1
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Valdivia MP, Perez-Callejo G, Bouffetier V, Collins GW, Stoeckl C, Filkins T, Mileham C, Romanofsky M, Begishev IA, Theobald W, Klein SR, Schneider MK, Beg FN, Casner A, Stutman D. Current advances on Talbot-Lau x-ray imaging diagnostics for high energy density experiments (invited). THE REVIEW OF SCIENTIFIC INSTRUMENTS 2022; 93:115102. [PMID: 36461483 DOI: 10.1063/5.0101865] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/03/2022] [Accepted: 09/14/2022] [Indexed: 06/17/2023]
Abstract
Talbot-Lau x-ray interferometry is a refraction-based diagnostic that can map electron density gradients through phase-contrast methods. The Talbot-Lau x-ray deflectometry (TXD) diagnostics have been deployed in several high energy density experiments. To improve diagnostic performance, a monochromatic TXD was implemented on the Multi-Tera Watt (MTW) laser using 8 keV multilayer mirrors (Δθ/θ = 4.5%-5.6%). Copper foil and wire targets were irradiated at 1014-1015 W/cm2. Laser pulse length (∼10 to 80 ps) and backlighter target configurations were explored in the context of Moiré fringe contrast and spatial resolution. Foil and wire targets delivered increased contrast <30%. The best spatial resolution (<6 μm) was measured for foils irradiated 80° from the surface. Further TXD diagnostic capability enhancement was achieved through the development of advanced data postprocessing tools. The Talbot Interferometry Analysis (TIA) code enabled x-ray refraction measurements from the MTW monochromatic TXD. Additionally, phase, attenuation, and dark-field maps of an ablating x-pinch load were retrieved through TXD. The images show a dense wire core of ∼60 μm diameter surrounded by low-density material of ∼40 μm thickness with an outer diameter ratio of ∼2.3. Attenuation at 8 keV was measured at ∼20% for the dense core and ∼10% for the low-density material. Instrumental and experimental limitations for monochromatic TXD diagnostics are presented. Enhanced postprocessing capabilities enabled by TIA are demonstrated in the context of high-intensity laser and pulsed power experimental data analysis. Significant advances in TXD diagnostic capabilities are presented. These results inform future diagnostic technique upgrades that will improve the accuracy of plasma characterization through TXD.
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Affiliation(s)
- M P Valdivia
- Center for Energy Research, University of California San Diego, La Jolla, California 92093, USA
| | - G Perez-Callejo
- Departamento de Física Teórica, Atómica y Óptica, Universidad de Valladolid, 47011 Valladolid, Spain
| | - V Bouffetier
- European XFEL GmbH, Holzkoppel 4, 22869 Schenefeld, Germany
| | - G W Collins
- General Atomics, Inertial Fusion Technology, San Diego, California 92121, USA
| | - C Stoeckl
- Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623, USA
| | - T Filkins
- Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623, USA
| | - C Mileham
- Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623, USA
| | - M Romanofsky
- Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623, USA
| | - I A Begishev
- Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623, USA
| | - W Theobald
- Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623, USA
| | - S R Klein
- University of Michigan, Ann Arbor, Michigan 48109, USA
| | - M K Schneider
- Johns Hopkins University, Applied Physics Laboratory, Laurel, Maryland 20723, USA
| | - F N Beg
- Center for Energy Research, University of California San Diego, La Jolla, California 92093, USA
| | - A Casner
- CEA-CESTA, 15 Avenue des Sablières, CS 60001, 33116 Le Barp CEDEX, France
| | - D Stutman
- ELI-NP, Institute for Physics and Nuclear Engineering, Bucharest-Magurele 077125, Romania
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2
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Beier NF, Allison H, Efthimion P, Flippo KA, Gao L, Hansen SB, Hill K, Hollinger R, Logantha M, Musthafa Y, Nedbailo R, Senthilkumaran V, Shepherd R, Shlyaptsev VN, Song H, Wang S, Dollar F, Rocca JJ, Hussein AE. Homogeneous, Micron-Scale High-Energy-Density Matter Generated by Relativistic Laser-Solid Interactions. PHYSICAL REVIEW LETTERS 2022; 129:135001. [PMID: 36206410 DOI: 10.1103/physrevlett.129.135001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/02/2022] [Revised: 08/01/2022] [Accepted: 08/26/2022] [Indexed: 06/16/2023]
Abstract
Short-pulse, laser-solid interactions provide a unique platform for studying complex high-energy-density matter. We present the first demonstration of solid-density, micron-scale keV plasmas uniformly heated by a high-contrast, 400 nm wavelength laser at intensities up to 2×10^{21} W/cm^{2}. High-resolution spectral analysis of x-ray emission reveals uniform heating up to 3.0 keV over 1 μm depths. Particle-in-cell simulations indicate the production of a uniformly heated keV plasma to depths of 2 μm. The significant bulk heating and presence of highly ionized ions deep within the target are attributed to the few MeV hot electrons that become trapped and undergo refluxing within the target sheath fields. These conditions enabled the differentiation of atomic physics models of ionization potential depression in high-energy-density environments.
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Affiliation(s)
- N F Beier
- Department of Electrical and Computer Engineering, University of Alberta, Edmonton, Alberta T6G 2R3, Canada
- STROBE, NSF Science and Technology Center, University of California, Irvine, California 92617, USA
| | - H Allison
- STROBE, NSF Science and Technology Center, University of California, Irvine, California 92617, USA
| | - P Efthimion
- Princeton Plasma Physics Laboratory, Princeton, New Jersey 08536, USA
| | - K A Flippo
- Los Alamos National Laboratory, P.O. Box 1163, Los Alamos, New Mexico 87545, USA
| | - L Gao
- Princeton Plasma Physics Laboratory, Princeton, New Jersey 08536, USA
| | - S B Hansen
- Sandia National Laboratories, Albuquerque, New Mexico 87185, USA
| | - K Hill
- Princeton Plasma Physics Laboratory, Princeton, New Jersey 08536, USA
| | - R Hollinger
- Department of Electrical and Computer Engineering, Colorado State University, Fort Collins, Colorado 80521, USA
| | - M Logantha
- STROBE, NSF Science and Technology Center, University of California, Irvine, California 92617, USA
| | - Y Musthafa
- STROBE, NSF Science and Technology Center, University of California, Irvine, California 92617, USA
| | - R Nedbailo
- Department of Electrical and Computer Engineering, Colorado State University, Fort Collins, Colorado 80521, USA
| | - V Senthilkumaran
- Department of Electrical and Computer Engineering, University of Alberta, Edmonton, Alberta T6G 2R3, Canada
| | - R Shepherd
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - V N Shlyaptsev
- Department of Electrical and Computer Engineering, Colorado State University, Fort Collins, Colorado 80521, USA
| | - H Song
- Department of Electrical and Computer Engineering, Colorado State University, Fort Collins, Colorado 80521, USA
| | - S Wang
- Department of Electrical and Computer Engineering, Colorado State University, Fort Collins, Colorado 80521, USA
| | - F Dollar
- STROBE, NSF Science and Technology Center, University of California, Irvine, California 92617, USA
| | - J J Rocca
- Department of Electrical and Computer Engineering, Colorado State University, Fort Collins, Colorado 80521, USA
- Department of Physics, Colorado State University, Fort Collins, Colorado 80521, USA
| | - A E Hussein
- Department of Electrical and Computer Engineering, University of Alberta, Edmonton, Alberta T6G 2R3, Canada
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3
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Wang Y, Yin L, Wang S, Marconi MC, Dunn J, Gullikson E, Rocca JJ. Single-shot soft x-ray laser linewidth measurement using a grating interferometer. OPTICS LETTERS 2013; 38:5004-5007. [PMID: 24281495 DOI: 10.1364/ol.38.005004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
The linewidth of a 14.7 nm wavelength Ni-like Pd soft x-ray laser was measured in a single shot using a soft x-ray diffraction grating interferometer. The instrument uses the time delay introduced by the gratings across the beam to measure the temporal coherence. The spectral linewidth of the 4d1S0-4p1P1 Ni-like Pd lasing line was measured to be Δλ/λ=3×10(-5) from the Fourier transform of the fringe visibility. This single shot linewidth measurement technique provides a rapid and accurate way to determine the temporal coherence of soft x-ray lasers that can contribute to the development of femtosecond plasma-based soft x-ray lasers.
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4
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Liu Y, Fuchs HJ, Liu Z, Chen H, He S, Fu S, Kley EB, Tünnermann A. Investigation on the properties of a laminar grating as a soft x-ray beam splitter. APPLIED OPTICS 2010; 49:4450-4459. [PMID: 20697449 DOI: 10.1364/ao.49.004450] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Laminar-type gratings as soft x-ray beam splitters for interferometry are presented. Gold-coated grating beam splitters with 1000 lines/mm are designed for grazing incidence operation at 13.9 nm. They are routinely fabricated using electron beam lithography and ion etching techniques. The laminar grating is measured to have almost equal absolute efficiencies of about 20% in the zeroth and -1st orders, which enables a fringe visibility up to 0.99 in the interferometer. The discrepancy of the grating profiles between the optimized theoretical and the experimental results is analyzed according to the comparison of the optimized simulation results and the measurement realization of the grating efficiencies. By a precise control of the grating profile, the grating efficiency in the -1st order and the fringe visibility could be improved to 25% and 1, respectively.
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Affiliation(s)
- Ying Liu
- Institut für Angewandte Physik, Friedrich-Schiller-Universität Jena, Max-Wien-Platz 1, 07743 Jena, Germany.
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5
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Purvis MA, Grava J, Filevich J, Ryan DP, Moon SJ, Dunn J, Shlyaptsev VN, Rocca JJ. Collimation of dense plasma jets created by low-energy laser pulses and studied with soft x-ray laser interferometry. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2010; 81:036408. [PMID: 20365883 DOI: 10.1103/physreve.81.036408] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/23/2009] [Indexed: 05/29/2023]
Abstract
The physical mechanisms driving the collimation of dense plasma jets created by low-energy ( approximately 0.6 J) laser pulse irradiation of triangular grooves were studied for different target materials using soft-x-ray interferometry and hydrodynamic code simulations. The degree of collimation of jets created by irradiating C, Al, Cu, and Mo targets at intensities of I=1x10(12) W cm(-2) with 120 ps laser pulses was observed to increase significantly with the atomic number. Radiation cooling is found to be the cause of the increased collimation, while the main effect of the increase in mass is to slow the jet evolution.
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Affiliation(s)
- Michael A Purvis
- Department of Electrical and Computer Engineering, Colorado State University, NSF ERC for Extreme Ultraviolet Science and Technology, Fort Collins, Colorado 80523, USA
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6
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Liu J, Zhang XC. Terahertz-radiation-enhanced emission of fluorescence from gas plasma. PHYSICAL REVIEW LETTERS 2009; 103:235002. [PMID: 20366153 DOI: 10.1103/physrevlett.103.235002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/23/2009] [Indexed: 05/29/2023]
Abstract
We report the study of femtosecond laser-induced air plasma fluorescence under the illumination of terahertz (THz) pulses. Semiclassical modeling and experimental verification indicate that time-resolved THz radiation-enhanced emission of fluorescence is dominated by the electron kinetics and the electron-impact excitation of gas molecules or ions. We demonstrate that the temporal waveform of the THz field could be retrieved from the transient enhanced fluorescence, making omnidirectional, coherent detection available for THz time-domain spectroscopy.
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Affiliation(s)
- Jingle Liu
- Center for Terahertz Research, Rensselaer Polytechnic Institute, Troy, New York 12180, USA
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7
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Dobosz S, Stabile H, Tortora A, Monot P, Réau F, Bougeard M, Merdji H, Carré B, Martin P, Joyeux D, Phalippou D, Delmotte F, Gautier J, Mercier R. Internal frequency conversion extreme ultraviolet interferometer using mutual coherence properties of two high-order-harmonic sources. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2009; 80:113102. [PMID: 19947712 DOI: 10.1063/1.3257676] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
We report on an innovative two-dimensional imaging extreme ultraviolet (XUV) interferometer operating at 32 nm based on the mutual coherence of two laser high order harmonics (HOH) sources, separately generated in gas. We give the first evidence that the two mutually coherent HOH sources can be produced in two independent spatially separated gas jets, allowing for probing centimeter-sized objects. A magnification factor of 10 leads to a micron resolution associated with a subpicosecond temporal resolution. Single shot interferograms with a fringe visibility better than 30% are routinely produced. As a test of the XUV interferometer, we measure a maximum electronic density of 3x10(20) cm(-3) 1.1 ns after the creation of a plasma on aluminum target.
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Affiliation(s)
- S Dobosz
- CEA, IRAMIS, Service des Photons Atomes et Molécules, F-91191 Gif- sur-Yvette, France.
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8
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Zastrau U, Fortmann C, Fäustlin RR, Cao LF, Döppner T, Düsterer S, Glenzer SH, Gregori G, Laarmann T, Lee HJ, Przystawik A, Radcliffe P, Reinholz H, Röpke G, Thiele R, Tiggesbäumker J, Truong NX, Toleikis S, Uschmann I, Wierling A, Tschentscher T, Förster E, Redmer R. Bremsstrahlung and line spectroscopy of warm dense aluminum plasma heated by xuv free-electron-laser radiation. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2008; 78:066406. [PMID: 19256961 DOI: 10.1103/physreve.78.066406] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/25/2008] [Revised: 10/20/2008] [Indexed: 05/27/2023]
Abstract
We report the creation of solid-density aluminum plasma using free-electron laser (FEL) radiation at 13.5nm wavelength. Ultrashort pulses were focused on a bulk Al target, yielding an intensity of 2x10;{14}Wcm;{2} . The radiation emitted from the plasma was measured using an xuv spectrometer. Bremsstrahlung and line intensity ratios yield consistent electron temperatures of about 38eV , supported by radiation hydrodynamics simulations. This shows that xuv FELs heat up plasmas volumetrically and homogeneously at warm-dense-matter conditions, which are accurately characterized by xuv spectroscopy.
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Affiliation(s)
- U Zastrau
- Institut für Optik und Quantenelektronik, Friedrich-Schiller-Universität, Max-Wien Platz 1, 07743 Jena, Germany.
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9
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Liu Y, Tan X, Liu Z, Xu X, Hong Y, Fu S. Soft X-ray holographic grating beam splitter including a double frequency grating for interferometer pre-alignment. OPTICS EXPRESS 2008; 16:14761-14770. [PMID: 18795013 DOI: 10.1364/oe.16.014761] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Grating beam splitters have been fabricated for soft X-ray Mach- Zehnder interferometer using holographic interference lithography. The grating beam splitter consists of two gratings, one works at X-ray laser wavelength of 13.9 nm with the spatial frequency of 1000 lines/mm as the operation grating, the other works at visible wavelength of 632.8 nm for pre-aligning the X-ray interferometer with the spatial frequency of 22 lines/mm as the pre-alignment grating. The two gratings lie vertically on the same substrate. The main feature of the beam splitter is the use of low-spatial- frequency beat grating of a holographic double frequency grating as the pre-alignment grating of the X-ray interferometer. The grating line parallelism between the two gratings can be judged by observing the diffraction patterns of the pre-alignment grating directly.
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Affiliation(s)
- Ying Liu
- National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei, People's Republic of China.
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10
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Grava J, Purvis MA, Filevich J, Marconi MC, Rocca JJ, Dunn J, Moon SJ, Shlyaptsev VN. Dynamics of a dense laboratory plasma jet investigated using soft x-ray laser interferometry. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2008; 78:016403. [PMID: 18764063 DOI: 10.1103/physreve.78.016403] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/02/2008] [Indexed: 05/26/2023]
Abstract
The formation and evolution of a collisional aluminum plasma jet created by optical laser irradiation of triangular grooves with pulses of 120ps duration at an intensity of 1x10(12)W cm(-2) were studied with experiments and simulations. Series of high-contrast soft x-ray laser interferograms obtained with a 46.9nm laser mapped the plasma density evolution of an initially narrow plasma jet that expands along the symmetry plane and evolves into a broader plasma plume with significant side lobes. Two-dimensional simulations performed using the radiation hydrodynamic code HYDRA reveal that the jet formation is initiated by accelerated material ablated from the vertex and is augmented by the continual sequential arrival of wall material along the symmetry plane, where it collides and is redirected outward. Radiative cooling is identified as an important process in maintaining the collimation of the jet. These results demonstrate that well collimated collisional plasma jets with parameters in a range of interest can be generated with low-energy laser pulses (<1J) , opening the possibility of studying relevant plasma phenomena in a small laboratory setting.
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Affiliation(s)
- Jonathan Grava
- NSF ERC for Extreme Ultraviolet Science and Technology, and Department of Electrical and Computer Engineering, Colorado State University, Fort Collins, Colorado 80523, USA
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11
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Purvis M, Grava J, Filevich J, Marconi MC, Dunn J, Moon SJ, Shlyaptsev VN, Jankowska E, Rocca JJ. Dynamics of converging laser-created plasmas in semicylindrical cavities studied using soft x-ray laser interferometry. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2007; 76:046402. [PMID: 17995117 DOI: 10.1103/physreve.76.046402] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/30/2007] [Indexed: 05/25/2023]
Abstract
The evolution of dense aluminum and carbon plasmas produced by laser irradiation of 500-microm -diam semicylindrical targets was studied using soft x-ray laser interferometry. Plasmas created heating the cavity walls with 120-ps -duration optical laser pulses of approximately 1x10;{12}Wcm;{-2} peak intensity were observed to expand and converge on axis to form a localized high-density plasma region. Electron density maps were measured using a 46.9-nm -wavelength tabletop capillary discharge soft x-ray laser probe in combination with an amplitude division interferometer based on diffraction gratings. The measurements show that the plasma density on axis exceeds 1x10;{20}cm;{-3} . The electron density profiles are compared with simulations conducted using the hydrodynamic code HYDRA, which show that the abrupt density increase near the axis is dominantly caused by the convergence of plasma generated at the bottom of the groove during laser irradiation.
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Affiliation(s)
- Mike Purvis
- Department of Electrical and Computer Engineering, Colorado State University, Fort Collins, Colorado 80523, USA
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12
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Tobey RI, Siemens ME, Cohen O, Murnane MM, Kapteyn HC, Nelson KA. Ultrafast extreme ultraviolet holography: dynamic monitoring of surface deformation. OPTICS LETTERS 2007; 32:286-8. [PMID: 17215947 DOI: 10.1364/ol.32.000286] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
We demonstrate femtosecond time-resolved dynamic Gabor holography using highly coherent extreme ultraviolet light generated by high harmonic upconversion of a femtosecond laser. By reflecting this light from an impulsively heated surface, we implement a simple and robust single-reflection geometry for phase-sensitive holographic detection at extreme UV wavelengths. Using this setup, we study the ultrafast deformation and subsequent acoustic oscillations within a thin metal film. These measurements exhibit subpicometer spatial sensitivity in the vertical dimension.
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Affiliation(s)
- Ra'anan I Tobey
- Department of Physics and JILA, University of Colorado and NIST, and NSF Engineering Research Center in Extreme Ultraviolet Science and Technology, Boulder, Colorado 80309-0440, USA.
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13
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Filevich J, Grava J, Purvis M, Marconi MC, Rocca JJ, Nilsen J, Dunn J, Johnson WR. Prediction and observation of tin and silver plasmas with index of refraction greater than one in the soft x-ray range. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2006; 74:016404. [PMID: 16907195 DOI: 10.1103/physreve.74.016404] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/23/2006] [Revised: 05/18/2006] [Indexed: 05/11/2023]
Abstract
We present the calculated prediction and the experimental confirmation that doubly ionized Ag and Sn plasmas can have an index of refraction greater than one for soft x-ray wavelengths. Interferometry experiments conducted using a capillary discharge soft x-ray laser operating at a wavelength of confirm that in few times ionized laser-created plasmas of these elements the anomalous dispersion from bound electrons can dominate the free electron contribution, making the index of refraction greater than one. The results confirm that bound electrons can strongly influence the index of refraction of numerous plasmas over a broad range of soft x-ray wavelengths confirming recent observations. The understanding of index of refraction at short wavelengths will become even more essential during the next decade as x-ray free electron lasers will become available to probe a wider variety of plasmas at higher densities and shorter wavelengths.
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Affiliation(s)
- Jorge Filevich
- Department of Physics, National Science Foundation ERC for Extreme Ultraviolet Science and Technology, Colorado State University, Fort Collins, CO 80523, USA
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14
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Wang X, Zhai H, Mu G. Pulsed digital holography system recording ultrafast process of the femtosecond order. OPTICS LETTERS 2006; 31:1636-8. [PMID: 16688245 DOI: 10.1364/ol.31.001636] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
We report, for the first time to our knowledge, a pulsed digital microholographic system with spatial angular multiplexing for recording the ultrafast process of the femtosecond order. The optimized design of the two sets of subpulse-train generators in this system makes it possible to implement a digital holographic recording with spatial angular multiplexing of a frame interval of the femtosecond order, while keeping the incident angle of the object beams unchanged. Three pairs of amplitude and phase images from the same view angle digitally reconstructed by the system demonstrated the ultrafast dynamic process of laser-induced ionization of ambient air at a wavelength of 800 nm, with a time resolution of 50 fs and a frame interval of 300 fs.
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Affiliation(s)
- Xiaolei Wang
- Institute of Modern Optics, Key Laboratory of Optoelectronic Information Science & Technology, Ministry of Education of China, China
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15
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Filevich J, Rocca JJ, Marconi MC, Moon SJ, Nilsen J, Scofield JH, Dunn J, Smith RF, Keenan R, Hunter JR, Shlyaptsev VN. Observation of a multiply ionized plasma with index of refraction greater than one. PHYSICAL REVIEW LETTERS 2005; 94:035005. [PMID: 15698278 DOI: 10.1103/physrevlett.94.035005] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2004] [Indexed: 05/24/2023]
Abstract
We present clear experimental evidence showing that the contribution of bound electrons can dominate the index of refraction of laser-created plasmas at soft x-ray wavelengths. We report anomalous fringe shifts in soft x-ray laser interferograms of Al laser-created plasmas. The comparison of measured and simulated interferograms shows that this results from the dominant contribution of low charge ions to the index of refraction. This usually neglected bound electron contribution can affect the propagation of soft x-ray radiation in plasmas and the interferometric diagnostics of plasmas for many elements.
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Affiliation(s)
- J Filevich
- NSF ERC for Extreme Ultraviolet Science and Technology and Department of Electrical and Computer Engineering, Colorado State University, Fort Collins, Colorado 80523, USA
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