62 Matching Results

Search Results

Advanced search parameters have been applied.

Spectroscopic temperature measurements of non-equilibrium plasmas

Description: The characterization of laser-produced plasmas has required the application of spectroscopic techniques to non-standard conditions where kinetics models have not been extensively tested. The plasmas are produced by the Nova laser for the study of inertial confinement fusion, can be mm in size, and evolve on sub-nanosecond time scales. These targets typically achieve electron temperatures from 2-4 keV and electron densities of 10{sup 20}-10{sup 22} cm{sup {minus}3}. The authors have measured the electron temperature of two types of targets: bags of gas and hohlraums, Au cylinders with laser entrance holes in the flat ends. By comparing data from different targets, they examine the time-dependence of spectroscopic plasma diagnostics.
Date: April 24, 1996
Creator: Back, C.A.; Glenzer, S.H.; Lee, R.W. & MacGowan, B.J.
Partner: UNT Libraries Government Documents Department

Laser scattering in large-scale-length plasmas relevant to National Ignition Facility hohlraums

Description: We have used homogeneous plasmas of high density (up to 1.3 X 10{sup 21} electrons per cm{sup 3}) and temperature ({approximately} 3 keV) with large density scale lengths ({approximately}2 mm) to approximate conditions within National Ignition Facility (NIF) hohlraums. Within these plasmas we have studied the dependence of stimulated Raman (SRS) and Brillouin (SBS) scattering on beam smoothing and plasma conditions at the relevant laser intensity (3{omega}, 2 X 10{sup 15}Wcm{sup 2}). Both SBS and SRS are reduced by the use of smoothing by spectral dispersion (SSD).
Date: October 1, 1996
Creator: MacGowan, B.J.; Berger, R.L. & Afeyan, B.B.
Partner: UNT Libraries Government Documents Department

Observation of multiple mechanisms for stimulating ion waves in ignition scale plasmas

Description: The laser and plasma conditions expected in ignition experiments using indirect drive inertial confinement have been studied experimentally. It has been found that there are at least three ways in which ion waves can be stimulated in these plasmas and have significant effect on the energy balance and distribution in the target. First ion waves can be stimulated by a single laser beam by the process of Stimulated Brillouin Scattering (SBS) in which an ion acoustic and a scattered electromagnetic wave grow from noise. Second, in a plasma where more than one beam intersect, ion waves can be excited at the `beat` frequency and wave number of the intersecting beams, causing the side scatter instability to be seeded, and substantial energy to be transferred between the beams [R. K. Kirkwood et. al. Phys. Re0319v. Lett. 76, 2065 (1996)]. And third, ion waves may be stimulated by the decay of electron plasma waves produced by Stimulated Raman Scattering (SRS), thereby inhibiting the SRS process [R. K. Kirkwood et. al. Phys. Rev. Lett. 77, 2706 (1996)].
Date: November 1, 1996
Creator: Kirkwood, R.K.; MacGowan, B.J. & Montgomery, D.S.
Partner: UNT Libraries Government Documents Department

Observation of multiple mechanisms for stimulating ion waves in ignition scale plasmas. Revision 1

Description: The laser and plasma conditions expected in ignition experiments using indirect drive inertial confinement have been studied experimentally. It has been shown that there are at least three ways in which ion waves can be stimulated in these plasmas and have significant effect on the energy balance and distribution in the target. First ion waves can be stimulated by a single laser beam by the process of Stimulated Brillouin Scattering (SBS) in which an ion acoustic and a scattered electromagnetic wave grow from noise. Second, in a plasma where more than one beam intersect, ion waves can Lie excited at the `beat` frequency and wave number of the intersecting beams,, causing the side scatter instability to be seeded, and substantial energy to be transferred between the beams [R. K. Kirkwood et. al. Phys. Rev. Lett. 76, 2065 (1996)]. And third, ion waves may be stimulated by the decay of electron plasma waves produced by Stimulated Raman Scattering (SRS), thereby inhibiting the SRS process [R. K. Kirkwood et. al. Phys. Rev. Lett. 77, 2706 (1996)].
Date: March 3, 1997
Creator: Kirkwood, R.K.; MacGowan, B.J. & Montgomery, D.S.
Partner: UNT Libraries Government Documents Department

Interaction between stimulated raman scattering and ion acoustic waves in ignition relevant plasmas

Description: We have observed that the scattering of light by stimulated Langmuir waves (SRS) in ignition scale plasmas is dependent on the properties of the ion acoustic wave, indicating that a nonlinear coupling between the two waves limits the scattered energy.
Date: June 1, 1997
Creator: Kirkwood, R.K.; MacGowan, B.J. & Montgomery, D.S.
Partner: UNT Libraries Government Documents Department

Thomson scattering in the corona of laser-produced gold plasmas

Description: Thomson scattering measurements of the electron temperature in laser- produced gold plasmas are presented. We irradiated a flat gold disk target with one laser beam of the Nova laser facility. A second laser beam probed the plasma at a distance of 500{mu}m with temporally resolved Thomson scattering. The electron temperature measurements are compared with hydrodynamic simulations using the code LASNEX for experiments applying smoothed and unsmoothed heater beams. In case of an unsmoothed heater beam the simulations predict temperatures which are about 40% higher than our measured data. Although the agreement is improved for a smoothed heater beam, discrepancies exist in the decay phase of the plasma. We discuss possible explanations for these observations.
Date: May 8, 1996
Creator: Glenzer, S.H.; Back, C.A.; Estabrook, K.G. & MacGowan, B.J.
Partner: UNT Libraries Government Documents Department

The study of parametric instabilities in NIF-scale plasmas on Nova

Description: At the same time we experimentally reproduced the plasma conditions expected within the NIF using plasmas produced by the Nova laser. The plasmas were created by irradiating a thin walled gas balloon or a sealed hohlraum containing of order one atmosphere of a low-Z gas (e.g. C{sub 5}H{sub 12}, C{sub 5}D{sub 12} or CO{sub 2}). When the gas is ionized and heated the resultant plasmas are homogeneous, and of high density ({approximately}10{sup 21} electron/cm{sup 3}) and temperature ({approximately}3 keV) with large scale density scale lengths ({approximately}2 mm). Nine of the Nova beams were used to produce the plasma, the tenth beam was configured as an interaction beam that was sent through the performed plasma after a delay of order 500 psec. The SRS and SBS scattered from the plasma, together with the effects of the plasma on the transmitted beam, were studied as a function of the interaction beam intensity, beam smoothing and plasma constituents. The interaction beam was smoothed by using radon phase plates (RPPs), and 4 different colors within the f/8 beam to mimic the NIF laser architecture. The 4-color set-up divided the f/8 beam in to 4 separate quadrants each of which had its wavelength shifted relative to the other quadrants. The wavelength separation of the colors was approximately 1.4{Angstrom} at 3{omega}. Since each beam quadrant could have its frequency conversion crystals individually tuned for its wavelength, the 4-color scheme approximated ``bandwidth`` on the interaction beam without losing 3{omega} conversion efficiency. We have also studied the use of a laser bandwidth of approximately 0.7{Angstrom} and smoothing by Spectral Dispersion (SSD) with all of the quadrants set at the same color, to further reduce the reflected SBS. These studies were performed with both f/4.3 and f/8 interaction beam focusing.
Date: September 26, 1994
Creator: MacGowan, B.J.; Back, C.A. & Berger, R.L.
Partner: UNT Libraries Government Documents Department

X-ray imaging of uniform large scale-length plasmas created from gas-filled targets on Nova

Description: We report on the production and characterization of large scale-length plasmas created by illuminating gas-filled thin-walled balloon-like targets using the Nova laser. The targets consisted of a 4--5000 {angstrom} skin surrounding 1 atm of neopentane which when ionized becomes a plasma with 10{sup 21} electrons/cm{sup 3}. Results are presented from x-ray imaging used to evaluate the uniformity of the plasma. The most uniform plasmas were produced by illuminating the target with large converging beams that overlapped to cover most of the surface of the gasbag. An alternate focus geometry using small beam spots resulted in a less uniform plasma with low density holes in it.
Date: May 1, 1994
Creator: Kalantar, D. H.; MacGowan, B. J. & Bernat, T. P.
Partner: UNT Libraries Government Documents Department

Measurements of line overlap for resonant spoiling of x-ray lasing transitions

Description: High-precision measurements are presented of candidate line pairs for resonant spoiling of x-ray lasing transitions in the nickel-like W{sup 46+}, the neon-like Fe{sup 16+}, and the neon-like La{sup 47+} x-ray lasers. Our measurements were carried out with high-resolution crystal spectrometers, and a typical precision of 20--50 ppM was achieved. While most resonances appear insufficient for effective photo-spoiling, two resonance pairs are identified that provide a good overlap. These are the 4p{sub 1/2} {yields} 3d{sub 3/2} transition in nickel-like W{sup 46+} with the 2p{sub 3/2} {yields} 1s{sub 1/2} transition in hydrogenic Al{sup 12+}, and the 3s{sub 1/2} {yields} 2p{sub 3/2} transition in neon-like La{sup 47+} with the 1{sup 1}S{sub 0}-2{sup 1}P{sub 1} line in heliumlike Ti{sup 20+}.
Date: June 1, 1994
Creator: Beiersdorfer, P.; Elliott, S. R.; MacGowan, B. J. & Nilsen, J.
Partner: UNT Libraries Government Documents Department

X-ray diagnostics of hohlraum plasma flow

Description: In this study we use spectroscopy and x-ray imaging to investigate the macroscopic plasma flow in mm-sized laser-produced hohlraum plasmas. By using multiple diagnostics to triangulate the emission on a single experiment, we can pinpoint the position of dopants placed inside the hohlraum. X-ray emission from the foil has been used in the past to measure electron temperature. Here we analyze the spatial movement of dopant plasmas for comparison to hydrodynamic calculations.
Date: May 13, 1996
Creator: Back, C.A.; Glenzer, S.H.; Landen, O.L.; MacGowan, B.J. & Shepard, T.D.
Partner: UNT Libraries Government Documents Department

Spatially resolved x-ray laser spectra and demonstration of gain in nickel-like systems

Description: A recent series of experiments have provided spatially resolved near field images of several candidate x-ray lasing transition in neon-like, nickel-like, and hydrogen-like ions from laser-produced plasmas. From these time-gated, spatially, and spectrally resolved measurements the source size for the J = 0 - 1 and the J = 2 - 1 transitions in Ne-like selenium have been determined. Source regions as small as 50 ..mu..m have been observed on transitions with gain-length products >9. In addition, we have obtained the first experimental evidence for the amplification of spontaneous emission in the nickel-like ions of europium and ytterbium. Gains of order 1 cm/sup -1/ and gain-length products of up to 3.8 are observed on the J = 0 - 1, 4d-4p transitions in Eu + 35 at 65.26 and 71.00 A. Analogous transitions in Yb = +42 have been identified and some evidence for ASE has been observed. 7 refs., 11 figs.
Date: September 25, 1987
Creator: Whelan, D.A.; Keane, C.J.; MacGowan, B.J.; Matthews, D.L.; Trebes, J.E. & Eckart, M.J.
Partner: UNT Libraries Government Documents Department

Modeling NIF Experimental Designs with Adaptive Mesh Refinement and Lagrangian Hydrodynamics

Description: Incorporation of adaptive mesh refinement (AMR) into Lagrangian hydrodynamics algorithms allows for the creation of a highly powerful simulation tool effective for complex target designs with three-dimensional structure. We are developing an advanced modeling tool that includes AMR and traditional arbitrary Lagrangian-Eulerian (ALE) techniques. Our goal is the accurate prediction of vaporization, disintegration and fragmentation in National Ignition Facility (NIF) experimental target elements. Although our focus is on minimizing the generation of shrapnel in target designs and protecting the optics, the general techniques are applicable to modern advanced targets that include three-dimensional effects such as those associated with capsule fill tubes. Several essential computations in ordinary radiation hydrodynamics need to be redesigned in order to allow for AMR to work well with ALE, including algorithms associated with radiation transport. Additionally, for our goal of predicting fragmentation, we include elastic/plastic flow into our computations. We discuss the integration of these effects into a new ALE-AMR simulation code. Applications of this newly developed modeling tool as well as traditional ALE simulations in two and three dimensions are applied to NIF early-light target designs.
Date: August 31, 2005
Creator: Koniges, A E; Anderson, R W; Wang, P; Gunney, B N; Becker, R; Eder, D C et al.
Partner: UNT Libraries Government Documents Department

Polarization Smoothing on the National Ignition Facility

Description: We have recently implemented polarization smoothing (PS) on one quad of the NIF laser. Specially cut KDP and DKDP crystals at 420 x 420 mm sizes were used to scramble the incident 351 nm laser polarization over the beam aperture. The intensity contrast deduced from the measured focal spot images for one of the NIF beams is in very good agreement with the expected contrast. KDP and DKDP crystals are known to produce considerable amount of transverse stimulated Raman scattering (SRS) when irradiated with large beams at {approx}1-2 GW/cm2. In order to measure the transverse SRS, we attached optical fibers on the side of one of the PS crystals. The KDP PS crystal showed > 1 J/cm2 side scattered SRS at irradiances of 1.2 GW/cm2. The DKDP (70% deuteration level) PS crystal showed significantly less SRS. Detailed analysis of the SRS scattering in the PS crystal is in progress.
Date: September 2, 2005
Creator: Dixit, S N; Munro, D; Murray, J R; Nostrand, M; Wegner, P J; Froula, D et al.
Partner: UNT Libraries Government Documents Department

On the Accuracy of X-Ray Spectra Modeling of Inertial Confinement Fusion Plasmas

Description: We have performed x-ray spectroscopic experiments in homogeneous gas bag plasmas where we independently measure the temperature with Thomson scattering. We find that collisional radiative (kinetics) modeling of the intensities of the He-{beta} line and its dielectronic capture satellites is generally in agreement with the measured spectra. On the other hand, for the particular case of satellites arising from inner-shell electron collisional excitation, we find discrepancies of up to a factor of two between experiment and kinetics models. We have ruled out possible effects on the line emission due to plasma gradients, radiative transport, and suprathermal electron excitation leaving errors in the atomic physics modeling to be the most likely explanation. The determination that there are problems with the collisionally populated states is important for the interpretation of inertial confinement fusion capsule implosions where electron densities and temperature have been measured using the spectral line shape of the He-{beta} transition of Ar XVII. The analysis of the implosion data has required Stark broadening calculations coupled to a kinetics model to calculate the detailed line intensities and widths. Despite remaining discrepancies, the good agreement between the experimental dielectronic capture satellites and the HULLAC calculations suggests that HULLAC is a more appropriate code for the construction of the kinetics models of the He-{beta} complex from high density plasmas than previously used codes (e.g. MCDF). HULLAC results in higher temperatures for the implosion conditions of Ref.(5,6) in closer agreement with the 2-D radiation hydrodynamic modeling and other spectroscopic techniques. These results indicate that benchmarking kinetics codes with Thomson scattering is an important area in present ICF research.
Date: May 30, 2000
Creator: Glenzer, S.H.; Fournier, K.B.; Hammel, B.A.; Lee, L.W.; MacGowan, B.J. & Back, C.A.
Partner: UNT Libraries Government Documents Department

Characterization of laser-produced fusion plasmas with thomson scattering

Description: Thomson scattering has been developed at the Nova laser facility as a direct and accurate diagnostic to characterize inertial confinement fusion plasmas. Measurements from methane-filled, ignition relevant hohlraums apply the theory for two ion species plasmas, which has been tested in separate open geometry experiments, to obtain electron and ion temperatures. The experimental data provide a benchmark for two-dimensional hydrodynamic simulations using LASNEX, which is presently in use to predict he performance of future megajoule laser- driven hohlraums of the National Ignition Facility (NIF). The data are consistent with modeling using significantly inhibited heat transport at the peak of the drive. Furthermore, we find that stagnating plasma regions on the hohlraum axis are well described by the calculations. The result implies that stagnation in gas-filled hohlraums occurs too late to directly affect the capsule implosion in ignition experiments.
Date: July 9, 1997
Creator: Glenzer, S.H.; Back, C.A.; Suter, L.J.; MacGowan, B.J.; Landen, O.L.; Lindl, J.D. et al.
Partner: UNT Libraries Government Documents Department

Recent advances in indirect drive ICF target physics at LLNL

Description: In preparation for ignition on the National Ignition Facility, the Lawrence Livermore National Laboratory´┐Ż s Inertial Confinement Fusion Program, working in collaboration with Los Alamos National Laboratory, Commissariat a 1´┐Ż Energie Atomique (CEA), and Laboratory for Laser Energetics at the University of Rochester, has performed a broad range of experiments on the Nova and Omega lasers to test the fundamentals of the NIF target designs. These studies have refined our understanding of the important target physics, and have led to many of the specifications for the NIF laser and the cryogenic ignition targets. Our recent work has been focused in the areas of hohlraum energetics, symmetry, shock physics, and target design optimization & fabrication.
Date: January 13, 1998
Creator: Bernat, T P; Collins, G W; Haan, S; Hammel, B A; Landen, O L; MacGowan, B J et al.
Partner: UNT Libraries Government Documents Department

Target experimental area and systems of the U.S. National Ignition Facility

Description: One of the major goals of the US National Ignition Facility is the demonstration of laser driven fusion ignition and burn of targets by inertial confinement and provide capability for a wide variety of high energy density physics experiments. The NIF target area houses the optical systems required to focus the 192 beamlets to a target precisely positioned at the center of the 10 meter diameter, 10-cm thick aluminum target chamber. The chamber serves as mounting surface for the 48 final optics assemblies, the target alignment and positioning equipment, and the target diagnostics. The internal surfaces of the chamber are protected by louvered steel beam dumps. The target area also provides the necessary shielding against target emission and environmental protection equipment. Despite its complexity, the design provides the flexibility to accommodate the needs of the various NIF user groups, such as direct and indirect drive irradiation geometries, modular final optics design, capability to handle cryogenic targets, and easily re-configurable diagnostic instruments. Efficient target area operations are ensured by using line-replaceable designs for systems requiring frequent inspection, maintenance and reconfiguration, such as the final optics, debris shields, phase plates and the diagnostic instruments. A precision diagnostic instrument manipulator (DIMS) allows fast removal and precise repositioning of diagnostic instruments. In addition the authors describe several activities to enhance the target chamber availability, such as the target debris mitigation, the use of standard experimental configurations and the development of smart shot operations planning tools.
Date: December 17, 1999
Creator: Tobin, M; Van Wonterghem, B; MacGowan, B J; Hibbard, W; Kalantar, D; Lee, F D et al.
Partner: UNT Libraries Government Documents Department

Recombination x-ray laser experiments using exploding ribbon Al targets

Description: We present data obtained from recent recombination x-ray laser experiments carried out at the Nova and Phebus lasers using exploding ribbon Al targets irradiated with 100 ps pulses of 0.53-{mu}m light. Spatially and temporally resolved x-ray and soft x-ray spectra will be shown. These spectra revealed the plasma to be insufficiently ionized so as to produce inversions in H-like Al. Conditions were found to be appropriate for inversion in He- and Li-like Al, however, and evidence for amplification of the AlXI 105.7 {Angstrom} (5f-3d) and AlXII 88.9 (5f-3d) and 130.1 {Angstrom} (4f-3d) lines was seen. These results will be discussed in detail and related to other work regarding the discrepancies between expected and measured electron temperatures in plasmas of this type.
Date: November 1, 1990
Creator: Keane, C.J.; Eder, D.C.; MacGowan, B.J.; Matthews, D.L. & Whelan, D.A.
Partner: UNT Libraries Government Documents Department

Gain measurements at 5 nm in nickel-like ytterbium

Description: Soft x-ray gain has been demonstrated at 5.03 nm within a laser produced plasma of Ni-like ytterbium. Experiments will also be described with higher Z Ni-like ions which can produce even shorter wavelength x-ray laser transition. 3 refs.
Date: March 1, 1988
Creator: MacGowan, B.J.; Bourgade, J.L.; Combis, P.; Keane, C.J.; Louis-Jacquet, M.; Matthews, D.L. et al.
Partner: UNT Libraries Government Documents Department

Progress in understanding and improving X-ray lasers

Description: We discuss the use of a prepulse technique to achieve lasing in low-Z neon-like ions on the 3p {yields} 3s(J = 0 {yields} 1) transition. In neon-like titanium(Z=22), chromium(Z=24), iron(Z=26), nickel(Z=28), zinc(Z=30), and germanium(Z=32) this transition lases at 326, 285, 255, 231, 212 and 196 {Angstrom} respectively. We present results using this technique on selenium(Z=34) and show how the J = 0 {yields} 1 transition at 182 {Angstrom} suddenly becomes a strong line. The observation that the low-Z ions with odd Z have not lased lead us to investigate the potential impact of hyperfine splitting on the laser gain. In our experiments we measure the lineshape of the 3p {yields} 3s(J = 0 {yields} 1) transition in neon-like niobium and zirconium and observe a 28 m{Angstrom} splitting between the two largest hyperfine components in the niobium(Z=41) line at 145.9 in good agreement with theory. In zirconium(Z=40), no splitting is observed since the hyperfine effect is proportional to the nuclear moment, and the principal isotopes of zirconium have zero nuclear moment, as is typical for even-Z elements. Finally we discuss the use of low density foams for the laser target and present results which show lasing in zirconium aerogel with an initial density of 90 mg/cm{sup 3}.
Date: January 11, 1994
Creator: Nilsen, J.; Moreno, J. C.; Koch, J. A.; Scofield, J. H.; MacGowan, B. J. & DaSilva, L. B.
Partner: UNT Libraries Government Documents Department

Impact of observed hyperfine splitting on X-ray laser gain

Description: Line broadening mechanisms play an important role in determining the gain of X-ray laser transitions. Typically Doppler broadening is the primary mechanism which determines the linewidth of these transitions. However, the authors present cases where the hyperfine effect is the dominant line broadening mechanism. Studying laser lines, which tend to have gain narrowed linewidths, enables one to observe these dramatic hyperfine effects which would be difficult to observe in opacity or Stark broadened lines. In this work the authors report the observation of hyperfine splitting on an X-ray laser transition and discuss how hyperfine splitting has a major impact on the laser gain. In the experiments they measure the lineshape of the 3p {yields} 3s, J = 0 {yields} 1 transition in neon-like niobium and zirconium and observe a 28 m{angstrom} splitting between the two largest hyperfine components in the niobium(Z=41) line at 145.9{angstrom}, in good agreement with theory. In zirconium(Z=40), no splitting is observed since the hyperfine effect is proportional to the nuclear moment, and zirconium has zero nuclear moment, as is typical for even-Z elements. The hyperfine effect is shown to effect transitions which have a 2p{sub 1/2} vacancy in the closed neon-like core much more than those with a 2p{sub 3/2} vacancy. A comparison of the neon-like niobium laser spectrum with that of zirconium shows a dramatic reduction in the relative intensity of the niobium laser lines with the 2p{sub 1/2} vacancy. The authors also report the unusual behavior noticed recently in low-Z neon-like X-ray lasers in which ions with odd Z lase poorly, if at all, relative to ions with even Z. The hyperfine effect is shown to have a substantial impact on the gain of the low-Z and helps explain their poor performance.
Date: November 1, 1993
Creator: Nilsen, J.; Koch, J. A.; Scofield, J. H.; MacGowan, B. J.; Moreno, J. C. & Da Silva, L. B.
Partner: UNT Libraries Government Documents Department

Hyperfine splittings, prepulse technique, and other new results for collisional excitation neon-like x-ray lasers

Description: The observation of hyperfine splitting on an X-ray laser transition is presented and the impact on the laser gain is discussed. We measure the lineshape of the 3p {yields} 3s(J = 0 {yields} 1) transition in neon-like niobium and zirconium and observe a 28 m{Angstrom} splitting between the two largest hyperfine components in the niobium(Z=41) line at 145.9 {Angstrom}, in good agreement with theory. In zirconium(Z=40), no splitting is predicted or observed since the hyperfine effect is proportional to the nuclear moment and this is present primarily in elements with odd Z. The hyperfine splitting is used to explain why the low-Z ions with odd Z have not lased. We discuss the use of a prepulse technique to achieve lasing in low-Z neon-like ions from Z = 22 to 32 on the 3p {yields} 3s(J = 0 {yields} 1) transition with wavelengths from 326 to 196 {Angstrom}. Using this technique on selenium(Z--34) we show a large enhancement of the J = 0 {yields} 1 transition at 182 {Angstrom} . Using a series of short pulses to drive selenium we observe the 182 {Angstrom} line to completely dominate the spectra. In an effort to reduce the large density gradients associated with hydrodynamic expansion, we discuss the use of low density foams for the laser target and present results which show lasing in zirconium aerogel with an initial density of 20 mg/cm{sup 3}. Finally, we discuss recent double slab experiments with ruthenium(Z--44) targets in which we observe lasing at 117 and 118 {Angstrom} for the first time.
Date: June 1, 1994
Creator: Nilsen, J.; Moreno, J. C.; Koch, J. A.; Scofield, J. H.; MacGowan, B. J. & Da Silva, L. B.
Partner: UNT Libraries Government Documents Department

Development of short pulse soft x-ray lasers

Description: X-ray lasers with pulse duration shorter than 20 ps allow the possibility of imaging laser produced plasmas with {mu}m resolution. In addition, the high peak brightness of these new sources will allow us to study nonlinear optics in the xuv region. In this paper we will describe our efforts to produce collisionally pumped short pulse x-ray lasers. Initial results, which have produced {approximately} 45 ps (FWHM) x-ray lasers, using a double pulse irradiation technique are presented along with a discussion of the prospects for reducing the pulse width.
Date: February 1, 1993
Creator: Da Silva, L. B.; MacGowan, B. J.; Koch, J. A.; Mrowka, S.; Matthews, D. L.; Eder, D. et al.
Partner: UNT Libraries Government Documents Department