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Dulat A, Aparajit C, Choudhary A, Lad AD, Ved YM, Paradkar BS, Ravindra Kumar G. Subpicosecond pre-plasma dynamics of a high contrast, ultraintense laser-solid target interaction. OPTICS LETTERS 2022; 47:5684-5687. [PMID: 37219303 DOI: 10.1364/ol.461452] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/19/2022] [Accepted: 10/03/2022] [Indexed: 05/24/2023]
Abstract
Using the spectral interferometry technique, we measured subpicosecond time-resolved pre-plasma scale lengths and early expansion (<12 ps) of the plasma produced by a high intensity (6 × 1018 W/cm2) pulse with high contrast (109). We measured pre-plasma scale lengths in the range of 3-20 nm, before the arrival of the peak of the femtosecond pulse. This measurement plays a crucial role in understanding the mechanism of laser coupling its energy to hot electrons and is hence important for laser-driven ion acceleration and the fast ignition approach to fusion.
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2
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Lin J, Batson T, Nees J, Thomas AGR, Krushelnick K. Towards isolated attosecond electron bunches using ultrashort-pulse laser-solid interactions. Sci Rep 2020; 10:18354. [PMID: 33110187 PMCID: PMC7591899 DOI: 10.1038/s41598-020-75418-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2020] [Accepted: 10/12/2020] [Indexed: 11/09/2022] Open
Abstract
We investigate MeV-level attosecond electron bunches from ultrashort-pulse laser-solid interactions through similarities between experimental and simulated electron energy spectra. We show measurements of the bunch duration and temporal structure from particle-in-cell simulations. The experimental observation of such bunches favors specular reflection direction when focusing the laser pulse onto a subwavelength boundary of thick overdense plasmas at grazing incidence. Particle-in-cell simulation further reveals that the attosecond duration is a result of ultra-thin ([Formula: see text]tenth of a micron) gaps of zero electromagnetic energy density in the modulated reflected radiation, while the bunching (locally peaked electron concentration) comes from the highly-directional electron angular distribution acquired by the electrons in a grazing incidence setup. To isolate a single electron bunch, we perform simulations using 1-cycle laser pulses and analyze the effect of carrier-envelop phase with particle tracking. The duration of the electron bunch can be further decreased by increasing the laser intensity and the focal spot size, while its direction can be changed by tuning the preplasma density gradient.
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Affiliation(s)
- Jinpu Lin
- Center for Ultrafast Optical Science, University of Michigan, Ann Arbor, MI, 48109, USA.
| | - Thomas Batson
- Center for Ultrafast Optical Science, University of Michigan, Ann Arbor, MI, 48109, USA
| | - John Nees
- Center for Ultrafast Optical Science, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Alexander G R Thomas
- Center for Ultrafast Optical Science, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Karl Krushelnick
- Center for Ultrafast Optical Science, University of Michigan, Ann Arbor, MI, 48109, USA
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3
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Linear discriminant analysis based predator-prey analysis of hot electron effects on the X-pinch plasma produced K-shell Aluminum spectra. Sci Rep 2019; 9:11867. [PMID: 31413271 PMCID: PMC6694104 DOI: 10.1038/s41598-019-47997-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2017] [Accepted: 07/11/2019] [Indexed: 11/25/2022] Open
Abstract
In this study, Linear Discriminant Analysis (LDA) is applied to investigate the electron beam effects on the X-pinch produced K-shell Aluminum plasma. The radiating plasma is produced by the explosion of two 25-μm Al wires on a compact L-C (40 kV, 200 kA and 200 ns) generator, and the time integrated spectra are recorded using de Broglie spectrographs. The ion and electron oscillations of K-shell Al plasma are extracted using LDA of spectral database of non-LTE K-shell Al model. A three dimensional representation of LDA shows that the presence of electron beam exhibits outward spirals of Langmuir turbulence and the center region of the spirals recieves lower electron temperatures of 50–100 eV. These spirals then are modeled by logistic growth of predator-prey model. This modeling suggests that the ions (LD1: most dominant eigenvector of LDA) and electrons (LD2: second most dominant eigenvector of LDA) represent the predators and preys, respectively. Besides, addition of electron beams transforms evanescent oscillations to the standing ones.
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Iwata N, Kojima S, Sentoku Y, Hata M, Mima K. Plasma density limits for hole boring by intense laser pulses. Nat Commun 2018; 9:623. [PMID: 29434203 PMCID: PMC5809619 DOI: 10.1038/s41467-018-02829-5] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2017] [Accepted: 01/03/2018] [Indexed: 11/09/2022] Open
Abstract
High-power lasers in the relativistic intensity regime with multi-picosecond pulse durations are available in many laboratories around the world. Laser pulses at these intensities reach giga-bar level radiation pressures, which can push the plasma critical surface where laser light is reflected. This process is referred to as the laser hole boring (HB), which is critical for plasma heating, hence essential for laser-based applications. Here we derive the limit density for HB, which is the maximum plasma density the laser can reach, as a function of laser intensity. The time scale for when the laser pulse reaches the limit density is also derived. These theories are confirmed by a series of particle-in-cell simulations. After reaching the limit density, the plasma starts to blowout back toward the laser, and is accompanied by copious superthermal electrons; therefore, the electron energy can be determined by varying the laser pulse length.
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Affiliation(s)
- Natsumi Iwata
- Institute of Laser Engineering, Osaka University, 2-6 Yamadaoka, Suita, Osaka, 565-0871, Japan.
| | - Sadaoki Kojima
- Institute of Laser Engineering, Osaka University, 2-6 Yamadaoka, Suita, Osaka, 565-0871, Japan
- Advanced Research Center for Beam Science, Institute for Chemical Research, Kyoto University, Gokasho, Uji, Kyoto, 611-0011, Japan
| | - Yasuhiko Sentoku
- Institute of Laser Engineering, Osaka University, 2-6 Yamadaoka, Suita, Osaka, 565-0871, Japan
| | - Masayasu Hata
- Institute of Laser Engineering, Osaka University, 2-6 Yamadaoka, Suita, Osaka, 565-0871, Japan
| | - Kunioki Mima
- The Graduate School for the Creation of New Photon Industries, 1955-1 Kurematsu, Nishiku, Hamamatsu, Shizuoka, 141-1201, Japan
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5
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Contrasting levels of absorption of intense femtosecond laser pulses by solids. Sci Rep 2015; 5:17870. [PMID: 26648399 PMCID: PMC4673463 DOI: 10.1038/srep17870] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2015] [Accepted: 11/05/2015] [Indexed: 11/08/2022] Open
Abstract
The absorption of ultraintense, femtosecond laser pulses by a solid unleashes relativistic electrons, thereby creating a regime of relativistic optics. This has enabled exciting applications of relativistic particle beams and coherent X-ray radiation, and fundamental leaps in high energy density science and laboratory astrophysics. Obviously, central to these possibilities lies the basic problem of understanding and if possible, manipulating laser absorption. Surprisingly, the absorption of intense light largely remains an open question, despite the extensive variations in target and laser pulse structures. Moreover, there are only few experimental measurements of laser absorption carried out under very limited parameter ranges. Here we present an extensive investigation of absorption of intense 30 femtosecond laser pulses by solid metal targets. The study, performed under varying laser intensity and contrast ratio over four orders of magnitude, reveals a significant and non-intuitive dependence on these parameters. For contrast ratio of 10−9 and intensity of 2 × 1019 W cm−2, three observations are revealed: preferential acceleration of electrons along the laser axis, a ponderomotive scaling of electron temperature, and red shifting of emitted second-harmonic. These point towards the role of J × B absorption mechanism at relativistic intensity. The experimental results are supported by particle-in-cell simulations.
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6
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Levy MC, Wilks SC, Tabak M, Libby SB, Baring MG. Petawatt laser absorption bounded. Nat Commun 2014; 5:4149. [PMID: 24938656 PMCID: PMC4083416 DOI: 10.1038/ncomms5149] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2014] [Accepted: 05/16/2014] [Indexed: 11/09/2022] Open
Abstract
The interaction of petawatt (10(15) W) lasers with solid matter forms the basis for advanced scientific applications such as table-top particle accelerators, ultrafast imaging systems and laser fusion. Key metrics for these applications relate to absorption, yet conditions in this regime are so nonlinear that it is often impossible to know the fraction of absorbed light f, and even the range of f is unknown. Here using a relativistic Rankine-Hugoniot-like analysis, we show for the first time that f exhibits a theoretical maximum and minimum. These bounds constrain nonlinear absorption mechanisms across the petawatt regime, forbidding high absorption values at low laser power and low absorption values at high laser power. For applications needing to circumvent the absorption bounds, these results will accelerate a shift from solid targets, towards structured and multilayer targets, and lead the development of new materials.
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Affiliation(s)
- Matthew C. Levy
- Department of Physics and Astronomy, Rice University, Houston, Texas 77005, USA
- Lawrence Livermore National Laboratory, Livermore, California 94551, USA
| | - Scott C. Wilks
- Lawrence Livermore National Laboratory, Livermore, California 94551, USA
| | - Max Tabak
- Lawrence Livermore National Laboratory, Livermore, California 94551, USA
| | - Stephen B. Libby
- Lawrence Livermore National Laboratory, Livermore, California 94551, USA
| | - Matthew G. Baring
- Department of Physics and Astronomy, Rice University, Houston, Texas 77005, USA
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7
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Héron A, Adam JC. 2D PIC simulations of collisional transport of relativistic electrons in dense plasma. EPJ WEB OF CONFERENCES 2013. [DOI: 10.1051/epjconf/20135917015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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8
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Ping Y, Kemp AJ, Divol L, Key MH, Patel PK, Akli KU, Beg FN, Chawla S, Chen CD, Freeman RR, Hey D, Higginson DP, Jarrott LC, Kemp GE, Link A, McLean HS, Sawada H, Stephens RB, Turnbull D, Westover B, Wilks SC. Dynamics of relativistic laser-plasma interaction on solid targets. PHYSICAL REVIEW LETTERS 2012; 109:145006. [PMID: 23083255 DOI: 10.1103/physrevlett.109.145006] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/06/2011] [Indexed: 06/01/2023]
Abstract
A novel time-resolved diagnostic is used to record the critical surface motion during picosecond-scale relativistic laser interaction with a solid target. Single-shot measurements of the specular light show a redshift decreasing with time during the interaction, corresponding to a slowing-down of the hole boring process into overdense plasma. On-shot full characterization of the laser pulse enables simulations of the experiment without any free parameters. Two-dimensional particle-in-cell simulations yield redshifts that agree with the data, and support a simple explanation of the slowing-down of the critical surface based on momentum conservation between ions and reflected laser light.
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Affiliation(s)
- Y Ping
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
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9
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Kluge T, Cowan T, Debus A, Schramm U, Zeil K, Bussmann M. Electron temperature scaling in laser interaction with solids. PHYSICAL REVIEW LETTERS 2011; 107:205003. [PMID: 22181740 DOI: 10.1103/physrevlett.107.205003] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/27/2011] [Indexed: 05/31/2023]
Abstract
A precise knowledge of the temperature and number of hot electrons generated in the interaction of short-pulse high-intensity lasers with solids is crucial for harnessing the energy of a laser pulse in applications such as laser-driven ion acceleration or fast ignition. Nevertheless, present scaling laws tend to overestimate the hot electron temperature when compared to experiment and simulations. We present a novel approach that is based on a weighted average of the kinetic energy of an ensemble of electrons. We find that the scaling of electron energy with laser intensity can be derived from a general Lorentz invariant electron distribution ansatz that does not rely on a specific model of energy absorption. The scaling derived is in perfect agreement with simulation results and clearly follows the trend seen in recent experiments, especially at high laser intensities where other scalings fail to describe the simulations accurately.
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Affiliation(s)
- T Kluge
- Helmholtz-Zentrum Dresden-Rossendorf e.V., Germany.
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10
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Zhang Z, Nishikino M, Nishimura H, Kawachi T, Pirozhkov AS, Sagisaka A, Orimo S, Ogura K, Yogo A, Okano Y, Ohshima S, Fujioka S, Kiriyama H, Kondo K, Shimomura T, Kanazawa S. Efficient multi-keV x-ray generation from a high-Z target irradiated with a clean ultra-short laser pulse. OPTICS EXPRESS 2011; 19:4560-4565. [PMID: 21369288 DOI: 10.1364/oe.19.004560] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Kα line emissions from Mo and Ag plates were experimentally studied using clean, ultrahigh-intensity femtosecond laser pulses. The absolute yields of Kα x-rays at 17 keV from Mo and 22 keV from Ag were measured as a function of the laser pulse contrast ratio and irradiation intensity. Significantly enhanced Kα yields were obtained for both Mo and Ag by employing high contrast ratios and irradiances. Conversion efficiencies of 4.28×10⁻⁵/sr for Mo and 4.84×10⁻⁵/sr for Ag, the highest values obtained to date, were demonstrated with contrast ratios in the range 10⁻¹⁰ to 10⁻¹¹.
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Affiliation(s)
- Z Zhang
- Institute of Laser Engineering, Osaka University, Osaka, Japan.
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11
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Nilson PM, Solodov AA, Myatt JF, Theobald W, Jaanimagi PA, Gao L, Stoeckl C, Craxton RS, Delettrez JA, Yaakobi B, Zuegel JD, Kruschwitz BE, Dorrer C, Kelly JH, Akli KU, Patel PK, Mackinnon AJ, Betti R, Sangster TC, Meyerhofer DD. Scaling hot-electron generation to high-power, kilojoule-class laser-solid interactions. PHYSICAL REVIEW LETTERS 2010; 105:235001. [PMID: 21231472 DOI: 10.1103/physrevlett.105.235001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/10/2009] [Revised: 09/08/2010] [Indexed: 05/30/2023]
Abstract
Thin-foil targets were irradiated with high-power (1 ≤ P(L) ≤ 210 TW), 10-ps pulses focused to intensities of I>10(18) W/cm(2) and studied with K-photon spectroscopy. Comparing the energy emitted in K photons to target-heating calculations shows a laser-energy-coupling efficiency to hot electrons of η(L-e) = 20 ± 10%. Time-resolved x-ray emission measurements suggest that laser energy is coupled to hot electrons over the entire duration of the incident laser drive. Comparison of the K-photon emission data to previous data at similar laser intensities shows that η(L-e) is independent of laser-pulse duration from 1 ≤ τ(p) ≤ 10 ps.
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Affiliation(s)
- P M Nilson
- Fusion Science Center for Extreme States of Matter and Fast Ignition Physics, University of Rochester, Rochester, New York, USA
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12
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Ramakrishna B, Kar S, Robinson APL, Adams DJ, Markey K, Quinn MN, Yuan XH, McKenna P, Lancaster KL, Green JS, Scott RHH, Norreys PA, Schreiber J, Zepf M. Laser-driven fast electron collimation in targets with resistivity boundary. PHYSICAL REVIEW LETTERS 2010; 105:135001. [PMID: 21230778 DOI: 10.1103/physrevlett.105.135001] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/25/2009] [Indexed: 05/30/2023]
Abstract
We demonstrate experimentally that the relativistic electron flow in a dense plasma can be efficiently confined and guided in targets exhibiting a high-resistivity-core-low-resistivity-cladding structure analogous to optical waveguides. The relativistic electron beam is shown to be confined to an area of the order of the core diameter (50 μm), which has the potential to substantially enhance the coupling efficiency of electrons to the compressed fusion fuel in the Fast Ignitor fusion in full-scale fusion experiments.
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Affiliation(s)
- B Ramakrishna
- School of Mathematics and Physics, Queen's University of Belfast, Belfast, UK
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13
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Kemp AJ, Sentoku Y, Tabak M. Hot-electron energy coupling in ultraintense laser-matter interaction. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2009; 79:066406. [PMID: 19658611 DOI: 10.1103/physreve.79.066406] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/12/2009] [Indexed: 05/28/2023]
Abstract
We investigate the hydrodynamic response of plasma gradients during the interaction with ultraintense energetic laser pulses using kinetic particle simulations. Energetic laser pulses are capable of compressing preformed plasma gradients over short times, while accelerating low-density plasma backward. As light is absorbed on a steepened interface, hot-electron temperature and coupling efficiency drop below the ponderomotive scaling and we are left with an absorption mechanism that strongly relies on the electrostatic potential caused by low-density preformed plasma. We describe this process, discuss properties of the resulting electron spectra and identify the parameter regime where strong compression occurs. Finally, we discuss implications for fast ignition and other applications.
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Affiliation(s)
- A J Kemp
- Lawrence Livermore National Laboratory, Livermore, CA 94551, USA
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14
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Elberson LN, Ping Y, Shepherd RL, Patel PK, Mackinnon AJ, Hill WT. A picosecond time-resolved electron energy spectrometer based on Cerenkov radiation. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2009; 80:023302. [PMID: 19256640 DOI: 10.1063/1.3080555] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
The energy spectrum of relativistic electrons is an important characterization of high intensity laser-matter interactions. We present a technique that utilizes Cerenkov radiation to measure the time-resolved energy distribution of electrons. Electrons escaping from targets irradiated by high-intensity laser pulses were measured, demonstrating the feasibility of such a novel diagnostic. Limitations on the time resolution of this diagnostic are also discussed.
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Affiliation(s)
- Lee N Elberson
- Institute for Physical Science and Technology, University of Maryland, College Park, Maryland 20742, USA
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15
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MacPhee AG, Akli KU, Beg FN, Chen CD, Chen H, Clarke R, Hey DS, Freeman RR, Kemp AJ, Key MH, King JA, Le Pape S, Link A, Ma TY, Nakamura H, Offermann DT, Ovchinnikov VM, Patel PK, Phillips TW, Stephens RB, Town R, Tsui YY, Wei MS, Van Woerkom LD, Mackinnon AJ. Diagnostics for fast ignition science (invited). THE REVIEW OF SCIENTIFIC INSTRUMENTS 2008; 79:10F302. [PMID: 19044615 DOI: 10.1063/1.2978199] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
The ignition concept for electron fast ignition inertial confinement fusion requires sufficient energy be transferred from an approximately 20 ps laser pulse to the compressed fuel via approximately MeV electrons. We have assembled a suite of diagnostics to characterize such transfer, simultaneously fielding absolutely calibrated extreme ultraviolet multilayer imagers at 68 and 256 eV; spherically bent crystal imagers at 4.5 and 8 keV; multi-keV crystal spectrometers; MeV x-ray bremmstrahlung, electron and proton spectrometers (along the same line of sight), and a picosecond optical probe interferometer. These diagnostics allow careful measurement of energy transport and deposition during and following the laser-plasma interactions at extremely high intensities in both planar and conical targets. Together with accurate on-shot laser focal spot and prepulse characterization, these measurements are yielding new insights into energy coupling and are providing critical data for validating numerical particle-in-cell (PIC) and hybrid PIC simulation codes in an area crucial for fast ignition and other applications. Novel aspects of these diagnostics and how they are combined to extract quantitative data on ultrahigh intensity laser-plasma interactions are discussed.
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Affiliation(s)
- A G MacPhee
- Lawrence Livermore National Laboratory, Livermore, California 94551, USA.
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