada, Satoshi [Advanced Science Institute, RIKEN, 2-1 Hirosawa, Wako, Saitama, 351-0198 (Japan); Bakule, Pavel [STFC, ISIS Facility, Rutherford Appleton Laboratory, Chilton, Oxfordshire OX11 0QX (United Kingdom); Yokoyama, Koji [Advanced Science Institute, RIKEN, 2-1 Hirosawa, Wako, Saitama, 351-0198 (Japan); Advanced Meson Science Laboratory, RIKEN Nishina Center, RIKEN, Wako, Saitama 351-0198 (Japan); Ishida, Katsuhiko; Iwasaki, Masahiko [Advanced Meson Science Laboratory, RIKEN Nishina Center, RIKEN, Wako, Saitama 351-0198 (Japan)

    2011-09-15T23:59:59.000Z

    We present a theoretical model combined with a computational study of a laser four-wave mixing process under optical discharge in which the non-steady-state four-wave amplitude equations are integrated with the kinetic equations of initial optical discharge and electron avalanche ionization in Kr-Ar gas. The model is validated by earlier experimental data showing strong inhibition of the generation of pulsed, tunable Lyman-{alpha} (Ly-{alpha}) radiation when using sum-difference frequency mixing of 212.6 nm and tunable infrared radiation (820-850 nm). The rigorous computational approach to the problem reveals the possibility and mechanism of strong auto-oscillations in sum-difference resonant Ly-{alpha} generation due to the combined effect of (i) 212.6-nm (2+1)-photon ionization producing initial electrons, followed by (ii) the electron avalanche dominated by 843-nm radiation, and (iii) the final breakdown of the phase matching condition. The model shows that the final efficiency of Ly-{alpha} radiation generation can achieve a value of {approx}5x10{sup -4} which is restricted by the total combined absorption of the fundamental and generated radiation.

  12. ADVANCES IN APPLIED PLASMA SCIENCE, Vol.9, 2013 ISAPS '13, Istanbul Design and Optimization of Laser Produced Plasma Devices for

    E-Print Network [OSTI]

    Harilal, S. S.

    of optimization included simulation and benchmarking of LPP devices with single and dual-beam pulses, producing efficient sources showing the highest rate of laser energy conversion to EUV photons output. Several by an initial pre-pulse laser for the following subsequent heating and ionization by the main laser pulse

  13. Control of Laser Plasma Based Accelerators up to 1 GeV

    E-Print Network [OSTI]

    Nakamura, Kei

    2008-01-01T23:59:59.000Z

    self-modulated intense short laser pulse. Phys. Rev. Lett. ,eld generated by a short laser pulse in an underdenseof an intense ultra-short laser pulse with a gas jet.

  14. Biomaterials Design for Control of Cell Behavior by Femtosecond Laser Processing

    E-Print Network [OSTI]

    Jeon, Hojeong

    2011-01-01T23:59:59.000Z

    hybrid polymers with ultra-short laser pulses. PhysicaWhen highly intense ultra-short laser pulses are focusedWhen highly intense ultra-short laser pulses are focused

  15. GeV electron beams from a laser-plasma accelerator

    E-Print Network [OSTI]

    2008-01-01T23:59:59.000Z

    beams [5]–[7] using an ultra-intense laser pulse focused on5]–[7], an ultra-intense ?10 19 W/cm 2 laser pulse focusedpulse laser driver, making such a source ideal for ultra-

  16. Two-gigawatt burst-mode operation of the intense microwave prototype (IMP) free-electron laser (FEL) for the microwave tokamak experiment (MTX)

    SciTech Connect (OSTI)

    Felker, B.; Allen, S.; Bell, H. [and others

    1993-10-06T23:59:59.000Z

    The MTX explored the plasma heating effects of 140 GHz microwaves from both Gyrotrons and from the IMP FEL wiggler. The Gyrotron was long pulse length (0.5 seconds maximum) and the FEL produced short-pulse length, high-peak power, single and burst modes of 140 GHZ microwaves. Full-power operations of the IMP FEL wiggler were commenced in April of 1992 and continued into October of 1992. The Experimental Test Accelerator H (ETA-II) provided a 50-nanosecond, 6-MeV, 2--3 kAmp electron beam that was introduced co-linear into the IMP FEL with a 140 GHz Gyrotron master oscillator (MO). The FEL was able to amplify the MO signal from approximately 7 kW to peaks consistently in the range of 1--2 GW. This microwave pulse was transmitted into the MTX and allowed the exploration of the linear and non-linear effects of short pulse, intense power in the MTX plasma. Single pulses were used to explore and gain operating experience in the parameter space of the IMP FEL, and finally evaluate transmission and absorption in the MTX. Single-pulse operations were repeatable. After the MTX was shut down burst-mode operations were successful at 2 kHz. This paper will describe the IMP FEL, Microwave Transmission System to MTX, the diagnostics used for calorimetric measurements, and the operations of the entire Microwave system. A discussion of correlated and uncorrelated errors that affect FEL performance will be made Linear and non-linear absorption data of the microwaves in the MTX plasma will be presented.

  17. Device Architecture Simplification of Laser Pattering in High-Volume Crystalline Silicon Solar Cell Fabrication using Intensive Computation for Design and Optimization

    SciTech Connect (OSTI)

    Grupp Mueller, Guenther [SolarWorld; Herfurth, Hans [Fraunhofer CLT; Dunham, Scott [University of Washington; Xu, Baomin [PARC

    2013-11-15T23:59:59.000Z

    Prices of Si based solar modules have been continuously declining in recent years. Goodrich is pointing out that a significant portion of these cost reductions have come about due to ?economies of scale? benefits, but there is a point of diminishing returns when trying to lower cost by simply expanding production capacity [1]. Developing innovative high volume production technologies resulting in an increase of conversion efficiency without adding significant production cost will be necessary to continue the projected cost reductions. The Foundational Program to Advance Cell Efficiency (F-PACE) is seeking to achieve this by closing the PV efficiency gap between theoretical achievable maximum conversion efficiency - 29% for c-Si - and the current typical production - 18.5% for a typical full area back contact c-Si Solar cell ? while targeting a module cost of $0.50/Watt . The research conducted by SolarWorldUSA and it?s partners within the FPACE framework focused on the development of a Hybrid metal-wrap-through (MWT) and laser-ablated PERC solar cell design employing a extrusion metallization scheme to achieve >20% efficient devices. The project team was able to simulate, develop and demonstrate the technologies necessary to build p-type MWT PERC cells with extruded front contacts. Conversion efficiencies approaching 20% were demonstrated and a path for further efficiency improvements identified. A detailed cost of ownership calculation for such a device was based on a NREL cost model and is predicting a $/Watt cost below 85 cents on a 180 micron substrate. Several completed or planned publications by SolarWorldUSA and our partners are based on the research conducted within this project and are adding to a better understanding of the involved technologies and materials. Several aspects and technologies of the proposed device have been assessed in regards to technical effectiveness and economic feasibility. It has been shown in a pilot demonstration with wafer thicknesses down to 120 micron that further wafer thickness reduction is only economically viable if handling and contact formation limitations are addressed simultaneously. Furthermore the project partners assessed and demonstrated the feasibility of processing wafers with vias connecting front and back sides through a PERC cell process and aligning and connecting those vias with a non-contact metallization. A close cooperation between industry and institutes of higher education in the Pacific Northwest as shown in this project is of direct benefit to the public and is contributing to the education of the next generation of PV engineers and scientist.

  18. Laser Plasma Interactions

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

    processes. A typical configuration uses a low intensity laser beam (2nd, 3rd, or 4th harmonic of 1054-nm) to probe a plasma volume. The Thomson scattered light is collected by a...

  19. X-ray laser

    DOE Patents [OSTI]

    Nilsen, Joseph (Livermore, CA)

    1991-01-01T23:59:59.000Z

    An X-ray laser (10) that lases between the K edges of carbon and oxygen, i.e. between 44 and 23 Angstroms, is provided. The laser comprises a silicon (12) and dysprosium (14) foil combination (16) that is driven by two beams (18, 20) of intense line focused (22, 24) optical laser radiation. Ground state nickel-like dysprosium ions (34) are resonantly photo-pumped to their upper X-ray laser state by line emission from hydrogen-like silicon ions (32). The novel X-ray laser should prove especially useful for the microscopy of biological specimens.

  20. Explosively pumped laser light

    DOE Patents [OSTI]

    Piltch, Martin S. (Los Alamos, NM); Michelotti, Roy A. (Los Alamos, NM)

    1991-01-01T23:59:59.000Z

    A single shot laser pumped by detonation of an explosive in a shell casing. The shock wave from detonation of the explosive causes a rare gas to luminesce. The high intensity light from the gas enters a lasing medium, which thereafter outputs a pulse of laser light to disable optical sensors and personnel.

  1. Dye laser amplifier

    DOE Patents [OSTI]

    Moses, E.I.

    1992-12-01T23:59:59.000Z

    An improved dye laser amplifier is disclosed. The efficiency of the dye laser amplifier is increased significantly by increasing the power of a dye beam as it passes from an input window to an output window within the dye chamber, while maintaining the intensity of the dye beam constant. 3 figs.

  2. Earth Sciences Environmental Earth Sciences,

    E-Print Network [OSTI]

    Brierley, Andrew

    84 Earth Sciences­ Environmental Earth Sciences, Geology MGeol (Single Honours Degrees) Earth Sciences BSc (Single Honours Degrees) Environmental Earth Sciences Geology BSc (Joint Honours Degrees) and among the most research-intensive in Europe. Features * The Department of Earth and Environmental

  3. Laser acceleration of ion beams

    E-Print Network [OSTI]

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

    2007-02-01T23:59:59.000Z

    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.

  4. PAPER www.rsc.org/pps | Photochemical & Photobiological Sciences Ionisation of fullerenes and fullerene clusters using ultrashort laser pulses

    E-Print Network [OSTI]

    Hansen, Klavs

    of fullerenes are exposed to ultra-short laser pulses. Pump­probe measurements give a decay time constant of freedom of the molecule? In the following we will briefly review the results using ultra-short laser pulse review of the literature concerning the ultra-short pulse ionisation of fullerenes in the gas phase

  5. Injection locked oscillator system for pulsed metal vapor lasers

    DOE Patents [OSTI]

    Warner, Bruce E. (Livermore, CA); Ault, Earl R. (Dublin, CA)

    1988-01-01T23:59:59.000Z

    An injection locked oscillator system for pulsed metal vapor lasers is disclosed. The invention includes the combination of a seeding oscillator with an injection locked oscillator (ILO) for improving the quality, particularly the intensity, of an output laser beam pulse. The present invention includes means for matching the first seeder laser pulses from the seeding oscillator to second laser pulses of a metal vapor laser to improve the quality, and particularly the intensity, of the output laser beam pulse.

  6. C. R. Physique 10 (2009) 188196 Laser acceleration of particles in plasmas / Acclration laser de particules dans les plasmas

    E-Print Network [OSTI]

    Strathclyde, University of

    2009-01-01T23:59:59.000Z

    the properties of beams of protons accelerated in ultra-intense laser irradiation of planar foil targets accélérés par l'interaction d'une impulsion laser ultra intense avec une cible solide est discuté. PlusC. R. Physique 10 (2009) 188­196 Laser acceleration of particles in plasmas / Accélération laser de

  7. Final Report for DE-SC0002298 Agency Number: DE-PS02-09ER09-01 An Advanced Network and distributed Storage Laboratory (ANDSL) for Data Intensive Science

    SciTech Connect (OSTI)

    Livny, Miron [Computer Sciences Department, University of Wisconsin - Madison

    2014-08-17T23:59:59.000Z

    The original intent of this project was to build and operate an Advanced Network and Distributed Storage Laboratory (ANDSL) for Data Intensive Science that will prepare the Open Science Grid (OSG) community for a new generation of wide area communication capabilities operating at a 100Gb rate. Given the significant cut in our proposed budget we changed the scope of the ANDSL to focus on the software aspects of the laboratory – workload generators and monitoring tools and on the offering of experimental data to the ANI project. The main contributions of our work are twofold: early end-user input and experimental data to the ANI project and software tools for conducting large scale end-to-end data placement experiments.

  8. Laser Heater and seeded Free Electron Laser

    E-Print Network [OSTI]

    Dattoli, G; Sabia, E

    2014-01-01T23:59:59.000Z

    In this paper we consider the effect of laser heater on a seeded Free Electron Laser. We develop a model embedding the effect of the energy modulation induced by the heater with those due to the seeding. The present analysis is compatible with the experimental results obtained at FERMI displaying secondary maxima with increasing heater intensity. The treatment developed in the paper confirms and extends previous analyses and put in evidence further effects which can be tested in future experiments.

  9. Laser Created Relativistic Positron Jets

    SciTech Connect (OSTI)

    Chen, H; Wilks, S C; Meyerhofer, D D; Bonlie, J; Chen, C D; Chen, S N; Courtois, C; Elberson, L; Gregori, G; Kruer, W; Landoas, O; Mithen, J; Murphy, C; Nilson, P; Price, D; Scheider, M; Shepherd, R; Stoeckl, C; Tabak, M; Tommasini, R; Beiersdorder, P

    2009-10-08T23:59:59.000Z

    Electron-positron jets with MeV temperature are thought to be present in a wide variety of astrophysical phenomena such as active galaxies, quasars, gamma ray bursts and black holes. They have now been created in the laboratory in a controlled fashion by irradiating a gold target with an intense picosecond duration laser pulse. About 10{sup 11} MeV positrons are emitted from the rear surface of the target in a 15 to 22-degree cone for a duration comparable to the laser pulse. These positron jets are quasi-monoenergetic (E/{delta}E {approx} 5) with peak energies controllable from 3-19 MeV. They have temperatures from 1-4 MeV in the beam frame in both the longitudinal and transverse directions. Positron production has been studied extensively in recent decades at low energies (sub-MeV) in areas related to surface science, positron emission tomography, basic antimatter science such as antihydrogen experiments, Bose-Einstein condensed positronium, and basic plasma physics. However, the experimental tools to produce very high temperature positrons and high-flux positron jets needed to simulate astrophysical positron conditions have so far been absent. The MeV temperature jets of positrons and electrons produced in our experiments offer a first step to evaluate the physics models used to explain some of the most energetic phenomena in the universe.

  10. Laser Programs Highlight 1995

    SciTech Connect (OSTI)

    Jacobs, R.R.

    1997-01-31T23:59:59.000Z

    Our contributions to laser science and technology and corresponding applications range from concept to design of the National Ignition Facility, transfer of Atomic Vapor Laser Isotope Separation technology to the private sector, and from new initiatives in industry and defense to micro-optics for improving human vision.

  11. Fundamental Physics at the Intensity Frontier

    E-Print Network [OSTI]

    J. L. Hewett; H. Weerts; R. Brock; J. N. Butler; B. C. K. Casey; J. Collar; A. de Gouvea; R. Essig; Y. Grossman; W. Haxton; J. A. Jaros; C. K. Jung; Z. T. Lu; K. Pitts; Z. Ligeti; J. R. Patterson; M. Ramsey-Musolf; J. L. Ritchie; A. Roodman; K. Scholberg; C. E. M. Wagner; G. P. Zeller; S. Aefsky; A. Afanasev; K. Agashe; C. Albright; J. Alonso; C. Ankenbrandt; M. Aoki; C. A. Arguelles; N. Arkani-Hamed; J. R. Armendariz; C. Armendariz-Picon; E. Arrieta Diaz; J. Asaadi; D. M. Asner; K. S. Babu; K. Bailey; O. Baker; B. Balantekin; B. Baller; M. Bass; B. Batell; J. Beacham; J. Behr; N. Berger; M. Bergevin; E. Berman; R. Bernstein; A. J. Bevan; M. Bishai; M. Blanke; S. Blessing; A. Blondel; T. Blum; G. Bock; A. Bodek; G. Bonvicini; F. Bossi; J. Boyce; R. Breedon; M. Breidenbach; S. J. Brice; R. A. Briere; S. Brodsky; C. Bromberg; A. Bross; T. E. Browder; D. A. Bryman; M. Buckley; R. Burnstein; E. Caden; P. Campana; R. Carlini; G. Carosi; C. Castromonte; R. Cenci; I. Chakaberia; M. C. Chen; C. H. Cheng; B. Choudhary; N. H. Christ; E. Christensen; M. E. Christy; T. E. Chupp; E. Church; D. B. Cline; T. E. Coan; P. Coloma; J. Comfort; L. Coney; J. Cooper; R. J. Cooper; R. Cowan; D. F. Cowen; D. Cronin-Hennessy; A. Datta; G. S. Davies; M. Demarteau; D. P. DeMille; A. Denig; R. Dermisek; A. Deshpande; M. S. Dewey; R. Dharmapalan; J. Dhooghe; M. R. Dietrich; M. Diwan; Z. Djurcic; S. Dobbs; M. Duraisamy; B. Dutta; H. Duyang; D. A. Dwyer; M. Eads; B. Echenard; S. R. Elliott; C. Escobar; J. Fajans; S. Farooq; C. Faroughy; J. E. Fast; B. Feinberg; J. Felde; G. Feldman; P. Fierlinger; P. Fileviez Perez; B. Filippone; P. Fisher; B. T. Flemming; K. T. Flood; R. Forty; M. J. Frank; A. Freyberger; A. Friedland; R. Gandhi; K. S. Ganezer; A. Garcia; F. G. Garcia; S. Gardner; L. Garrison; A. Gasparian; S. Geer; V. M. Gehman; T. Gershon; M. Gilchriese; C. Ginsberg; I. Gogoladze; M. Gonderinger; M. Goodman; H. Gould; M. Graham; P. W. Graham; R. Gran; J. Grange; G. Gratta; J. P. Green; H. Greenlee; R. C. Group; E. Guardincerri; V. Gudkov; R. Guenette; A. Haas; A. Hahn; T. Han; T. Handler; J. C. Hardy; R. Harnik; D. A. Harris; F. A. Harris; P. G. Harris; J. Hartnett; B. He; B. R. Heckel; K. M. Heeger; S. Henderson; D. Hertzog; R. Hill; E. A Hinds; D. G. Hitlin; R. J. Holt; N. Holtkamp; G. Horton-Smith; P. Huber; W. Huelsnitz; J. Imber; I. Irastorza; J. Jaeckel; I. Jaegle; C. James; A. Jawahery; D. Jensen; C. P. Jessop; B. Jones; H. Jostlein; T. Junk; A. L. Kagan; M. Kalita; Y. Kamyshkov; D. M. Kaplan; G. Karagiorgi; A. Karle; T. Katori; B. Kayser; R. Kephart; S. Kettell; Y. K. Kim; M. Kirby; K. Kirch; J. Klein; J. Kneller; A. Kobach; M. Kohl; J. Kopp; M. Kordosky; W. Korsch; I. Kourbanis; A. D. Krisch; P. Krizan; A. S. Kronfeld; S. Kulkarni; K. S. Kumar; Y. Kuno; T. Kutter; T. Lachenmaier; M. Lamm; J. Lancaster; M. Lancaster; C. Lane; K. Lang; P. Langacker; S. Lazarevic; T. Le; K. Lee; K. T. Lesko; Y. Li; M. Lindgren; A. Lindner; J. Link; D. Lissauer; L. S. Littenberg; B. Littlejohn; C. Y. Liu; W. Loinaz; W. Lorenzon; W. C. Louis; J. Lozier; L. Ludovici; L. Lueking; C. Lunardini; D. B. MacFarlane; P. A. N. Machado; P. B. Mackenzie; J. Maloney; W. J. Marciano; W. Marsh; M. Marshak; J. W. Martin; C. Mauger; K. S. McFarland; C. McGrew; G. McLaughlin; D. McKeen; R. McKeown; B. T. Meadows; R. Mehdiyev; D. Melconian; H. Merkel; M. Messier; J. P. Miller; G. Mills; U. K. Minamisono; S. R. Mishra; I. Mocioiu; S. Moed Sher; R. N. Mohapatra; B. Monreal; C. D. Moore; J. G. Morfin; J. Mousseau; L. A. Moustakas; G. Mueller; P. Mueller; M. Muether; H. P. Mumm; C. Munger; H. Murayama; P. Nath; O. Naviliat-Cuncin; J. K. Nelson; D. Neuffer; J. S. Nico; A. Norman; D. Nygren; Y. Obayashi; T. P. O'Connor; Y. Okada; J. Olsen; L. Orozco; J. L. Orrell; J. Osta; B. Pahlka; J. Paley; V. Papadimitriou; M. Papucci; S. Parke; R. H. Parker; Z. Parsa; K. Partyka; A. Patch; J. C. Pati; R. B. Patterson; Z. Pavlovic; G. Paz; G. N. Perdue; D. Perevalov; G. Perez; R. Petti; W. Pettus; A. Piepke; M. Pivovaroff; R. Plunkett; C. C. Polly; M. Pospelov; R. Povey; A. Prakesh; M. V. Purohit; S. Raby; J. L. Raaf; R. Rajendran; S. Rajendran; G. Rameika; R. Ramsey; A. Rashed; B. N. Ratcliff; B. Rebel; J. Redondo; P. Reimer; D. Reitzner; F. Ringer; A. Ringwald; S. Riordan; B. L. Roberts; D. A. Roberts; R. Robertson; F. Robicheaux; M. Rominsky; R. Roser; J. L. Rosner; C. Rott; P. Rubin; N. Saito; M. Sanchez; S. Sarkar; H. Schellman; B. Schmidt; M. Schmitt; D. W. Schmitz; J. Schneps; A. Schopper; P. Schuster; A. J. Schwartz; M. Schwarz; J. Seeman; Y. K. Semertzidis; K. K. Seth; Q. Shafi; P. Shanahan; R. Sharma; S. R. Sharpe; M. Shiozawa; V. Shiltsev; K. Sigurdson; P. Sikivie; J. Singh; D. Sivers; T. Skwarnicki; N. Smith; J. Sobczyk; H. Sobel; M. Soderberg; Y. H. Song; A. Soni; P. Souder; A. Sousa; J. Spitz; M. Stancari; G. C. Stavenga; J. H. Steffen

    2012-05-11T23:59:59.000Z

    The Proceedings of the 2011 workshop on Fundamental Physics at the Intensity Frontier. Science opportunities at the intensity frontier are identified and described in the areas of heavy quarks, charged leptons, neutrinos, proton decay, new light weakly-coupled particles, and nucleons, nuclei, and atoms.

  12. Fundamental Physics at the Intensity Frontier

    E-Print Network [OSTI]

    Hewett, J L; Brock, R; Butler, J N; Casey, B C K; Collar, J; de Gouvea, A; Essig, R; Grossman, Y; Haxton, W; Jaros, J A; Jung, C K; Lu, Z T; Pitts, K; Ligeti, Z; Patterson, J R; Ramsey-Musolf, M; Ritchie, J L; Roodman, A; Scholberg, K; Wagner, C E M; Zeller, G P; Aefsky, S; Afanasev, A; Agashe, K; Albright, C; Alonso, J; Ankenbrandt, C; Aoki, M; Arguelles, C A; Arkani-Hamed, N; Armendariz, J R; Armendariz-Picon, C; Diaz, E Arrieta; Asaadi, J; Asner, D M; Babu, K S; Bailey, K; Baker, O; Balantekin, B; Baller, B; Bass, M; Batell, B; Beacham, J; Behr, J; Berger, N; Bergevin, M; Berman, E; Bernstein, R; Bevan, A J; Bishai, M; Blanke, M; Blessing, S; Blondel, A; Blum, T; Bock, G; Bodek, A; Bonvicini, G; Bossi, F; Boyce, J; Breedon, R; Breidenbach, M; Brice, S J; Briere, R A; Brodsky, S; Bromberg, C; Bross, A; Browder, T E; Bryman, D A; Buckley, M; Burnstein, R; Caden, E; Campana, P; Carlini, R; Carosi, G; Castromonte, C; Cenci, R; Chakaberia, I; Chen, M C; Cheng, C H; Choudhary, B; Christ, N H; Christensen, E; Christy, M E; Chupp, T E; Church, E; Cline, D B; Coan, T E; Coloma, P; Comfort, J; Coney, L; Cooper, J; Cooper, R J; Cowan, R; Cowen, D F; Cronin-Hennessy, D; Datta, A; Davies, G S; Demarteau, M; DeMille, D P; Denig, A; Dermisek, R; Deshpande, A; Dewey, M S; Dharmapalan, R; Dhooghe, J; Dietrich, M R; Diwan, M; Djurcic, Z; Dobbs, S; Duraisamy, M; Dutta, B; Duyang, H; Dwyer, D A; Eads, M; Echenard, B; Elliott, S R; Escobar, C; Fajans, J; Farooq, S; Faroughy, C; Fast, J E; Feinberg, B; Felde, J; Feldman, G; Fierlinger, P; Perez, P Fileviez; Filippone, B; Fisher, P; Flemming, B T; Flood, K T; Forty, R; Frank, M J; Freyberger, A; Friedland, A; Gandhi, R; Ganezer, K S; Garcia, A; Garcia, F G; Gardner, S; Garrison, L; Gasparian, A; Geer, S; Gehman, V M; Gershon, T; Gilchriese, M; Ginsberg, C; Gogoladze, I; Gonderinger, M; Goodman, M; Gould, H; Graham, M; Graham, P W; Gran, R; Grange, J; Gratta, G; Green, J P; Greenlee, H; Guardincerri, E; Gudkov, V; Guenette, R; Haas, A; Hahn, A; Han, T; Handler, T; Hardy, J C; Harnik, R; Harris, D A; Harris, F A; Harris, P G; Hartnett, J; He, B; Heckel, B R; Heeger, K M; Henderson, S; Hertzog, D; Hill, R; Hinds, E A; Hitlin, D G; Holt, R J; Holtkamp, N; Horton-Smith, G; Huber, P; Huelsnitz, W; Imber, J; Irastorza, I; Jaeckel, J; Jaegle, I; James, C; Jawahery, A; Jensen, D; Jessop, C P; Jones, B; Jostlein, H; Junk, T; Kagan, A L; Kalita, M; Kamyshkov, Y; Kaplan, D M; Karagiorgi, G; Karle, A; Katori, T; Kayser, B; Kephart, R; Kettell, S; Kim, Y K; Kirby, M; Kirch, K; Klein, J; Kneller, J; Kobach, A; Kohl, M; Kopp, J; Kordosky, M; Korsch, W; Kourbanis, I; Krisch, A D; Krizan, P; Kronfeld, A S; Kulkarni, S; Kumar, K S; Kuno, Y; Kutter, T; Lachenmaier, T; Lamm, M; Lancaster, J; Lancaster, M; Lane, C; Lang, K; Langacker, P; Lazarevic, S; Le, T; Lee, K; Lesko, K T; Li, Y; Lindgren, M; Lindner, A; Link, J; Lissauer, D; Littenberg, L S; Littlejohn, B; Liu, C Y; Loinaz, W; Lorenzon, W; Louis, W C; Lozier, J; Ludovici, L; Lueking, L; Lunardini, C; MacFarlane, D B; Machado, P A N; Mackenzie, P B; Maloney, J; Marciano, W J; Marsh, W; Marshak, M; Martin, J W; Mauger, C; McFarland, K S; McGrew, C; McLaughlin, G; McKeen, D; McKeown, R; Meadows, B T; Mehdiyev, R; Melconian, D; Merkel, H; Messier, M; Miller, J P; Mills, G; Minamisono, U K; Mishra, S R; Mocioiu, I; Sher, S Moed; Mohapatra, R N; Monreal, B; Moore, C D; Morfin, J G; Mousseau, J; Moustakas, L A; Mueller, G; Mueller, P; Muether, M; Mumm, H P; Munger, C; Murayama, H; Nath, P; Naviliat-Cuncin, O; Nelson, J K; Neuffer, D; Nico, J S; Norman, A; Nygren, D; Obayashi, Y; O'Connor, T P; Okada, Y; Olsen, J; Orozco, L; Orrell, J L; Osta, J; Pahlka, B; Paley, J; Papadimitriou, V; Papucci, M; Parke, S; Parker, R H; Parsa, Z; Partyka, K; Patch, A; Pati, J C; Patterson, R B; Pavlovic, Z; Paz, G; Perdue, G N; Perevalov, D; Perez, G; Petti, R; Pettus, W; Piepke, A; Pivovaroff, M; Plunkett, R; Polly, C C; Pospelov, M; Povey, R; Prakesh, A; Purohit, M V; Raby, S; Raaf, J L; Rajendran, R; Rajendran, S; Rameika, G; Ramsey, R; Rashed, A; Ratcliff, B N; Rebel, B; Redondo, J; Reimer, P; Reitzner, D; Ringer, F; Ringwald, A; Riordan, S; Roberts, B L; Roberts, D A; Robertson, R; Robicheaux, F; Rominsky, M; Roser, R; Rosner, J L; Rott, C; Rubin, P; Saito, N; Sanchez, M; Sarkar, S; Schellman, H; Schmidt, B; Schmitt, M; Schmitz, D W; Schneps, J; Schopper, A; Schuster, P; Schwartz, A J; Schwarz, M; Seeman, J; Semertzidis, Y K; Seth, K K; Shafi, Q; Shanahan, P; Sharma, R; Sharpe, S R; Shiozawa, M; Shiltsev, V; Sigurdson, K; Sikivie, P; Singh, J; Sivers, D; Skwarnicki, T; Smith, N; Sobczyk, J; Sobel, H; Soderberg, M; Song, Y H; Soni, A; Souder, P; Sousa, A; Spitz, J; Stancari, M; Stavenga, G C; Steffen, J H; Stepanyan, S; Stoeckinger, D; Stone, S; Strait, J; Strassler, M; Sulai, I A; Sundrum, R; Svoboda, R; Szczerbinska, B; Szelc, A; Takeuchi, T; Tanedo, P

    2012-01-01T23:59:59.000Z

    The Proceedings of the 2011 workshop on Fundamental Physics at the Intensity Frontier. Science opportunities at the intensity frontier are identified and described in the areas of heavy quarks, charged leptons, neutrinos, proton decay, new light weakly-coupled particles, and nucleons, nuclei, and atoms.

  13. fLasHThe Free-Electron Laser new technologies for new science: Soon X-ray free-electron lasers

    E-Print Network [OSTI]

    , how molecular machines really work. Accelerators | photon Science | particle physics Deutsches in the accel- erator tunnel. The photon beam transport system in the hall delivers the FEL pulses ­ as short the feasibility of a superconducting linear electron-positron collider for elementary particle phy- sics

  14. Crop and Soil Science Degree Checklist Name: ____________________________

    E-Print Network [OSTI]

    Grünwald, Niklaus J.

    and Soil Science Degree Checklist Name: ____________________________ ID Intensive (SOIL 325) (3) _______ HHS 231 ­ Lifetime Fitness for Health (2. Global Issues (3) (*soil science electives meeting requirement) _______ Science

  15. A new method for generating ultraintense and ultrashort laser pulses

    E-Print Network [OSTI]

    Loss, Daniel

    -cost ultrahigh-intensity laser systems. The field of amplification and compression of short laser pulses laser system, where the short laser pulse is amplified and compressed in plasma through resonantARTICLES A new method for generating ultraintense and ultrashort laser pulses JUN REN, WEIFENG

  16. Control of Laser Plasma Based Accelerators up to 1 GeV

    E-Print Network [OSTI]

    Nakamura, Kei

    2008-01-01T23:59:59.000Z

    interaction of an intense ultra-short laser pulse with a gasUltrashort laser pulses and ultra- short electron bunches

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

    E-Print Network [OSTI]

    Rittershofer, W.

    2010-01-01T23:59:59.000Z

    P/P c ultra-intense laser pulses, such that a 2 ?laser-plasma accel- erators are actively being investigated as ultra-

  18. THz radiation as a bunch diagnostic for laser-wakefield-accelerated electron bunches

    E-Print Network [OSTI]

    2006-01-01T23:59:59.000Z

    the vacuum chamber by an ultra-intense laser pulse. A secondEO) crystal. An ultra-short NIR laser beam was used to probe

  19. Coherent instabilities in random lasers

    SciTech Connect (OSTI)

    Andreasen, Jonathan; Sebbah, Patrick; Vanneste, Christian [Laboratoire de Physique de la Matiere Condensee, CNRS UMR 6622, Universite de Nice-Sophia Antipolis, Parc Valrose, F-06108, Nice Cedex 02 (France)

    2011-08-15T23:59:59.000Z

    A numerical study is presented of random lasers as a function of the pumping rate above the threshold for lasing. Depending on the leakiness of the system resonances, which is typically larger in random lasers compared to conventional lasers, we observe that the stationary lasing regime becomes unstable above a second threshold. Coherent instabilities are observed as self pulsation at a single frequency of the output intensity, population inversion, as well as the atomic polarization. We find these Rabi oscillations have the same frequency everywhere in the random laser despite the fact that the field intensity strongly depends on the spatial location.

  20. Design of an XUV FEL Driven by the Laser-Plasma Accelerator at the LBNL LOASIS Facility

    E-Print Network [OSTI]

    Schroeder, Carl B.; Fawley, W.M.; Esarey, Eric; Leemans, W.P.

    2006-01-01T23:59:59.000Z

    laser system to focus ultra-short (?30 fs) laser pulses ofdrive laser pulse, enabling pump- probe studies in ultra-used an ultra- intense ?10 19 W/cm 2 laser pulse focused on

  1. LaserFest Celebration

    SciTech Connect (OSTI)

    Dr. Alan Chodos; Elizabeth A. Rogan

    2011-08-25T23:59:59.000Z

    LaserFest was the yearlong celebration, during 2010, of the 50th anniversary of the demonstration of the first working laser. The goals of LaserFest were: to highlight the impact of the laser in its manifold commercial, industrial and medical applications, and as a tool for ongoing scientific research; to use the laser as one example that illustrates, more generally, the route from scientific innovation to technological application; to use the laser as a vehicle for outreach, to stimulate interest among students and the public in aspects of physical science; to recognize and honor the pioneers who developed the laser and its many applications; to increase awareness among policymakers of the importance of R&D funding as evidenced by such technology as lasers. One way in which LaserFest sought to meet its goals was to encourage relevant activities at a local level all across the country -- and also abroad -- that would be identified with the larger purposes of the celebration and would carry the LaserFest name. Organizers were encouraged to record and advertise these events through a continually updated web-based calendar. Four projects were explicitly detailed in the proposals: 1) LaserFest on the Road; 2) Videos; 3) Educational material; and 4) Laser Days.

  2. Free-Electron Lasers: Present Status and Future Prospects

    E-Print Network [OSTI]

    Kim, K.-J.

    2008-01-01T23:59:59.000Z

    1977). C. Brau, "Free-Electron Lasers", Science 239, 115 (T. Marshall, "Free-Electron Lasers", MacMillan (1985);C Brau, "Free- Electron Lasers", Academic Press (1990). W.B.

  3. High Intensity Polarized Electron Gun

    SciTech Connect (OSTI)

    Redwine, Robert

    2012-07-31T23:59:59.000Z

    The goal of the project was to investigate the possibility of building a very high intensity polarized electron gun for the Electron-Ion Collider. This development is crucial for the eRHIC project. The gun implements a large area cathode, ring-shaped laser beam and active cathode cooling. A polarized electron gun chamber with a large area cathode and active cathode cooling has been built and tested. A preparation chamber for cathode activation has been built and initial tests have been performed. Major parts for a load-lock chamber, where cathodes are loaded into the vacuum system, have been manufactured.

  4. The River Campus Libraries comprised of the Annex Storage Library; the Carlson Science and Engineering Library; the Laboratory for Laser Energetics Library; the Physics-Optics-Astronomy Library; and the Rush Rhees

    E-Print Network [OSTI]

    , Collaborative Solutions, and Digital Capabilities. Through these priorities, the River Campus Libraries aimsThe River Campus Libraries ­ comprised of the Annex Storage Library; the Carlson Science and Engineering Library; the Laboratory for Laser Energetics Library; the Physics-Optics-Astronomy Library

  5. Sandia National Laboratories: Materials Science

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

    Science, News, News & Events, Office of Science, Research & Capabilities Research on topological insulators (TIs) has drawn intensive interests. The type-II InAsGaSb...

  6. Science

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:Energy: Grid Integration Redefining What's PossibleRadiationImplementingnpitcheResearch BriefsTenney, Office of Science Office of Science β

  7. Science

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:Energy: Grid Integration Redefining What's PossibleRadiationImplementingnpitcheResearch BriefsTenney, Office of Science Office of Science

  8. 474 IEEE TRANSACTIONS ON PLASMA SCIENCE, VOL. 33, NO. 2, APRIL 2005 Fast Photography of a Laser Generated Plasma

    E-Print Network [OSTI]

    Harilal, S. S.

    . Bindhu, and F. Najmabadi Abstract--The dynamics and confinement of laser generated Carbon plumes. Photographic studies showed the collapse of the ablation plume after the bubble lifetime, and formation of two graphitic carbon plasmas expanding across a transverse magnetic field have been investigated using fast

  9. Final LDRD report : science-based solutions to achieve high-performance deep-UV laser diodes.

    SciTech Connect (OSTI)

    Armstrong, Andrew M.; Miller, Mary A.; Crawford, Mary Hagerott; Alessi, Leonard J.; Smith, Michael L.; Henry, Tanya A.; Westlake, Karl R.; Cross, Karen Charlene; Allerman, Andrew Alan; Lee, Stephen Roger

    2011-12-01T23:59:59.000Z

    We present the results of a three year LDRD project that has focused on overcoming major materials roadblocks to achieving AlGaN-based deep-UV laser diodes. We describe our growth approach to achieving AlGaN templates with greater than ten times reduction of threading dislocations which resulted in greater than seven times enhancement of AlGaN quantum well photoluminescence and 15 times increase in electroluminescence from LED test structures. We describe the application of deep-level optical spectroscopy to AlGaN epilayers to quantify deep level energies and densities and further correlate defect properties with AlGaN luminescence efficiency. We further review our development of p-type short period superlattice structures as an approach to mitigate the high acceptor activation energies in AlGaN alloys. Finally, we describe our laser diode fabrication process, highlighting the development of highly vertical and smooth etched laser facets, as well as characterization of resulting laser heterostructures.

  10. Radiation Reaction in High-Intense Fields

    E-Print Network [OSTI]

    Seto, Keita

    2015-01-01T23:59:59.000Z

    After the development of the radiating electron model by P. A. M. Dirac in 1938, many authors have tried to reformulate this model so-called radiation reaction. Recently, this effects has become important for ultra-intense laser-electron (plasma) interactions. In our recent research, we found a method for the stabilization of radiation reaction in quantum vacuum [PTEP 2014, 043A01 (2014), PTEP 2015, 023A01 (2015)]. In the other hand, the field modification by high-intense fields should be required under 10PW lasers, like ELI-NP facility. In this paper, I propose the combined method how to adopt the high-intense field correction with the stabilization by quantum vacuum as the extension from the model by Dirac.

  11. Fundamental physics on natures of the macroscopic vacuum under high intense electromagnetic fields with accelerators

    E-Print Network [OSTI]

    Kensuke Homma

    2009-11-30T23:59:59.000Z

    High intense electromagnetic fields can be unique probes to study natures of macroscopic vacua by themselves. Combining accelerators with the intense field can provide more fruitful probes which can neither be achieved by only intense fields nor only high energy accelerators. We will overview the natures of vacua which can be accessible via intense laser-laser and intense laser-electron interactions. In the case of the laser-laser interaction, we propose how to observe nonlinear QED effects and effects of new fields like light scalar and pseudo scalar fields which may contribute to a macroscopic nature of our universe such as dark energy. In the case of the laser-electron interaction, in addition to nonlinear QED effects, we can further discuss the nature of accelerating field in the vacuum where we can access physics related with event horizons such as Hawking-Unruh radiations. We will introduce a recent experimental trial to search for this kind of odd radiations.

  12. Efficient Modeling of Laser-Plasma Accelerators with INF&RNO

    E-Print Network [OSTI]

    Benedetti, C.

    2011-01-01T23:59:59.000Z

    the interaction of a short laser pulse with an underdensethe fact that the (short) laser pulse is not monochromatic.LPA) [1,2], where a short and intense laser pulse interacts

  13. Shock Wave Acceleration of Monoenergetic Protons using a Multi-Terawatt CO2 Laser

    E-Print Network [OSTI]

    Haberberger, Dan

    2012-01-01T23:59:59.000Z

    by an ultra intense and short- pulsed laser in under-denseatoms in strong short-pulse laser ?elds,” Nature, vol. 461,techniques for high-power short-pulse laser- produced heavy-

  14. Nonlinear pulse propagation and phase velocity of laser-driven plasma waves

    E-Print Network [OSTI]

    Schroeder, Carl B.

    2011-01-01T23:59:59.000Z

    a relativistically-intense short-pulse laser in un- derdensevelocity driven by a short-pulse laser is intrinsicallya 0 ? 1) short-pulse (k p L ? 1) laser in an underdense (k

  15. Adapting High Brightness Relativistic Electron Beams for Ultrafast Science

    E-Print Network [OSTI]

    Scoby, Cheyne Matthew

    2012-01-01T23:59:59.000Z

    for material removal in ultra- fast pulsed laser ablation ofspecifically the ultra- fast laser-induced melting of gold.of an ultra- short, high intensity laser pulse pumping a

  16. Optical Fiber High Temperature Sensor Instrumentation for Energy Intensive Industries

    SciTech Connect (OSTI)

    Cooper, Kristie L.; Wang, Anbo; Pickrell, Gary R.

    2006-11-14T23:59:59.000Z

    This report summarizes technical progress during the program “Optical Fiber High Temperature Sensor Instrumentation for Energy Intensive Industries”, performed by the Center for Photonics Technology of the Bradley Department of Electrical and Computer Engineering at Virginia Tech. The objective of this program was to use technology recently invented at Virginia Tech to develop and demonstrate the application of self-calibrating optical fiber temperature and pressure sensors to several key energy-intensive industries where conventional, commercially available sensors exhibit greatly abbreviated lifetimes due primarily to environmental degradation. A number of significant technologies were developed under this program, including • a laser bonded silica high temperature fiber sensor with a high temperature capability up to 700°C and a frequency response up to 150 kHz, • the world’s smallest fiber Fabry-Perot high temperature pressure sensor (125 x 20 ?m) with 700°C capability, • UV-induced intrinsic Fabry-Perot interferometric sensors for distributed measurement, • a single crystal sapphire fiber-based sensor with a temperature capability up to 1600°C. These technologies have been well demonstrated and laboratory tested. Our work plan included conducting major field tests of these technologies at EPRI, Corning, Pratt & Whitney, and Global Energy; field validation of the technology is critical to ensuring its usefulness to U.S. industries. Unfortunately, due to budget cuts, DOE was unable to follow through with its funding commitment to support Energy Efficiency Science Initiative projects and this final phase was eliminated.

  17. Short-Pulse Laser-Produced Plasmas Jean-Claude Gauthier

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Short-Pulse Laser-Produced Plasmas Jean-Claude Gauthier Centre Lasers Intenses et Applications Summary. In this review, the physics of short-pulse laser-produced plasmas at moderate intensities-ray sources [14]. In this short review, we concentrate on "low" (non-relativistic) laser in- tensities, i.e. I

  18. Laser Noise Reduction in Air

    E-Print Network [OSTI]

    Pierre Bejot; Jerome Kasparian; Estelle Salmon; Roland Ackermann; Nicolas Gisin; Jean-Pierre Wolf

    2006-08-09T23:59:59.000Z

    Fluctuations of the white-light supercontinuum produced by ultrashort laser pulses in selfguided filaments (spatio-temporal solitons) in air are investigated. We demonstrate that correlations exist within the white-light supercontinuum, and that they can be used to significantly reduce the laser intensity noise by filtering the spectrum. More precisely, the fundamental wavelength is anticorrelated with the wings of the continuum, while conjugated wavelength pairs on both sides of the continuum are strongly correlated. Spectral filtering of the continuum reduces the laser intensity noise by 1.2 dB, showing that fluctuations are rejected to the edges of the spectrum.

  19. Measurement of laser absorptivity for operating parameters characteristic of

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Measurement of laser absorptivity for operating parameters characteristic of laser drilling regime Boulevard de l'Hôpital 75013 Paris France E-mail: matthieu.schneider@ensam.eu Abstract Laser drilling. Characteristic laser intensities in the range of 10 MW cm-2 are typically employed for drilling metallic targets

  20. JOURNAL DE PHYSIQUE Colloque C1, supplkment au n o 2, Tome 40,fkvrier 1979,page C1-91 INTENSITY AND SHAPE OF SPECTRAL LINES FROM LASER-PRODUCED PLASMAS

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    thermonuclear fusion experiments. A simple sketch of such an ex- A view of features exhibited,by a plasma; cing thermonuclear reactions by laser. grd: the possible occurence of population inver- sions leading of spontaneous emission. pression being followed by heating the plasma, conditions for getting thermonuclear

  1. Laser cooling of solids

    SciTech Connect (OSTI)

    Epstein, Richard I [Los Alamos National Laboratory; Sheik-bahae, Mansoor [UNM

    2008-01-01T23:59:59.000Z

    We present an overview of solid-state optical refrigeration also known as laser cooling in solids by fluorescence upconversion. The idea of cooling a solid-state optical material by simply shining a laser beam onto it may sound counter intuitive but is rapidly becoming a promising technology for future cryocooler. We chart the evolution of this science in rare-earth doped solids and semiconductors.

  2. Speckle-free laser imaging

    E-Print Network [OSTI]

    Redding, Brandon; Cao, Hui

    2011-01-01T23:59:59.000Z

    Many imaging applications require increasingly bright illumination sources, motivating the replacement of conventional thermal light sources with light emitting diodes (LEDs), superluminescent diodes (SLDs) and lasers. Despite their brightness, lasers and SLDs are poorly suited for full-field imaging applications because their high spatial coherence leads to coherent artifacts known as speckle that corrupt image formation. We recently demonstrated that random lasers can be engineered to provide low spatial coherence. Here, we exploit the low spatial coherence of specifically-designed random lasers to perform speckle-free full-field imaging in the setting of significant optical scattering. We quantitatively demonstrate that images generated with random laser illumination exhibit higher resolution than images generated with spatially coherent illumination. By providing intense laser illumination without the drawback of coherent artifacts, random lasers are well suited for a host of full-field imaging applicatio...

  3. E-Print Network 3.0 - advanced laser remote Sample Search Results

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

    50 Summary: and the applications to fundamental science of gravitational wave detection, remote sensing, and laser induced fusion... Group Early advances in lasers --- 2009 a...

  4. Science

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOE Office of ScienceandMesa del Sol HomeFacebook Twitter Principalfuel cells" Find + AdvancedSignScience

  5. Science

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625 1,006 492 742EnergyOnItemResearch > TheNuclearHomeland Science Stockpile Stewardship National Security

  6. Short rise time intense electron beam generator

    DOE Patents [OSTI]

    Olson, Craig L. (Albuquerque, NM)

    1987-01-01T23:59:59.000Z

    A generator for producing an intense relativistic electron beam having a subnanosecond current rise time includes a conventional generator of intense relativistic electrons feeding into a short electrically conductive drift tube including a cavity containing a working gas at a low enough pressure to prevent the input beam from significantly ionizing the working gas. Ionizing means such as a laser simultaneously ionize the entire volume of working gas in the cavity to generate an output beam having a rise time less than one nanosecond.

  7. Short rise time intense electron beam generator

    DOE Patents [OSTI]

    Olson, C.L.

    1984-03-16T23:59:59.000Z

    A generator for producing an intense relativisitc electron beam having a subnanosecond current rise time includes a conventional generator of intense relativistic electrons feeding into a short electrically conductive drift tube including a cavity containing a working gas at a low enough pressure to prevent the input beam from significantly ionizing the working gas. Ionizing means such as a laser simultaneously ionize the entire volume of working gas in the cavity to generate an output beam having a rise time less than one nanosecond.

  8. Fast-ion spectrometry of ICF implosions and laser-foil experiments at the omega and MTW laser facilities

    E-Print Network [OSTI]

    Sinenian, Nareg

    2013-01-01T23:59:59.000Z

    Fast ions generated from laser-plasma interactions (LPI) have been used to study inertial confinement fusion (ICF) implosions and laser-foil interactions. LPI, which vary in nature depending on the wavelength and intensity ...

  9. Collaborative Research: Instability and transport of laser beam in plasma

    SciTech Connect (OSTI)

    Rose, Harvey Arnold [New Mexico Consortium; Lushnikov, Pavel [University of New Mexico

    2014-11-18T23:59:59.000Z

    Our goal was to determine the onset of laser light scattering due to plasma wave instabilities. Such scatter is usually regarded as deleterious since laser beam strength is thereby diminished. While this kind of laser-plasma-instability (LPI) has long been understood for the case of coherent laser light, the theory of LPI onset for a laser beam with degraded coherence is recent. Such a laser beam fills plasma with a mottled intensity distribution, which has large fluctuations. The key question is: do the exceptionally large fluctuations control LPI onset or is it controlled by the relatively quiescent background laser intensity? We have answered this question. This is significant because LPI onset power in the former case is typically small compared to that of the latter. In addition, if large laser intensity fluctuations control LPI onset, then nonlinear effects become significant for less powerful laser beams than otherwise estimated.

  10. Copyright c 2002 Tech Science Press CMES, vol.3, no.5, pp.539-555, 2002 Multiscale Modeling of Laser Ablation: Applications to Nanotechnology

    E-Print Network [OSTI]

    Zhigilei, Leonid V.

    of Laser Ablation: Applications to Nanotechnology Leonid V. Zhigilei1 and Avinash M. Dongare 1 Abstract-driven methods in nanotechnology. In this pa- per we discuss two computational schemes developed for simulation, applications of laser ablation have been extended into emerging area of nanotechnology. In particular, laser

  11. Quantitative laser-induced breakdown spectroscopy data using peak area step-wise regression analysis: an alternative method for interpretation of Mars science laboratory results

    SciTech Connect (OSTI)

    Clegg, Samuel M [Los Alamos National Laboratory; Barefield, James E [Los Alamos National Laboratory; Wiens, Roger C [Los Alamos National Laboratory; Dyar, Melinda D [MT HOLYOKE COLLEGE; Schafer, Martha W [LSU; Tucker, Jonathan M [MT HOLYOKE COLLEGE

    2008-01-01T23:59:59.000Z

    The ChemCam instrument on the Mars Science Laboratory (MSL) will include a laser-induced breakdown spectrometer (LIBS) to quantify major and minor elemental compositions. The traditional analytical chemistry approach to calibration curves for these data regresses a single diagnostic peak area against concentration for each element. This approach contrasts with a new multivariate method in which elemental concentrations are predicted by step-wise multiple regression analysis based on areas of a specific set of diagnostic peaks for each element. The method is tested on LIBS data from igneous and metamorphosed rocks. Between 4 and 13 partial regression coefficients are needed to describe each elemental abundance accurately (i.e., with a regression line of R{sup 2} > 0.9995 for the relationship between predicted and measured elemental concentration) for all major and minor elements studied. Validation plots suggest that the method is limited at present by the small data set, and will work best for prediction of concentration when a wide variety of compositions and rock types has been analyzed.

  12. Second user workshop on high-power lasers at the Linac Coherent Light Source

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

    Heimann, Phil; Glenzer, Siegfried

    2015-05-04T23:59:59.000Z

    The second international workshop on the physics enabled by the unique combination of high-power lasers with the world-class Linac Coherent Light Source (LCLS) free-electron X-ray laser beam was held in Stanford, CA, on October 7–8, 2014. The workshop was co-organized by UC Berkeley, Lawrence Berkeley, Lawrence Livermore, and SLAC National Accelerator Laboratories. More than 120 scientists, including 40 students and postdoctoral scientists who are working in high-intensity laser-matter interactions, fusion research, and dynamic high-pressure science came together from North America, Europe, and Asia. The focus of the second workshop was on scientific highlights and the lessons learned from 16 newmore »experiments that were performed on the Matter in Extreme Conditions (MEC) instrument since the first workshop was held one year ago.« less

  13. Enhancing extreme ultraviolet photons emission in laser produced plasmas for advanced lithography

    E-Print Network [OSTI]

    Harilal, S. S.

    subjected to laser beam energy with different intensities and laser wavelength to dual-beam lasers, i of vapor expansion rate, which can be produced as a result of droplet heating by pre-pulse laser energy, and the remaining part of the laser heats the plasma instead of inter- acting with the target. For obtaining

  14. Laser isotope separation by multiple photon absorption

    DOE Patents [OSTI]

    Robinson, C. Paul (Los Alamos, NM); Rockwood, Stephen D. (Los Alamos, NM); Jensen, Reed J. (Los Alamos, NM); Lyman, John L. (Los Alamos, NM); Aldridge, III, Jack P. (Los Alamos, NM)

    1987-01-01T23:59:59.000Z

    Multiple photon absorption from an intense beam of infrared laser light may be used to induce selective chemical reactions in molecular species which result in isotope separation or enrichment. The molecular species must have a sufficient density of vibrational states in its vibrational manifold that, is the presence of sufficiently intense infrared laser light tuned to selectively excite only those molecules containing a particular isotope, multiple photon absorption can occur. By this technique, for example, intense CO.sub.2 laser light may be used to highly enrich .sup.34 S in natural SF.sub.6 and .sup.11 B in natural BCl.sub.3.

  15. Laser isotope separation by multiple photon absorption

    DOE Patents [OSTI]

    Robinson, C.P.; Rockwood, S.D.; Jensen, R.J.; Lyman, J.L.; Aldridge, J.P. III.

    1987-04-07T23:59:59.000Z

    Multiple photon absorption from an intense beam of infrared laser light may be used to induce selective chemical reactions in molecular species which result in isotope separation or enrichment. The molecular species must have a sufficient density of vibrational states in its vibrational manifold that, is the presence of sufficiently intense infrared laser light tuned to selectively excite only those molecules containing a particular isotope, multiple photon absorption can occur. By this technique, for example, intense CO[sub 2] laser light may be used to highly enrich [sup 34]S in natural SF[sub 6] and [sup 11]B in natural BCl[sub 3]. 8 figs.

  16. Sandia National Laboratories: Office of Science

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

    Science, News, News & Events, Office of Science, Research & Capabilities Research on topological insulators (TIs) has drawn intensive interests. The type-II InAsGaSb...

  17. Sandia National Laboratories: Basic Energy Sciences

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

    Science, News, News & Events, Office of Science, Research & Capabilities Research on topological insulators (TIs) has drawn intensive interests. The type-II InAsGaSb...

  18. Laser Plasma Material Interactions

    SciTech Connect (OSTI)

    Schaaf, Peter; Carpene, Ettore [Universitaet Goettingen, II. Physikalisches Institut, Friedrich-Hund-Platz 1, 37077 Goettingen (Germany)

    2004-12-01T23:59:59.000Z

    Surface treatment by means of pulsed laser beams in reactive atmospheres is an attractive technique to enhance the surface features, such as corrosion and wear resistance or the hardness. Many carbides and nitrides play an important role for technological applications, requiring the mentioned property improvements. Here we present a new promising fast, flexible and clean technique for a direct laser synthesis of carbide and nitride surface films by short pulsed laser irradiation in reactive atmospheres (e.g. methane, nitrogen). The corresponding material is treated by short intense laser pulses involving plasma formation just above the irradiated surface. Gas-Plasma-Surface reactions lead to a fast incorporation of the gas species into the material and subsequently the desired coating formation if the treatment parameters are chosen properly. A number of laser types have been used for that (Excimer Laser, Nd:YAG, Ti:sapphire, Free Electron Laser) and a number of different nitride and carbide films have been successfully produced. The mechanisms and some examples will be presented for Fe treated in nitrogen and Si irradiated in methane.

  19. Fiber laser coupled optical spark delivery system

    DOE Patents [OSTI]

    Yalin, Azer (Fort Collins, CO); Willson, Bryan (Fort Collins, CO); Defoort, Morgan (Fort Collins, CO); Joshi, Sachin (Fort Collins, CO); Reynolds, Adam (Fort Collins, CO)

    2008-03-04T23:59:59.000Z

    A spark delivery system for generating a spark using a laser beam is provided, and includes a laser light source and a laser delivery assembly. The laser delivery assembly includes a hollow fiber and a launch assembly comprising launch focusing optics to input the laser beam in the hollow fiber. The laser delivery assembly further includes exit focusing optics that demagnify an exit beam of laser light from the hollow fiber, thereby increasing the intensity of the laser beam and creating a spark. Other embodiments use a fiber laser to generate a spark. Embodiments of the present invention may be used to create a spark in an engine. Yet other embodiments include collecting light from the spark or a flame resulting from the spark and conveying the light for diagnostics. Methods of using the spark delivery systems and diagnostic systems are provided.

  20. Ultrahigh-Intensity Optical Slow-Wave Structure B. D. Layer,1,3

    E-Print Network [OSTI]

    Milchberg, Howard

    Ultrahigh-Intensity Optical Slow-Wave Structure B. D. Layer,1,3 A. York,1,3 T. M. Antonsen,2,3 S on the extended diffraction- suppressed propagation of extreme intensity laser pulses in plasma optical guiding structures. Plasma waveguides for intense optical pulses were first generated through the radial hydrodynamic

  1. Light intensity compressor

    DOE Patents [OSTI]

    Rushford, Michael C. (Livermore, CA)

    1990-01-01T23:59:59.000Z

    In a system for recording images having vastly differing light intensities over the face of the image, a light intensity compressor is provided that utilizes the properties of twisted nematic liquid crystals to compress the image intensity. A photoconductor or photodiode material that is responsive to the wavelength of radiation being recorded is placed adjacent a layer of twisted nematic liquid crystal material. An electric potential applied to a pair of electrodes that are disposed outside of the liquid crystal/photoconductor arrangement to provide an electric field in the vicinity of the liquid crystal material. The electrodes are substantially transparent to the form of radiation being recorded. A pair of crossed polarizers are provided on opposite sides of the liquid crystal. The front polarizer linearly polarizes the light, while the back polarizer cooperates with the front polarizer and the liquid crystal material to compress the intensity of a viewed scene. Light incident upon the intensity compressor activates the photoconductor in proportion to the intensity of the light, thereby varying the field applied to the liquid crystal. The increased field causes the liquid crystal to have less of a twisting effect on the incident linearly polarized light, which will cause an increased percentage of the light to be absorbed by the back polarizer. The intensity of an image may be compressed by forming an image on the light intensity compressor.

  2. OPTICAL SCIENCE & ENGINEERINGOPTICAL SCIENCE & ENGINEERINGOPTICAL SCIENCE & ENGINEERINGOPTICAL SCIENCE & ENGINEERING University of New Mexico

    E-Print Network [OSTI]

    New Mexico, University of

    OPTICAL SCIENCE & ENGINEERINGOPTICAL SCIENCE & ENGINEERINGOPTICAL SCIENCE & ENGINEERINGOPTICAL-locked femtosecond laser. While proving itself to be fantastically successful in its role as the "gears" of optical atomic clocks, the optical frequency comb has further evolved into a valuable tool for a wide range

  3. The Intense Radiation Gas

    E-Print Network [OSTI]

    M. Marklund; P. K. Shukla; B. Eliasson

    2005-03-08T23:59:59.000Z

    We present a new dispersion relation for photons that are nonlinearly interacting with a radiation gas of arbitrary intensity due to photon-photon scattering. It is found that the photon phase velocity decreases with increasing radiation intensity, it and attains a minimum value in the limit of super-intense fields. By using Hamilton's ray equations, a self-consistent kinetic theory for interacting photons is formulated. The interaction between an electromagnetic pulse and the radiation gas is shown to produce pulse self-compression and nonlinear saturation. Implications of our new results are discussed.

  4. SLAC All Access: Laser Labs

    SciTech Connect (OSTI)

    Minitti, Mike; Woods Mike

    2013-03-01T23:59:59.000Z

    From supermarket checkouts to video game consoles, lasers are ubiquitous in our lives. Here at SLAC, high-power lasers are critical to the cutting-edge research conducted at the laboratory. But, despite what you might imagine, SLAC's research lasers bear little resemblance to the blasters and phasers of science fiction. In this edition of All Access we put on our safety goggles for a peek at what goes on inside some of SLAC's many laser labs. LCLS staff scientist Mike Minitti and SLAC laser safety officer Mike Woods detail how these lasers are used to study the behavior of subatomic particles, broaden our understanding of cosmic rays and even unlock the mysteries of photosynthesis.

  5. SLAC All Access: Laser Labs

    ScienceCinema (OSTI)

    Minitti, Mike; Woods Mike

    2014-06-03T23:59:59.000Z

    From supermarket checkouts to video game consoles, lasers are ubiquitous in our lives. Here at SLAC, high-power lasers are critical to the cutting-edge research conducted at the laboratory. But, despite what you might imagine, SLAC's research lasers bear little resemblance to the blasters and phasers of science fiction. In this edition of All Access we put on our safety goggles for a peek at what goes on inside some of SLAC's many laser labs. LCLS staff scientist Mike Minitti and SLAC laser safety officer Mike Woods detail how these lasers are used to study the behavior of subatomic particles, broaden our understanding of cosmic rays and even unlock the mysteries of photosynthesis.

  6. Effect of the laser wavefront in a laser-plasma accelerator

    E-Print Network [OSTI]

    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

    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.

  7. Traveling-wave laser-produced-plasma energy source for photoionization laser pumping and lasers incorporating said

    DOE Patents [OSTI]

    Sher, Mark H. (Los Altos, CA); Macklin, John J. (Stanford, CA); Harris, Stephen E. (Palo Alto, CA)

    1989-09-26T23:59:59.000Z

    A traveling-wave, laser-produced-plasma, energy source used to obtain single-pass gain saturation of a photoionization pumped laser. A cylindrical lens is used to focus a pump laser beam to a long line on a target. Grooves are cut in the target to present a surface near normal to the incident beam and to reduce the area, and hence increase the intensity and efficiency, of plasma formation.

  8. Laser focus compensating sensing and imaging device

    DOE Patents [OSTI]

    Vann, C.S.

    1993-08-31T23:59:59.000Z

    A laser focus compensating sensing and imaging device permits the focus of a single focal point of different frequency laser beams emanating from the same source point. In particular it allows the focusing of laser beam originating from the same laser device but having differing intensities so that a low intensity beam will not convert to a higher frequency when passing through a conversion crystal associated with the laser generating device. The laser focus compensating sensing and imaging device uses a Cassegrain system to fold the lower frequency, low intensity beam back upon itself so that it will focus at the same focal point as a high intensity beam. An angular tilt compensating lens is mounted about the secondary mirror of the Cassegrain system to assist in alignment. In addition cameras or CCD's are mounted with the primary mirror to sense the focused image. A convex lens is positioned co-axial with the Cassegrain system on the side of the primary mirror distal of the secondary for use in aligning a target with the laser beam. A first alternate embodiment includes a Cassegrain system using a series of shutters and an internally mounted dichroic mirror. A second alternate embodiment uses two laser focus compensating sensing and imaging devices for aligning a moving tool with a work piece.

  9. Laser-assisted nuclear photoeffect

    E-Print Network [OSTI]

    Anis Dadi; Carsten Müller

    2012-04-17T23:59:59.000Z

    Proton emission from nuclei via the nuclear photoeffect in the combined electromagnetic fields of a gamma-ray photon and an intense laser wave is studied. An S-matrix approach to the process is developed by utilizing methods known from the theory of nonperturbative laser-atom interactions. As a specific example, photo-proton ejection from halo nuclei is considered. We show that, due to the presence of the laser field, rich sideband structures arise in the photo-proton energy spectra. Their dependence on the parameters and relative orientation of the photon fields is discussed.

  10. Laser ablation based fuel ignition

    DOE Patents [OSTI]

    Early, James W. (Los Alamos, NM); Lester, Charles S. (San Juan Pueblo, NM)

    1998-01-01T23:59:59.000Z

    There is provided a method of fuel/oxidizer ignition comprising: (a) application of laser light to a material surface which is absorptive to the laser radiation; (b) heating of the material surface with the laser light to produce a high temperature ablation plume which emanates from the heated surface as an intensely hot cloud of vaporized surface material; and (c) contacting the fuel/oxidizer mixture with the hot ablation cloud at or near the surface of the material in order to heat the fuel to a temperature sufficient to initiate fuel ignition.

  11. Laser ablation based fuel ignition

    DOE Patents [OSTI]

    Early, J.W.; Lester, C.S.

    1998-06-23T23:59:59.000Z

    There is provided a method of fuel/oxidizer ignition comprising: (a) application of laser light to a material surface which is absorptive to the laser radiation; (b) heating of the material surface with the laser light to produce a high temperature ablation plume which emanates from the heated surface as an intensely hot cloud of vaporized surface material; and (c) contacting the fuel/oxidizer mixture with the hot ablation cloud at or near the surface of the material in order to heat the fuel to a temperature sufficient to initiate fuel ignition. 3 figs.

  12. Fiber laser development for LISA

    E-Print Network [OSTI]

    Kenji Numata; Jeffrey R. Chen; Jordan Camp

    2010-03-18T23:59:59.000Z

    We have developed a linearly-polarized Ytterbium-doped fiber ring laser with single longitudinal-mode output at 1064nm for LISA and other space applications. Single longitudinal-mode selection was achieved by using a fiber Bragg grating (FBG) and a fiber Fabry-Perot (FFP). The FFP also serves as a frequency-reference within our ring laser. Our laser exhibits comparable low frequency and intensity noise to Non-Planar Ring Oscillator (NPRO). By using a fiber-coupled phase modulator as a frequency actuator, the laser frequency can be electro-optically tuned at a rate of 100kHz. It appears that our fiber ring laser is promising for space applications where robustness of fiber optics is desirable.

  13. Laser induced electron acceleration in vacuum K. P. Singha)

    E-Print Network [OSTI]

    Singh, Kunwar Pal

    Laser induced electron acceleration in vacuum K. P. Singha) Department of Physics, Indian Institute acceleration by a plane polarized laser wave has been studied in vacuum. Relativistic equations of motion have been solved exactly for electron trajectory and energy as a function of laser intensity, phase

  14. Enhanced subthreshold electron-positron production in short laser pulses

    E-Print Network [OSTI]

    A. I. Titov; H. Takabe; B. Kampfer; A. Hosaka

    2012-05-17T23:59:59.000Z

    The emission of electron-positron pairs off a probe photon propagating through a polarized short-pulsed electromagnetic (e.g.\\ laser) wave field is analyzed. A significant increase of the total cross section of pair production in the subthreshold region is found for decreasing laser pulse duration even in case of moderate laser pulse intensities.

  15. A simple model for laser drilling Jeb Collins a,1

    E-Print Network [OSTI]

    A simple model for laser drilling Jeb Collins a,1 , Pierre Gremaud b,2, aDepartment of Mathematics drilling is proposed. Assuming axi-symmetry of the process around the axis of the laser beam, a one, implemented and validated for drilling using lasers with intensities in the GW/cm2 range and microsecond

  16. Analysis of Capillary Guided Laser Plasma Accelerator Experiments at LBNL

    E-Print Network [OSTI]

    Geddes, Cameron Guy Robinson

    Analysis of Capillary Guided Laser Plasma Accelerator Experiments at LBNL K. Nakamura , A. J (LBNL) [5, 6]. In this scheme, intense laser pulses were guided over a distance 10 times the Rayleigh facility at LBNL. The laser was focused onto the entrance of a capillary discharge waveguide by an f/25 off

  17. Raman laser amplification in preformed and ionizing plasmas

    E-Print Network [OSTI]

    ~CPA! technique for generating ultra-intense, ultra-short laser pulses is determined by the damageRaman laser amplification in preformed and ionizing plasmas D.S. CLARK1 and N.J. FISCH2 1 Lawrence 1 October 2004; Accepted 2 November 2004! Abstract The recently proposed backward Raman laser

  18. Ambient methods and apparatus for rapid laser trace constituent analysis

    DOE Patents [OSTI]

    Snyder, Stuart C. (Idaho Falls, ID); Partin, Judy K. (Idaho Falls, ID); Grandy, Jon D. (Idaho Falls, ID); Jeffery, Charles L. (Blackfoot, ID)

    2002-01-01T23:59:59.000Z

    A method and apparatus are disclosed for measuring trace amounts of constituents in samples by using laser induced breakdown spectroscopy and laser induced fluorescence under ambient conditions. The laser induced fluorescence is performed at a selected wavelength corresponding to an absorption state of a selected trace constituent. The intensity value of the emission decay signal which is generated by the trace constituent is compared to calibrated emission intensity decay values to determine the amount of trace constituent present.

  19. Predicting threshold and location of laser damage on optical surfaces

    DOE Patents [OSTI]

    Siekhaus, Wigbert (Berkeley, CA)

    1987-01-01T23:59:59.000Z

    An apparatus useful in the prediction of the damage threshold of various optical devices, the location of weak spots on such devices and the location, identification, and elimination of optical surface impurities comprising, a focused and pulsed laser, an photo electric detector/imaging means, and a timer. The weak spots emit photoelectrons when subjected to laser intensities that are less than the intensity actually required to produce the damage. The weak spots may be eliminated by sustained exposure to the laser beam.

  20. Page 1Laser Safety Training Laser Institute of America Laser Safety Laser Institute of America

    E-Print Network [OSTI]

    Farritor, Shane

    Page 1Laser Safety Training © Laser Institute of America 1 Laser Safety © Laser Institute of America Laser Safety: Hazards, Bioeffects, and Control Measures Laser Institute of America Gus Anibarro Education Manager 2Laser Safety © Laser Institute of America Laser Safety Overview Laser Safety Accidents

  1. Zone folding effect in Raman G-band intensity of twisted bilayer graphene

    E-Print Network [OSTI]

    Dresselhaus, Mildred

    The G-band Raman intensity is calculated for twisted bilayer graphene as a function of laser excitation energy based on the extended tight binding method. Here we explicitly consider the electron-photon and electron-phonon ...

  2. Direct Laser Synthesis of Functional Coatings

    SciTech Connect (OSTI)

    P. Schaaf; Michelle D. Shinn; E. Carpene; J. Kaspar

    2005-06-01T23:59:59.000Z

    The direct laser synthesis of functional coatings employs the irradiation of materials with short intensive laser pulses in a reactive atmosphere. The material is heated and plasma is ignited in the reactive atmosphere. This leads to an intensive interaction of the material with the reactive species and a coating is directly formed on the materials surface. By that functional coatings can be easily produced a fast way on steel, aluminium, and silicon by irradiation in nitrogen, methane, or even hydrogen. The influence of the processing parameters to the properties of the functional coatings will be presented for titanium nitride coating produced on titanium with the free electron laser.

  3. Energy Intensity Strategy 

    E-Print Network [OSTI]

    Rappolee, D.; Shaw, J.

    2008-01-01T23:59:59.000Z

    Our presentation will cover how we began the journey of conserving energy at our facility. We’ll discuss a basic layout of our energy intensity plan and the impact our team has had on the process, what tools we’re using, what goals have been...

  4. Laser microphone

    DOE Patents [OSTI]

    Veligdan, James T. (Manorville, NY)

    2000-11-14T23:59:59.000Z

    A microphone for detecting sound pressure waves includes a laser resonator having a laser gain material aligned coaxially between a pair of first and second mirrors for producing a laser beam. A reference cell is disposed between the laser material and one of the mirrors for transmitting a reference portion of the laser beam between the mirrors. A sensing cell is disposed between the laser material and one of the mirrors, and is laterally displaced from the reference cell for transmitting a signal portion of the laser beam, with the sensing cell being open for receiving the sound waves. A photodetector is disposed in optical communication with the first mirror for receiving the laser beam, and produces an acoustic signal therefrom for the sound waves.

  5. THE INSTITUTE FOR SOLID STATE PHYSICS 2013 Laser and Synchrotron Research Center

    E-Print Network [OSTI]

    Katsumoto, Shingo

    develops new lasers with extreme performance of ultra-precise, high intensity and ultra-short pulse lasers67 THE INSTITUTE FOR SOLID STATE PHYSICS 2013 Laser and Synchrotron Research Center LASOR X X LASOR D X E SPring-8 BL07 X Laser and Synchrotron Research (LASOR) Center

  6. Laser ignition

    DOE Patents [OSTI]

    Early, James W.; Lester, Charles S.

    2004-01-13T23:59:59.000Z

    Sequenced pulses of light from an excitation laser with at least two resonator cavities with separate output couplers are directed through a light modulator and a first polarzing analyzer. A portion of the light not rejected by the first polarizing analyzer is transported through a first optical fiber into a first ignitor laser rod in an ignitor laser. Another portion of the light is rejected by the first polarizing analyzer and directed through a halfwave plate into a second polarization analyzer. A first portion of the output of the second polarization analyzer passes through the second polarization analyzer to a second, oscillator, laser rod in the ignitor laser. A second portion of the output of the second polarization analyzer is redirected by the second polarization analyzer to a second optical fiber which delays the beam before the beam is combined with output of the first ignitor laser rod. Output of the second laser rod in the ignitor laser is directed into the first ignitor laser rod which was energized by light passing through the first polarizing analyzer. Combined output of the first ignitor laser rod and output of the second optical fiber is focused into a combustible fuel where the first short duration, high peak power pulse from the ignitor laser ignites the fuel and the second long duration, low peak power pulse directly from the excitation laser sustains the combustion.

  7. SPIE Proceedings, Laser-Tissue Interactions XVI, vol. 5695, BIOS 2005 Cellular tolerance to pulsed heating

    E-Print Network [OSTI]

    Palanker, Daniel

    radiation. Laser beam was focused onto sample providing Gaussian intensity distribution in the focal plane. A large variety of laser and radiofrequency therapies induce thermal stress in tissue with exposure time

  8. The mechanism of thin film Si nanomachining using femtosecond laser pulses

    E-Print Network [OSTI]

    Jia, Jimmy Yi-Jie, 1980-

    2004-01-01T23:59:59.000Z

    Femtosecond (fs) laser ablation has been the subject of intense recent research. The pulse time ('width') is shorter than the electronic relaxation time, resulting in a decoupling of the period of laser illumination and ...

  9. Tiled-Grating Compressor with Uncompensated Dispersion for Near-Field-Intensity Smoothing

    SciTech Connect (OSTI)

    Huang, H.; Kessler, T.J.

    2007-07-02T23:59:59.000Z

    A tiled-grating compressor, in which the spatial dispersion is not completely compensated, reduces the near-field-intensity modulation caused by tiling gaps and provides near-field spatial filtering of the input laser beam, thus reducing the laser damage to the final optics.

  10. Laser device

    DOE Patents [OSTI]

    Scott, Jill R. (Idaho Falls, ID); Tremblay, Paul L. (Idaho Falls, ID)

    2007-07-10T23:59:59.000Z

    A laser device includes a target position, an optical component separated a distance J from the target position, and a laser energy source separated a distance H from the optical component, distance H being greater than distance J. A laser source manipulation mechanism exhibits a mechanical resolution of positioning the laser source. The mechanical resolution is less than a spatial resolution of laser energy at the target position as directed through the optical component. A vertical and a lateral index that intersect at an origin can be defined for the optical component. The manipulation mechanism can auto align laser aim through the origin during laser source motion. The laser source manipulation mechanism can include a mechanical index. The mechanical index can include a pivot point for laser source lateral motion and a reference point for laser source vertical motion. The target position can be located within an adverse environment including at least one of a high magnetic field, a vacuum system, a high pressure system, and a hazardous zone. The laser source and an electro-mechanical part of the manipulation mechanism can be located outside the adverse environment. The manipulation mechanism can include a Peaucellier linkage.

  11. Laser ignition

    DOE Patents [OSTI]

    Early, James W. (Los Alamos, NM); Lester, Charles S. (San Juan Pueblo, NM)

    2003-01-01T23:59:59.000Z

    In the apparatus of the invention, a first excitation laser or other excitation light source is used in tandem with an ignitor laser to provide a compact, durable, engine deployable fuel ignition laser system. Reliable fuel ignition is provided over a wide range of fuel conditions by using a single remote excitation light source for one or more small lasers located proximate to one or more fuel combustion zones. In a third embodiment, alternating short and long pulses of light from the excitation light source are directed into the ignitor laser. Each of the embodiments of the invention can be multiplexed so as to provide laser light energy sequentially to more than one ignitor laser.

  12. High-performance laser processing using manipulated ultrafast laser pulses

    SciTech Connect (OSTI)

    Sugioka, Koji; Cheng Ya; Xu Zhizhan; Hanada, Yasutaka; Midorikawa, Katsumi [RIKEN - Advanced Science Institute, Wako, Saitama 351-0198 (Japan); State Key Laboratory of High Field Laser Physics, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences (China); RIKEN - Advanced Science Institute, Wako, Saitama 351-0198 (Japan)

    2012-07-30T23:59:59.000Z

    We employ manipulated ultrafast laser pulses to realize microprocessing with high-performance. Efficient microwelding of glass substrates by irradiation by a double-pulse train of ultrafast laser pulses is demonstrated. The bonding strength of two photostructurable glass substrates welded by double-pulse irradiation was evaluated to be 22.9 MPa, which is approximately 22% greater than that of a sample prepared by conventional irradiation by a single pulse train. Additionally, the fabrication of hollow microfluidic channels with a circular cross-sectional shape embedded in fused silica is realized by spatiotemporally focusing the ultrafast laser beam. We show both theoretically and experimentally that the spatiotemporal focusing of ultrafast laser beam allows for the creation of a three-dimensionally symmetric spherical peak intensity distribution at the focal spot.

  13. Free-Electron Laser FLASH Injector Laser

    E-Print Network [OSTI]

    FLASH. Free-Electron Laser in Hamburg FLASH Injector Laser Laser 1 Laser 2 Next steps Siegfried | FLASH Meeting | 16-Nov-2009 FLASH. Free-Electron Laser in Hamburg Laser 1 System Overview fround trip A 541 (2005) 467­477 #12;Siegfried Schreiber | FLASH Meeting | 16-Nov-2009 FLASH. Free-Electron Laser

  14. Ultraviolet laser beam monitor using radiation responsive crystals

    DOE Patents [OSTI]

    McCann, Michael P. (Oliver Springs, TN); Chen, Chung H. (Knoxville, TN)

    1988-01-01T23:59:59.000Z

    An apparatus and method for monitoring an ultraviolet laser beam includes disposing in the path of an ultraviolet laser beam a substantially transparent crystal that will produce a color pattern in response to ultraviolet radiation. The crystal is exposed to the ultraviolet laser beam and a color pattern is produced within the crystal corresponding to the laser beam intensity distribution therein. The crystal is then exposed to visible light, and the color pattern is observed by means of the visible light to determine the characteristics of the laser beam that passed through crystal. In this manner, a perpendicular cross sectional intensity profile and a longitudinal intensity profile of the ultraviolet laser beam may be determined. The observation of the color pattern may be made with forward or back scattered light and may be made with the naked eye or with optical systems such as microscopes and television cameras.

  15. Nonlinear Compton scattering in ultra-short laser pulses

    E-Print Network [OSTI]

    Mackenroth, F

    2010-01-01T23:59:59.000Z

    A detailed analysis of the photon emission spectra of an electron scattered by a laser pulse containing only very few cycles of the carrying electromagnetic field is presented. The analysis is performed in the framework of strong-field quantum electrodynamics, with the laser field taken into account exactly in the calculations. We consider different emission regimes depending on the laser intensity, placing special emphasis on the regime of one-cycle beams and of high laser intensities, where the emission spectra depend nonperturbatively on the laser intensity. In this regime we in particular present an accurate stationary phase analysis of the integrals that are shown to determine the computed emission spectra. The emission spectra show significant differences with respect to those in a long pulsed or monochromatic laser field: the emission lines obtained here are much broader and, more important, no dressing of the electron mass is observed.

  16. Nonlinear Compton scattering in ultra-short laser pulses

    E-Print Network [OSTI]

    F. Mackenroth; A. Di Piazza

    2011-03-10T23:59:59.000Z

    A detailed analysis of the photon emission spectra of an electron scattered by a laser pulse containing only very few cycles of the carrying electromagnetic field is presented. The analysis is performed in the framework of strong-field quantum electrodynamics, with the laser field taken into account exactly in the calculations. We consider different emission regimes depending on the laser intensity, placing special emphasis on the regime of one-cycle beams and of high laser intensities, where the emission spectra depend nonperturbatively on the laser intensity. In this regime we in particular present an accurate stationary phase analysis of the integrals that are shown to determine the computed emission spectra. The emission spectra show significant differences with respect to those in a long pulsed or monochromatic laser field: the emission lines obtained here are much broader and, more important, no dressing of the electron mass is observed.

  17. Both the October and November Fall Science Series Lectures Were...

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

    Shinn On Oct. 15, Michelle Shinn, chief optics scientist for Jefferson Lab's Free-Electron Laser, will present "Exploring the Nature of Matter Along the High-Intensity...

  18. OBSERBATION OF HIGH INTENSITY X-RAYS IN INVERSE COMPTON SCATTERING EXPERIMENT

    E-Print Network [OSTI]

    OBSERBATION OF HIGH INTENSITY X-RAYS IN INVERSE COMPTON SCATTERING EXPERIMENT S. Kashiwagi, M the first results of high intensity x-ray generation using Inverse Laser Compton scattering. This experiment Synchrotron Source (LSS). It is based on inverse Compton scattering via interaction between pulsed high power

  19. Imaging System With Confocally Self-Detecting Laser.

    DOE Patents [OSTI]

    Webb, Robert H. (Lincoln, MA); Rogomentich, Fran J. (Concord, MA)

    1996-10-08T23:59:59.000Z

    The invention relates to a confocal laser imaging system and method. The system includes a laser source, a beam splitter, focusing elements, and a photosensitive detector. The laser source projects a laser beam along a first optical path at an object to be imaged, and modulates the intensity of the projected laser beam in response to light reflected from the object. A beam splitter directs a portion of the projected laser beam onto a photodetector. The photodetector monitors the intensity of laser output. The laser source can be an electrically scannable array, with a lens or objective assembly for focusing light generated by the array onto the object of interest. As the array is energized, its laser beams scan over the object, and light reflected at each point is returned by the lens to the element of the array from which it originated. A single photosensitive detector element can generate an intensity-representative signal for all lasers of the array. The intensity-representative signal from the photosensitive detector can be processed to provide an image of the object of interest.

  20. Fusion pumped laser

    DOE Patents [OSTI]

    Pappas, D.S.

    1987-07-31T23:59:59.000Z

    The apparatus of this invention may comprise a system for generating laser radiation from a high-energy neutron source. The neutron source is a tokamak fusion reactor generating a long pulse of high-energy neutrons and having a temperature and magnetic field effective to generate a neutron flux of at least 10/sup 15/ neutrons/cm/sup 2//center dot/s. Conversion means are provided adjacent the fusion reactor at a location operable for converting the high-energy neutrons to an energy source with an intensity and energy effective to excite a preselected lasing medium. A lasing medium is spaced about and responsive to the energy source to generate a population inversion effective to support laser oscillations for generating output radiation. 2 figs., 2 tabs.

  1. Fusion pumped laser

    DOE Patents [OSTI]

    Pappas, Daniel S. (Los Alamos, NM)

    1989-01-01T23:59:59.000Z

    Apparatus is provided for generating energy in the form of laser radiation. A tokamak fusion reactor is provided for generating a long, or continuous, pulse of high-energy neutrons. The tokamak design provides a temperature and a magnetic field which is effective to generate a neutron flux of at least 10.sup.15 neutrons/cm.sup.2.s. A conversion medium receives neutrons from the tokamak and converts the high-energy neutrons to an energy source with an intensity and an energy effective to excite a preselected lasing medium. The energy source typically comprises fission fragments, alpha particles, and radiation from a fission event. A lasing medium is provided which is responsive to the energy source to generate a population inversion which is effective to support laser oscillations for generating output radiation.

  2. Optical diagnostics integrated with laser spark delivery system

    DOE Patents [OSTI]

    Yalin, Azer (Fort Collins, CO); Willson, Bryan (Fort Collins, CO); Defoort, Morgan (Fort Collins, CO); Joshi, Sachin (Fort Collins, CO); Reynolds, Adam (Fort Collins, CO)

    2008-09-02T23:59:59.000Z

    A spark delivery system for generating a spark using a laser beam is provided, and includes a laser light source and a laser delivery assembly. The laser delivery assembly includes a hollow fiber and a launch assembly comprising launch focusing optics to input the laser beam in the hollow fiber. The laser delivery assembly further includes exit focusing optics that demagnify an exit beam of laser light from the hollow fiber, thereby increasing the intensity of the laser beam and creating a spark. Other embodiments use a fiber laser to generate a spark. Embodiments of the present invention may be used to create a spark in an engine. Yet other embodiments include collecting light from the spark or a flame resulting from the spark and conveying the light for diagnostics. Methods of using the spark delivery systems and diagnostic systems are provided.

  3. Biocavity Lasers

    SciTech Connect (OSTI)

    Gourley, P.L.; Gourley, M.F.

    2000-10-05T23:59:59.000Z

    Laser technology has advanced dramatically and is an integral part of today's healthcare delivery system. Lasers are used in the laboratory analysis of human blood samples and serve as surgical tools that kill, burn or cut tissue. Recent semiconductor microtechnology has reduced the size o f a laser to the size of a biological cell or even a virus particle. By integrating these ultra small lasers with biological systems, it is possible to create micro-electrical mechanical systems that may revolutionize health care delivery.

  4. Laser ignition

    DOE Patents [OSTI]

    Early, James W. (Los Alamos, NM); Lester, Charles S. (San Juan Pueblo, NM)

    2002-01-01T23:59:59.000Z

    In the apparatus of the invention, a first excitation laser or other excitation light source capable of producing alternating beams of light having different wavelengths is used in tandem with one or more ignitor lasers to provide a compact, durable, engine deployable fuel ignition laser system. Reliable fuel ignition is provided over a wide range of fuel conditions by using the single remote excitation light source for pumping one or more small lasers located proximate to one or more fuel combustion zones with alternating wavelengths of light.

  5. Intensity Frontier Instrumentation

    SciTech Connect (OSTI)

    Kettell S.; Rameika, R.; Tshirhart, B.

    2013-09-24T23:59:59.000Z

    The fundamental origin of flavor in the Standard Model (SM) remains a mystery. Despite the roughly eighty years since Rabi asked “Who ordered that?” upon learning of the discovery of the muon, we have not understood the reason that there are three generations or, more recently, why the quark and neutrino mixing matrices and masses are so different. The solution to the flavor problem would give profound insights into physics beyond the Standard Model (BSM) and tell us about the couplings and the mass scale at which the next level of insight can be found. The SM fails to explain all observed phenomena: new interactions and yet unseen particles must exist. They may manifest themselves by causing SM reactions to differ from often very precise predictions. The Intensity Frontier (1) explores these fundamental questions by searching for new physics in extremely rare processes or those forbidden in the SM. This often requires massive and/or extremely finely tuned detectors.

  6. Science and Technology Review January/February 2011

    SciTech Connect (OSTI)

    Blobaum, K J

    2010-11-22T23:59:59.000Z

    This month's issue has the following articles: (1) World's Most Intense X-Ray Laser Focuses on Livermore Science - Commentary by William H. Goldstein; (2) Groundbreaking Science with the World's Brightest X Rays - Experiments with x rays of unparalleled brightness and extremely short duration aim to reveal new information about atoms and molecules in motion; (3) From Data to Discovery - Ongoing control system enhancements at the National Ignition Facility bolster the understanding of experimental data and keep the system performing at its peak; (4) The Sun in All Its Splendor - Onboard the Solar Dynamics Observatory, Livermore-developed multilayer mirrors are enabling unprecedented full-disk, high-resolution images of the Sun; and (5) Drilling Deep into Plant Veins - A novel combination of imaging techniques is being used to understand the three-dimensional architecture of plant cell walls.

  7. SLAC All Access: Atomic, Molecular and Optical Science Instrument

    SciTech Connect (OSTI)

    Bozek, John

    2013-11-05T23:59:59.000Z

    John Bozek, a staff scientist at SLAC's Linac Coherent Light Source (LCLS) X-ray laser who manages the LCLS Soft X-ray Department, takes us behind the scenes at the Atomic, Molecular and Optical Science (AMO) instrument, the first of six experimental stations now operating at LCLS. Samples used in AMO experiments include atoms, molecules, clusters, and nanoscale objects such as protein crystals or viruses. Science performed at AMO includes fundamental studies of light-matter interactions in the extreme X-ray intensity of the LCLS pules, time-resolved studies of increasingly charged states of atoms and molecules, X-ray diffraction imaging of nanocrystals, and single-shot imaging of a variety of objects.

  8. SLAC All Access: Atomic, Molecular and Optical Science Instrument

    ScienceCinema (OSTI)

    Bozek, John

    2014-06-03T23:59:59.000Z

    John Bozek, a staff scientist at SLAC's Linac Coherent Light Source (LCLS) X-ray laser who manages the LCLS Soft X-ray Department, takes us behind the scenes at the Atomic, Molecular and Optical Science (AMO) instrument, the first of six experimental stations now operating at LCLS. Samples used in AMO experiments include atoms, molecules, clusters, and nanoscale objects such as protein crystals or viruses. Science performed at AMO includes fundamental studies of light-matter interactions in the extreme X-ray intensity of the LCLS pules, time-resolved studies of increasingly charged states of atoms and molecules, X-ray diffraction imaging of nanocrystals, and single-shot imaging of a variety of objects.

  9. Nonlinear magneto-optic polarization rotation with intense laser fields

    E-Print Network [OSTI]

    Hsu, Paul S.; Patnaik, Anil K.; Welch, George R.

    2008-01-01T23:59:59.000Z

    spectroscopy measurements #3;1,2#4;, both for fun- damental and practical reasons such as optical magnetometry #3;3#4;. The sensitivity of optical pumping magnetometers #1;OPMs#2; has already achieved 10?9 G /#5;Hz under laboratory conditions #3...;4,5#4;. Also, nonlinear magneto-optic rotation has been used in magnetometry to reach very high sensitivity #3;6#4;. In such devices, the Zeeman level shift measurements are based on light absorption #3;7#4;, but the sensitivity is limited if the absorption...

  10. [142] D. S. Clark and N. J. Fisch, Raman laser amplification in preformed and ionizing plasmas, Laser and Particle Beams, 23, (1) 101106 (January, 2005).

    E-Print Network [OSTI]

    . M. Malkin, and N. J. Fisch, Manipulating ultra-intense laser pulses in plasmas, Physics of Plasma 12[142] D. S. Clark and N. J. Fisch, Raman laser amplification in preformed and ionizing plasmas, Laser and Particle Beams, 23, (1) 101­106 (January, 2005). [143] W. Cheng, Y. Avitzour, Y. Ping, S

  11. Compression of laser radiation in plasmas via electromagnetic cascading

    SciTech Connect (OSTI)

    Kalmykov, Serguei; Shvets, Gennady [Department of Physics and Institute for Fusion Studies, University of Texas at Austin, One University Station C1500, Austin, Texas 78712 (United States)

    2006-05-15T23:59:59.000Z

    A train of few-laser-cycle relativistically intense radiation spikes with a terahertz repetition rate can be organized self-consistently in plasma from two frequency detuned co-propagating laser beams of low intensity. Large frequency bandwidth for the compression of spikes is produced via laser-induced periodic modulation of the plasma refractive index. The beat-wave-driven electron plasma wave downshifted from the plasma frequency creates a moving index grating thus inducing a periodic phase modulation of the driving laser (in spectral terms, electromagnetic cascading). The group velocity dispersion compresses the chirped laser beat notes to a few-cycle duration and relativistic intensity either concurrently in the same, or sequentially in different plasmas. Particle-in-cell simulations indicate that the effect persists in a realistic three-dimensional axisymmetric geometry.

  12. Confocal unstable-resonator semiconductor laser

    SciTech Connect (OSTI)

    Salzman, J.; Lang, R.; Larson, A.; Yariv, A.

    1986-08-01T23:59:59.000Z

    GaAs/GaAlAs heterostructure lasers with a monolithic confocal unstable resonator were demonstrated. The curved mirrors satisfying the confocal condition were fabricated by etching. Close to threshold, the lasers operate in a single lateral mode with a nearly collimated output beam. A single-lobe far-field intensity distribution as narrow as 1.9/sup 0/ full width at half maximum was measured.

  13. Confocal unstable-resonator semiconductor laser

    SciTech Connect (OSTI)

    Salzman, J.; Lang, R.; Larson, A.; Yariv

    1986-08-01T23:59:59.000Z

    GaAs/GaA1As heterostructure lasers with a monolithic confocal unstable resonator were demonstrated. The curved mirrors satisfying the confocal condition were fabricated by etching. Close to threshold, the lasers operate in a single lateral mode with a nearly collimated out beam. A single-lobe far-field intensity distribution as narrow as 1.9 deg full width at half maximum was measured.

  14. Joining of materials using laser heating

    DOE Patents [OSTI]

    Cockeram, Brian V.; Hicks, Trevor G.; Schmid, Glenn C.

    2003-07-01T23:59:59.000Z

    A method for diffusion bonding ceramic layers such as boron carbide, zirconium carbide, or silicon carbide uses a defocused laser beam to heat and to join ceramics with the use of a thin metal foil insert. The metal foil preferably is rhenium, molybdenum or titanium. The rapid, intense heating of the ceramic/metal/ceramic sandwiches using the defocused laser beam results in diffusive conversion of the refractory metal foil into the ceramic and in turn creates a strong bond therein.

  15. "USING LASERS TO CONTROL AND PROBE THE BRAIN", Prof. Adam Cohen...

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

    February 18, 2012, 9:30am Science On Saturday "USING LASERS TO CONTROL AND PROBE THE BRAIN", Prof. Adam Cohen, Department of Physics, Harvard University USING LASERS TO CONTROL AND...

  16. Intensity dependence narrowing of electromagnetically induced absorption in a Doppler-broadened medium

    SciTech Connect (OSTI)

    Dimitrijevic, J.; Arsenovic, D.; Jelenkovic, B. M. [Institute of Physics, 11080 Belgrade (Serbia)

    2007-07-15T23:59:59.000Z

    In this paper, we present a theoretical model for studying the interaction between linearly polarized laser light and near-degenerated Zeeman sublevels for a multiple V-type atomic system of {sup 2}S{sub 1/2}F{sub g}=2{yields}{sup 2}P{sub 3/2}F{sub e}=3 transition in {sup 87}Rb. We have calculated the laser absorption in a Hanle configuration, as well as the amplitudes and the widths of electromagnetically induced absorption (EIA) in the range of laser intensities from 0.01 to 40 mW/cm{sup 2}. Our results, showing nonvanishing EIA amplitude, a nonmonotonic increase of the EIA width for the increase of laser intensity, and pronounced shape differences of the Hanle EIA curves at different laser intensities, are in good agreement with recent experimental results. We have found that the EIA behaves differently than the electromagnetically induced transparency (EIT) as a function of the laser intensity. Both the amplitude and width of the EIA have narrow maximums at 1 to 2 mW/cm{sup 2}. We have shown the strong influence of Doppler broadening of atomic transition on Hanle resonances and have suggested the explanation of it.

  17. Northern New Mexico Math & Science Academy

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

    Northern New Mexico Math & Science Academy for Teachers (MSA) Program Description MSA is an intensive and comprehensive professional development program for K-12 teachers....

  18. Geometry of attosecond laser pulses and photon-photon scattering at high energies

    E-Print Network [OSTI]

    Tuchin, Kirill

    2009-01-01T23:59:59.000Z

    We derive the total cross section for scattering of a photon on an ultra-short laser pulse at high energies. We take into account all multi-photon interactions. We argue that the nonlinear effects due to these interactions become important at very high intensities of the laser pulse. We demonstrate however, that these intensities are significantly lower than the Schwinger critical value.

  19. Laser goniometer

    DOE Patents [OSTI]

    Fairer, George M. (Boulder, CO); Boernge, James M. (Lakewood, CO); Harris, David W. (Lakewood, CO); Campbell, DeWayne A. (Littleton, CO); Tuttle, Gene E. (Littleton, CO); McKeown, Mark H. (Golden, CO); Beason, Steven C. (Lakewood, CO)

    1993-01-01T23:59:59.000Z

    The laser goniometer is an apparatus which permits an operator to sight along a geologic feature and orient a collimated lamer beam to match the attitude of the feature directly. The horizontal orientation (strike) and the angle from horizontal (dip), are detected by rotary incremental encoders attached to the laser goniometer which provide a digital readout of the azimuth and tilt of the collimated laser beam. A microprocessor then translates the square wave signal encoder outputs into an ASCII signal for use by data recording equipment.

  20. Sub-femtosecond electron bunches created by direct laser acceleration in a laser wakefield accelerator with ionization injection

    E-Print Network [OSTI]

    Lemos, N; Marsh, K A; Joshi, C

    2015-01-01T23:59:59.000Z

    In this work, we will show through three-dimensional particle-in-cell simulations that direct laser acceleration in laser a wakefield accelerator can generate sub-femtosecond electron bunches. Two simulations were done with two laser pulse durations, such that the shortest laser pulse occupies only a fraction of the first bubble, whereas the longer pulse fills the entire first bubble. In the latter case, as the trapped electrons moved forward and interacted with the high intensity region of the laser pulse, micro-bunching occurred naturally, producing 0.5 fs electron bunches. This is not observed in the short pulse simulation.

  1. Laser induced phosphorescence uranium analysis

    DOE Patents [OSTI]

    Bushaw, Bruce A. (Kennewick, WA)

    1986-01-01T23:59:59.000Z

    A method is described for measuring the uranium content of aqueous solutions wherein a uranyl phosphate complex is irradiated with a 5 nanosecond pulse of 425 nanometer laser light and resultant 520 nanometer emissions are observed for a period of 50 to 400 microseconds after the pulse. Plotting the natural logarithm of emission intensity as a function of time yields an intercept value which is proportional to uranium concentration.

  2. Laser induced phosphorescence uranium analysis

    DOE Patents [OSTI]

    Bushaw, B.A.

    1983-06-10T23:59:59.000Z

    A method is described for measuring the uranium content of aqueous solutions wherein a uranyl phosphate complex is irradiated with a 5 nanosecond pulse of 425 nanometer laser light and resultant 520 nanometer emissions are observed for a period of 50 to 400 microseconds after the pulse. Plotting the natural logarithm of emission intensity as a function of time yields an intercept value which is proportional to uranium concentration.

  3. Proposed Laser-Based HED physics experiments for Stockpile Stewardship

    SciTech Connect (OSTI)

    Benage, John F. [Los Alamos National Laboratory; Albright, Brian J. [Los Alamos National Laboratory; Fernandez, Juan C. [Los Alamos National Laboratory

    2012-09-04T23:59:59.000Z

    An analysis of the scientific areas in High Energy Density (HED) physics that underpin the enduring LANL mission in Stockpile Stewardship (SS) has identified important research needs that are not being met. That analysis has included the work done as part of defining the mission need for the High Intensity Laser Laboratory (HILL) LANL proposal to NNSA, LDRD DR proposal evaluations, and consideration of the Predictive Capability Framework and LANL NNSA milestones. From that evaluation, we have identified several specific and scientifically-exciting experimental concepts to address those needs. These experiments are particularly responsive to physics issues in Campaigns 1 and 10. These experiments are best done initially at the LANL Trident facility, often relying on the unique capabilities available there, although there are typically meritorious extensions envisioned at future facilities such as HILL, or the NIF once the ARC short-pulse laser is available at sufficient laser intensity. As the focus of the LANL HEDP effort broadens from ICF ignition of the point design at the conclusion of the National Ignition Campaign, into a more SS-centric effort, it is useful to consider these experiments, which address well-defined issues, with specific scientific hypothesis to test or models to validate or disprove, via unit-physics experiments. These experiments are in turn representative of a possible broad experimental portfolio to elucidate the physics of interest to these campaigns. These experiments, described below, include: (1) First direct measurement of the evolution of particulates in isochorically heated dense plasma; (2) Temperature relaxation measurements in a strongly-coupled plasma; (3) Viscosity measurements in a dense plasma; and (4) Ionic structure factors in a dense plasma. All these experiments address scientific topics of importance to our sponsors, involve excellent science at the boundaries of traditional fields, utilize unique capabilities at LANL, and contribute to the Campaign milestone in 2018. Given their interdisciplinary nature, it is not surprising that these research needs are not being addressed by the other excellent high-energy density physics (HEDP) facilities coming on line, facilities aimed squarely at more established fields and missions. Although energy rich, these facilities deliver radiation (e.g., particle beams for isochoric heating) over a timescale that is too slow in these unit physics experiments to eliminate hydrodynamic evolution of the target plasma during the time it is being created. A theme shared by all of these experiments is the need to quickly create a quasi-homogeneous 'initial state' whose properties and evolution we wish to study. Otherwise, we cannot create unit experiments to isolate the physics of interest and validate the models in our codes, something that cannot be done with the integrated experiments often done in HED. Moreover, these experiments in some cases involve combinations of solid and plasmas, or matter in the warm-dense matter state, where neither the theoretical approximations of solid state or of fully-ionized weakly-coupled plasmas can be used. In all cases, the capability of 'isochoric heating' ('flash' heating at constant density) is important. In some cases, the ability to selectively heat to different degrees different species within a target, whether mixed or adjacent to each other, is critical for the experiment. This capability requires the delivery of very high power densities, which require the conversion of the laser into very short and intense pulses of secondary radiation (electrons, ions, neutrons, x-rays). Otherwise, there is no possibility of a clean experiment to constrain the models, in the cases there are any, or inform the creation of one. Another typical requirement of these experiments is the ability to probe these exotic extreme conditions of matter with flexible and diverse sources of secondary radiation. Without a high-intensity high-power laser with some unique attributes available on Trident today (e.g., ultra-high laser-puls

  4. Non-intrusive beam power monitor for high power pulsed or continuous wave lasers

    DOE Patents [OSTI]

    Hawsey, Robert A. (Oak Ridge, TN); Scudiere, Matthew B. (Oak Ridge, TN)

    1993-01-01T23:59:59.000Z

    A system and method for monitoring the output of a laser is provided in which the output of a photodiode disposed in the cavity of the laser is used to provide a correlated indication of the laser power. The photodiode is disposed out of the laser beam to view the extraneous light generated in the laser cavity whose intensity has been found to be a direct correlation of the laser beam output power level. Further, the system provides means for monitoring the phase of the laser output beam relative to a modulated control signal through the photodiode monitor.

  5. Intensity-dependent enhancements in high-order above-threshold ionization

    SciTech Connect (OSTI)

    Milosevic, D. B. [Faculty of Science, University of Sarajevo, Zmaja od Bosne 35, 71000 Sarajevo (Bosnia and Herzegowina); Max-Born-Institut, Max-Born-Strasse 2a, 12489 Berlin (Germany); Hasovic, E.; Gazibegovic-Busuladzic, A. [Faculty of Science, University of Sarajevo, Zmaja od Bosne 35, 71000 Sarajevo, Bosnia and Herzegovina (Bosnia and Herzegowina); Busuladzic, M. [Medical Faculty, University of Sarajevo, Cekalusa 90, 71000 Sarajevo (Bosnia and Herzegowina); Becker, W. [Max-Born-Institut, Max-Born-Strasse 2a, 12489 Berlin (Germany)

    2007-11-15T23:59:59.000Z

    The very pronounced intensity-dependent enhancements of groups of peaks of high-order above-threshold-ionization spectra of rare-gas atoms are investigated using an improved version of the strong-field approximation, which realistically models the respective atom. Two types of enhancements are found and explained in terms of constructive interference of the contributions of a large number of long quantum orbits. The first type is observed for intensities slightly below channel closings. Its intensity dependence is comparatively smooth and it is generated by comparatively few (of the order of 20) orbits. The second type occurs precisely at channel closings and exhibits an extremely sharp intensity dependence. It requires constructive interference of a very large number of long orbits (several hundreds) and generates cusps in the electron spectrum at integer multiples of the laser-photon energy. An interpretation of these enhancements as a threshold phenomenon is also given. An interplay of different types of the threshold anomalies is observed. The position of both types of enhancements, in the photoelectron-energy--laser-intensity plane, shifts to the next channel closing intensity with the change of the ground-state parity. The enhancements gradually disappear with decreasing laser pulse duration. This confirms the interpretation of enhancements as a consequence of the interference of long strong-laser-field-induced quantum orbits.

  6. Laser-induced fluorescence of fused silica irradiated by ArF excimer laser

    SciTech Connect (OSTI)

    Zhang Haibo [Shanghai Key Laboratory of All Solid-state Laser and Applied Techniques, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Science, Shanghai 201800 (China); Graduate University of Chinese Academy of Science, Beijing 100049 (China); Yuan Zhijun; Zhou Jun; Dong Jingxing; Wei Yunrong; Lou Qihong [Shanghai Key Laboratory of All Solid-state Laser and Applied Techniques, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Science, Shanghai 201800 (China)

    2011-07-01T23:59:59.000Z

    Laser-induced fluorescence (LIF) of high-purity fused silica irradiated by ArF excimer laser is studied experimentally. LIF bands of the fused silica centered at 281 nm, 478 nm, and 650 nm are observed simultaneously. Furthermore, the angular distribution of the three fluorescence peaks is examined. Microscopic image of the laser modified fused silica indicates that scattering of the generated fluorescence by laser-induced damage sites is the main reason for the angular distribution of LIF signals. Finally, the dependence of LIF signals intensities of the fused silica on laser power densities is presented. LIF signals show a squared power density dependence, which indicates that laser-induced defects are formed mainly via two-photon absorption processes.

  7. Laser Optomechanics

    E-Print Network [OSTI]

    Yang, Weijian; Ng, Kar Wei; Rao, Yi; Chase, Christopher; Chang-Hasnain, Connie J

    2015-01-01T23:59:59.000Z

    Cavity optomechanics explores the coupling between the optical field and the mechanical oscillation to induce cooling and regenerative oscillation in a mechanical oscillator. So far, optomechanics relies on the detuning between the cavity and an external pump laser, where the laser acts only as a power supply. Here, we report a new scheme with mutual coupling between a mechanical oscillator that supports a mirror of a vertical-cavity surface-emitting laser (VCSEL) and the optical field, greatly enhancing the light-matter energy transfer. In this work, we used an ultra-light-weight (130 pg) high-contrast-grating (HCG) mirror in a VCSEL, whose reflectivity spectrum is designed to facilitate strong optomechanical coupling, to demonstrate optomechanically-induced regenerative oscillation of the laser optomechanical cavity with > 550 nm self-oscillation amplitude of the micro-mechanical oscillator, two to three orders of magnitude larger than typical. This new scheme not only offers an efficient approach for high-...

  8. Laser barometer

    SciTech Connect (OSTI)

    Abercrombie, K.R.; Shiels, D.; Rash, T.

    1998-04-01T23:59:59.000Z

    This paper describes an invention of a pressure measuring instrument which uses laser radiation to sense the pressure in an enclosed environment by means of measuring the change in refractive index of a gas - which is pressure dependent.

  9. Laser Plasma Interactions

    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: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOE Office of Science (SC)Integrated Codes |Is Your Home asLCLSLaboratoryRowlandRevolutionizing theLaser

  10. The 22nd International Photovoltaic Science and Engineering Conference, November 05-09, 2012, Hangzhou, China Limits for short-pulse laser processing of high efficiency

    E-Print Network [OSTI]

    The 22nd International Photovoltaic Science and Engineering Conference, November 05-09, 2012 in the range of the ablation threshold of dielectric layers can result in a degradation of the front side efficiencies are considered as very important for reducing the cost of photovoltaic electricity production. [1

  11. Generation of Stable (3+1)-dimensional High-intensity Ultrashort Light Pulses

    SciTech Connect (OSTI)

    Todorov, T. P.; Koprinkov, I. G. [Department of Applied Physics, Technical University of Sofia, 1000 Sofia (Bulgaria); Todorova, M. E. [College of Energetics and Electronics, Technical University of Sofia, 1000 Sofia (Bulgaria); Todorov, M. D. [Faculty of Appl. Math. and Informatics, Technical University of Sofia, 1000 Sofia (Bulgaria)

    2010-11-25T23:59:59.000Z

    The spatiotemporal dynamics of high-intensity femtosecond laser pulses is studied within a rigorous physical model. The pulse propagation is described by the nonlinear envelope equation. The propagation and the material equations are solved self-consistently at realistic physical conditions. Self-compression of the pulse around single-cycle regime and dramatic increase of the pulse intensity is found. At certain conditions, the peak intensity, transversal width, time duration, and the spatiotemporal pulse shape remain stable with the propagation of the pulse, resembling a soliton formation process. This, to our knowledge, is the first simulation of high-intensity ultrashort soliton formation dynamics in the (3+1)-dimensional case.

  12. Semiclassical theory of noise in semiconductor lasers - part 1

    SciTech Connect (OSTI)

    Vahala, K.; Yariv, A.

    1983-06-01T23:59:59.000Z

    A Van der Pol analysis of laser noise which includes the field intensity dependence of the refractive index is presented. The consequent amplitude phase coupling affects all laser spectra except the power fluctuations spectrum. An analytic expression for the linewidth broadening enhancement due to index variation is given.

  13. Vanadium-pumped titanium x-ray laser

    DOE Patents [OSTI]

    Nilsen, J.

    1992-05-26T23:59:59.000Z

    A resonantly photo-pumped x-ray laser is formed of a vanadium and titanium foil combination that is driven by two beams of intense line focused optical laser radiation. Ground state neon-like titanium ions are resonantly photo-pumped by line emission from fluorine-like vanadium ions. 4 figs.

  14. Subthreshold pair production in short laser pulses

    E-Print Network [OSTI]

    T. Nousch; D. Seipt; B. Kampfer; A. I. Titov

    2012-06-01T23:59:59.000Z

    The $e^+e^-$ pair production by a probe photon traversing a linearly polarized laser pulse is treated as generalized nonlinear Breit-Wheeler process. For short laser pulses with very few oscillations of the electromagnetic field we find below the perturbative weak-field threshold $\\sqrt{s} = 2m$ a similar enhancement of the pair production rate as for circular polarization. The strong subthreshold enhancement is traced back to the finite bandwidth of the laser pulse. A folding model is developed which accounts for the interplay of the frequency spectrum and the intensity distribution in the course of the pulse.

  15. Exploding conducting film laser pumping apparatus

    DOE Patents [OSTI]

    Ware, Kenneth D. (San Diego, CA); Jones, Claude R. (Los Alamos, NM)

    1986-01-01T23:59:59.000Z

    Exploding conducting film laser optical pumping apparatus. The 342-nm molecular iodine and the 1.315-.mu.m atomic iodine lasers have been optically pumped by intense light from exploding-metal-film discharges. Brightness temperatures for the exploding-film discharges were approximately 25,000 K. Although lower output energies were achieved for such discharges when compared to exploding-wire techniques, the larger surface area and smaller inductance inherent in the exploding-film should lead to improved efficiency for optically-pumped gas lasers.

  16. Ion Acceleration by Short Chirped Laser Pulses

    E-Print Network [OSTI]

    Li, Jian-Xing; Keitel, Christoph H; Harman, Zoltán

    2015-01-01T23:59:59.000Z

    Direct laser acceleration of ions by short frequency-chirped laser pulses is investigated theoretically. We demonstrate that intense beams of ions with a kinetic energy broadening of about 1 % can be generated. The chirping of the laser pulse allows the particles to gain kinetic energies of hundreds of MeVs, which is required for hadron cancer therapy, from pulses of energies of the order of 100 J. It is shown that few-cycle chirped pulses can accelerate ions more efficiently than long ones, i.e. higher ion kinetic energies are reached with the same amount of total electromagnetic pulse energy.

  17. High-brightness switchable multiwavelength remote laser in air

    SciTech Connect (OSTI)

    Yao Jinping; Cheng Ya; Xu Zhizhan [State Key Laboratory of High Field Laser Physics, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800 (China); Zeng Bin; Li Guihua; Chu Wei; Ni Jielei; Zhang Haisu [State Key Laboratory of High Field Laser Physics, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800 (China); Graduate School of Chinese Academy of Sciences, Beijing 100080 (China); Xu Huailiang [State Key Laboratory on Integrated Optoelectronics, College of Electronic Science and Engineering, Jilin University, Changchun 130012 (China); Chin, See Leang [Center for Optics, Universite Laval, Quebec City, Quebec G1V 0A6 (Canada)

    2011-11-15T23:59:59.000Z

    We demonstrate a harmonic-seeded switchable multiwavelength laser in air driven by intense midinfrared femtosecond laser pulses, in which population inversion occurs at an ultrafast time scale (i.e., less than {approx}200 fs) owing to direct formation of excited molecular nitrogen ions by strong-field ionization of inner-valence electrons. The bright multiwavelength laser in air opens the perspective for remote detection of multiple pollutants based on nonlinear optical spectroscopy.

  18. Laser ablation in analytical chemistry - A review

    SciTech Connect (OSTI)

    Russo, Richard E.; Mao, Xianglei; Liu, Haichen; Gonzalez, Jhanis; Mao, Samuel S.

    2001-10-10T23:59:59.000Z

    Laser ablation is becoming a dominant technology for direct solid sampling in analytical chemistry. Laser ablation refers to the process in which an intense burst of energy delivered by a short laser pulse is used to sample (remove a portion of) a material. The advantages of laser ablation chemical analysis include direct characterization of solids, no chemical procedures for dissolution, reduced risk of contamination or sample loss, analysis of very small samples not separable for solution analysis, and determination of spatial distributions of elemental composition. This review describes recent research to understand and utilize laser ablation for direct solid sampling, with emphasis on sample introduction to an inductively coupled plasma (ICP). Current research related to contemporary experimental systems, calibration and optimization, and fractionation is discussed, with a summary of applications in several areas.

  19. Improvement of classical accelerators by lasers

    E-Print Network [OSTI]

    Hora, Heinrich

    1991-01-01T23:59:59.000Z

    Of the unconventional accelerator techniques those including lasers are reported. After explaining the advances by lasers for classical accelerator techniques, as FELs and other methods for 100 GHz generation of GW pulses, a survey is given of far field and near field laser acceleration. Problems of the beat-wave accelerator are discussed and schemes for particle interaction in vacuum without plasma are elaborated. One scheme is the Boreham experiment and another is the acceleration of "standing" wave fields where charged particles are trapped in the intensity minima. Another scheme uses the relativistic acceleration by half waves where the now available petawatt-picosecond laser pulses should produce GeV electron pulses of high luminosity. Increase of these electron enrgies would need very large lasers in the future.

  20. Design Considerations for Plasma Accelerators Driven by Lasers or Particle Beams

    E-Print Network [OSTI]

    Geddes, Cameron Guy Robinson

    Design Considerations for Plasma Accelerators Driven by Lasers or Particle Beams C. B. Schroeder, E of an intense laser or the space-charge force of a charged particle beam. The implications for accelerator-charge force of a charged particle beam. Laser-driven plasma accelerators (LPAs) were first proposed in 1979

  1. Thermal Simulation of Laser Annealing for 3D Integration B. Rajendran, S. H. Jain1

    E-Print Network [OSTI]

    Pease, R. Fabian W.

    laser annealing is a very promising technology for dopant activation [4]. Ultra-short, high intensityThermal Simulation of Laser Annealing for 3D Integration B. Rajendran, S. H. Jain1 , T. A. Kramer of various interconnect and device layers of an exemplary 3D IC structure during laser annealing for dopant

  2. Submitted IEEE Trans. Plasma Science Shvets Fisch

    E-Print Network [OSTI]

    /injector charged particle bunches. Since phase equiva- lently, ####) enhanced wake be controlled the detuning initially moves with v v acceler- ated velocity larger laser group velocity. The intensity threshold becomes

  3. Picoseconds-Laser Modification of Thin Films

    SciTech Connect (OSTI)

    Gakovic, Biljana; Trtica, Milan [Institute of Nuclear Sciences 'VINCA' 522, 11001 Belgrade (Serbia and Montenegro); Batani, Dimitri; Desai, Tara; Redaelli, Renato [Dipartimento di Fisica 'G. Occhialini', Universita' degli Studi Milano-Bicocca, Piazza della Scienza 3, Milan 20126 (Italy)

    2006-04-07T23:59:59.000Z

    The interaction of a Nd:YAG laser, pulse duration of 40 ps, with a titanium nitride (TiN) and tungsten-titanium (W-Ti) thin films deposited at silicon was studied. The peak intensity on targets was up to 1012 W/cm2. Results have shown that the TiN surface was modified, by the laser beam, with energy density of {>=}0.18 J/cm2 ({lambda}laser= 532 nm) as well as of 30.0 J/cm2 ({lambda}laser= 1064 nm). The W-Ti was surface modified with energy density of 5.0 J/cm2 ({lambda}laser= 532 nm). The energy absorbed from the Nd:YAG laser beam is partially converted to thermal energy, which generates a series of effects such as melting, vaporization of molten materials, dissociation and ionization of the vaporized material, appearance of plasma, etc. The following morphological changes of both targets were observed: (i) The appearance of periodic microstructures, in the central zone of the irradiated area, for laser irradiation at 532 nm. Accumulation of great number of laser pulses caused film ablation and silicon modification. (ii) Hole formation on the titanium nitride/silicon target was registered at 1064 nm. The process of the Nd:YAG laser interaction with both targets was accompanied by plasma formation above the target.

  4. Proceedings of the Gas and Chemical Lasers and Intense Beam Applications III Conference, San Jose, California 22-24 January 2002, The Int. Soc. for Opt. Eng. Vol. 4631, P.O. Box 10, Bellingham, WA 98227-0010, pp. 154-160.

    E-Print Network [OSTI]

    Carroll, David L.

    by a liquid chemistry singlet oxygen generator (SOG). Workers at CUA and UIUC are now addressing. Keywords: chemical oxygen-iodine laser, COIL, ElectriCOIL, RF excitation of oxygen, singlet-delta oxygen 1 oxygen-iodine laser (COIL) [McDermott, 1978] operates on the electronic transition of the iodine atom

  5. Accelerators for Intensity Frontier Research

    SciTech Connect (OSTI)

    Derwent, Paul; /Fermilab

    2012-05-11T23:59:59.000Z

    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.

  6. AFM CHARACTERIZATION OF LASER INDUCED DAMAGE ON CDZNTE CRYSTAL SURFACES

    SciTech Connect (OSTI)

    Hawkins, S; Lucile Teague, L; Martine Duff, M; Eliel Villa-Aleman, E

    2008-06-10T23:59:59.000Z

    Semi-conducting CdZnTe (or CZT) crystals can be used in a variety of detector-type applications. CZT shows great promise for use as a gamma radiation spectrometer. However, its performance is adversely affected by point defects, structural and compositional heterogeneities within the crystals, such as twinning, pipes, grain boundaries (polycrystallinity), secondary phases and in some cases, damage caused by external forces. One example is damage that occurs during characterization of the surface by a laser during Raman spectroscopy. Even minimal laser power can cause Te enriched areas on the surface to appear. The Raman spectra resulting from measurements at moderate intensity laser power show large increases in peak intensity that is attributed to Te. Atomic Force Microscopy (AFM) was used to characterize the extent of damage to the CZT crystal surface following exposure to the Raman laser. AFM data reveal localized surface damage in the areas exposed to the Raman laser beam. The degree of surface damage to the crystal is dependent on the laser power, with the most observable damage occurring at high laser power. Moreover, intensity increases in the Te peaks of the Raman spectra are observed even at low laser power with little to no visible damage observed by AFM. AFM results also suggest that exposure to the same amount of laser power yields different amounts of surface damage depending on whether the exposed surface is the Te terminating face or the Cd terminating face of CZT.

  7. Laser Program annual report, 1985

    SciTech Connect (OSTI)

    Rufer, M.L.; Murphy, P.W. (eds.)

    1986-11-01T23:59:59.000Z

    This volume presents the unclassified activities and accomplishments of the Inertial Confinement Fusion and Advanced Laser Development elements of the Laser Program at the Lawrence Livermore National Laboratory for the calendar year 1985. This report has been organized into major sections that correspond to our principal technical activities. Section 1 provides an overview. Section 2 comprises work in target theory, design, and code development. Target development and fabrication and the related topics in materials science are contained in Section 3. Section 4 presents work in experiments and diagnostics and includes developments in data acquisition and management capabilities. In Section 5 laser system (Nova) operation and maintenance are discussed. Activities related to supporting laser and optical technologies are described in Section 6. Basic laser research and development is reported in Section 7. Section 8 contains the results of studies in ICF applications where the work reported deals principally with the production of electric power with ICF. Finally, Section 9 is a comprehensive discussion of work to date on solid state lasers for average power applications. Individual sections, two through nine, have been cataloged separately.

  8. FREE ELECTRON LASERS

    E-Print Network [OSTI]

    Colson, W.B.

    2008-01-01T23:59:59.000Z

    1984). Colson, W. B. , "Free electron laser theory," Ph.D.aspects of the free electron laser," Laser Handbook i,Quant. Elect. Bendor Free Electron Laser Conference, Journal

  9. ITP Energy Intensive Processes: Energy-Intensive Processes Portfolio...

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

    teChnologIes Program IntroduCtIon the research and development (r&d) portfolio for energy-Intensive Processes (eIP) addresses the top technology opportunities to save energy...

  10. Rapid Proton Transfer Mediated by a Strong Laser Field

    SciTech Connect (OSTI)

    Markevitch, Alexei N.; Levis, Robert J. [Department of Chemistry, Center for Advanced Photonics Research, Temple University, Philadelphia, Pennsylvania 19122 (United States); Romanov, Dmitri A. [Department of Physics, Center for Advanced Photonics Research, Temple University, Philadelphia, Pennsylvania 19122 (United States); Smith, Stanley M. [Department of Chemistry, Wayne State University, Detroit, Michigan 48202 (United States)

    2006-04-28T23:59:59.000Z

    Kinetic energy distributions of H{sup +} ejected from a polyatomic molecule, anthraquinone, subjected to 60 fs, 800 nm laser pulses of intensity between 0.2 and 4.0x10{sup 14} W{center_dot}cm{sup -2}, reveal field-driven restructuring of the molecule prior to Coulomb explosion. Calculations demonstrate fast intramolecular proton migration into a field-dressed metastable potential energy minimum. The proton migration occurs in the direction perpendicular to the polarization of the laser field. Rapid field-mediated isomerization is an important new phenomenon in coupling of polyatomic molecules with intense lasers.

  11. Predicting threshold and location of laser damage on optical surfaces

    DOE Patents [OSTI]

    Siekhaus, W.

    1985-02-04T23:59:59.000Z

    Disclosed is an apparatus useful in the prediction of the damage threshold of various optical devices, the location of weak spots on such devices and the location, identification, and elimination of optical surface impurities. The apparatus comprises a focused and pulsed laser, a photo electric detector/imaging means, and a timer. The weak spots emit photoelectrons when subjected to laser intensities that are less than the intensity actually required to produce the damage. The weak spots may be eliminated by sustained exposure to the laser beam.

  12. Trapping and Destruction of Long-Range High-Intensity Optical Filaments by Molecular Quantum Wakes in Air

    E-Print Network [OSTI]

    Milchberg, Howard

    in Air S. Varma, Y.-H. Chen, and H. M. Milchberg Institute for Research in Electronics and Applied in atmospheric air on the long-range filamentary propagation of intense femtosecond laser pulses. In a pump following a pump pulse filamenting in air has a dramatic effect on the propagation of an intense probe pulse

  13. Intensity-Intensity Correlations of Classically Entangled Light

    E-Print Network [OSTI]

    Partha Ghose; Anirban Mukherjee

    2014-01-03T23:59:59.000Z

    An experiment is proposed to show that after initial frequency and polarization selection, classical thermal light from two independent sources can be made path-polarization entangled. Such light will show new intensity-intensity correlations involving both path and polarization phases, formally similar to those for four-particle GHZ states. For fixed polarization phases, the correlations reduce to the Hanbury Brown-Twiss phase correlations. It is also shown that these classical correlations violate noncontextuality.

  14. Ponderomotive self-focusing of Gaussian laser beam in warm collisional plasma

    SciTech Connect (OSTI)

    Jafari Milani, M. R., E-mail: mrj.milani@gmail.com [Plasma Physics Research School, Tehran (Iran, Islamic Republic of); Department of Energy Engineering and Physics, Amirkabir University of Technology, Tehran (Iran, Islamic Republic of); Niknam, A. R., E-mail: a-niknam@sbu.ac.ir [Laser and Plasma Research Institute, Shahid Beheshti University, G.C., Tehran (Iran, Islamic Republic of); Farahbod, A. H. [Plasma Physics Research School, Tehran (Iran, Islamic Republic of)

    2014-06-15T23:59:59.000Z

    The propagation characteristics of a Gaussian laser beam through warm collisional plasma are investigated by considering the ponderomotive force nonlinearity and the complex eikonal function. By introducing the dielectric permittivity of warm unmagnetized plasma and using the WKB and paraxial ray approximations, the coupled differential equations defining the variations of laser beam parameters are obtained and solved numerically. Effects of laser and plasma parameters such as the collision frequency, the initial laser intensity and its spot size on the beam width parameter and the axis laser intensity distribution are analyzed. It is shown that, self-focusing of the laser beam takes place faster by increasing the collision frequency and initial laser spot size and then after some distance propagation the laser beam abruptly loses its initial diameter and vastly diverges. Furthermore, the modified electron density distribution is obtained and the collision frequency effect on this distribution is studied.

  15. Tailoring femtosecond laser pulse filamentation using plasma photonic lattices

    SciTech Connect (OSTI)

    Suntsov, Sergiy; Abdollahpour, Daryoush; Panagiotopoulos, Paris [Institute of Electronic Structure and Laser, Foundation for Research and Technology Hellas, P.O. Box 1527, 71110 Heraklion (Greece); Papazoglou, Dimitrios G.; Tzortzakis, Stelios [Institute of Electronic Structure and Laser, Foundation for Research and Technology Hellas, P.O. Box 1527, 71110 Heraklion (Greece); Materials Science and Technology Department, University of Crete, P.O. Box 2208, 71003 Heraklion (Greece); Couairon, Arnaud [Centre de Physique Theorique, CNRS, Ecole Polytechnique, F-91128 Palaiseau (France)

    2013-07-08T23:59:59.000Z

    We demonstrate experimentally that by using transient plasma photonic lattices, the attributes of intense femtosecond laser filaments, such as peak intensity and length, can be dynamically controlled. The extended plasma lattice structure is generated using two co-propagating non-diffracting intense Bessel beams in water. The use of such transient lattice structures to control the competition between linear and nonlinear effects involved in filamentation opens the way for extensive control of the filamentation process.

  16. The effects of stocking density on two Tilapia species raised in an intensive culture system

    E-Print Network [OSTI]

    Henderson-Arzapalo, Anne

    1979-01-01T23:59:59.000Z

    THE EFFECTS'OF STOCKING DENSITY ON TWO TILAPIA SPECIES RAISED IN AN INTENSIVE CULTURE SYSTEM A Thesis by ANNE HENDERSON-ARZAPALO Submitted to the Graduate College of Texas A&M University in partial fulfillment of the requirement... for the degree of MASTER OF SCIENCE December l979 Major Subject: Wildlife and Fisheries Science THE EFFECTS OF STOCKING DENSITY ON TWO TILAPIA SPECIES RAISED IN AN INTENSIVE CULTURE SYSTEM A Thesis by ANNE HENDERSON-ARZAPALO Approved as to style...

  17. Laser barometer

    DOE Patents [OSTI]

    Abercrombie, Kevin R. (Westminster, CO); Shiels, David (Thornton, CO); Rash, Tim (Aurora, CO)

    2001-02-06T23:59:59.000Z

    A pressure measuring instrument that utilizes the change of the refractive index of a gas as a function of pressure and the coherent nature of a laser light to determine the barometric pressure within an environment. As the gas pressure in a closed environment varies, the index of refraction of the gas changes. The amount of change is a function of the gas pressure. By illuminating the gas with a laser light source, causing the wavelength of the light to change, pressure can be quantified by measuring the shift in fringes (alternating light and dark bands produced when coherent light is mixed) in an interferometer.

  18. Iron and Steel Energy Intensities

    U.S. Energy Information Administration (EIA) Indexed Site

    If you are having trouble, call 202-586-8800 for help. Home > >Energy Users > Energy Efficiency Page > Iron and Steel Energy Intensities First Use of Energy Blue Bullet First Use...

  19. Synchronous Characterization of Semiconductor Microcavity Laser Beam

    E-Print Network [OSTI]

    Wang, Tao

    2015-01-01T23:59:59.000Z

    We report on a high-resolution double-channel imaging method used to synchronously map the intensity- and optical-frequency-distribution of a laser beam in the plane orthogonal to the propagation direction. The synchronous measurement allows us to show that the laser frequency is an inhomogeneous distribution below threshold, but that it becomes homogeneous across the fundamental Gaussian mode above threshold. The beam's tails deviations from the Gaussian shape, however, are accompanied by sizeable fluctuations in the laser wavelength, possibly deriving from manufacturing details and from the influence of spontaneous emission in the very low intensity wings. In addition to the synchronous spatial characterization, a temporal analysis at any given point in the beam cross-section is carried out. Using this method, the beam homogeneity and spatial shape, energy density, energy center and the defects-related spectrum can also be extracted from these high-resolution pictures.

  20. Gamma radiation field intensity meter

    DOE Patents [OSTI]

    Thacker, L.H.

    1994-08-16T23:59:59.000Z

    A gamma radiation intensity meter measures dose rate of a radiation field. The gamma radiation intensity meter includes a tritium battery emitting beta rays generating a current which is essentially constant. Dose rate is correlated to an amount of movement of an electroscope element charged by the tritium battery. Ionizing radiation decreases the voltage at the element and causes movement. A bleed resistor is coupled between the electroscope support element or electrode and the ionization chamber wall electrode. 4 figs.

  1. Gamma radiation field intensity meter

    DOE Patents [OSTI]

    Thacker, Louis H. (Knoxville, TN)

    1995-01-01T23:59:59.000Z

    A gamma radiation intensity meter measures dose rate of a radiation field. The gamma radiation intensity meter includes a tritium battery emitting beta rays generating a current which is essentially constant. Dose rate is correlated to an amount of movement of an electroscope element charged by the tritium battery. Ionizing radiation decreases the voltage at the element and causes movement. A bleed resistor is coupled between the electroscope support element or electrode and the ionization chamber wall electrode.

  2. Gamma radiation field intensity meter

    DOE Patents [OSTI]

    Thacker, L.H.

    1995-10-17T23:59:59.000Z

    A gamma radiation intensity meter measures dose rate of a radiation field. The gamma radiation intensity meter includes a tritium battery emitting beta rays generating a current which is essentially constant. Dose rate is correlated to an amount of movement of an electroscope element charged by the tritium battery. Ionizing radiation decreases the voltage at the element and causes movement. A bleed resistor is coupled between the electroscope support element or electrode and the ionization chamber wall electrode. 4 figs.

  3. Gamma radiation field intensity meter

    DOE Patents [OSTI]

    Thacker, Louis H. (Knoxville, TN)

    1994-01-01T23:59:59.000Z

    A gamma radiation intensity meter measures dose rate of a radiation field. The gamma radiation intensity meter includes a tritium battery emitting beta rays generating a current which is essentially constant. Dose rate is correlated to an amount of movement of an electroscope element charged by the tritium battery. Ionizing radiation decreases the voltage at the element and causes movement. A bleed resistor is coupled between the electroscope support element or electrode and the ionization chamber wall electrode.

  4. OPTICAL SCIENCE & ENGINEERINGOPTICAL SCIENCE & ENGINEERINGOPTICAL SCIENCE & ENGINEERINGOPTICAL SCIENCE & ENGINEERING University of New Mexico

    E-Print Network [OSTI]

    New Mexico, University of

    SCIENCE & ENGINEERING University of New Mexico Abstract: The concept of optical refrigeration (also known of Physics at the University of New Mexico (UNM) in Albuquerque, NM (USA). He obtained his PhD from State and semiconductor photonics. Mansoor Sheik-Bahae University of New Mexico Lasers Running in Reverse Friday, November

  5. Self-healing organic-dye-based random lasers

    E-Print Network [OSTI]

    Anderson, Benjamin R; Eilers, Hergen

    2015-01-01T23:59:59.000Z

    One of the primary difficulties in the implementation of organic-dye-based random lasers is the tendency of organic dyes to irreversibly photodecay. In this letter we report the observation of "reversible" photodegradation in a Rhodamine 6G and ZrO$_2$ nanoparticle doped polyurethane random laser. We find that during degradation the emission broadens, redshifts, and decreases in intensity. After degradation the system is observed to self-heal leading to the emission returning to its pristine intensity, giving a recovery efficiency of 100%. While the peak intensity fully recovers, the process is not strictly "reversible" as the emission after recovery is still found to be broadened and redshifted. The combination of the peak emission fully recovering and the broadening of the emission leads to a remarkable result: the random laser cycled through degradation and recovery has a greater integrated emission intensity than the pristine system.

  6. Luminescent light source for laser pumping and laser system containing same

    DOE Patents [OSTI]

    Hamil, Roy A. (Tijeras, NM); Ashley, Carol S. (Albuquerque, NM); Brinker, C. Jeffrey (Albuquerque, NM); Reed, Scott (Albuquerque, NM); Walko, Robert J. (Albuquerque, NM)

    1994-01-01T23:59:59.000Z

    The invention relates to a pumping lamp for use with lasers comprising a porous substrate loaded with a component capable of emitting light upon interaction of the component with exciting radiation and a source of exciting radiation. Preferably, the pumping lamp comprises a source of exciting radiation, such as an electron beam, and an aerogel or xerogel substrate loaded with a component capable of interacting with the exciting radiation, e.g., a phosphor, to produce light, e.g., visible light, of a suitable band width and of a sufficient intensity to generate a laser beam from a laser material.

  7. Quilting Together a Career in Science

    E-Print Network [OSTI]

    Richmond, Geraldine L.

    Quilting Together a Career in Science About the speaker: Professor Geri Richmond holds the Richard is recognized for her fundamental studies in contemporary surface science using state-of-the-art laser 160 publications to her credit. Richmond is also known widely for her innovative science teaching

  8. Robust Collimation Control of Laser-Generated Ion Beam

    E-Print Network [OSTI]

    Kawata, S; Kamiyama, D; Nagashima, T; Barada, D; Gu, Y J; Li, X; Yu, Q; Kong, Q; Wang, P X

    2015-01-01T23:59:59.000Z

    The robustness of a structured collimation device is discussed for an intense-laser-produced ion beam. In this paper the ion beam collimation is realized by the solid structured collimation device, which produces the transverse electric field; the electric field contributes to reduce the ion beam transverse velocity and collimate the ion beam. Our 2.5 dimensional particle-in cell simulations demonstrate that the collimation device is rather robust against the changes in the laser parameters and the collimation target sizes. The intense short-pulse lasers are now available, and are used to generate an ion beam. The issues in the laser ion acceleration include an ion beam collimation, ion energy spectrum control, ion production efficiency, ion energy control, ion beam bunching, etc. The laser-produced ion beam tends to expand in the transverse and longitudinal directions during the ion beam propagation. The ion beam collimation is focused in this paper.

  9. Data-intensive computing laying foundation for biological breakthroughs

    SciTech Connect (OSTI)

    Hachigian, David J.

    2007-06-18T23:59:59.000Z

    Finding a different way is the goal of the Data-Intensive Computing for Complex Biological Systems (Biopilot) project—a joint research effort between the Pacific Northwest National Laboratory (PNNL) and Oak Ridge National Laboratory funded by the U.S. Department of Energy’s Office of Advanced Scientific Computing Research. The two national laboratories, both of whom are world leaders in computing and computational sciences, are teaming to support areas of biological research in urgent need of data-intensive computing capabilities.

  10. 600-T Magnetic Fields due to Cold Electron Flow in a simple Cu-Coil irradiated by High Power Laser pulses

    E-Print Network [OSTI]

    Zhu, Baojun; Yuan, Dawei; Li, Yanfei; Li, Fang; Liao, Guoqian; Zhao, Jiarui; Zhong, Jiayong; Xue, Feibiao; Wei, Huigang; Zhang, Kai; Han, Bo; Pei, Xiaoxing; Liu, Chang; Zhang, Zhe; Wang, Weimin; Zhu, Jianqiang; Zhao, Gang; Zhang, Jie

    2015-01-01T23:59:59.000Z

    A new simple mechanism due to cold electron flow to produce strong magnetic field is proposed. A 600-T strong magnetic field is generated in the free space at the laser intensity of 5.7x10^15 Wcm^-2. Theoretical analysis indicates that the magnetic field strength is proportional to laser intensity. Such a strong magnetic field offers a new experimental test bed to study laser-plasma physics, in particular, fast-ignition laser fusion research and laboratory astrophysics.

  11. astronomical laser guide: Topics by E-print Network

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

    Next Page Last Page Topic Index 1 Astronomical Science with Laser Guide Star Adaptive Optics: A Brief Review, a Current Snapshot, and a Bright Future CERN Preprints Summary: We...

  12. SCIENCE CHINA Technological Sciences

    E-Print Network [OSTI]

    Wang, Zhong L.

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

  13. Increased efficiency of ion acceleration by using femtosecond laser pulses at higher harmonic frequency

    SciTech Connect (OSTI)

    Psikal, J., E-mail: jan.psikal@fjfi.cvut.cz [FNSPE, Czech Technical University in Prague, 11519 Prague (Czech Republic); Klimo, O. [FNSPE, Czech Technical University in Prague, 11519 Prague (Czech Republic); ELI-Beamlines Project, Institute of Physics of the ASCR, 18221 Prague (Czech Republic); Weber, S.; Margarone, D. [ELI-Beamlines Project, Institute of Physics of the ASCR, 18221 Prague (Czech Republic)

    2014-07-15T23:59:59.000Z

    The influence of laser frequency on laser-driven ion acceleration is investigated by means of two-dimensional particle-in-cell simulations. When ultrashort intense laser pulse at higher harmonic frequency irradiates a thin solid foil, the target may become re lativistically transparent for significantly lower laser pulse intensity compared with irradiation at fundamental laser frequency. The relativistically induced transparency results in an enhanced heating of hot electrons as well as increased maximum energies of accelerated ions and their numbers. Our simulation results have shown the increase in maximum proton energy and increase in the number of high-energy protons by a factor of 2 after the interaction of an ultrashort laser pulse of maximum intensity 7?×?10{sup 21?}W/cm{sup 2} with a fully ionized plastic foil of realistic density and of optimal thickness between 100?nm and 200?nm when switching from the fundamental frequency to the third harmonics.

  14. Gas lasers with wave-chaotic resonators

    E-Print Network [OSTI]

    Oleg Zaitsev

    2010-10-28T23:59:59.000Z

    Semiclassical multimode laser theory is extended to gas lasers with open two-dimensional resonators of arbitrary shape. The Doppler frequency shift of the linear-gain coefficient leads to an additional linear coupling between the modes, which, however, is shown to be negligible. The nonlinear laser equations simplify in the special case of wave-chaotic resonators. In the single-mode regime, the intensity of a chaotic laser, as a function of the mode frequency, displays a local minimum at the frequency of the atomic transition. The width of the minimum scales with the inhomogeneous linewidth, in contrast to the Lamb dip in uniaxial resonators whose width is given by the homogeneous linewidth.

  15. Fabry-Perot fiber optic sensor using multimode laser diode

    E-Print Network [OSTI]

    Chu, Siu Yi Andrew

    1993-01-01T23:59:59.000Z

    FABRY-PEROT FIBER OPTIC SENSOR USING MULTIMODE LASER DIODE A Thesis SIU YI ANDREW CHU Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE August... 1993 Major Subject: Electrical Engineering FABRY-PEROT FIBER OPTIC SENSOR USING MULTIMODE LASER DIODE A Thesis SIU YI ANDREW CHU Submitted to Texas ARM University in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE...

  16. Infrared Spectroscopy of Laser Irradiated Dental Hard Tissues using the Advanced Light Source

    E-Print Network [OSTI]

    on the laser ablation/drilling process and may lead to a reduction in the ablation rate and efficiencyInfrared Spectroscopy of Laser Irradiated Dental Hard Tissues using the Advanced Light Source D Dental Sciences, San Francisco, CA 94143-0758, USA INTRODUCTION Infrared lasers are ideally suited

  17. Mechanisms of small clusters production by short and ultra-short laser ablation

    E-Print Network [OSTI]

    Zhigilei, Leonid V.

    Mechanisms of small clusters production by short and ultra-short laser ablation Tatiana E. Itina a Lasers, Plasmas et Proce´de´s Photoniques (LP3 UMR 6182 CNRS), Faculte´ des Sciences de Luminy, Case 917 The mechanisms involved into the formation of clusters by pulsed laser ablation are studied both numerically

  18. Light induced modulation instability of surfaces under intense illumination

    SciTech Connect (OSTI)

    Burlakov, V. M., E-mail: burlakov@maths.ox.ac.uk; Goriely, A. [Mathematical Institute, University of Oxford, Woodstock Road, Oxford OX2 6GG (United Kingdom)] [Mathematical Institute, University of Oxford, Woodstock Road, Oxford OX2 6GG (United Kingdom); Foulds, I. [4700 King Abdullah University of Science and Technology, Thuwal 23955-6900 (Saudi Arabia)] [4700 King Abdullah University of Science and Technology, Thuwal 23955-6900 (Saudi Arabia)

    2013-12-16T23:59:59.000Z

    We show that a flat surface of a polymer in rubber state illuminated with intense electromagnetic radiation is unstable with respect to periodic modulation. Initial periodic perturbation is amplified due to periodic thermal expansion of the material heated by radiation. Periodic heating is due to focusing-defocusing effects caused by the initial surface modulation. The surface modulation has a period longer than the excitation wavelength and does not require coherent light source. Therefore, it is not related to the well-known laser induced periodic structures on polymer surfaces but may contribute to their formation and to other phenomena of light-matter interaction.

  19. Time-resolved diffraction profiles and atomic dynamics in short-pulse laser-induced structural transformations: Molecular dynamics study

    E-Print Network [OSTI]

    Zhigilei, Leonid V.

    Time-resolved diffraction profiles and atomic dynamics in short-pulse laser-induced structural Short pico- and femtosecond pulse laser irradiation has the ability to bring material into a highly dynamics simulations of a 20 nm Au film irradiated with 200 fs laser pulses of different intensity

  20. Atlas of uranium emission intensities in a hollow cathode discharge

    SciTech Connect (OSTI)

    Palmer, B.A.; Keller, R.A.; Engleman, R. Jr.

    1980-07-01T23:59:59.000Z

    The uranium emission spectrum from a hollow cathode discharge is displayed from 11,000 to 26,000 cm/sup -1/. This atlas lists 4928 spectral lines of uranium; 3949 are classified to the neutral spectrum and 431 are classified to the singly ionized spectrum. Listed wavenumbers are accurate to +-0.003 cm/sup -1/ and the listed relative intensities to +-8%. The richness of the spectrum makes this atlas useful for wavenumber calibration of lasers, spectrographs, and monochromators to an accuracy of 1 part in 10/sup 7/. This atlas is also useful as a guide to the uranium spectrum, and relative oscillator strengths (gf values) can be calculated from the intensities to a precision of +-20%.

  1. BNL | CO2 Laser

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

    CO2 Laser The ATF is one of the only two facilities worldwide operating picosecond, terawatt-class CO2 lasers. Our laser system consists of a picoseconds pulse-injector based on...

  2. FREE-ELECTRON LASERS

    E-Print Network [OSTI]

    Sessler, A.M.

    2008-01-01T23:59:59.000Z

    Variable-Wiggler Free-Electron-Laser Oscillat.ion. Phys. :_.The Los Alamos Free Electron Laser: Accelerator Perfoemance.First Operation of a Free-Electron Laser. Phys . __ Rev~.

  3. Effects of laser polarization in the expansion of plasma waveguides

    SciTech Connect (OSTI)

    Lemos, N.; Grismayer, T.; Cardoso, L.; Geada, J.; Figueira, G.; Dias, J. M. [GoLP/Instituto de Plasmas e Fusão Nuclear, Instituto Superior Técnico (IST), Universidade Técnica de Lisboa (UTL), 1049-001 Lisbon (Portugal)] [GoLP/Instituto de Plasmas e Fusão Nuclear, Instituto Superior Técnico (IST), Universidade Técnica de Lisboa (UTL), 1049-001 Lisbon (Portugal)

    2013-10-15T23:59:59.000Z

    We experimentally demonstrate that a column of hydrogen plasma generated by an ultra-short (sub-picosecond), moderate intensity (?10{sup 15–16} W.cm{sup –2}) laser, radially expands at a higher velocity when using a circularly polarized laser beam instead of a linearly polarized beam. Interferometry shows that after 1 ns there is a clear shock structure formed, that can be approximated to a cylindrical blast wave. The shock velocity was measured for plasmas created with linearly and circularly polarized laser beams, indicating an approximately 20% higher velocity for plasmas generated with a circularly polarized laser beam, thus implying a higher plasma electron temperature. The heating mechanism was determined to be the Above Threshold Ionization effect. The calculated electrum energy spectrum for a circularly polarized laser beam was broader when compared to the one generated by a linearly polarized laser beam, leading to a higher plasma temperature.

  4. Laser detection of material thickness

    DOE Patents [OSTI]

    Early, James W. (Los Alamos, NM)

    2002-01-01T23:59:59.000Z

    There is provided a method for measuring material thickness comprising: (a) contacting a surface of a material to be measured with a high intensity short duration laser pulse at a light wavelength which heats the area of contact with the material, thereby creating an acoustical pulse within the material: (b) timing the intervals between deflections in the contacted surface caused by the reverberation of acoustical pulses between the contacted surface and the opposite surface of the material: and (c) determining the thickness of the material by calculating the proportion of the thickness of the material to the measured time intervals between deflections of the contacted surface.

  5. Specific energy for pulsed laser rock drilling.

    SciTech Connect (OSTI)

    Xu, Z.; Reed, C. B.; Kornecki, G.; Gahan, B. C.; Parker, R. A.; Batarseh, S.; Graves, R. M.; Figueroa, H.; Skinner, N.; Technology Development

    2003-02-01T23:59:59.000Z

    Application of advanced high power laser technology to oil and gas well drilling has been attracting significant research interests recently among research institutes, petroleum industries, and universities. Potential laser or laser-aided oil and gas well drilling has many advantages over the conventional rotary drilling, such as high penetration rate, reduction or elimination of tripping, casing, and bit costs, and enhanced well control, perforating and side-tracking capabilities. The energy required to remove a unit volume of rock, namely the specific energy (SE), is a critical rock property data that can be used to determine both the technical and economic feasibility of laser oil and gas well drilling. When a high power laser beam is applied on a rock, it can remove the rock by thermal spallation, melting, or vaporization depending on the applied laser energy and the way the energy is applied. The most efficient rock removal mechanism would be the one that requires the minimum energy to remove a unit volume of rock. Samples of sandstone, shale, and limestone were prepared for laser beam interaction with a 1.6 kW pulsed Nd:yttrium-aluminum-garnet laser beam to determine how the beam size, power, repetition rate, pulse width, exposure time and energy can affect the amount of energy transferred to the rock for the purposes of spallation, melting, and vaporization. The purpose of the laser rock interaction experiment was to determine the optimal parameters required to remove a maximum rock volume from the samples while minimizing energy input. Absorption of radiant energy from the laser beam gives rise to the thermal energy transfer required for the destruction and removal of the rock matrix. Results from the tests indicate that each rock type has a set of optimal laser parameters to minimize specific energy (SE) values as observed in a set of linear track and spot tests. As absorbed energy outpaces heat diffusion by the rock matrix, local temperatures can rise to the melting points of the minerals and quickly increase observed SE values. Tests also clearly identified the spallation and melting zones for shale samples while changing the laser power. The lowest SE values are obtained in the spalling zone just prior to the onset of mineral melt. The laser thermally spalled and saw mechanically cut rocks show similarity of surface microstructure. The study also found that increasing beam repetition rate within the same material removal mechanism would increase the material removal rate, which is believed due to an increase of maximum temperature, thermal cycling frequency, and intensity of laser-driven shock wave within the rock.

  6. Laser Safety Management Policy Statement ............................................................................................................1

    E-Print Network [OSTI]

    Davidson, Fordyce A.

    Laser Safety Management Policy Statement...........................................................2 Laser Users.............................................................................................................2 Unit Laser Safety Officer (ULSO

  7. Laser programs highlights 1994

    SciTech Connect (OSTI)

    NONE

    1994-12-31T23:59:59.000Z

    This report provides highlights of the Lawrence Livermore National Laboratories` laser programs. Laser uses and technology assessment and utilization are provided.

  8. BNL | ATF Laser Safety

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

    be continuously escorted by someone who has such training: The training consists of an eye exam, BNL general laser safety lecture, and formal ATF laser familiarization. Untrained...

  9. Laser satellite power systems

    SciTech Connect (OSTI)

    Walbridge, E.W.

    1980-01-01T23:59:59.000Z

    A laser satellite power system (SPS) converts solar power captured by earth-orbiting satellites into electrical power on the earth's surface, the satellite-to-ground transmission of power being effected by laser beam. The laser SPS may be an alternative to the microwave SPS. Microwaves easily penetrate clouds while laser radiation does not. Although there is this major disadvantage to a laser SPS, that system has four important advantages over the microwave alternative: (1) land requirements are much less, (2) radiation levels are low outside the laser ground stations, (3) laser beam sidelobes are not expected to interfere with electromagnetic systems, and (4) the laser system lends itself to small-scale demonstration. After describing lasers and how they work, the report discusses the five lasers that are candidates for application in a laser SPS: electric discharge lasers, direct and indirect solar pumped lasers, free electron lasers, and closed-cycle chemical lasers. The Lockheed laser SPS is examined in some detail. To determine whether a laser SPS will be worthy of future deployment, its capabilities need to be better understood and its attractiveness relative to other electric power options better assessed. First priority should be given to potential program stoppers, e.g., beam attenuation by clouds. If investigation shows these potential program stoppers to be resolvable, further research should investigate lasers that are particularly promising for SPS application.

  10. High Energy Density Science at the Linac Coherent Light Source

    SciTech Connect (OSTI)

    Lee, R W

    2007-10-19T23:59:59.000Z

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

  11. Zigzag laser with reduced optical distortion

    DOE Patents [OSTI]

    Albrecht, G.F.; Comaskey, B.; Sutton, S.B.

    1994-04-19T23:59:59.000Z

    The architecture of the present invention has been driven by the need to solve the beam quality problems inherent in Brewster's angle tipped slab lasers. The entrance and exit faces of a solid state slab laser are cut perpendicular with respect to the pump face, thus intrinsically eliminating distortion caused by the unpumped Brewster's angled faces. For a given zigzag angle, the residual distortions inherent in the remaining unpumped or lightly pumped ends may be reduced further by tailoring the pump intensity at these ends. 11 figures.

  12. Ultra-high speed semiconductor lasers

    SciTech Connect (OSTI)

    Lau, K.Y.; Yariv, A.

    1985-02-01T23:59:59.000Z

    Recent research efforts which have led to the development of advanced laser structures possessing a direct modulation bandwidth of beyond 10 GHz under reliable room temperature continuous operation is described. Theoretical considerations on the relevant physical parameter are addressed, and experimental results on bandwidth modulation in short-cavity lasers and direct amplitude modulation in low-temperature operation are discussed. High-photon density devices and parasitic elements limitation are addressed, and mechanisms for bandwidth enhancement are considered. Intermodulation products, intensity noise, and superluminescent damping are discussed. 65 references.

  13. Terahertz radiation from a laser plasma filament

    SciTech Connect (OSTI)

    Wu, H.-C.; Meyer-ter-Vehn, J. [Max-Planck-Institut fuer Quantenoptik, D-85748 Garching (Germany); Ruhl, H. [Department fuer Physik der Ludwig-Maximillians-Universitaet, Theresienstrasse 37A, D-80333 Muenchen (Germany); Sheng, Z.-M. [Institute of Plasma Studies, Department of Physics, Shanghai Jiaotong University, Shanghai 200240 (China); Beijing National Laboratory of Condensed Matter Physics, Institute of Physics, CAS, Beijing 100190 (China)

    2011-03-15T23:59:59.000Z

    By the use of two-dimensional particle-in-cell simulations, we clarify the terahertz (THz) radiation mechanism from a plasma filament formed by an intense femtosecond laser pulse. The nonuniform plasma density of the filament leads to a net radiating current for THz radiation. This current is mainly located within the pulse and the first cycle of the wakefield. As the laser pulse propagates, a single-cycle and radially polarized THz pulse is constructively built up forward. The single-cycle shape is mainly due to radiation damping effect.

  14. Zigzag laser with reduced optical distortion

    DOE Patents [OSTI]

    Albrecht, Georg F. (Livermore, CA); Comaskey, Brian (Stockton, CA); Sutton, Steven B. (Manteca, CA)

    1994-01-01T23:59:59.000Z

    The architecture of the present invention has been driven by the need to solve the beam quality problems inherent in Brewster's angle tipped slab lasers. The entrance and exit faces of a solid state slab laser are cut perpendicular with respect to the pump face, thus intrinsically eliminating distortion caused by the unpumped Brewster's angled faces. For a given zigzag angle, the residual distortions inherent in the remaining unpumped or lightly pumped ends may be reduced further by tailoring the pump intensity at these ends.

  15. Assessment of the precision and accuracy of laser ablation-ICPMS analyses in the Fluids Research Laboratory within the Department of

    E-Print Network [OSTI]

    Bodnar, Robert J.

    1 Assessment of the precision and accuracy of laser ablation-ICPMS analyses in the Fluids Research describes results of laser ablation ICP-MS analyses of several standards of known composition conducted (AMS) for reduction of laser ablation ICPMS data. In Laser-Ablation-ICPMS in the Earth Sciences

  16. Fiber Lasers

    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: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625 1,006 492 742EnergyOnItem NotEnergy,ARMFormsGasReleaseSpeechesHall ATours, Programs and EventsFiber Lasers NIF

  17. Laser Faraday

    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: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOEThe Bonneville PowerCherries 82981-1cnHigh SchoolIn12electron 9 5 - -/e),,sandLaser Decontamination ofFaraday

  18. Optical laser systems at the Linac Coherent Light Source

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

    Minitti, Michael P.; Robinson, Joseph S.; Coffee, Ryan N.; Edstrom, Steve; Gilevich, Sasha; Glownia, James M.; Granados, Eduardo; Hering, Philippe; Hoffmann, Matthias C.; Miahnahri, Alan; et al

    2015-05-01T23:59:59.000Z

    Ultrafast optical lasers play an essential role in exploiting the unique capabilities of recently commissioned X-ray free-electron laser facilities such as the Linac Coherent Light Source (LCLS). Pump–probe experimental techniques reveal ultrafast dynamics in atomic and molecular processes and reveal new insights in chemistry, biology, material science and high-energy-density physics. This manuscript describes the laser systems and experimental methods that enable cutting-edge optical laser/X-ray pump–probe experiments to be performed at LCLS.

  19. Neutrino physics with an intense \

    E-Print Network [OSTI]

    R. Henning

    2010-11-16T23:59:59.000Z

    We study some of the physics potential of an intense $1\\,\\mathrm{MCi}$ $^{51}\\mathrm{Cr}$ source combined with the {\\sc Majorana Demonstrator} enriched germanium detector array. The {\\sc Demonstrator} will consist of detectors with ultra-low radioactive backgrounds and extremely low energy thresholds of~$\\sim 400\\,\\mathrm{eV}$. We show that it can improve the current limit on the neutrino magnetic dipole moment. We briefly discuss physics applications of the charged-current reaction of the $^{51}\\mathrm{Cr} neutrino with the $^{73}\\mathrm{Ge} isotope. Finally, we argue that the rate from a realistic, intense tritium source is below the detectable limit of even a tonne-scale HPGe experiment

  20. Phase conjugation of high energy lasers.

    SciTech Connect (OSTI)

    Bliss, David Emery; Valley, Michael T.; Atherton, Briggs W.; Bigman, Verle; Boye, Lydia Ann; Broyles, Robin Scott; Kimmel, Mark W.; Law, Ryan J.; Yoder, James R.

    2013-01-01T23:59:59.000Z

    In this report we explore claims that phase conjugation of high energy lasers by stimulated Brillouin scattering (SBS) can compensate optical aberrations associated with severely distorted laser amplifier media and aberrations induced by the atmosphere. The SBS media tested was a gas cell pressurized up to 300 psi with SF6 or Xe or both. The laser was a 10 Hz, 3J, Q-switched Nd:YAG with 25 ns wide pulses. Atmospheric aberrations were created with space heaters, helium jets and phase plates designed with a Kolmogorov turbulence spectrum characterized by a Fried parameter, ro , ranging from 0.6 - 6.0 mm. Phase conjugate tests in the laboratory were conducted without amplification. For the strongest aberrations, D/ro ~ 20, created by combining the space heaters with the phase plate, the Strehl ratio was degraded by a factor of ~50. Phase conjugation in SF6 restored the peak focusable intensity to about 30% of the original laser. Phase conjugate tests at the outdoor laser range were conducted with laser amplifiers providing gain in combination with the SBS cell. A large 600,000 BTU kerosene space heater was used to create turbulence along the beam path. An atmospheric structure factor of Cn2 = 5x10-13 m2/3 caused the illumination beam to expand to a diameter 250mm and overfill the receiver. The phase conjugate amplified return could successfully be targeted back onto glints 5mm in diameter. Use of a lenslet arrays to lower the peak focusable intensity in the SBS cell failed to produce a useful phase conjugate beam; The Strehl ratio was degraded with multiple random lobes instead of a single focus. I will review literature results which show how multiple beams can be coherently combined by SBS when a confocal reflecting geometry is used to focus the laser in the SBS cell.

  1. Influence of laser beam profile on electromagnetically induced absorption

    SciTech Connect (OSTI)

    Cuk, S. M.; Radonjic, M.; Krmpot, A. J.; Nikolic, S. N.; Grujic, Z. D.; Jelenkovic, B. M. [Institute of Physics, University of Belgrade, Pregrevica 118, 11080 Belgrade (Serbia)

    2010-12-15T23:59:59.000Z

    We compared, experimentally and theoretically, Hanle electromagnetically induced absorption (EIA) obtained using Gaussian and {Pi}-shaped laser beams 3 mm in diameter. The study was done by measuring the transmission of a laser locked to the F{sub g}=2{yields}F{sub e}=3 transition at the D{sub 2} line of {sup 87}Rb in a vacuum cell. EIA linewidths obtained for the two laser profiles were significantly different in the range of laser intensities 1-4 mW/cm{sup 2}. EIA with the {Pi}-shaped laser beam has a broad intensity maximum and linewidths larger than those obtained with the Gaussian beam profile. We also studied Hanle EIA by measuring the transmission of selected segments of the entire laser beam by placing a small movable aperture in front of the detector. Waveforms so obtained in Hanle EIA resonances were strongly influenced both by the radial distance of the transmitted segment from the beam center and by the radial profile of the laser beam. We show that outer regions of Gaussian beam, and central regions of the {Pi}-shaped beam generate the narrowest lines. The different behaviors of EIA owing to different beam profiles revealed by both theory and experiment indicate the importance of the radial profile of the laser beam for proper modeling of coherent effects in alkali metal vapors.

  2. Intensity Frontier| U.S. DOE Office of Science (SC)

    Office of Science (SC) Website

    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: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:Energy: Grid Integration Redefining What'sis Taking Over OurThe Iron4 Self-Scrubbing:,,ofOpportunitieshighlights/ Theisc/about/jobs/ Below

  3. Proof-of-principle experiments of laser Wakefield acceleration

    SciTech Connect (OSTI)

    Nakajima, K.; Kawakubo, T.; Nakanishi, H. [National Lab. for Higher Energy Physics, Ibaraki (Japan)] [and others

    1994-04-01T23:59:59.000Z

    Recently there has been a great interest in laser-plasma accelerators as possible next-generation particle accelerators because of their potential for ultra high accelerating gradients and compact size compared with conventional accelerators. It is known that the laser pulse is capable of exciting a plasma wave propagating at a phase velocity close to the velocity of light by means of beating two-frequency lasers or an ultra short laser pulse. These schemes came to be known as the Beat Wave Accelerator (BWA) for beating lasers or as the Laser Wakefield Accelerator (LWFA) for a short pulse laser. In this paper, the principle of laser wakefield particle acceleration has been tested by the Nd:glass laser system providing a short pulse with a power of 10 TW and a duration of 1 ps. Electrons accelerated up to 18 MeV/c have been observed by injecting 1 MeV/c electrons emitted from a solid target by an intense laser impact. The accelerating field gradient of 30 GeV/m is inferred.

  4. Waves in Nature, Lasers to Tsumanis and Beyond

    ScienceCinema (OSTI)

    LLNL - University of California Television

    2009-09-01T23:59:59.000Z

    Waves are everywhere. Microwaves, laser beams, music, tsunamis. Electromagnetic waves emanating from the Big Bang fill the universe. Learn about the similarities and difference in all of these wavy phenomena with Ed Moses and Rick Sawicki, Lawrence Livermore National Laboratory scientists Series: Science on Saturday [10/2006] [Science] [Show ID: 11541

  5. Switching of 800 nm femtosecond laser pulses using a compact PMN-PT modulator

    E-Print Network [OSTI]

    Adany, Peter; Price, E. Shane; Johnson, Carey K.; Zhang, Run; Hui, Rongqing

    2009-03-13T23:59:59.000Z

    A voltage-controlled birefringent cell based on ceramic PMN-PT material is used to enable fast intensity modulation of femtosecond laser pulses in the 800 nm wavelength window. The birefringent cell based on a PMN-PT ...

  6. Dynamics of coupled electron-nucleon motion in a laser field

    SciTech Connect (OSTI)

    Hartmann, F.X.; Garcia, K.K.; Munro, J.K. Jr.; Noid, D.W.

    1987-01-01T23:59:59.000Z

    Energy transfer processes in single particle coupled nucleon-electron models interacting with an intense laser field are studied using semi-classical quantization of the coupled classical Hamiltonian. 11 refs., 2 figs.

  7. All-optical measurement of the hot electron sheath driving laser ion acceleration from thin foils

    E-Print Network [OSTI]

    Jackel, O.

    We present experimental results from an all-optical diagnostic method to directly measure the evolution of the hot-electron distribution driving the acceleration of ions from thin foils using high-intensity lasers. Central ...

  8. Growing Crystaline Sapphire Fibers By Laser Heated Pedestal Techiques

    DOE Patents [OSTI]

    Phomsakha, Vongvilay (St. Petersburg, FL); Chang, Robert S. F. (Tampa, FL); Djeu, Nicholas I. (Tampa, FL)

    1997-03-04T23:59:59.000Z

    An improved system and process for growing crystal fibers comprising a means for creating a laser beam having a substantially constant intensity profile through its cross sectional area, means for directing the laser beam at a portion of solid feed material located within a fiber growth chamber to form molten feed material, means to support a seed fiber above the molten feed material, means to translate the seed fiber towards and away from the molten feed material so that the seed fiber can make contact with the molten feed material, fuse to the molten feed material and then be withdrawn away from the molten feed material whereby the molten feed material is drawn off in the form of a crystal fiber. The means for creating a laser beam having a substantially constant intensity profile through its cross sectional area includes transforming a previously generated laser beam having a conventional gaussian intensity profile through its cross sectional area into a laser beam having a substantially constant intensity profile through its cross sectional area by passing the previously generated laser beam through a graded reflectivity mirror. The means for directing the laser beam at a portion of solid feed material is configured to direct the laser beam at a target zone which contains the molten feed material and a portion of crystal fiber drawn off the molten feed material by the seed fiber. The means to support the seed fiber above the molten feed material is positioned at a predetermined height above the molten feed material. This predetermined height provides the seed fiber with sufficient length and sufficient resiliency so that surface tension in the molten feed material can move the seed fiber to the center of the molten feed material irrespective of where the seed fiber makes contact with the molten feed material. The internal atmosphere of the fiber growth chamber is composed substantially of Helium gas.

  9. Longitudinal discharge laser baffles

    DOE Patents [OSTI]

    Warner, B.E.; Ault, E.R.

    1994-06-07T23:59:59.000Z

    The IR baffles placed between the window and the electrode of a longitudinal discharge laser improve laser performance by intercepting off-axis IR radiation from the laser and in doing so reduce window heating and subsequent optical distortion of the laser beam. 1 fig.

  10. Short wavelength laser

    DOE Patents [OSTI]

    Hagelstein, P.L.

    1984-06-25T23:59:59.000Z

    A short wavelength laser is provided that is driven by conventional-laser pulses. A multiplicity of panels, mounted on substrates, are supported in two separated and alternately staggered facing and parallel arrays disposed along an approximately linear path. When the panels are illuminated by the conventional-laser pulses, single pass EUV or soft x-ray laser pulses are produced.

  11. Narrow gap laser welding

    DOE Patents [OSTI]

    Milewski, John O. (Santa Fe, NM); Sklar, Edward (Santa Fe, NM)

    1998-01-01T23:59:59.000Z

    A laser welding process including: (a) using optical ray tracing to make a model of a laser beam and the geometry of a joint to be welded; (b) adjusting variables in the model to choose variables for use in making a laser weld; and (c) laser welding the joint to be welded using the chosen variables.

  12. Narrow gap laser welding

    DOE Patents [OSTI]

    Milewski, J.O.; Sklar, E.

    1998-06-02T23:59:59.000Z

    A laser welding process including: (a) using optical ray tracing to make a model of a laser beam and the geometry of a joint to be welded; (b) adjusting variables in the model to choose variables for use in making a laser weld; and (c) laser welding the joint to be welded using the chosen variables. 34 figs.

  13. Scaling the Yield of Laser-Driven Electron-Positron Jets to Laboratory Astrophysical Applications

    E-Print Network [OSTI]

    Chen, Hui; Link, A; Hazi, A; Hill, M; Hoarty, D; James, S; Kerr, S; Meyerhofer, D D; Myatt, J; Park, J; Sentoku, Y; Williams, G J

    2015-01-01T23:59:59.000Z

    We report new experimental results obtained on three different laser facilities that show directed laser-driven relativistic electron-positron jets with up to 30 times larger yields than previously obtained and a quadratic (~ E^2) dependence of the positron yield on the laser energy. This favorable scaling stems from a combination of higher energy electrons due to increased laser intensity and the recirculation of MeV electrons in the mm-thick target. Based on this scaling, first principles simulations predict the possibility of using such electron-positron jets, produced at upcoming high-energy laser facilities, to probe the physics of relativistic collisionless shocks in the laboratory.

  14. Laser Processing of Metals and Polymers

    SciTech Connect (OSTI)

    Senthilraja Singaravelu

    2012-05-31T23:59:59.000Z

    A laser offers a unique set of opportunities for precise delivery of high quality coherent energy. This energy can be tailored to alter the properties of material allowing a very flexible adjustment of the interaction that can lead to melting, vaporization, or just surface modification. Nowadays laser systems can be found in nearly all branches of research and industry for numerous applications. Sufficient evidence exists in the literature to suggest that further advancements in the field of laser material processing will rely significantly on the development of new process schemes. As a result they can be applied in various applications starting from fundamental research on systems, materials and processes performed on a scientific and technical basis for the industrial needs. The interaction of intense laser radiation with solid surfaces has extensively been studied for many years, in part, for development of possible applications. In this thesis, I present several applications of laser processing of metals and polymers including polishing niobium surface, producing a superconducting phase niobium nitride and depositing thin films of niobium nitride and organic material (cyclic olefin copolymer). The treated materials were examined by scanning electron microscopy (SEM), electron probe microanalysis (EPMA), atomic force microscopy (AFM), high resolution optical microscopy, surface profilometry, Fourier transform infrared spectroscopy (FTIR) and x-ray diffraction (XRD). Power spectral density (PSD) spectra computed from AFM data gives further insight into the effect of laser melting on the topography of the treated niobium.

  15. Applications of microlens-conditioned laser diode arrays

    SciTech Connect (OSTI)

    Beach, R.J.; Emanuel, M.A.; Freitas, B.L. [and others

    1995-01-01T23:59:59.000Z

    The ability to condition the radiance of laser diodes using shaped-fiber cylindrical-microlens technology has dramatically increased the number of applications that can be practically engaged by diode laser arrays. Lawrence Livermore National Laboratory (LLNL) has actively pursued optical efficiency and engineering improvements in this technology in an effort to supply large radiance-conditioned laser diode array sources for its own internal programs. This effort has centered on the development of a modular integrated laser diode packaging technology with the goal of enabling the simple and flexible construction of high average power, high density, two-dimensional arrays with integrated cylindrical microlenses. Within LLNL, the principal applications of microlens-conditioned laser diode arrays are as high intensity pump sources for diode pumped solid state lasers (DPSSLs). A simple end-pumping architecture has been developed and demonstrated that allows the radiation from microlens-conditioned, two-dimensional diode array apertures to be efficiently delivered to the end of rod lasers. To date, pump powers as high as 2.5 kW have been delivered to 3 mm diameter laser rods. Such high power levels are critical for pumping solid state lasers in which the terminal laser level is a Stark level lying in the ground state manifold. Previously, such systems have often required operation of the solid state gain medium at low temperature to freeze out the terminal laser Stark level population. The authors recently developed high intensity pump sources overcome this difficulty by effectively pumping to much higher inversion levels, allowing efficient operation at or near room temperature. Because the end-pumping technology is scalable in absolute power, the number of rare-earth ions and transitions that can be effectively accessed for use in practical DPSSL systems has grown tremendously.

  16. Laser assisted proton collision on light nuclei at moderate energies

    E-Print Network [OSTI]

    I. F Barna; S. Varro

    2014-06-24T23:59:59.000Z

    We present analytic angular differential cross section model for laser assisted proton nucleon scattering on a Woods-Saxon optical potential where the nth-order photon absorption is taken into account simultaneously. As a physical example we calculate cross sections for proton - $^{12}$C collision at 49 MeV in the laboratory frame where the laser intensity is in the range of $ 10^{7} - 10^{21}$ W/cm$^2$ at optical frequencies. The upper intensity limit is slightly below the relativistic regime.

  17. Method for changing the cross section of a laser beam

    DOE Patents [OSTI]

    Sweatt, William C. (Albuquerque, NM); Seppala, Lynn (Livermore, CA)

    1995-01-01T23:59:59.000Z

    A technique is disclosed herein in which a circular optical beam, for example a copper vapor laser (CVL) beam, is converted to a beam having a profile other than circular, e.g. square or triangular. This is accomplished by utilizing a single optical mirror having a reflecting surface designed in accordance with a specifically derived formula in order to make the necessary transformation, without any substantial light loss and without changing substantially the intensity profile of the circular beam which has a substantially uniform intensity profile. In this way, the output beam can be readily directed into the dye cell of a dye laser.

  18. Method for changing the cross section of a laser beam

    DOE Patents [OSTI]

    Sweatt, W.C.; Seppala, L.

    1995-12-05T23:59:59.000Z

    A technique is disclosed herein in which a circular optical beam, for example a copper vapor laser (CVL) beam, is converted to a beam having a profile other than circular, e.g. square or triangular. This is accomplished by utilizing a single optical mirror having a reflecting surface designed in accordance with a specifically derived formula in order to make the necessary transformation, without any substantial light loss and without changing substantially the intensity profile of the circular beam which has a substantially uniform intensity profile. In this way, the output beam can be readily directed into the dye cell of a dye laser. 4 figs.

  19. Future STEM Leaders Prepare for the National Science Bowl

    SciTech Connect (OSTI)

    Benjamin, Angela

    2014-06-11T23:59:59.000Z

    Each year, students from across the country converge on Washington, DC, for the National Science Bowl, an intense academic competition that tests the students' knowledge in science, engineering, chemistry, math and Earth science. Follow one team, from Washington DC's Woodrow Wilson High School, as they prepare for and compete in the 2014 National Science Bowl.

  20. Future STEM Leaders Prepare for the National Science Bowl

    ScienceCinema (OSTI)

    Benjamin, Angela

    2014-09-15T23:59:59.000Z

    Each year, students from across the country converge on Washington, DC, for the National Science Bowl, an intense academic competition that tests the students' knowledge in science, engineering, chemistry, math and Earth science. Follow one team, from Washington DC's Woodrow Wilson High School, as they prepare for and compete in the 2014 National Science Bowl.

  1. Intensive Observation Period Projects Scheduled

    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: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOEThe Bonneville PowerCherries 82981-1cnHigh SchoolIn Other NewsSpin andInterimInvokingInspector XE 20131 Intensive

  2. Scattering apodizer for laser beams

    DOE Patents [OSTI]

    Summers, M.A.; Hagen, W.F.; Boyd, R.D.

    1984-01-01T23:59:59.000Z

    A method is disclosed for apodizing a laser beam to smooth out the production of diffraction peaks due to optical discontinuities in the path of the laser beam, such method comprising introduction of a pattern of scattering elements for reducing the peak intensity in the region of such optical discontinuities, such pattern having smoothly tapering boundaries in which the distribution density of the scattering elements is tapered gradually to produce small gradients in the distribution density, such pattern of scattering elements being effective to reduce and smooth out the diffraction effects which would otherwise be produced. The apodizer pattern may be produced by selectively blasting a surface of a transparent member with fine abrasive particles to produce a multitude of minute pits. In one embodiment, a scattering apodizer pattern is employed to overcome diffraction patterns in a multiple element crystal array for harmonic conversion of a laser beam. The interstices and the supporting grid between the crystal elements are obscured by the gradually tapered apodizer pattern of scattering elements.

  3. Scattering apodizer for laser beams

    DOE Patents [OSTI]

    Summers, Mark A. (Livermore, CA); Hagen, Wilhelm F. (Livermore, CA); Boyd, Robert D. (Livermore, CA)

    1985-01-01T23:59:59.000Z

    A method is disclosed for apodizing a laser beam to smooth out the production of diffraction peaks due to optical discontinuities in the path of the laser beam, such method comprising introduction of a pattern of scattering elements for reducing the peak intensity in the region of such optical discontinuities, such pattern having smoothly tapering boundaries in which the distribution density of the scattering elements is tapered gradually to produce small gradients in the distribution density, such pattern of scattering elements being effective to reduce and smooth out the diffraction effects which would otherwise be produced. The apodizer pattern may be produced by selectively blasting a surface of a transparent member with fine abrasive particles to produce a multitude of minute pits. In one embodiment, a scattering apodizer pattern is employed to overcome diffraction patterns in a multiple element crystal array for harmonic conversion of a laser beam. The interstices and the supporting grid between the crystal elements are obscured by the gradually tapered apodizer pattern of scattering elements.

  4. Earth Sciences Environmental Earth Sciences,

    E-Print Network [OSTI]

    Brierley, Andrew

    94 Earth Sciences­ Environmental Earth Sciences, Geology Degree options MGeol (Single Honours Degrees) Earth Sciences BSc (Single Honours Degrees) Environmental Earth Sciences Geology BSc (Joint placement. * The Geology and Environmental Earth Sciences degrees are accredited by the Geological Society

  5. Superlinear growth of Rayleigh scattering-induced intensity noise in single-mode fibers

    E-Print Network [OSTI]

    Cahill, James P; Zhou, Weimin; Menyuk, Curtis R; Carter, Gary M

    2015-01-01T23:59:59.000Z

    Rayleigh scattering generates intensity noise close to an optical carrier that propagates in a single-mode optical fiber. This noise degrades the performance of optoelectronic oscillators and RF-photonic links. When using a broad linewidth laser, we previously found that the intensity noise power scales linearly with optical power and fiber length, which is consistent with guided entropy mode Rayleigh scattering (GEMRS), a third order nonlinear scattering process, in the spontaneous limit. In this work, we show that this behavior changes significantly with the use of a narrow linewidth laser. Using a narrow linewidth laser, we measured the bandwidth of the intensity noise plateau to be 10 kHz. We found that the scattered noise power scales superlinearly with fiber length up to lengths of 10 km in the frequency range of 500 Hz to 10 kHz, while it scales linearly in the frequency range of 10 Hz to 100 Hz. These results suggest that the Rayleigh-scattering-induced intensity noise cannot be explained by third-ord...

  6. Three-Dimensional Laser Cooling

    E-Print Network [OSTI]

    Okamato, H.

    2008-01-01T23:59:59.000Z

    Three-Dimensional Laser Cooling H. Okamoto, A.M. Sessler,effective transverse laser cooling simultaneously withlongitudinal laser cooling, two possibilities are

  7. PALM - Laser Capture Microdissection | EMSL

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

    PALM - Laser Capture Microdissection PALM - Laser Capture Microdissection This Laser Capture Microdissection system is equipped with 100 x objective lens for enriching distinct...

  8. SCIENCE CHINA Technological Sciences

    E-Print Network [OSTI]

    Ahmad, Sajjad

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

  9. SCIENCE CHINA Technological Sciences

    E-Print Network [OSTI]

    Simons, Jack

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

  10. Roadmap: Physical Science -Bachelor of Science in Education [EH-BSE-PHSC

    E-Print Network [OSTI]

    Sheridan, Scott

    Roadmap: Physical Science - Bachelor of Science in Education [EH-BSE-PHSC] College of Education-2013 Page 1 of 2 | Last Updated: 18-May-12/JS This roadmap is a recommended semester-by-semester plan-intensive course requirement PHY 36001 Introduction to Modern Physics 3 C #12;Roadmap: Physical Science

  11. Experimental investigation of velocity biasing in laser Doppler anemometry

    E-Print Network [OSTI]

    Wiedner, Brian Gregory

    1988-01-01T23:59:59.000Z

    Tech University; Chair of Advisory Commettee: Dr. Gerald L. Morrison The effects of several velocity bias reduction schemes were invest- igated using a 3-D laser Doppler anemometer and counter type (burst) signal processors. Amongst these schemes... of Sample Size on Effects of Sample Size on Effects of Sample Size on Effects of Sample Size on Velocity and Reynolds Stresses Axial Mean Velocity Radial Mean Velocity Axial Turbulence Intensity Radial Turbulence Intensity Axial/Radial Correlation...

  12. Quantum fluctuations and saturable absorption in mesoscale lasers

    SciTech Connect (OSTI)

    Roy-Choudhury, Kaushik [Department of Physics and Astronomy, University of Southern California, Los Angeles, California 90089-0484 (United States); Levi, A. F. J. [Department of Physics and Astronomy, University of Southern California, Los Angeles, California 90089-0484 (United States); Department of Electrical Engineering, University of Southern California, Los Angeles, California 90089-2533 (United States)

    2011-04-15T23:59:59.000Z

    We present a quantum-mechanical treatment of fluctuations and saturable absorption in mesoscale lasers. The time evolution of the density matrix is obtained from numerical integration and field-field and intensity-intensity correlations are calculated to obtain steady-state linewidth and photon statistics. Inclusion of a saturable absorber in the otherwise homogeneous medium is shown to suppress lasing, increase fluctuations, and enhance spontaneous emission near threshold.

  13. Documentation - Laboratory for Laser Energetics

    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: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625 1,006 492 742EnergyOnItem NotEnergy,ARMFormsGasRelease Date: Contact:DisclaimersMaterials SciencesOmega Laser

  14. Femtosecond Near-Infrared Laser Desorption of Multilayer Benzene on Pt{111}: A Molecular Newton's Cradle?

    E-Print Network [OSTI]

    Levis, Robert J.

    Femtosecond Near-Infrared Laser Desorption of Multilayer Benzene on Pt{111}: A Molecular Newton Recently, the intense near-infrared laser desorption of intact benzene molecules has been reported.1 Three to alter the pure thermal distribution to one having a stream velocity.4 The high heating rates achievable

  15. Ultra-powerful compact amplifiers for short laser pulses* V. M. Malkin,

    E-Print Network [OSTI]

    modification of the material refraction index causes unacceptable distortions of the laser pulses terawatt (TW 1012 W) per cm2 intensities by means of longitudinal compression of laser pulses after their amplification. The compression of specially prepared chirped pulses is usually accomplished by two parallel dif

  16. Numerical simulations of self-focusing of ultrafast laser pulses Gadi Fibich*

    E-Print Network [OSTI]

    Wang, Xiao-Ping

    Numerical simulations of self-focusing of ultrafast laser pulses Gadi Fibich* School November 2002; published 7 May 2003 Simulation of nonlinear propagation of intense ultrafast laser pulses, space-time focusing, and self-steepening. Our simulations show that, after the asymmetric temporal pulse

  17. Lateral coherence properties of broad-area semiconductor quantum-well lasers

    SciTech Connect (OSTI)

    Larsson, A.; Salzman, J.; Mittelstein, M.; Yariv, A.

    1986-07-01T23:59:59.000Z

    The lateral coherence of broad-area lasers fabricated form a GaAs/GaAlAs graded index waveguide separate confinement and single quantum-well heterostructure grown by molecular beam epitaxy was investigated. These lasers exhibit a high degree of coherence along the junction plane, thus producing a stable and very narrow far-field intensity distribution.

  18. Lateral coherence properties of broad-area semiconductor quantum well lasers

    SciTech Connect (OSTI)

    Larsson, A.; Salzman, J.; Mittelstein, M.; Yariv, A.

    1986-07-01T23:59:59.000Z

    The lateral coherence of broad-area lasers fabricated from a GaAs/GaAlAs graded index waveguide separate confinement and single quantum well heterostructure grown by molecular-beam epitaxy was investigated. These lasers exhibit a high degree of coherence along the junction plane, thus producing a stable and very narrow far field intensity distribution.

  19. Observation of laser-induced associative ionization in crossed-beam Na+Li collisions

    SciTech Connect (OSTI)

    Polak-Dingels, P.; Keller, J.; Weiner, J.; Gauthier, J.h.; Bras, N.

    1981-08-01T23:59:59.000Z

    We report the observation of NaLi/sup +/ produced by crossed-beam collisions of Na and Li in the presence of a single laser field. The magnitude of the cross section and its dependence on laser intensity are in accord with a simple second-order perturbation theory.

  20. Parametric distortion of the optical absorption edge of a magnetic semiconductor by a strong laser field

    SciTech Connect (OSTI)

    Nunes, O.A.C.

    1985-09-15T23:59:59.000Z

    The influence of a strong laser field on the optical absorption edge of a direct-gap magnetic semiconductor is considered. It is shown that as the strong laser intensity increases the absorption coefficient is modified so as to give rise to an absorption tail below the free-field forbidden gap. An application is made for the case of the EuO.

  1. Negative-coupling resonances in pump-coupled lasers

    E-Print Network [OSTI]

    T. W. Carr; M. L. Taylor; I. B. Schwartz

    2005-10-28T23:59:59.000Z

    We consider coupled lasers, where the intensity deviations from the steady state, modulate the pump of the other lasers. Most of our results are for two lasers where the coupling constants are of opposite sign. This leads to a Hopf bifurcation to periodic output for weak coupling. As the magnitude of the coupling constants is increased (negatively) we observe novel amplitude effects such as a weak coupling resonance peak and, strong coupling subharmonic resonances and chaos. In the weak coupling regime the output is predicted by a set of slow evolution amplitude equations. Pulsating solutions in the strong coupling limit are described by discrete map derived from the original model.

  2. SNS Laser Stripping for H- Injection

    SciTech Connect (OSTI)

    V.V. Danilov, Y. Liu, K.B. Beard, V.G. Dudnikov, R.P. Johnson, Michelle D. Shinn

    2009-05-01T23:59:59.000Z

    The ORNL spallation neutron source (SNS) user facility requires a reliable, intense beams of protons. The technique of H- charge exchange injection into a storage ring or synchrotron has the potential to provide the needed beam currents, but it will be limited by intrinsic limitations of carbon and diamond stripping foils. A laser in combination with magnetic stripping has been used to demonstrate a new technique for high intensity proton injection, but several problems need to be solved before a practical system can be realized. Technology developed for use in Free Electron Lasers is being used to address the remaining challenges to practical implementation of laser controlled H- charge exchange injection for the SNS. These technical challenges include (1) operation in vacuum, (2) the control of the UV laser beam to synchronize with the H- beam and to shape the proton beam, (3) the control and stabilization of the Fabry-Perot resonator, and (4) protection of the mirrors from radiation.

  3. Experimental transport of intensity diffraction tomography

    E-Print Network [OSTI]

    Lee, Justin Wu

    2011-01-01T23:59:59.000Z

    In this thesis, I perform intensity-based tomographic phase imaging in two ways. First, I utilize the paraxial transport of intensity equation (TIE) to construct phase maps of a phase object at multiple projection angles ...

  4. Thermal plasma irradiation under the action of the microwave-frequency-modulated laser beam

    SciTech Connect (OSTI)

    Rudenko, V. V., E-mail: jasmin@spnet.ru [12 Central Scientific Research Institute (Russian Federation)

    2011-12-15T23:59:59.000Z

    The results of the calculation of the thermal irradiation of the laser plasma formed by a powerful laser beam with the microwave-frequency-modulated intensity are presented. The analytical solution has been obtained for the case of the light detonation regime. It has been shown that the modulation of the gasdynamic parameters due to the absorption of the laser radiation leads to the modulation of the spectral and integral brightness observed from the thermal plasma irradiation.

  5. High-power terahertz optically pumped NH{sub 3} laser for plasma diagnostics

    SciTech Connect (OSTI)

    Mishchenko, V. A.; Petrushevich, Yu. V.; Sobolenko, D. N.; Starostin, A. N. [Troitsk Institute for Innovation and Fusion Research (Russian Federation)

    2012-06-15T23:59:59.000Z

    The parameter of a terahertz (THz) laser intended for plasma diagnostics in electrodynamic accelerators and tokamaks with a strong magnetic field are discussed. Generation of THz radiation in an ammonia laser under the action of high-power pulsed optical pumping by the radiation of a 10P(32) CO{sub 2} laser is simulated numerically. The main characteristics of the output radiation, such as its spectrum, peak intensity, time dependence, and total energy, are calculated.

  6. Microwave guiding in air along single femtosecond laser filament

    SciTech Connect (OSTI)

    Ren Yu; Alshershby, Mostafa; Qin Jiang; Hao Zuoqiang; Lin Jingquan [School of Science, Changchun University of Science and Technology, Changchun 130022 (China)

    2013-03-07T23:59:59.000Z

    Microwave guiding along single plasma filament generated through the propagation of femtosecond (fs) laser pulses in air has been demonstrated over a distance of about 6.5 cm, corresponding to a microwave signal intensity enhancement of more than 3-fold over free space propagation. The current propagation distance along the fs laser filament is in agreement with the calculations and limited by the relatively high resistance of the single plasma filament. Using a single fs laser filament to channel microwave radiation considerably alleviate requirements to the power of fs laser pulses compared to the case of the circular filaments waveguide. In addition, it can be used as a simple and non-intrusive method to obtain the basic parameters of laser-generated plasma filament.

  7. Nighttime atmospheric stability changes and their effects on the temporal intensity of a mesoscale convective complex

    E-Print Network [OSTI]

    Hovis, Jeffrey Scott

    1988-01-01T23:59:59.000Z

    NIGHTTIME ATMOSPHERIC STABILITY CHANGES AND THEIR EFFECTS ON THE TEMPORAL INTENSITY OF A MESOSCALE CONVECTIVE COMPLEX A Thesis JEFFREY SCOTT HOVIS Submitted to the Graduate College of Texas A&M University in partial fulfillment... of the requirements for the degree of MASTER OF SCIENCE May 1988 Major Subject: Meteorology NIGHTTIME ATMOSPHERIC STABILITY CHANGES AND THEIR EFFECTS ON THE TEMPORAL INTENSITY OF A MESOSCALE CONVECTIVE COMPLEX A Thesis JEFFREY SCOTT HOVIS Approved as to style...

  8. Laser Roadshow

    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: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOE Office of Science (SC)Integrated Codes |Is Your Home asLCLSLaboratoryRowlandRevolutionizing theLaseroutreach

  9. PLASMA WAKE EXCITATION BY LASERS OR PARTICLE BEAMS C. B. Schroeder, E. Esarey, C. Benedetti, Cs. Toth, C. G. R. Geddes, W. P. Leemans

    E-Print Network [OSTI]

    Geddes, Cameron Guy Robinson

    recent experimental success using lasers and particle beam drivers for plasma acceler- ationPLASMA WAKE EXCITATION BY LASERS OR PARTICLE BEAMS C. B. Schroeder, E. Esarey, C. Benedetti, Cs. T be driven by the ponderomo- tive force of an intense laser or the space-charge force of a charged particle

  10. PHYSICAL REVIEW A 84, 043423 (2011) Dynamic of rescattering-electron wave packets in strong and short-wavelength laser fields

    E-Print Network [OSTI]

    2011-01-01T23:59:59.000Z

    and short-wavelength laser fields: Roles of Coulomb potential and excited states Yanjun Chen* Beijing and molecules exposed in strong and short- wavelength (shorter than 800 nm) laser fields. Our simulations show the potential, to explain the electronic response in intense and relatively high-frequency laser fields. DOI: 10

  11. JLMN-Journal of Laser Micro/Nanoengineering Vol. 4, No. 3, 2009 Control of Ionization Processes in High Band Gap Materials

    E-Print Network [OSTI]

    Kassel, Universität

    nanoprocessing 1. Introduction Ultra-short laser radiation has emerged as a powerful tool for processing by nonlinear proc- esses requiring large intensities available for example via ultra-short laser radiation make use of the enormous co- herent bandwidth associated with ultra-short laser radiation in order

  12. Ion acceleration with ultra-thin foils using elliptically polarized laser pulses This article has been downloaded from IOPscience. Please scroll down to see the full text article.

    E-Print Network [OSTI]

    Ion acceleration with ultra-thin foils using elliptically polarized laser pulses This article has of Physics Ion acceleration with ultra-thin foils using elliptically polarized laser pulses S G Rykovanov1 of ions with ultra-high intensity laser pulses has attracted broad interest over the last decade. The high

  13. Optical-acoustic effect in laser optics investigations N. E. Aver'anov (1), Yu. A. Baloshin (1), K. F. Bukhanov (1), I. V. Pavlishin (1),

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    -induced damage such as evaporation of heat insulated defects, melting and optical breakdown off irradiated to laser induced damage greatly depends on an ability to absorb the laser radiation because at intense of an optical material, that is its damage. In laser optics, among well known methods of light absorption

  14. Laser stimulation can activate autophagy in HeLa cells

    SciTech Connect (OSTI)

    Wang, Yisen; Hu, Minglie; Wang, Chingyue [Ultrafast Laser Laboratory, Key Laboratory of Optoelectronic Information Technology (Ministry of Education), College of Precision Instrument and Optoelectronics Engineering, Tianjin University, Tianjin (China); Lan, Bei; Cao, Youjia [Key Laboratory of Microbial Functional Genomics of Ministry of Education, College of Life Sciences, Nankai University, Tianjin (China); He, Hao, E-mail: haohe@tju.edu.cn [Ultrafast Laser Laboratory, Key Laboratory of Optoelectronic Information Technology (Ministry of Education), College of Precision Instrument and Optoelectronics Engineering, Tianjin University, Tianjin (China); Med-X Research Institute, School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai (China)

    2014-10-27T23:59:59.000Z

    For decades, lasers have been a daily tool in most biological research for fluorescent excitation by confocal or multiphoton microscopy. More than 20 years ago, cell photodamage caused by intense laser stimulation was noticed by generating reactive oxygen species, which was then thought as the main damage effect by photons. In this study, we show that laser stimulation can induce autophagy, an important cell lysosomal pathway responding to immune stimulation and starvation, without any biochemical treatment. Two different types of laser stimulations are found to be capable of activating autophagy: continuous scanning by continuous-wave visible lasers and a short-time flash of femtosecond laser irradiation. The autophagy generation is independent from wavelength, power, and scanning duration of the visible lasers. In contrast, the power of femtosecond laser is very critical to autophagy because the multiphoton excited Ca{sup 2+} dominates autophagy signaling. In general, we show here the different mechanisms of autophagy generation by such laser stimulation, which correspond to confocal microscopy and cell surgery, respectively. Those results can help further understanding of photodamage and autophagy signaling.

  15. Laser diagnostics | Princeton Plasma Physics Lab

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOE Office of Science (SC)Integrated Codes |Is Your Home asLCLSLaboratoryRowlandRevolutionizingLaserLaser

  16. Laser research shows promise for cancer treatment

    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: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOE Office of Science (SC)Integrated Codes |Is Your Home asLCLSLaboratoryRowlandRevolutionizingLaserLaserCancer

  17. Explore Science

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

    Science Explore Science Explore Explore these Topics Activities Videos Cool Links Favorite Q&A invisible utility element Science is thinking in an organized way about things...

  18. Institute for Engineering and Systems Sciences

    E-Print Network [OSTI]

    Canet, Léonie

    Sciences #12;A policy of international cooperation The Institute is engaged in intense international many different forms, ranging from the simple exchange of researchers to International Joint Units joint publications in prestigious scientific journals, the setting up of scientific platforms

  19. Beam intensity upgrade at Fermilab

    SciTech Connect (OSTI)

    Marchionni, A.; /Fermilab

    2006-07-01T23:59:59.000Z

    The performance of the Fermilab proton accelerator complex is reviewed. The coming into operation of the NuMI neutrino line and the implementation of slip-stacking to increase the anti-proton production rate has pushed the total beam intensity in the Main Injector up to {approx} 3 x 10{sup 13} protons/pulse. A maximum beam power of 270 kW has been delivered on the NuMI target during the first year of operation. A plan is in place to increase it to 350 kW, in parallel with the operation of the Collider program. As more machines of the Fermilab complex become available with the termination of the Collider operation, a set of upgrades are being planned to reach first 700 kW and then 1.2 MW by reducing the Main Injector cycle time and by implementing proton stacking.

  20. 131Cognitive Science COGNITIVE SCIENCE

    E-Print Network [OSTI]

    Marsh, David

    131Cognitive Science COGNITIVE SCIENCE PROFESSOR ELMES* MAJOR A major in cognitive science leading courses: Cognitive Science 110, 395, 403, 473; Computer Science 111, 211; Philosophy 106, 313; Psychology Science: Com- puter Science 295 (LISP, PROLOG or C), 313, 315; Psychology 207 b. Philosophical Foundations

  1. Nonlinear pair production in scattering of photons on ultra-short laser pulses at high energy

    E-Print Network [OSTI]

    Tuchin, Kirill

    2009-01-01T23:59:59.000Z

    We consider scattering of a photon on a short intense laser pulse at high energy. We argue that for ultra-short laser pulses the interaction is coherent over the entire length of the pulse. At low pulse intensity $I$ the total cross section for electron-positron pair production is proportional to $I$. However, at pulse intensities higher than the characteristic value $I_s$, the total cross section saturates -- it becomes proportional to the logarithm of intensity. This nonlinear effect is due to multi-photon interactions. We derive the total cross section for pair production at high energies by resuming the multi-photon amplitudes to all orders in intensity. We calculate the saturation intensity $I_s$ and show that it is significantly lower than the Schwinger's critical value. We discuss possible experimental tests.

  2. Nonlinear pair production in scattering of photons on ultra-short laser pulses at high energy

    E-Print Network [OSTI]

    Kirill Tuchin

    2010-02-15T23:59:59.000Z

    We consider scattering of a photon on a short intense laser pulse at high energy. We argue that for ultra-short laser pulses the interaction is coherent over the entire length of the pulse. At low pulse intensity $I$ the total cross section for electron-positron pair production is proportional to $I$. However, at pulse intensities higher than the characteristic value $I_s$, the total cross section saturates -- it becomes proportional to the logarithm of intensity. This nonlinear effect is due to multi-photon interactions. We derive the total cross section for pair production at high energies by resuming the multi-photon amplitudes to all orders in intensity. We calculate the saturation intensity $I_s$ and show that it is significantly lower than the Schwinger's critical value. We discuss possible experimental tests.

  3. Laser preheat enhanced ignition

    DOE Patents [OSTI]

    Early, James W. (Los Alamos, NM)

    1999-01-01T23:59:59.000Z

    A method for enhancing fuel ignition performance by preheating the fuel with laser light at a wavelength that is absorbable by the fuel prior to ignition with a second laser is provided.

  4. Laser-assisted electrochemistry

    SciTech Connect (OSTI)

    Glenn, D.F.

    1995-05-01T23:59:59.000Z

    The effect of laser irradiation on electrodeposition processes has been investigated. These studies demonstrated that the addition of laser irradiation to an electroplating process can dramatically enhance plating rates and current efficiencies, as well as improve the morphology of the resultant electrodeposit. During the course of these investigations, the mechanism for the laser enhancement of electrodeposition processes was determined. Experimental evidence was obtained to show that laser irradiation of the substrate results in increased metal ion concentrations at the surface of the electrode due to a laser-induced Soret effect. The laser-induced Soret effect has important implications for laser-assisted electrochemical processing. The increase in the surface concentration of ions allows efficient electrodeposition from dilute solutions. As such, laser- assisted electrodeposition may develop into an environmentally conscious manufacturing process by reducing waste and limiting worker exposure to toxic chemicals.

  5. Calibration of a gated flat field spectrometer as a function of x-ray intensity

    SciTech Connect (OSTI)

    Xiong, Gang; Yang, Guohong; Li, Hang; Zhang, Jiyan, E-mail: zhangjiyanzjy@sina.com; Zhao, Yang; Hu, Zhimin; Wei, Minxi; Qing, Bo; Yang, Jiamin; Liu, Shenye; Jiang, Shaoen [Research Center of Laser Fusion, China Academy of Engineering Physics, P. O. Box 919-986, Mianyang 621900 (China)] [Research Center of Laser Fusion, China Academy of Engineering Physics, P. O. Box 919-986, Mianyang 621900 (China)

    2014-04-15T23:59:59.000Z

    We present an experimental determination of the response of a gated flat-field spectrometer at the Shenguang-II laser facility. X-rays were emitted from a target that was heated by laser beams and then were divided into different intensities with a step aluminum filter and collected by a spectrometer. The transmission of the filter was calibrated using the Beijing Synchrotron Radiation Facility. The response characteristics of the spectrometer were determined by comparing the counts recorded by the spectrometer with the relative intensities of the x-rays transmitted through the step aluminum filter. The response characteristics were used to correct the transmission from two shots of an opacity experiment using the same samples. The transmissions from the two shots are consistent with corrections, but discrepant without corrections.

  6. Interaction of intense fields with plasmaInteraction of intense fields with plasma Strathclyde Intense Laser Interaction Studies (SILIS) Group, Department Of PhysicsStrathclyde Intense Laser Interaction Studies (SILIS) Group, Department Of Physics

    E-Print Network [OSTI]

    Strathclyde, University of

    . Large scale thermonuclear fusion processes, involving l i f i t t i tt t In an operating fusion reactor fusion is the process in which two or more atomic nuclei join together, or "fuse", to form a single at very high densities and temperatures. fusion reaction. It is one of the earliest controlled fusion

  7. Short wavelength laser

    DOE Patents [OSTI]

    Hagelstein, Peter L. (Livermore, CA)

    1986-01-01T23:59:59.000Z

    A short wavelength laser (28) is provided that is driven by conventional-laser pulses (30, 31). A multiplicity of panels (32), mounted on substrates (34), are supported in two separated and alternately staggered facing and parallel arrays disposed along an approximately linear path (42). When the panels (32) are illuminated by the conventional-laser pulses (30, 31), single pass EUV or soft x-ray laser pulses (44, 46) are produced.

  8. Optical emission in magnetically confined laser-induced breakdown spectroscopy

    SciTech Connect (OSTI)

    Shen, X. K.; Lu, Y. F.; Gebre, T.; Ling, H.; Han, Y. X. [Department of Electrical Engineering, University of Nebraska-Lincoln, Lincoln, Nebraska 68588-0511 (United States)

    2006-09-01T23:59:59.000Z

    Magnetically confined laser-induced breakdown spectroscopy was investigated by studying the optical emission from laser-induced plasma plumes expanding across an external transverse magnetic field. KrF excimer laser pulses with a pulse duration of 23 ns and a wavelength of 248 nm were used to produce plasmas from Al, Cu, and Co targets. Various optical emission lines obtained from Al and Cu targets show an obvious enhancement in the intensity of optical emission when a magnetic field of {approx}0.8 T is applied, while the optical emission lines from Co targets show a decrease in the optical emission intensity. The enhancement factors of optical emission lines were measured to be around 2 for the Al and Mn (impurity) lines from Al targets, and 6-8 for Cu lines from Cu targets. Temporal evolution of the optical emission lines from the Al samples shows a maximum enhancement in emission intensity at time delays of 8-20 {mu}s after the incident laser pulse, while from the Cu targets it shows a continuous enhancement at time delays of 3-20 {mu}s after the pulse. The enhancement in the optical emission from the Al and Cu plasmas was presumably due to the increase in the effective plasma density as a result of magnetic confinement. The decrease in the emission intensity from the Co plasmas was suggested to be due to the decrease of effective plasma density as a result of the magnetic force.

  9. INERTIAL FUSION DRIVEN BY INTENSE HEAVY-ION BEAMS

    SciTech Connect (OSTI)

    Sharp, W. M.; Friedman, A.; Grote, D. P.; Barnard, J. J.; Cohen, R. H.; Dorf, M. A.; Lund, S. M.; Perkins, L. J.; Terry, M. R.; Logan, B. G.; Bieniosek, F. M.; Faltens, A.; Henestroza, E.; Jung, J. Y.; Kwan, J. W.; Lee, E. P.; Lidia, S. M.; Ni, P. A.; Reginato, L. L.; Roy, P. K.; Seidl, P. A.; Takakuwa, J. H.; Vay, J.-L.; Waldron, W. L.; Davidson, R. C.; Gilson, E. P.; Kaganovich, I. D.; Qin, H.; Startsev, E.; Haber, I.; Kishek, R. A.; Koniges, A. E.

    2011-03-31T23:59:59.000Z

    Intense heavy-ion beams have long been considered a promising driver option for inertial-fusion energy production. This paper briefly compares inertial confinement fusion (ICF) to the more-familiar magnetic-confinement approach and presents some advantages of using beams of heavy ions to drive ICF instead of lasers. Key design choices in heavy-ion fusion (HIF) facilities are discussed, particularly the type of accelerator. We then review experiments carried out at Lawrence Berkeley National Laboratory (LBNL) over the past thirty years to understand various aspects of HIF driver physics. A brief review follows of present HIF research in the US and abroad, focusing on a new facility, NDCX-II, being built at LBNL to study the physics of warm dense matter heated by ions, as well as aspects of HIF target physics. Future research directions are briefly summarized.

  10. Laser EYE SURGERY LASIK and Excimer Lasers

    E-Print Network [OSTI]

    Fygenson, Deborah Kuchnir

    Laser EYE SURGERY LASIK and Excimer Lasers Michael Hutchins #12;The PROBLEM opia - near sightedness. ically corrected with concave #12;THE PROBLEM eropia - far sightedness sed by a flat cornea or ort eye from different focal points in different nes of the eye. used by non-uniform curvature of the cornea

  11. Transmyocardial Laser Revascularization

    E-Print Network [OSTI]

    Fygenson, Deborah Kuchnir

    Transmyocardial Laser Revascularization Max Wiedmann #12;What is TMR? · TMR is used to improve blood flow to heart muscle tissue (myocardial tissue). · This is done using a laser to create small with bypass surgery so no additional opening is required. · The surgeon uses the laser to create 20 to 40 1mm

  12. Laser bottom hole assembly

    DOE Patents [OSTI]

    Underwood, Lance D; Norton, Ryan J; McKay, Ryan P; Mesnard, David R; Fraze, Jason D; Zediker, Mark S; Faircloth, Brian O

    2014-01-14T23:59:59.000Z

    There is provided for laser bottom hole assembly for providing a high power laser beam having greater than 5 kW of power for a laser mechanical drilling process to advance a borehole. This assembly utilizes a reverse Moineau motor type power section and provides a self-regulating system that addresses fluid flows relating to motive force, cooling and removal of cuttings.

  13. Theoretical analysis and experiments on antireflection coatings for laser diodes

    E-Print Network [OSTI]

    Chin, Kai Jian

    1987-01-01T23:59:59.000Z

    TEIEORETICAL 'NAI. YSIS AND EXPERIMENTS ON ANTIBEFLECTION COATINGS FOR LASER DIODES A Thesis by KAI 3IAN CHIN Submitted to the Graduate College of Texas AkM University in partial fulfillment of the requirement, for the degree of MASTER... OF SCIENCE December 19SI Major Subject: Electrical Engineering THEORETICAL ANALYSIS AND EXPERIMENTS ON ANTIREFLECTION COATINGS FOR. LASER DIODES A Thesis KAI JIAN CHIN Approved as to style and content by: Henry . Taylor (Chairman of Committee...

  14. Theoretical analysis and experiments on antireflection coatings for laser diodes 

    E-Print Network [OSTI]

    Chin, Kai Jian

    1987-01-01T23:59:59.000Z

    TEIEORETICAL 'NAI. YSIS AND EXPERIMENTS ON ANTIBEFLECTION COATINGS FOR LASER DIODES A Thesis by KAI 3IAN CHIN Submitted to the Graduate College of Texas AkM University in partial fulfillment of the requirement, for the degree of MASTER... OF SCIENCE December 19SI Major Subject: Electrical Engineering THEORETICAL ANALYSIS AND EXPERIMENTS ON ANTIREFLECTION COATINGS FOR. LASER DIODES A Thesis KAI JIAN CHIN Approved as to style and content by: Henry . Taylor (Chairman of Committee...

  15. The design of laser trimmable temperature invariant active NMOS filters

    E-Print Network [OSTI]

    Rybicki, Mathew Anton

    1983-01-01T23:59:59.000Z

    THE DESIGN OF LASER TRIMMABLE TEMPERATURE INVARIANT ACTIVE NMOS FILTERS A Thesis MATHEW ANTON RYBICKI Submitted to the Graduate College of Teras A&M University in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE... December 1983 Major Subject: Electrical Engineering THE DESIGN OF LASER TRIMMABLE TEMPERA'IURE INVARIANT ACTIVE NMOS FILTERS A Thesis by MATHEW ANTON RYBICKI Approved as to style and content by: Randall L. Geiger (Chairman of Committee) Phil ip ED...

  16. Fiber optic laser-induced breakdown spectroscopy sensor for molten material analysis

    DOE Patents [OSTI]

    Zhang, Hansheng; Rai, Awadesh K.; Singh, Jagdish P.; Yueh, Fang-Yu

    2004-07-13T23:59:59.000Z

    A fiber optic laser-induced breakdown spectroscopy (LIBS) sensor, including a laser light source, a harmonic separator for directing the laser light, a dichroic mirror for reflecting the laser light, a coupling lens for coupling the laser light at an input of a multimode optical fiber, a connector for coupling the laser light from an output of the multimode optical fiber to an input of a high temperature holder, such as a holder made of stainless steel, and a detector portion for receiving emission signal and analyzing LIBS intensities. In one variation, the multimode optical fiber has silica core and silica cladding. The holder includes optical lenses for collimating and focusing the laser light in a molten alloy to produce a plasma, and for collecting and transmitting an emission signal to the multimode optical fiber.

  17. Temperature distributions in the laser-heated diamond anvil cell from 3-D numerical modeling

    SciTech Connect (OSTI)

    Rainey, E. S. G.; Kavner, A. [Department of Earth and Space Sciences, University of California, Los Angeles, California 90095 (United States); Hernlund, J. W. [Department of Earth and Planetary Science, University of California, Berkeley, California 94720 (United States); Earth-Life Science Institute, Megoro, Tokyo 152-8551 (Japan)

    2013-11-28T23:59:59.000Z

    We present TempDAC, a 3-D numerical model for calculating the steady-state temperature distribution for continuous wave laser-heated experiments in the diamond anvil cell. TempDAC solves the steady heat conduction equation in three dimensions over the sample chamber, gasket, and diamond anvils and includes material-, temperature-, and direction-dependent thermal conductivity, while allowing for flexible sample geometries, laser beam intensity profile, and laser absorption properties. The model has been validated against an axisymmetric analytic solution for the temperature distribution within a laser-heated sample. Example calculations illustrate the importance of considering heat flow in three dimensions for the laser-heated diamond anvil cell. In particular, we show that a “flat top” input laser beam profile does not lead to a more uniform temperature distribution or flatter temperature gradients than a wide Gaussian laser beam.

  18. Strong laser fields as a probe for fundamental physics

    E-Print Network [OSTI]

    Holger Gies

    2008-12-03T23:59:59.000Z

    Upcoming high-intensity laser systems will be able to probe the quantum-induced nonlinear regime of electrodynamics. So far unobserved QED phenomena such as the discovery of a nonlinear response of the quantum vacuum to macroscopic electromagnetic fields can become accessible. In addition, such laser systems provide for a flexible tool for investigating fundamental physics. Primary goals consist in verifying so far unobserved QED phenomena. Moreover, strong-field experiments can search for new light but weakly interacting degrees of freedom and are thus complementary to accelerator-driven experiments. I review recent developments in this field, focusing on photon experiments in strong electromagnetic fields. The interaction of particle-physics candidates with photons and external fields can be parameterized by low-energy effective actions and typically predict characteristic optical signatures. I perform first estimates of the accessible new-physics parameter space of high-intensity laser facilities such as POLARIS and ELI.

  19. Laser beam apparatus and method for analyzing solar cells

    DOE Patents [OSTI]

    Staebler, David L. (Lawrenceville, NJ)

    1980-01-01T23:59:59.000Z

    A laser beam apparatus and method for analyzing, inter alia, the current versus voltage curve at the point of illumination on a solar cell and the open circuit voltage of a solar cell. The apparatus incorporates a lock-in amplifier, and a laser beam light chopper which permits the measurement of the AC current of the solar cell at an applied DC voltage at the position on the solar cell where the cell is illuminated and a feedback scheme which permits the direct scanning measurements of the open circuit voltage. The accuracy of the measurement is a function of the intensity and wavelength of the laser light with respect to the intensity and wavelength distribution of sunlight and the percentage the dark current is at the open circuit voltage to the short circuit current of the solar cell.

  20. How much laser power can propagate through fusion plasma?

    E-Print Network [OSTI]

    Pavel M. Lushnikov; Harvey A. Rose

    2006-03-28T23:59:59.000Z

    Propagation of intense laser beams is crucial for inertial confinement fusion, which requires precise beam control to achieve the compression and heating necessary to ignite the fusion reaction. The National Ignition Facility (NIF), where fusion will be attempted, is now under construction. Control of intense beam propagation may be ruined by laser beam self-focusing. We have identified the maximum laser beam power that can propagate through fusion plasma without significant self-focusing and have found excellent agreement with recent experimental data, and suggest a way to increase that maximum by appropriate choice of plasma composition with implication for NIF designs. Our theory also leads to the prediction of anti-correlation between beam spray and backscatter and suggests the indirect control of backscatter through manipulation of plasma ionization state or acoustic damping.

  1. Intense femtosecond photoexcitation of bulk and monolayer MoS{sub 2}

    SciTech Connect (OSTI)

    Paradisanos, I.; Fotakis, C. [Institute of Electronic Structure and Laser (IESL), Foundation for Research and Technology-Hellas (FORTH), Heraklion 71003 (Greece); Physics Department, University of Crete, Heraklion 71003 (Greece); Kymakis, E. [Center of Materials Technology and Photonics and Electrical Engineering Department, Technological Educational Institute (TEI) of Crete, Heraklion 71003 (Greece); Kioseoglou, G. [Materials Science and Technology Department, University of Crete, Heraklion 71003 (Greece); Stratakis, E., E-mail: stratak@iesl.forth.gr [Institute of Electronic Structure and Laser (IESL), Foundation for Research and Technology-Hellas (FORTH), Heraklion 71003 (Greece); Materials Science and Technology Department, University of Crete, Heraklion 71003 (Greece)

    2014-07-28T23:59:59.000Z

    The effect of femtosecond laser irradiation on bulk and single-layer MoS{sub 2} on silicon oxide is studied. Optical, field emission scanning electron microscopy and Raman microscopy were used to quantify the damage. The intensity of A{sub 1g} and E{sub 2g}{sup 1} vibrational modes was recorded as a function of the number of irradiation pulses. The observed behavior was attributed to laser-induced bond breaking and subsequent atoms removal due to electronic excitations. The single-pulse optical damage threshold was determined for the monolayer and bulk under 800?nm and 1030?nm pulsed laser irradiation, and the role of two-photon versus one photon absorption effects is discussed.

  2. Method and apparatus for laser-controlled proton beam radiology

    DOE Patents [OSTI]

    Johnstone, Carol J. (Warrenville, IL)

    1998-01-01T23:59:59.000Z

    A proton beam radiology system provides cancer treatment and proton radiography. The system includes an accelerator for producing an H.sup.- beam and a laser source for generating a laser beam. A photodetachment module is located proximate the periphery of the accelerator. The photodetachment module combines the H.sup.- beam and laser beam to produce a neutral beam therefrom within a subsection of the H.sup.- beam. The photodetachment module emits the neutral beam along a trajectory defined by the laser beam. The photodetachment module includes a stripping foil which forms a proton beam from the neutral beam. The proton beam is delivered to a conveyance segment which transports the proton beam to a patient treatment station. The photodetachment module further includes a laser scanner which moves the laser beam along a path transverse to the cross-section of the H.sup.- beam in order to form the neutral beam in subsections of the H.sup.- beam. As the scanning laser moves across the H.sup.- beam, it similarly varies the trajectory of the proton beam emitted from the photodetachment module and in turn varies the target location of the proton beam upon the patient. Intensity modulation of the proton beam can also be achieved by controlling the output of the laser.

  3. Method and apparatus for laser-controlled proton beam radiology

    DOE Patents [OSTI]

    Johnstone, C.J.

    1998-06-02T23:59:59.000Z

    A proton beam radiology system provides cancer treatment and proton radiography. The system includes an accelerator for producing an H{sup {minus}} beam and a laser source for generating a laser beam. A photodetachment module is located proximate the periphery of the accelerator. The photodetachment module combines the H{sup {minus}} beam and laser beam to produce a neutral beam therefrom within a subsection of the H{sup {minus}} beam. The photodetachment module emits the neutral beam along a trajectory defined by the laser beam. The photodetachment module includes a stripping foil which forms a proton beam from the neutral beam. The proton beam is delivered to a conveyance segment which transports the proton beam to a patient treatment station. The photodetachment module further includes a laser scanner which moves the laser beam along a path transverse to the cross-section of the H{sup {minus}} beam in order to form the neutral beam in subsections of the H{sup {minus}} beam. As the scanning laser moves across the H{sup {minus}} beam, it similarly varies the trajectory of the proton beam emitted from the photodetachment module and in turn varies the target location of the proton beam upon the patient. Intensity modulation of the proton beam can also be achieved by controlling the output of the laser. 9 figs.

  4. Wine Science Wine Sciencee Science

    E-Print Network [OSTI]

    Wine Science Wine Sciencee Science Thomas Henick-Kling Professor of Enology Director of Viticulture & Enology Program #12;Wine Science Wine Science Growth of Washington Wine Industry #12;Wine Science Wine Science Wine Grapes utilized 2007 2008 2009 2010 WA 127,000 145,000 156,000 160,000 NY 24,000 26,000 30

  5. High Energy Laser for Space Debris Removal

    SciTech Connect (OSTI)

    Barty, C; Caird, J; Erlandson, A; Beach, R; Rubenchik, A

    2009-10-30T23:59:59.000Z

    The National Ignition Facility (NIF) and Photon Science Directorate at Lawrence Livermore National Laboratory (LLNL) has substantial relevant experience in the construction of high energy lasers, and more recently in the development of advanced high average power solid state lasers. We are currently developing new concepts for advanced solid state laser drivers for the Laser Inertial Fusion Energy (LIFE) application, and other high average power laser applications that could become central technologies for use in space debris removal. The debris population most readily addressed by our laser technology is that of 0.1-10 cm sized debris in low earth orbit (LEO). In this application, a ground based laser system would engage an orbiting target and slow it down by ablating material from its surface which leads to reentry into the atmosphere, as proposed by NASA's ORION Project. The ORION concept of operations (CONOPS) is also described in general terms by Phipps. Key aspects of this approach include the need for high irradiance on target, 10{sup 8} to 10{sup 9} W/cm{sup 2}, which favors short (i.e., picoseconds to nanoseconds) laser pulse durations and high energy per pulse ({approx} > 10 kJ). Due to the target's orbital velocity, the potential duration of engagement is only of order 100 seconds, so a high pulse repetition rate is also essential. The laser technology needed for this application did not exist when ORION was first proposed, but today, a unique combination of emerging technologies could create a path to enable deployment in the near future. Our concepts for the laser system architecture are an extension of what was developed for the National Ignition Facility (NIF), combined with high repetition rate laser technology developed for Inertial Fusion Energy (IFE), and heat capacity laser technology developed for military applications. The 'front-end' seed pulse generator would be fiber-optics based, and would generate a temporally, and spectrally tailored pulse designed for high transmission through the atmosphere, as well as efficient ablative coupling to the target. The main amplifier would use either diode-pumped or flashlamp-pumped solid state gain media, depending on budget constraints of the project. A continuously operating system would use the gas-cooled amplifier technology developed for Mercury, while a burst-mode option would use the heat capacity laser technology. The ground-based system that we propose is capable of rapid engagement of targets whose orbits cross over the site, with potential for kill on a single pass. Very little target mass is ablated per pulse so the potential to create additional hazardous orbiting debris is minimal. Our cost estimates range from $2500 to $5000 per J depending on choices for laser gain medium, amplifier pump source, and thermal management method. A flashlamp-pumped, Nd:glass heat-capacity laser operating in the burst mode would have costs at the lower end of this spectrum and would suffice to demonstrate the efficacy of this approach as a prototype system. A diode-pumped, gas-cooled laser would have higher costs but could be operated continuously, and might be desirable for more demanding mission needs. Maneuverability can be incorporated in the system design if the additional cost is deemed acceptable. The laser system would need to be coupled with a target pointing and tracking telescope with guide-star-like wavefront correction capability.

  6. Femtosecond-scale response of GaAs to ultrafast laser pulses RID A-7793-2008

    E-Print Network [OSTI]

    Dumitrica, T.; Allen, Roland E.

    2002-01-01T23:59:59.000Z

    We present nonadiabatic simulations of the coherent response of crystalline GaAs irradiated by intense femtosecond-scale laser pulses. Above a threshold fluence, which corresponds to promotion of about 12% of the valence electrons...

  7. Gravitational Radiation Detection with Laser Interferometry

    E-Print Network [OSTI]

    Rana X Adhikari

    2014-03-13T23:59:59.000Z

    Gravitational-wave detection has been pursued relentlessly for over 40 years. With the imminent operation of a new generation of laser interferometers, it is expected that detections will become a common occurrence. The research into more ambitious detectors promises to allow the field to move beyond detection and into the realm of precision science using gravitational radiation. In this article, I review the state of the art for the detectors and describe an outlook for the coming decades.

  8. Gravitational Radiation Detection with Laser Interferometry

    E-Print Network [OSTI]

    Adhikari, Rana X

    2013-01-01T23:59:59.000Z

    Gravitational-wave detection has been pursued relentlessly for over 40 years. With the imminent operation of a new generation of laser interferometers, it is expected that detections will become a common occurrence. The research into more ambitious detectors promises to allow the field to move beyond detection and into the realm of precision science using gravitational radiation. In this article, I review the state of the art for the detectors and describe an outlook for the coming decades.

  9. Absorption coefficient of aluminum near the critical point and the consequences on high-power nanosecond laser ablation

    SciTech Connect (OSTI)

    Wu Benxin; Shin, Yung C. [Center for Laser-based Manufacturing, School of Mechanical Engineering, Purdue University, West Lafayette, Indiana 47907 (United States)

    2006-09-11T23:59:59.000Z

    During nanosecond laser ablation, the absorption coefficient determines the laser energy deposition in the target, the accurate knowledge of which near the material critical point is crucial for understanding the fundamental physics of high-power nanosecond laser ablation. In this letter, the absorption coefficient of aluminum near the critical point is calculated through the Drude model based on the measured electrical conductivity data, and its effect on laser ablation is investigated numerically using a heat transfer model. The result supports the experimental observations that phase explosion occurs for the ablation of aluminum by sufficiently intense laser pulses, and the model predicted phase explosion threshold is consistent with experimental measurements.

  10. Energy Intensity Baselining and Tracking Guidance

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

    Learn more at betterbuildings.energy.gov Energy Intensity Baselining and Tracking Guidance i Preface The U.S. Department of Energy's (DOE's) Better Buildings, Better Plants Program...

  11. Calculation of laser induced impulse based on the laser supported detonation wave model with dissociation, ionization and radiation

    SciTech Connect (OSTI)

    Gan, Li, E-mail: ligan0001@gmail.com; Mousen, Cheng; Xiaokang, Li [College of Aerospace Science and Engineering, National University of Defense Technology, Changsha (China)] [College of Aerospace Science and Engineering, National University of Defense Technology, Changsha (China)

    2014-03-15T23:59:59.000Z

    In the laser intensity range that the laser supported detonation (LSD) wave can be maintained, dissociation, ionization and radiation take a substantial part of the incidence laser energy. There is little treatment on the phenomenon in the existing models, which brings obvious discrepancies between their predictions and the experiment results. Taking into account the impact of dissociation, ionization and radiation in the conservations of mass, momentum and energy, a modified LSD wave model is developed which fits the experimental data more effectively rather than the existing models. Taking into consideration the pressure decay of the normal and the radial rarefaction, the laser induced impulse that is delivered to the target surface is calculated in the air; and the dependencies of impulse performance on laser intensity, pulse width, ambient pressure and spot size are indicated. The results confirm that the dissociation is the pivotal factor of the appearance of the momentum coupling coefficient extremum. This study focuses on a more thorough understanding of LSD and the interaction between laser and matter.

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

    SciTech Connect (OSTI)

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

    2012-12-14T23:59:59.000Z

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

  13. ECOS-LINCE: A HIGH INTENSITY MULTI-ION SUPERCONDUCTING LINAC FOR NUCLEAR STRUCTURE AND REACTIONS

    E-Print Network [OSTI]

    Boyer, Edmond

    ECOS-LINCE: A HIGH INTENSITY MULTI-ION SUPERCONDUCTING LINAC FOR NUCLEAR STRUCTURE AND REACTIONS I as part of the Long-Range Plan of the Nuclear-Physics community. LINCE will be a multi-user facility dedicated to ECOS science: fundamental physics, astrophysics, nuclear structure and reaction dynamics

  14. Plasma confinement by hemispherical cavity in laser-induced breakdown spectroscopy

    SciTech Connect (OSTI)

    Guo, L. B.; Li, C. M. [Department of Electrical Engineering, University of Nebraska-Lincoln, Lincoln, Nebraska 68588-0511 (United States); School of Optoelectronics Science and Engineering, Huazhong University of Science and Technology, Wuhan, Hubei 430074 (China); Hu, W.; Zhou, Y. S.; Zhang, B. Y.; Lu, Y. F. [Department of Electrical Engineering, University of Nebraska-Lincoln, Lincoln, Nebraska 68588-0511 (United States); Cai, Z. X.; Zeng, X. Y. [School of Optoelectronics Science and Engineering, Huazhong University of Science and Technology, Wuhan, Hubei 430074 (China)

    2011-03-28T23:59:59.000Z

    An aluminum hemispherical cavity (diameter: 11.1 mm) was used to confine plasmas produced by a KrF excimer laser in air from a steel target with a low concentration manganese in laser-induced breakdown spectroscopy. A significant enhancement (factor >12) in the emission intensity of Mn lines was observed at a laser fluence of 7.8 J/cm{sup 2} when the plasma was confined by the hemispherical cavity, leading to an increase in plasma temperature about 3600 K. The maximum emission enhancement increased with increasing laser fluence. The spatial confinement mechanism was discussed using shock wave theory.

  15. Modeling crater formation in femtosecond-pulse laser damage from basic principles

    E-Print Network [OSTI]

    Mitchell, Robert A; Chowdhury, Enam A

    2015-01-01T23:59:59.000Z

    We present the first fundamental simulation method for the determination of crater morphology due to femtosecond-pulse laser damage. To this end we have adapted the particle-in-cell (PIC) method commonly used in plasma physics for use in the study of laser damage, and developed the first implementation of a pair-potential for PIC codes. We find that the PIC method is a complementary approach to modeling laser damage, bridging the gap between fully ab-initio molecular dynamics approaches and empirical models. We demonstrate our method by modeling a femtosecond-pulse laser incident on a flat copper slab, for a range of intensities.

  16. Laser-induced synthesis and decay of Tritium under exposure of solid targets in heavy water

    E-Print Network [OSTI]

    E. V. Barmina; P. G. Kuzmin; S. F. Timashev; G. A. Shafeev

    2013-06-03T23:59:59.000Z

    The processes of laser-assisted synthesis of Tritium nuclei and their laser-induced decay in cold plasma in the vicinity of solid targets (Au, Ti, Se, etc.) immersed into heavy water are experimentally realized at peak laser intensity of 10E10-10E13 Watts per square centimeter. Initial stages of Tritium synthesis and their laser-induced beta-decay are interpreted on the basis of non-elastic interaction of plasma electrons having kinetic energy of 5-10 eV with nuclei of Deuterium and Tritium, respectively.

  17. A wide bandwidth free-electron laser with mode locking using current modulation.

    SciTech Connect (OSTI)

    Kur, E.; Dunning, D. J.; McNeil, B. W. J.; Wurtele, J.; Zholents, A. A. (Accelerator Systems Division (APS)); (Univ. of California at Berkeley); (Univ. of Strathclyde); (STFC Daresbury Lab.); (LBNL)

    2011-01-20T23:59:59.000Z

    A new scheme for mode locking a free-electron laser amplifier is proposed based on electron beam current modulation. It is found that certain properties of the original concept, based on the energy modulation of electrons, are improved including the spectral brightness of the source and the purity of the series of short pulses. Numerical comparisons are made between the new and old schemes and between a mode-locked free-electron laser and self-amplified spontaneous emission free-electron laser. Illustrative examples using a hypothetical mode-locked free-electron laser amplifier are provided. The ability to generate intense coherent radiation with a large bandwidth is demonstrated.

  18. Dynamic Fiber Optic Sensors Under Intense Radioactive Environments

    SciTech Connect (OSTI)

    Allison, S.W.; Earl, D.D.; Haines, J.R.; Tsai, C.C.

    1998-10-15T23:59:59.000Z

    A liquid mercury target will be used as the neutron source for the proposed Spallation Neutron Source facility. This target is subjected to bombardment by short-pulse, high-energy proton beams. The intense thermal loads caused by interaction of the pulsed proton beam with the mercury create an enormous rate of temperature rise ({approximately}10{sup 7} K/s) during a very brief beam pulse ({approximately } 0.5 {micro}s). The resulting pressure waves in the mercury will interact with the walls of the mercury target and may lead to large stresses. To gain confidence in the mercury target design concept and to benchmark the computer design codes, we tested various electrical and optical sensors for measuring the transient strains on the walls of a mercury container and the pressures in the mercury. The sensors were attached on several sample mercury targets that were tested at various beam facilities: Oak Ridge Electron Linear Accelerator, Los Alamos Neutron Science Center-Weapons Neutron Research, and Brookhaven National Laboratory's Alternating Gradient Synchrotron. The effects of intense background radiation on measured signals for each sensor are described and discussed. Preliminary results of limited tests at these facilities indicate that the fiber optic sensors function well in this intense radiation environment, whereas conventional electrical sensors are dysfunctional.

  19. Ferroplasmons: Intense Localized Surface Plasmons in Metal-Ferromagnetic Nanoparticles

    SciTech Connect (OSTI)

    Sachan, Ritesh [University of Tennessee, Knoxville (UTK); Malasi, Abhinav [ORNL; Ge, Jingxuan [Materials Science and Engineering Department, University of Tennessee, Knoxville, TN, USA; Yadavali, Sagar P [ORNL; Gangopadhyay, Anup [Washington University, St. Louis; Krishna, Dr. Hare [Washington University, St. Louis; Garcia, Hernando [Southern Illinois University; Duscher, Gerd J M [ORNL; Kalyanaraman, Ramki [University of Tennessee, Knoxville (UTK)

    2014-01-01T23:59:59.000Z

    Interaction of photons with matter at length scales far below their wavelengths has given rise to many novel phenomena, including localized surface plasmon resonance (LSPR). However, LSPR with narrow bandwidth (BW) is observed only in a select few noble metals, and ferromagnets are not among them. Here, we report the discovery of LSPR in ferromagnetic Co and CoFe alloy (8% Fe) in contact with Ag in the form of bimetallic nanoparticles prepared by pulsed laser dewetting. These plasmons in metal-erromagnetic nanostructures, or ferroplasmons (FP) for short, are in the visible spectrum with comparable intensity and BW to those of the LSPRs from the Ag regions. This finding was enabled by electron energy-loss mapping across individual nanoparticles in a monochromated scanning transmission electron microscope. The appearance of the FP is likely due to plasmonic interaction between the contacting Ag and Co nanoparticles. Since there is no previous evidence for materials that simultaneously show ferromagnetism and such intense LSPRs, this discovery may lead to the design of improved plasmonic materials and applications. It also demonstrates that materials with interesting plasmonic properties can be synthesized using bimetallic nanostructures in contact with each other.

  20. The effects of process variations on residual stress in laser peened 7049 T73 aluminum alloy

    E-Print Network [OSTI]

    Rankin, Jon E; Hill, Michael R; Hackel, Lloyd A

    2003-01-01T23:59:59.000Z

    Handbook - Aluminum and Aluminum Alloys, ASM International,the Fatigue Life of 7050 Aluminum Alloy, Defence Science &in laser peened 7049 T73 aluminum alloy Jon E. Rankin and