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Laser wakefield excitation and measurement by femtosecond longitudinal interferometry

Description: Plasma density oscillations (Langmuir waves) in the wake of an intense (I{sub peak} {approximately} 3 {times} 10{sup 17}W/cm{sup 2}) laser pulse (100 fs) are measured with ultrafast time resolution using a longitudinal interferometric technique. Phase shifts consistent with large amplitude ({delta}n{sub e}/n{sub e} {approximately} 1) density waves at the electron plasma frequency were observed in a fully tunnel-ionized He plasma, corresponding to longitudinal electric fields of {approximately} … more
Date: April 1, 1996
Creator: Siders, C. W.; Le Blanc, S. P.; Fisher, D.; Tajima, T.; Downer, M. C.; Babine, A. et al.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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First measurement of laser Wakefield oscillations by longitudinal interferometry

Description: Because the electrostatic fields present in plasma waves can exceed those achievable in conventional accelerators and approach atomic scale values (E{sub a} {approximately} 500 GV/m), plasma based accelerators have received considerable attention as compact sources of high-energy electron pulses. Although stimulated Raman scattering or terahertz radiation at {ital w{sub p}} provided spatially averaged optical signatures of the plasma wave`s existence, new diagnostic techniques are required to m… more
Date: December 31, 1996
Creator: Siders, C. W.; Le Blanc, S. P.; Rau, B.; Fisher, D.; Tajima, T.; Downer, M. C. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Ultrafast terawatt laser sources for high-field particle acceleration and short wavelength generation

Description: The Laser Sources working group concerned itself with recent advances in and future requirements for the development of laser sources relevant to high-energy physics (HEP) colliders, small scale accelerators, and the generation of short wave-length radiation. We heavily emphasized pulsed terawatt peak power laser sources for several reasons. First, their development over the past five years has been rapid and multi-faceted, and has made relativistic light intensity available to the advanced acc… more
Date: December 31, 1996
Creator: Downer, M. C. & Siders, C. W.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Non-Equilibrium Superconductivity and Quasiparticle Dynamics in YBaCuO

Description: The authors use optical pump, coherent terahertz probe spectroscopy to transiently excite nonequilibrium populations of quasiparticles in YBa{sub 2}Cu{sub 3}O{sub 7.{delta}} and monitor, with picosecond resolution, the superfluid and quasiparticle dynamics.
Date: May 21, 1999
Creator: Siders, J. L. W.; Jacobs, R. N.; Siders, C. W.; Trugman, S. A. & Taylor, A. J.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Observation of Optical Pulse and Material Dynamics on the Femtosecond Time-Scale

Description: The widespread availability of lasers that generate pulses on the femtosecond scale has opened new realms of investigation in the basic and applied sciences, rendering available excitations delivering intensities well in excess of 10{sup 21} W/cm{sup 2}, and furnishing probes capable of resolving molecular relaxation timescales. As a consequence and a necessity, sophisticated techniques to examine the pulse behavior on the femtosecond scale have been developed and are of crucial importance to g… more
Date: September 13, 1999
Creator: Omenetto, F.; Luce, B.; Siders, C. W. & Taylor, A. J.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Femtosecond Coherent Spectroscopy at 800nm: MI-FROG Measures High-Field Ionization Rates in Gases

Description: The authors report the first quantitative phase-sensitive measurement of ultrafast ionization rates in gases using Multi-phase Interferometric Frequency-Resolved Optical Gating. Ultrafast probe depletion via frequency mixing in the ionization front is observed.
Date: May 24, 1999
Creator: Siders, C. W.; Siders, J. L. W. & Taylor, A. J.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Determination of Optical-Field Ionization Dynamics in Plasmas through the Direct Measurement of the Optical Phase Change

Description: This is the final report of a three-year Laboratory Directed Research and Development (LDRD) Project at Los Alamos National Laboratory (LANL). The detailed dynamics of an atom in a strong laser field is rich in both interesting physics and potential applications. The goal of this project was to develop a technique for characterizing high-field laser-plasma interactions with femtosecond resolution based on the direct measurement of the phase change of an optical pulse. The authors developed the … more
Date: July 16, 1999
Creator: Taylor, A. J.; Omenetto, G.; Rodriguez, G.; Siders, C. W.; Siders, J. L. W. & Downer, C.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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High Power Picosecond Laser Pulse Recirculation

Description: We demonstrate a nonlinear crystal-based short pulse recirculation cavity for trapping the second harmonic of an incident high power laser pulse. This scheme aims to increase the efficiency and flux of Compton-scattering based light sources. We demonstrate up to 36x average power enhancement of frequency doubled sub-millijoule picosecond pulses, and 17x average power enhancement of 177 mJ, 10 ps, 10 Hz pulses.
Date: April 12, 2010
Creator: Shverdin, M Y; Jovanovic, I; Semenov, V A; Betts, S M; Brown, C; Gibson, D J et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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System Modeling of kJ-class Petawatt Lasers at LLNL

Description: Advanced Radiographic Capability (ARC) project at the National Ignition Facility (NIF) is designed to produce energetic, ultrafast x-rays in the range of 70-100 keV for backlighting NIF targets. The chirped pulse amplification (CPA) laser system will deliver kilo-Joule pulses at an adjustable pulse duration from 1 ps to 50 ps. System complexity requires sophisticated simulation and modeling tools for design, performance prediction, and comprehension of experimental results. We provide a brief o… more
Date: April 14, 2010
Creator: Shverdin, M Y; Rushford, M; Henesian, M A; Boley, C; Haefner, C; Heebner, J E et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Techniques and use of a tunable, laser-based, MeV-Class Compton scattering light source

Description: A Compton scattering {gamma}-ray source, capable of producing photons with energies ranging from 0.1 MeV to 0.9 MeV has been commissioned and characterized, and then used to perform nuclear resonance fluorescence (NRF) experiments. The key source parameters are the size (0.01 mm{sup 2}), horizontal and vertical divergence (6 x 10 mrad{sup 2}), duration (10 ps), spectrum and intensity (10{sup 5} photons/shot). These parameters are summarized by the peak brightness, 1.5 x 10{sup 15} photons/mm{su… more
Date: June 30, 2009
Creator: Albert, F.; Anderson, S. G.; Gibson, D. J.; Hagmann, C. A.; Johnson, M. S.; Messerly, M. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Overview of Mono-Energetic Gamma-Ray Sources & Applications

Description: Recent progress in accelerator physics and laser technology have enabled the development of a new class of tunable gamma-ray light sources based on Compton scattering between a high-brightness, relativistic electron beam and a high intensity laser pulse produced via chirped-pulse amplification (CPA). A precision, tunable Mono-Energetic Gamma-ray (MEGa-ray) source driven by a compact, high-gradient X-band linac is currently under development and construction at LLNL. High-brightness, relativisti… more
Date: May 18, 2010
Creator: Hartemann, F. V.; Albert, F.; Anderson, G. G.; Anderson, S. G.; Bayramian, A. J.; Betts, S. M. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Precision X-Band Linac Technologies for Nuclear Photonics Gamma-Ray Sources

Description: Nuclear photonics is an emerging field of research requiring new tools, including high spectral brightness, tunable gamma-ray sources; high photon energy, ultrahigh-resolution crystal spectrometers; and novel detectors. This presentation focuses on the precision linac technology required for Compton scattering gamma-ray light sources, and on the optimization of the laser and electron beam pulse format to achieve unprecedented spectral brightness. Within this context, high-gradient X-band techno… more
Date: August 31, 2011
Creator: Hartemann, F. V.; Albert, F.; Anderson, S. G.; Bayramian, A. J.; Cross, R. R.; Ebbers, C. A. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Low-Intensity Nonlinear Spectral Effects in Compton Scattering

Description: Nonlinear effects are known to occur in Compton scattering light sources, when the laser normalized 4-potential, A = e{radical}-A{sub {mu}}A{sup {mu}}/m{sub 0}c approaches unity. In this letter, it is shown that nonlinear spectral features can appear at arbitrarily low values of A, if the fractional bandwidth of the laser pulse, {Delta}{phi}{sup -1}, is sufficiently small to satisfy A{sup 2} {Delta}{phi} {approx_equal} 1. A three dimensional analysis, based on a local plane-wave, slow-varying e… more
Date: February 23, 2010
Creator: Hartemann, F V; Albert, F; Siders, C W & Barty, C P
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Power scaling analysis of fiber lasers and amplifiers based on non-silica materials

Description: A developed formalism for analyzing the power scaling of diffraction limited fiber lasers and amplifiers is applied to a wider range of materials. Limits considered include thermal rupture, thermal lensing, melting of the core, stimulated Raman scattering, stimulated Brillouin scattering, optical damage, bend induced limits on core diameter and limits to coupling of pump diode light into the fiber. For conventional fiber lasers based upon silica, the single aperture, diffraction limited power l… more
Date: March 30, 2010
Creator: Dawson, J W; Messerly, M J; Heebner, J E; Pax, P H; Sridharan, A K; Bullington, A L et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Fiber-Based, Spatially and Temporally Shaped Picosecond UV Laser for Advanced RF Gun Applications

Description: The fiber-based, spatially and temporally shaped, picosecond UV laser system described here has been specifically designed for advanced rf gun applications, with a special emphasis on the production of high-brightness electron beams for free-electron lasers and Compton scattering light sources. The laser pulse can be shaped to a flat-top in both space and time with a duration of 10 ps at full width of half-maximum (FWHM) and rise and fall times under 1 ps. The expected pulse energy is 50 {micro… more
Date: June 8, 2007
Creator: Shverdin, M Y; Anderson, S G; Betts, S M; Gibson, D J; Hartemann, F V; Hernandez, J E et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

COMMISSIONING OF A HIGH-BRIGHTNESS PHOTOINJECTOR FOR COMPTON SCATTERING X-RAY SOURCES

Description: Compton scattering of intense laser pulses with ultrarelativistic electron beams has proven to be an attractive source of high-brightness x-rays with keV to MeV energies. This type of x-ray source requires the electron beam brightness to be comparable with that used in x-ray free-electron lasers and laser and plasma based advanced accelerators. We describe the development and commissioning of a 1.6 cell RF photoinjector for use in Compton scattering experiments at LLNL. Injector development iss… more
Date: June 21, 2007
Creator: Anderson, S G; Gibson, D J; Hartemann, F V; Messerly, M; Shverdin, M; Siders, C W et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Optimal Design of a Tunable Thomson-Scattering Based Gamma-Ray Source

Description: Thomson-Scattering based systems offer a path to high-brightness high-energy (> 1 MeV) x-ray and {gamma}-ray sources due to their favorable scaling with electron energy. LLNL is currently engaged in an effort to optimize such a device, dubbed the ''Thomson-Radiated Extreme X-Ray'' (T-REX) source, targeting up to 680 keV photon energy. Such a system requires precise design of the interaction between a high-intensity laser pulse and a high-brightness electron beam. Presented here are the optim… more
Date: June 7, 2007
Creator: Gibson, D J; Anderson, S G; Betts, S M; Hartemann, F V; Jovanovic, I; McNabb, D P et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Scaling to Ultra-High Intensities by High-Energy Petawatt Beam Combining

Description: The output pulse energy from a single-aperture high-energy laser amplifier (e.g. fusion lasers such as NIF and LMJ) are critically limited by a number of factors including optical damage, which places an upper bound on the operating fluence; parasitic gain, which limits together with manufacturing costs the maximum aperture size to {approx} 40-cm; and non-linear phase effects which limits the peak intensity. For 20-ns narrow band pulses down to transform-limited sub-picosecond pulses, these lim… more
Date: June 23, 2006
Creator: Siders, C. W.; Jovanovic, I.; Crane, J.; Rushford, M.; Lucianetti, A. & Barty, C. P. J.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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High Brightness, Laser-Driven X-ray Source for Nanoscale Metrology and Femtosecond Dynamics

Description: This project developed and demonstrated a new, bright, ultrafast x-ray source based upon laser-driven K-alpha generation, which can produce an x-ray flux 10 to 100 times greater than current microfocus x-ray tubes. The short-pulse (sub-picosecond) duration of this x-ray source also makes it ideal for observing time-resolved dynamics of atomic motion in solids and thin films.
Date: February 26, 2007
Creator: Siders, C. W.; Crane, J. K.; Semenov, V.; Betts, S.; Kozioziemski, B.; Wharton, K. et al.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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