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Gong T, Habara H, Sumioka K, Yoshimoto M, Hayashi Y, Kawazu S, Otsuki T, Matsumoto T, Minami T, Abe K, Aizawa K, Enmei Y, Fujita Y, Ikegami A, Makiyama H, Okazaki K, Okida K, Tsukamoto T, Arikawa Y, Fujioka S, Iwasa Y, Lee S, Nagatomo H, Shiraga H, Yamanoi K, Wei MS, Tanaka KA. Direct observation of imploded core heating via fast electrons with super-penetration scheme. Nat Commun 2019; 10:5614. [PMID: 31819056 PMCID: PMC6901506 DOI: 10.1038/s41467-019-13574-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2019] [Accepted: 11/08/2019] [Indexed: 11/09/2022] Open
Abstract
Fast ignition (FI) is a promising approach for high-energy-gain inertial confinement fusion in the laboratory. To achieve ignition, the energy of a short-pulse laser is required to be delivered efficiently to the pre-compressed fuel core via a high-energy electron beam. Therefore, understanding the transport and energy deposition of this electron beam inside the pre-compressed core is the key for FI. Here we report on the direct observation of the electron beam transport and deposition in a compressed core through the stimulated Cu Kα emission in the super-penetration scheme. Simulations reproducing the experimental measurements indicate that, at the time of peak compression, about 1% of the short-pulse energy is coupled to a relatively low-density core with a radius of 70 μm. Analysis with the support of 2D particle-in-cell simulations uncovers the key factors improving this coupling efficiency. Our findings are of critical importance for optimizing FI experiments in a super-penetration scheme.
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Affiliation(s)
- T Gong
- Graduate School of Engineering, Osaka University, 2-1 Yamada-oka, Suita, Osaka, 565-0871, Japan.,Laser Fusion Research Center, China Academy of Engineering Physics, Mianyang, Sichuan, 621900, People's Republic of China
| | - H Habara
- Graduate School of Engineering, Osaka University, 2-1 Yamada-oka, Suita, Osaka, 565-0871, Japan.
| | - K Sumioka
- Graduate School of Engineering, Osaka University, 2-1 Yamada-oka, Suita, Osaka, 565-0871, Japan
| | - M Yoshimoto
- Graduate School of Engineering, Osaka University, 2-1 Yamada-oka, Suita, Osaka, 565-0871, Japan
| | - Y Hayashi
- Graduate School of Engineering, Osaka University, 2-1 Yamada-oka, Suita, Osaka, 565-0871, Japan
| | - S Kawazu
- Graduate School of Engineering, Osaka University, 2-1 Yamada-oka, Suita, Osaka, 565-0871, Japan
| | - T Otsuki
- Graduate School of Engineering, Osaka University, 2-1 Yamada-oka, Suita, Osaka, 565-0871, Japan
| | - T Matsumoto
- Graduate School of Engineering, Osaka University, 2-1 Yamada-oka, Suita, Osaka, 565-0871, Japan
| | - T Minami
- Graduate School of Engineering, Osaka University, 2-1 Yamada-oka, Suita, Osaka, 565-0871, Japan
| | - K Abe
- Graduate School of Engineering, Osaka University, 2-1 Yamada-oka, Suita, Osaka, 565-0871, Japan
| | - K Aizawa
- Graduate School of Engineering, Osaka University, 2-1 Yamada-oka, Suita, Osaka, 565-0871, Japan
| | - Y Enmei
- Graduate School of Engineering, Osaka University, 2-1 Yamada-oka, Suita, Osaka, 565-0871, Japan
| | - Y Fujita
- Graduate School of Engineering, Osaka University, 2-1 Yamada-oka, Suita, Osaka, 565-0871, Japan
| | - A Ikegami
- Graduate School of Engineering, Osaka University, 2-1 Yamada-oka, Suita, Osaka, 565-0871, Japan
| | - H Makiyama
- Graduate School of Engineering, Osaka University, 2-1 Yamada-oka, Suita, Osaka, 565-0871, Japan
| | - K Okazaki
- Graduate School of Engineering, Osaka University, 2-1 Yamada-oka, Suita, Osaka, 565-0871, Japan
| | - K Okida
- Graduate School of Engineering, Osaka University, 2-1 Yamada-oka, Suita, Osaka, 565-0871, Japan
| | - T Tsukamoto
- Graduate School of Engineering, Osaka University, 2-1 Yamada-oka, Suita, Osaka, 565-0871, Japan
| | - Y Arikawa
- Institute of Laser Engineering, Osaka University, 2-6 Yamada-oka, Suita, Osaka, 565-0871, Japan
| | - S Fujioka
- Institute of Laser Engineering, Osaka University, 2-6 Yamada-oka, Suita, Osaka, 565-0871, Japan
| | - Y Iwasa
- Institute of Laser Engineering, Osaka University, 2-6 Yamada-oka, Suita, Osaka, 565-0871, Japan
| | - S Lee
- Institute of Laser Engineering, Osaka University, 2-6 Yamada-oka, Suita, Osaka, 565-0871, Japan
| | - H Nagatomo
- Institute of Laser Engineering, Osaka University, 2-6 Yamada-oka, Suita, Osaka, 565-0871, Japan
| | - H Shiraga
- Institute of Laser Engineering, Osaka University, 2-6 Yamada-oka, Suita, Osaka, 565-0871, Japan
| | - K Yamanoi
- Institute of Laser Engineering, Osaka University, 2-6 Yamada-oka, Suita, Osaka, 565-0871, Japan
| | - M S Wei
- Laboratory for Laser Energetics, University of Rochester, Rochester, NY, 14623-1299, USA
| | - K A Tanaka
- Graduate School of Engineering, Osaka University, 2-1 Yamada-oka, Suita, Osaka, 565-0871, Japan. .,Extreme Light Infrastructure: Nuclear Physics, 30 Reatorului, Magurele-Bucharest, 077125, Romania.
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Gong C, Tochitsky SY, Fiuza F, Pigeon JJ, Joshi C. Plasma dynamics near critical density inferred from direct measurements of laser hole boring. Phys Rev E 2016; 93:061202. [PMID: 27415200 DOI: 10.1103/physreve.93.061202] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2015] [Indexed: 06/06/2023]
Abstract
We have used multiframe picosecond optical interferometry to make direct measurements of the hole boring velocity, v_{HB}, of the density cavity pushed forward by a train of CO_{2} laser pulses in a near critical density helium plasma. As the pulse train intensity rises, the increasing radiation pressure of each pulse pushes the density cavity forward and the plasma electrons are strongly heated. After the peak laser intensity, the plasma pressure exerted by the heated electrons strongly impedes the hole boring process and the v_{HB} falls rapidly as the laser pulse intensity falls at the back of the laser pulse train. A heuristic theory is presented that allows the estimation of the plasma electron temperature from the measurements of the hole boring velocity. The measured values of v_{HB}, and the estimated values of the heated electron temperature as a function of laser intensity are in reasonable agreement with those obtained from two-dimensional numerical simulations.
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Affiliation(s)
- Chao Gong
- Electrical Engineering Department, University of California Los Angeles, Los Angeles, California 90095
| | - Sergei Ya Tochitsky
- Electrical Engineering Department, University of California Los Angeles, Los Angeles, California 90095
| | - Frederico Fiuza
- SLAC National Accelerator Laboratory, Menlo Park, California 94025
- Lawrence Livermore National Laboratory, Livermore, California 94550
| | - Jeremy J Pigeon
- Electrical Engineering Department, University of California Los Angeles, Los Angeles, California 90095
| | - Chan Joshi
- Electrical Engineering Department, University of California Los Angeles, Los Angeles, California 90095
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Oh J, Weaver JL, Karasik M, Chan LY. Measurements of electron density and temperature profiles in plasma produced by Nike KrF laser for laser plasma instability research. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2015; 86:083501. [PMID: 26329186 DOI: 10.1063/1.4927452] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
A grid image refractometer (GIR) has been implemented at the Nike krypton fluoride laser facility of the Naval Research Laboratory. This instrument simultaneously measures propagation angles and transmissions of UV probe rays (λ = 263 nm, Δt = 10 ps) refracted through plasma. We report results of the first Nike-GIR measurement on a CH plasma produced by the Nike laser pulse (∼1 ns FWHM) with the intensity of 1.1 × 10(15) W/cm(2). The measured angles and transmissions were processed to construct spatial profiles of electron density (ne) and temperature (Te) in the underdense coronal region of the plasma. Using an inversion algorithm developed for the strongly refracted rays, the deployed GIR system probed electron densities up to 4 × 10(21) cm(-3) with the density scale length of 120 μm along the plasma symmetry axis. The resulting n(e) and T(e) profiles are verified to be self-consistent with the measured quantities of the refracted probe light.
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Affiliation(s)
- Jaechul Oh
- Plasma Physics Division, Naval Research Laboratory, Washington, DC 20375, USA
| | - J L Weaver
- Plasma Physics Division, Naval Research Laboratory, Washington, DC 20375, USA
| | - M Karasik
- Plasma Physics Division, Naval Research Laboratory, Washington, DC 20375, USA
| | - L Y Chan
- Plasma Physics Division, Naval Research Laboratory, Washington, DC 20375, USA
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Ivancic S, Haberberger D, Habara H, Iwawaki T, Anderson KS, Craxton RS, Froula DH, Meyerhofer DD, Stoeckl C, Tanaka KA, Theobald W. Channeling of multikilojoule high-intensity laser beams in an inhomogeneous plasma. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2015; 91:051101. [PMID: 26066111 DOI: 10.1103/physreve.91.051101] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/11/2014] [Indexed: 06/04/2023]
Abstract
Channeling experiments were performed that demonstrate the transport of high-intensity (>10(18)W/cm(2)), multikilojoule laser light through a millimeter-sized, inhomogeneous (∼300-μm density scale length) laser-produced plasma up to overcritical density, which is an important step forward for the fast-ignition concept. The background plasma density and the density depression inside the channel were characterized with a novel optical probe system. The channel progression velocity was measured, which agrees well with theoretical predictions based on large scale particle-in-cell simulations, confirming scaling laws for the required channeling laser energy and laser pulse duration, which are important parameters for future integrated fast-ignition channeling experiments.
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Affiliation(s)
- S Ivancic
- Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623, USA
- Department of Mechanical Engineering, University of Rochester, Rochester, New York 14623, USA
| | - D Haberberger
- Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623, USA
| | - H Habara
- Graduate School of Engineering, Osaka University, Suita, Osaka 5650871, Japan
| | - T Iwawaki
- Graduate School of Engineering, Osaka University, Suita, Osaka 5650871, Japan
| | - K S Anderson
- Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623, USA
| | - R S Craxton
- Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623, USA
| | - D H Froula
- Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623, USA
- Department of Physics and Astronomy, University of Rochester, Rochester, New York 14623, USA
| | - D D Meyerhofer
- Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623, USA
- Department of Mechanical Engineering, University of Rochester, Rochester, New York 14623, USA
- Department of Physics and Astronomy, University of Rochester, Rochester, New York 14623, USA
| | - C Stoeckl
- Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623, USA
| | - K A Tanaka
- Graduate School of Engineering, Osaka University, Suita, Osaka 5650871, Japan
| | - W Theobald
- Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623, USA
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Willingale L, Nilson PM, Thomas AGR, Cobble J, Craxton RS, Maksimchuk A, Norreys PA, Sangster TC, Scott RHH, Stoeckl C, Zulick C, Krushelnick K. High-power, kilojoule class laser channeling in millimeter-scale underdense plasma. PHYSICAL REVIEW LETTERS 2011; 106:105002. [PMID: 21469797 DOI: 10.1103/physrevlett.106.105002] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/10/2010] [Indexed: 05/30/2023]
Abstract
Experiments were performed using the Omega EP laser, operating at 740 J of energy in 8 ps (90 TW), which provides extreme conditions relevant to fast ignition studies. A carbon and hydrogen plasma plume was used as the underdense target and the interaction of the laser pulse propagating and channeling through the plasma was imaged using proton radiography. The early time expansion, channel evolution, filamentation, and self-correction of the channel was measured on a single shot via this method. A channel wall modulation was observed and attributed to surface waves. After around 50 ps, the channel had evolved to show bubblelike structures, which may be due to postsoliton remnants.
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Affiliation(s)
- L Willingale
- Center for Ultrafast Optical Science, University of Michigan, 2200 Bonisteel Boulevard, Ann Arbor, Michigan 48109, USA
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