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Experimental design of radiation reaction by 1 PW laser pulse and linear accelerator electron bunch High Energy Density Phys. (IF 1.192) Pub Date : 2020-12-01 Keita Seto; Jian Fuh Ong; Yoshihide Nakamiya; Mihai Cuciuc; Madalin-Mihai Rosu; Vanessa R.M. Rodrigues; Ovidiu Tesileanu; Kazuo A. Tanaka
Radiation reaction (RR) is the frictional effect of a relativistically energetic and radiating electron. This situation can be created when the energetic electron collides with an ultra-intense laser pulse. We propose a RR experiment by making use of the collision of a 600 MeV electron beam from the linear accelerator and an ultra-intense laser pulse focused to 1022W/cm2 at ELI-NP. Its purpose is to
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Effects of mixed laser beam irradiation with different wavelengths on fast electron generation High Energy Density Phys. (IF 1.192) Pub Date : 2020-11-28 Masayasu Hata; Yasunobu Arikawa; Hideo Nagatomo; Yasuhiko Sentoku
In fast ignition laser fusion, a high-intensity picosecond laser heats a compressed dense core to achieve ignition. It is theoretically expected that the energy coupling efficiency from the heating laser to the compressed core becomes higher as the wavelength of the heating laser is shorter. This prediction is ready to be experimentally demonstrated using second harmonic generation at Institute of
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Development two-stage frequency domain optical parametric amplification High Energy Density Phys. (IF 1.192) Pub Date : 2020-11-07 J. Ogino; L. Zhaoyang; S. Tokita; K. Tsubakimoto; N. Miyanaga; J. Kawanaka
From experiments, we analyzed the spatiotemporal characteristics of a laser pulse in the Fourier plane in the 4-f arrangement. Based on these characteristics, we demonstrated two-stage frequency domain optical parametric amplification (FDOPA). The 275-fs signal seed pulse of the 1054-nm central wavelength was amplified in Type I β-BaB2O4 crystals pumped by a 180-ps pulse of 532-nm wavelength 532 nm
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Review of the first charged-particle transport coefficient comparison workshop High Energy Density Phys. (IF 1.192) Pub Date : 2020-10-29 P.E. Grabowski; S.B. Hansen; M.S. Murillo; L.G. Stanton; F.R. Graziani; A.B. Zylstra; S.D. Baalrud; P. Arnault; A.D. Baczewski; L.X. Benedict; C. Blancard; O. Čertík; J. Clérouin; L.A. Collins; S. Copeland; A.A. Correa; J. Dai; J. Daligault; A. White
We present the results of the first Charged-Particle Transport Coefficient Code Comparison Workshop, which was held in Albuquerque, NM October 4–6, 2016. In this first workshop, scientists from eight institutions and four countries gathered to compare calculations of transport coefficients including thermal and electrical conduction, electron–ion coupling, inter-ion diffusion, ion viscosity, and charged
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Numerical analysis on a conical shaped target for laser fusion rocket High Energy Density Phys. (IF 1.192) Pub Date : 2020-10-16 Toru Yamamura; Masafumi Edamoto; Tomihiko Kojima; Taichi Morita; Naoji Yamamoto; Atsushi Sunahara; Tomoyuki Johzaki; Hideki Nakashima
Laser fusion rocket can achieve large thrust and high specific impulse by utilizing huge amount of fusion energy to heat up a propellant. One of the issues of this system is heavy neutron shields which are heated by neutrons. The propulsion performance of a conical target that can reduce neutron radiation to the coil is calculated by numerical analysis. The impulse bits of the spherical and the conical
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Verification of fast heating of core plasmas produced by counter-illumination of implosion lasers High Energy Density Phys. (IF 1.192) Pub Date : 2020-09-30 E. Miura; Y. Mori; K. Ishii; S. Sakata; Y. Abe; Y. Arikawa; N. Nakajima; R. Takizawa; H. Morita; K. Matsuo; S.R. Mirfayzi; A. Sunahara; T. Ozaki; A. Iwamoto; O. Komeda; R. Hanayama; S. Okihara; Y. Sentoku; Y. Kitagawa
We conducted fast heating of a core plasma produced by counter-illumination of two beam bundles of implosion lasers for two incident directions of the heating laser. For the axial heating configuration, wherein the heating laser was incident along the coaxial direction of the implosion lasers, the size and density of the counter-imploded core plasma were estimated. The incident timing of the heating
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Effects of pulse duration on magnetic fields generated with a laser-driven coil High Energy Density Phys. (IF 1.192) Pub Date : 2020-10-15 Baojun Zhu; Zhe Zhang; Weiman Jiang; Jinguang Wang; Changqing Zhu; Junhao Tan; Yihang Zhang; Yuhang He; Yifei Li; Jinglong Ma; Yutong Li
A Ti:sapphire femtosecond laser with a relativistic intensity is focused onto a four-loop solenoid target to produce an ultrafast pulsed magnetic field. The magnetic field is generated due to a cold electron bunch which flows toward the laser focal spot to neutralize the remaining positive charge from the escaping hot electrons. The temporal evolution of the magnetic fields is evaluated by an improved
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Construction of multi-directional high-speed imaging system using a streak camera and image compression method High Energy Density Phys. (IF 1.192) Pub Date : 2020-10-19 Shinichiro NAGAI; Kensho YAMAZAKI; Masahiro TSUMORI; Yusuke TAKAHASHI; Ryosuke HARAKAWA; Kazumasa TAKAHASHI; Toru SASAKI; Takashi KIKUCHI; Masahiro IWAHASHI
We evaluated the reconstruction quality from a conventional compressed ultrafast photography (CUP) system and demonstrated a multi-directional high-speed imaging system based on the CUP system. We evaluated the defect rate as a function of the reconstruction quality. The results showed that the dependence of the defect rate on the reconstruction quality is similar to that from numerical experiments
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The role of hot electrons on ultrahigh pressure generation relevant to shock ignition conditions High Energy Density Phys. (IF 1.192) Pub Date : 2020-10-07 Koki Kawasaki; Yoichiro Hironaka; Yuto Maeda; Toshihiro Iwasaki; Daisuke Tanaka; Kohei Miyanishi; Hideo Nagatomo; Shinsuke Fujioka; Norimasa Ozaki; Ryosuke Kodama; Takeshi Matsuoka; Dimitri Batani; Jocelag Trela; Phillipe Nicolai; Keisuke Shigemori
On shock ignition (SI) scheme of inertial confinement fusion (ICF), a spherical shell target is compressed by relatively low intensity laser pulse irradiation, and hot spot is ignited by converging shock waves by high intensity laser pulse called “spike pulse”. The SI scheme is considered as a promising scheme to reduce the required drive laser energy for ignition. On the SI scheme, the strong shock
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Optimized recursion relation for the computation of partition functions in the superconfiguration approach High Energy Density Phys. (IF 1.192) Pub Date : 2020-09-30 Jean-Christophe Pain; Franck Gilleron; Brian G. Wilson
Partition functions of a canonical ensemble of non-interacting bound electrons are a key ingredient of the super-transition-array approach to the computation of radiative opacity. A few years ago, we published a robust and stable recursion relation for the calculation of such partition functions. In this paper, we propose an optimization of the latter method and explain how to implement it in practice
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Power and efficiency enhancement of THz radiation in a plasma by dark hollow laser beams: Effects of magnetic field High Energy Density Phys. (IF 1.192) Pub Date : 2020-09-12 Farhad Bakhtiari; Mahdi Esmaeilzadeh
The power and efficiency of terahertz radiation (THz) in a rippled density plasma by dark hollow laser beams are very small due to the collisional effect. We show that when a magnetic field is applied perpendicularly to the plasma, the THz radiation power and efficiency significantly enhance. Also, the magnetic field changes the THz radiation profile to a profile similar to a dark hollow laser beam
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Near-100 mev proton acceleration from 1021 W/cm2 laser interacting with near-critical density plasma High Energy Density Phys. (IF 1.192) Pub Date : 2020-09-29 Na Zhao; Jinlong Jiao; Duan Xie; Hongyu Zhou; Shijie Zhang; Yue Lang; Debin Zou; Hongbin Zhuo
Ion acceleration with linearly polarized 1 petawatt (PW) intense laser pulses interacting with near critical density (NCD) gas targets was demonstrated by using two-dimensional (2D) particle-in-cell (PIC) simulations. The laser parameters considered are comfortably within the capabilities of PW laser facilities, e.g., Extreme Light Infrastructure - Nuclear Physics (ELI-NP), Shanghai Superintense Ultrafast
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Electron beam propagation and magnetic structure formation in a strongly magnetized, collisional plasma High Energy Density Phys. (IF 1.192) Pub Date : 2020-09-24 Toshihiro Taguchi; Thomas M. Antonsen; Kunioki Mima
Collisional effects on relativistic electron beam transport through high-density magnetized plasma are studied numerically and theoretically. An electron beam injected into cold high-density plasma induces the Weibel instability generating magnetic field components transverse to the direction of beam propagation. This field scatters the beam electrons. While an applied magnetic field suppresses the
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Role of opacity at the 9 keV back lighter energy used in measuring the equation of state of boron at pressures up to a Gbar High Energy Density Phys. (IF 1.192) Pub Date : 2020-09-19 Joseph Nilsen; Daniel Åberg; Heather D. Whitley; Brian G. Wilson; Lin H. Yang; Philip A. Sterne; Markus W. Daene; Madison E. Martin; Shuai Zhang; Walter R. Johnson
Many experiments have been conducted at the National Ignition Facility to measure the equation of state Hugoniot of plastic, boron, and diamond at extreme pressures up to a Gbar. The “Gbar” design employs a strong spherically converging shock launched through a solid ball of material using a hohlraum radiation drive. The shock front conditions are characterized using X-ray radiography, typically at
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Optimization of capsule dopant levels to improve fuel areal density* High Energy Density Phys. (IF 1.192) Pub Date : 2020-09-24 D.E. Hinkel; T. Döppner; L.P. Masse; K. Widmann; L. Divol; B. Bachmann; L.F. Berzak Hopkins; S. LePape; C.R. Weber; S.A. MacLaren; A.B. Zylstra; J.E. Ralph; L.R. Benedetti; A.S. Moore; C.A. Thomas; D.T. Casey; V.A. Smalyuk; H.F. Robey; O.A. Hurricane
Fuel areal density (ρR) of all recent indirectly driven, cryogenically-layered DT implosions at the National Ignition Facility (NIF) show a deficit when compared to simulations. Across all designs, experimental ρR is lower than in 1D simulations without alpha energy or momentum deposition. A series of layered implosions were fielded at NIF to assess the impact of fuel-ablator instability, as caused
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X-ray fluorescence imaging of laser-driven hydrodynamic instability systems with a Ross Pair Imager High Energy Density Phys. (IF 1.192) Pub Date : 2020-09-19 Li Yao; Yudong Pu; Xiayu Zhan; Minxi Wei; Jianhua Zheng; Xing Zhang; Ji Yan; Lifei Hou; Yimeng Yang; Yongkun Ding
An experiment has been conducted at the Shenguang-Ⅲ prototype laser facility, demonstrating the application of x-ray fluorescence imaging (XRFI) in diagnosing laser-driven hydrodynamic instability systems in planar geometry. An aluminum (Al)-foam target was used, including a modulated Al disk followed by a low density poly-4-methyl-1-pentene foam cylinder which was doped with titanium (Ti) dioxide
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Bayesian inference of deceleration-phase Rayleigh-Taylor growth rates in laser-driven cylindrical implosions High Energy Density Phys. (IF 1.192) Pub Date : 2020-09-19 B. Tobias; C.F. Kawaguchi; S. Palaniyappan; J.P. Sauppe; K.A. Flippo; J.L. Kline
An iterative forward modeling approach has been developed and applied to the analysis of radiography data from cylindrical Rayleigh-Taylor instability studies performed at the Omega laser facility. Synthetic radiographs are generated and iterated using the Bayes’ Inference Engine [1] to produce maximum likelihood estimates for the time-dependent amplitude of deceleration-phase Rayleigh-Taylor modes
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Application of laser-driven capacitor-coil to target normal sheath acceleration High Energy Density Phys. (IF 1.192) Pub Date : 2020-08-28 Hiroki Morita, Alexey Arefiev, Toma Toncian, Joao Jorge Santos, Daniil Golovin, Satoru Shokita, Takato Mori, King Fai Farley Law, Huan Li, Ryunosuke Takizawa, Kazuki Matsuo, Alessio Morace, Akifumi Yogo, Shinsuke Fujioka
A laser-driven accelerator generates protons with tens of MeV in energy by a compact, strong, and transient accelerating electric field produced as a result of laser–plasma interactions at relativistic intensities. In previous studies, two- and three-dimensional particle-in-cell simulations revealed that the application of a kT-level axial magnetic field results in an enhancement of proton acceleration
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Numerical study of momentum and energy transfer in the interaction of a laser pulse carrying orbital angular momentum with electrons High Energy Density Phys. (IF 1.192) Pub Date : 2020-08-25 V.T. Tikhonchuk, Ph. Korneev, E. Dmitriev, R. Nuter
Electromagnetic waves, in addition to the energy and momentum, can also carry an orbital angular momentum (OAM). Transfer of these quantities from laser to particles may find various applications. There are similarities between the process of OAM transfer from laser to electrons and a direct electron acceleration in a relativistic electromagnetic wave packet. In this paper, by using a numerical integration
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Plasma hydrodynamic experiments on NRL Nike KrF laser High Energy Density Phys. (IF 1.192) Pub Date : 2020-08-25 Y. Aglitskiy, C. Zulick, J. Oh, A.L. Velikovich, A.J. Schmitt, S.P. Obenschain, M. Karasik, J.L. Weaver
The krypton-fluoride Nike laser delivers up to 2 KJ in 248 nm ultraviolet radiation to planar targets with the most uniform illumination of all existing high-energy lasers for inertial confinement fusion (ICF) research. That, combined with high-resolution monochromatic x-ray imaging pioneered at NRL in the 1990s and the recently added two-dimensional (2D) VISAR diagnostics, provides a unique platform
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Mitigation of debris from a laser plasma EUV source and from focusing optics for thin film deposition by intense EUV radiation High Energy Density Phys. (IF 1.192) Pub Date : 2020-08-20 Nozomi Tanaka, Nao Wada, Yasuyuki Kageyama, Hiroaki Nishimura
Studies on extreme ultraviolet (EUV) light sources for practical applications have attracted much attention. Although a laser-driven EUV source in conjunction with focusing mirrors enables the use of intense EUV radiation, mitigation of debris from the source plasma and focusing mirrors is a challenge to satisfy requirements for advanced material synthesis, because even a tiny amount of contamination
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Generation of residual stress field in metal by an interference shock wave High Energy Density Phys. (IF 1.192) Pub Date : 2020-08-19 Yoichiro Hironaka, Eisuke Miura, Kohei Miyanishi, Keisuke Shigemori, Takeshi Matsuoka, Norimasa Ozaki, Takashi Kurita, Yuki Kabeya, Takeshi Watari, Yoshio Mizuta, Ryunosuke Kuroda, Ryosuke Kodama
In recent years, laser peening technique has been used for the purpose of improving the fatigue strength of metal materials. However, the compressive residual stress field created by laser peening has characteristic differences in the stress value and the thickness of the stress field layer compared to conventional technologies. We conducted experiments to clarify the peening mechanism of metals when
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Interpenetration and kinetic effects in converging, high-energy plasma jets High Energy Density Phys. (IF 1.192) Pub Date : 2020-08-13 William Riedel, Nathan Meezan, Drew Higginson, Matthias Hohenberger, Joseph Owen, Mark Cappelli
We report on numerical simulations of laser-driven convergent plasma fusion targets. These “inverted corona” fusion targets are useful for the study of counter-streaming and converging rarefied plasma flows, and previous experiments have demonstrated their potential as neutron sources. The scheme consists of a fuel layer lined along the interior surface of a hollow plastic shell that is laser-ablated
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Commissioning the new pulse dilation Gas Cherenkov Detector at the National Ignition Facility High Energy Density Phys. (IF 1.192) Pub Date : 2020-08-13 Hermann Geppert-Kleinrath, Yongho Kim, Kevin D. Meaney, Hans W. Herrmann, Nelson M. Hoffman, Annie Kritcher, Jorge A. Carrera, Steve Gales
The new Pulse Dilation – Photomultiplier Tube fielded on the Gas Cherenkov Detector GCD-3 at the National Ignition Facility allows for high band width DT gamma reaction history measurements. Crucial for successful data collection is precise timing of the dilation window. Using both a short pulse laser and test measurements on high yield ice layered DT shots the timing was set well within a 1-ns dilation
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Electron beam and betatron x-ray generation in a hybrid electron accelerator driven by high intensity picosecond laser pulses High Energy Density Phys. (IF 1.192) Pub Date : 2020-08-06 Y.F. Li, J. Feng, J.H. Tan, J.G. Wang, D.Z. Li, K.G. Dong, X.H. Zhang, B. Zhu, F. Tan, Y.C. Wu, Y.Q. Gu, L.M. Chen
We experimentally studied electron beams and synchrotron x-ray radiation generated from the interaction of high-intensity picosecond laser pulses of 1–3 × 1019 W/cm2 with underdense plasmas of 1–8 × 1019 cm−3. Electron beams with maximum energy over 120 MeV, hundreds mrad divergence and tens of nC charge were generated in the experiments. The measured x-ray spectra were fit well with a synchrotron
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Retardation effects on radiative transitions at solar interior conditions High Energy Density Phys. (IF 1.192) Pub Date : 2020-07-29 Michael K.G. Kruse, Carlos A. Iglesias
Existing discrepancies between helioseismic data and solar models have questioned the accuracy of theoretical opacities for the solar interior. The opacities were further challenged by recent estimates claiming significant retardation effects, often neglected in opacity calculations, for radiative transitions relevant to the solar problem. Contrary to these claims, it is shown that the retardation
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Laser-triggered stochastic volumetric heating of sub-microwire array target High Energy Density Phys. (IF 1.192) Pub Date : 2020-07-27 D.A. Gozhev, S.G. Bochkarev, N.I. Busleev, A.V. Brantov, S.I. Kudryashov, A.B. Savel’ev, V.Yu. Bychenkov
The interaction of an ultrashort laser pulse of moderate intensity ( ≳ 1018 W/cm2) with an innovative high-average-density target consisting of numerous sub-microwires was examined using 3D PIC simulations. We geometrically optimize the target to increase the absorption of laser light and energy (temperature) and the number of hot electrons. To explain the production of super-ponderomotive electrons
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Development of single-shot frequency-resolved optical gating for characterizing the instantaneous intensity and phase of LFEX laser pulses High Energy Density Phys. (IF 1.192) Pub Date : 2020-07-18 Sadaoki Kojima, Yugo Ochiai, Shunsuke Inoue, Yasunobu Arikawa, Mao Takemura, Masaki Hashida, Shinsuke Fujioka, Shuji Sakabe
Frequency-resolved optical gating (FROG) is a novel means of measuring the fast motion of a critical density surface during relativistic laser–plasma interaction. Herein, we present a design and demonstration results for a new single-shot FROG system and optical transport system for characterizing the instantaneous intensity and phase at the LFEX (Laser for Fast Ignition Experiment) laser facility
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Illuminating White Dwarf Spectra through Laboratory Experiments at Cosmic Conditions High Energy Density Phys. (IF 1.192) Pub Date : 2020-07-16 D.E. Winget, M.H. Montgomery, B.H. Dunlap, P.B. Cho, M.-A. Schaeuble, T.A. Gomez
We establish the work on white dwarf stars in the larger context of the experiments of the Wootton Center for Astrophysical Plasma Properties (WCAPP); these experiments are conducted at the plasma conditions found in the cosmos, without the need for scaling. We briefly summarize the results of these experiments to-date and their astrophysical and physical import, before focusing on the white dwarf
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Post-processing of face-on radiographic images for quantitative analysis in ablative Rayleigh-Taylor instability experiments High Energy Density Phys. (IF 1.192) Pub Date : 2020-07-09 L. Ceurvorst, S.F. Khan, C. Mailliet, D.A. Martinez, N. Izumi, P. Di Nicola, J.M. Di Nicola, T. Goudal, V. Bouffetier, D. Kalantar, I. Igumenshchev, E. Le Bel, B.A. Remington, L.P. Masse, V.A. Smalyuk, A. Casner
An experiment was performed at the National Ignition Facility investigating the ablative Rayleigh-Taylor instability’s dependence on initial conditions in the highly nonlinear stage. The detailed post-processing of the radiographic images which includes backlighter reconstruction, Wiener deconvolution of the raw data, and the calculation of a conversion factor from optical depth to physical units.
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Correction method for the energy spectrum of laser-accelerated protons measured by CR-39 track detectors with stepwise energy filters High Energy Density Phys. (IF 1.192) Pub Date : 2020-07-06 Masato Kanasaki, Keita Sakamoto, Takafumi Asai, Satoshi Jinno, Satoshi Kodaira, Tomoya Yamauchi, Keiji Oda, Yuji Fukuda
A combination of CR-39 track detectors and a stepwise energy filter is a simple method to measure the energy spectrum of laser-accelerated protons. The number of etch pits in each area of the CR-39 detector is expected to represent the energy spectrum because the different thicknesses of the filters result in different areas into which the energy reaches in CR-39. However, the higher energy regions
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Laser-driven generation of collimated quasi-monoenergetic proton beam using double-layer target with modulated interface High Energy Density Phys. (IF 1.192) Pub Date : 2020-06-27 Martin Matys, Katsunobu Nishihara, Mariana Kecova, Jan Psikal, Georg Korn, Sergei V. Bulanov
Usage of double-layer targets consisting of heavy and light material with modulated interface between them provides a way for laser-driven generation of collimated ion beams. With extensive 2D3V PIC simulations we show that this configuration may result in a development of a relativistic instability with Rayleigh-Taylor and Richtmyer-Meshkov like features. Initially small perturbations are amplified
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Dependences of morphology and surface roughness on growth conditions of diamond capsules for the direct-drive inertial confinement fusion High Energy Density Phys. (IF 1.192) Pub Date : 2020-06-24 T. Iwasaki, K. Kawasaki, H. Yamada, S. Ohmagari, D. Takeuchi, A. Chayahara, Y. Mokuno, Y. Hironaka, K. Shigemori
In order to achieve the ignition by direct-drive inertial confinement fusion (ICF), smooth and symmetric fuel capsule is required. Our previous research found that stiffness of the capsule material contributes to reduce the laser imprinting. Therefore, diamond is considered to be the most promising candidate as the stiff ablator material for direct-drive ICF capsule. In this study, aiming at improving
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Radiation damage in particle accelerator complex for heavy ion inertial fusion High Energy Density Phys. (IF 1.192) Pub Date : 2020-06-23 Suzuka Fujita, Hideki Tenzo, Kazumasa Takahashi, Toru Sasaki, Takashi Kikuchi
We investigated radiation damages induced by irradiating ions in a particle accelerator for a heavy-ion inertial fusion (HIF) system, because the radio-activation is an unavoidable issue to realize the future HIF power plant. In this study, we estimated the radio-activation at each part of the HIF accelerator. An evaluation using collisions due to Coulomb barrier gives the safer estimation in the radio-activation
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Demonstration of repetitive energetic proton generation by ultra-intense laser interaction with a tape target High Energy Density Phys. (IF 1.192) Pub Date : 2020-06-21 N.P. Dover, M. Nishiuchi, H. Sakaki, Ko. Kondo, H.F. Lowe, M.A. Alkhimova, E.J. Ditter, O.C. Ettlinger, A.Ya. Faenov, M. Hata, G.S. Hicks, N. Iwata, H. Kiriyama, J.K. Koga, T. Miyahara, Z. Najmudin, T.A. Pikuz, A.S. Pirozhkov, K. Kondo
High power laser systems are an attractive driver for compact energetic ion sources. We demonstrate repetitive acceleration at 0.1 Hz of proton beams up to 40 MeV from a reeled tape target irradiated by ultra-high intensities up to 5 × 1021 Wcm−2 and laser energies ≈ 15 J using the J-KAREN-P laser system. We investigate the stability of the source and its behaviour with laser spot focal size. We compare
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Observation of water-window soft x-ray emission from laser-produced Au plasma under optically thin condition High Energy Density Phys. (IF 1.192) Pub Date : 2020-06-19 Christian John, Maki Kishimoto, Yasuhiro Matsumoto, Takehiro Morishita, Takeshi Higashiguchi, Takuma Endo, Atsushi Sunahara, Tomoyuki Johzaki, Shinichi Namba
We present a systematic approach how to characterize the dynamics of a laser-produced Au plasma, generated with a commercial Joule-class laser system. By means of our diagnostic methods, we identify the dominant ionic species within the water-window spectral region, as well as the radiated energy, the x-ray emission duration and the total dimensions of the x-ray source. We present additional analysis
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Two-color laser-plasma interactions for efficient production of non-thermal hot electrons High Energy Density Phys. (IF 1.192) Pub Date : 2020-06-13 S. Lee, D. Kawahito, N. Iwata, Y. Sentoku, K.F.F. Law, S. Sakata, H. Morita, K. Matsuo, Y. Arikawa, K. Shigemori, T. Sano, H. Nagatomo, K. Mima, H. Azechi, R. Kodama, S. Fujioka
Efficient production of non-thermal hot electrons has been demonstrated experimentally by interactions of a plasma and two-color lasers with wavelengths of 527 and 1053 nm. The two-color-lasers and plasma interactions caused a 4.8 times enhancement of the temperature of the hot electrons and a 2.7 times enhancement of energy conversion from the lasers to the hot electrons compared with that obtained
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Transition of dominant heating process from relativistic electron beam heating to thermal diffusion in an over picoseconds relativistic laser-solid interaction High Energy Density Phys. (IF 1.192) Pub Date : 2020-06-12 Naoki Higashi, Natsumi Iwata, Takayoshi Sano, Kunioki Mima, Yasuhiko Sentoku
A mechanism of isochoric heating of a solid density plasma by a kilojoule (kJ) class laser with relativistic intensity and a ten picosecond (ps) pulse duration is delineated by collisional Particle-in-Cell (PIC) simulations. Before an emergence of kJ class lasers, plasma heating by the laser-accelerated relativistic electron beam (REB) has been studied as the dominant isochoric heating process by intense
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Intensification of laser-produced relativistic electron beam using converging magnetic fields for ignition in fast ignition laser fusion High Energy Density Phys. (IF 1.192) Pub Date : 2020-06-09 Tomoyuki Johzaki, Masaya Hino, Mie Horio, Shijuro Takeda, Wookyung Kim, Takuma Endo, Shinsuke Fujioka, Yasuhiko Sentoku, Hideo Nagatomo, Atsushi Sunahara
The kilo-tesla-class converging magnetic field effects on the core heating properties and the energy and duration of relativistic electron beam (REB) required for ignition in fast ignition laser fusion has been evaluated by parametric 2D hybrid simulations where a uniformly compressed DT core with ρ = 300 g/cm3 is heated by REB with TREB = 3 MeV, IREB = 0.69 × 1020 W/cm2 and θREB = 40° under sufficiently
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Enhancement of ion energy and flux by the influence of magnetic reconnection in foam targets High Energy Density Phys. (IF 1.192) Pub Date : 2020-06-07 Daniil O. Golovin, Seyed R. Mirfayzi, Yan Jun Gu, Yuki Abe, Yuki Honoki, Takato Mori, Hideo Nagatomo, Kazuki Okamoto, Satoru Shokita, Kohei Yamanoi, Yasunobu Arikawa, Georg Korn, Tatiana A. Pikuz, Shinsuke Fujioka, Ryosuke Kodama, Sergey V. Bulanov, Akifumi Yogo
Laser-driven ion acceleration attracts large attention due to variety of applications. In order to enhance accelerated proton energy and flux, we investigate the influence of laser-driven relativistic magnetic reconnection on the ion acceleration processes. In this relativistic regime, the longitudinal electric field becomes significantly enhanced and plays an important role in charged particle acceleration
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Nonlinear interaction between bulk vortices and the interface in the incompressible Richtmyer-Meshkov instability High Energy Density Phys. (IF 1.192) Pub Date : 2020-06-07 Chihiro Matsuoka
Nonlinear interaction between bulk point vortices and the interface in the incompressible Richtmyer-Meshkov instability (RMI) is investigated theoretically and numerically. When the strength of point vortices are large enough, they interact with the original vorticity existing on the vortex sheet and create new vortex cores. These vortex cores roll up like mushrooms, and a very complicated interfacial
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Conceptual design of a subcritical research reactor for inertial fusion energy with the J-EPoCH facility High Energy Density Phys. (IF 1.192) Pub Date : 2020-06-07 Akifumi Iwamoto, Ryosuke Kodama
The Japan Establishment for a Power-laser Community Harvest (J-EPoCH) is proposed as a next generation laser facility having multi-purpose high repetition laser beams at the maximum rate of 100 Hz. One of the experimental areas is assigned for laser fusion research. The omnidirectional 12 laser beams with 8 kJ and a 5 PW heating laser are arranged. A Large High Aspect Ratio Target (LHART) with the
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Shaping ion beams into hollow profiles using sextupole magnets High Energy Density Phys. (IF 1.192) Pub Date : 2020-06-02 Yosuke Yuri, Takahiro Yuyama, Tomohisa Ishizaka, Mitsuhiro Fukuda
It is essential to properly shape the intensity distribution or irradiation field of high-energy charged-particle beams to improve their utilization, e.g., high energy density physics and heavy-ion fusion. Recently, unique beam profile shaping that cannot be realized through conventional linear focusing (i.e., the formation of hollow transverse profiles) was achieved through nonlinear focusing using
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Flash X-ray backlight technique using a Fresnel phase zone plate for measuring interfacial instability High Energy Density Phys. (IF 1.192) Pub Date : 2020-06-01 Kazuki Matsuo, Takayoshi Sano, Kazuki Ishigure, Hiroki Kato, Natsuko Nagamatsu, Zhu Baojun, Guo Shuwang, Hideo Nagatomo, Nicolai Philippe, Youichi Sakawa, Yasunobu Arikawa, Shohei Sakata, SeungHo Lee, King Fai Farley Law, Hiroki Morita, Chang Liu, Huan Li, Jo Nishibata, Shinsuke Fujioka
Interfacial instabilities in high-energy-density plasmas are important topics in various research fields such as inertial confinement fusion, planetary sciences, and astrophysics. The growth of the instabilities can be examined in the laboratory by using high-power lasers coupled with high-resolution imaging technique. The resolutions both in space and time are essential for the observation of tiny
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The avalanche image intensifier panel for fast neutron radiography by using laser-driven neutron sources High Energy Density Phys. (IF 1.192) Pub Date : 2020-05-30 R. Mizutani, Y. Abe, Y. Arikawa, J. Nishibata, A. Yogo, S.R. Mirfayzi, H. Nishimura, K. Mima, S. Fujioka, M. Nakai, H. Shiraga, R. Kodama
Laser-driven neutrons have been expected as an optimum source for neutron radiography applications. Since the neutron fluence is lower than that of accelerator-based neutron source a new device for amplifying scintillation light has been required. The avalanche image intensifier panel discussed here has a large aperture and fast response which has been developed specifically for laser-driven neutron
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The role of fast electron energy transfer in the problem of shock ignition of laser thermonuclear target High Energy Density Phys. (IF 1.192) Pub Date : 2020-05-30 S.Yu. Gus’kov, P.A. Kuchugov, R.A. Yakhin, N.V. Zmitrenko
The role of energy transfer by fast electrons, which is responsible for the positive effect of increasing the ablative pressure and the negative effect of preheating, on the implosion and thermonuclear gain of the target designed for shock ignition is investigated in comparison with the target designed for traditional spark ignition. On the base of one-dimensional hydrodynamic simulations with kinetic
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Dependence of diameter on flow velocity of liquid metal jet for repeatable pulse powered plasma sources High Energy Density Phys. (IF 1.192) Pub Date : 2020-05-26 Ryota Mabe, Hiroki Ishikawa, Kazumasa Takahashi, Toru Sasaki, Takashi Kikuchi
To realize a pulsed-power discharge plasma using a liquid metal, we investigated the dependence of the diameter on the flow velocity of a liquid metal flow consisting of a U-alloy. The plasma temperature was measured using a pyrometric method. The results show that the flow velocity estimated by the parabolic corresponds to a theoretical value derived from the difference between the gas pressure and
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Electron runaway in a dense semiclassical plasma High Energy Density Phys. (IF 1.192) Pub Date : 2020-05-24 M.N. Jumagulov, M.M. Seisembayeva, E.O. Shalenov, Zh. Kossymkyzy, T.S. Ramazanov, K.N. Dzhumagulova
The phenomenon of electron runaway in a dense semiclassical plasma was investigated on the basis of the effective potentials of particle interactions. These effective potentials take into account the quantum-mechanical effect of diffraction and static or dynamic screening. The results of numerical calculations of the effective collision frequency, mean free path and friction force for various values
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Measurement of hydrodynamic instability growth during the deceleration of an inertial confinement fusion implosion High Energy Density Phys. (IF 1.192) Pub Date : 2020-05-23 L.A. Pickworth, V.A. Smalyuk, B.A. Hammel, C. Weber, D.S. Clark, H.F. Robey, A.G. MacPhee, S. Le Pape, D.T. Casey, L. Berzak-Hopkins, A. Zylstra, A. Kritcher, C.F. Walters, S.D. Bhandarkar, M. Stadermann, S. Johnson, S. Diaz, M. Ratledge, E. Hartouni
This paper presents an exploration of potential mitigation methods for the gas fuel fill tube in Inertial Confinement Fusion (ICF) implosions at the National Ignition Facility (NIF), and the impact of hydrodynamic growth seeded from other target imperfections using a specialized low convergence implosion experiment. Enhanced x-ray self- emission of this experiment design allows the impact of hydrodynamic
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Numerical Analysis of Relaxation Process with Fast Particle Generation in Malmberg-Penning Trap Experiment for Ion Beam Inertial Fusion High Energy Density Phys. (IF 1.192) Pub Date : 2020-05-23 Nozomi Suzutani, Youngsoo Park, Yukihiro Soga, Kazumasa Takahashi, Toru Sasaki, Takashi Kikuchi
To clarify a regeneration process of fast electrons in a Malmberg-Penning trap device, a numerical simulation was carried out using a multi-particle tracking code. The numerical simulations reproduced the fast particle regeneration by the rapid relaxation process observed in the experiment. In comparison with the experimental and the numerical results, it was considered that the rapid relaxation process
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Observation of MeV-energy ions from the interaction of over picosecond laser pulses with near-critical density foam targets High Energy Density Phys. (IF 1.192) Pub Date : 2020-05-23 Satoru Shokita, Akifumi Yogo, Seyed R. Mirfayzi, Yuki Honoki, Daniil Golovin, Takashi Ishimoto, Zechen Lan, Kazuki Matsuo, Takato Mori, Kazuki Okamoto, Hideo Nagatomo, Hiroaki Nishimura, Yasuhiko Sentoku, Kohei Yamanoi, Ryosuke Kodama
In order to enhance the conversion efficiency of ultra-intense laser energy into plasma leading to ion acceleration, we have performed an experiment with over-picosecond laser pulses having a relativistic intensity interacting with foam targets. We adjust the prepulse of the laser to control the plasma density near the critical density. The combination of hydrodynamic and particle-in-cell simulations
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3D xRAGE simulation of inertial confinement fusion implosion with imposed mode 2 laser drive asymmetry High Energy Density Phys. (IF 1.192) Pub Date : 2020-05-22 M. Gatu Johnson, B.M. Haines, P.J. Adrian, C. Forrest, J.A. Frenje, V.Yu. Glebov, W. Grimble, R. Janezic, J.P. Knauer, B. Lahmann, F.J. Marshall, T. Michel, F.H. Séguin, C. Stoeckl, R.D. Petrasso
Low-mode asymmetries represent an important obstacle to achieving high-gain inertial confinement fusion implosions. As a step in learning how to control such effects, an OMEGA experiment with imposed mode 2 laser drive asymmetries was done to study the expected signatures of this type of asymmetry [M. Gatu Johnson et al., PRE 2018]. In the present work, a 3D xRAGE simulation including the stalk mount
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Design of Cylindrical Implosion Experiments to Demonstrate Scale-Invariant Rayleigh-Taylor Instability Growth High Energy Density Phys. (IF 1.192) Pub Date : 2020-05-21 J.P. Sauppe, S. Palaniyappan, J.L. Kline, K.A. Flippo, O.L. Landen, D. Shvarts, S.H. Batha, P.A. Bradley, E.N. Loomis, B.J. Tobias, N.N. Vazirani, C.F. Kawaguchi, L. Kot, D.W. Schmidt, T.H. Day, A.B. Zylstra, E. Malka
Radiation-hydrodynamics simulations are used to design laser-driven cylindrical implosion experiments to directly measure hydrodynamic instability growth in convergent geometry. Designs for two different size targets, varying in radial dimension by a factor of three, are presented. A set of beam pointings and powers are identified for each scale design that result in a nearly axially uniform implosion
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Effect of solenoidal magnetic field on charge-state purity in laser ion source High Energy Density Phys. (IF 1.192) Pub Date : 2020-05-20 Kazumasa Takahashi, Takahiro Karino, Shunsuke Ikeda, Takeshi Kanesue, Masahiro Okamura, Toru Sasaki, Takashi Kikuchi
A solenoidal magnetic field has been used to enhance the ion flux of a laser ion source. However, the dependence of the increase in ion current on the charge-state has not been clarified. In this study, to control the purity of the charge-state in the laser ion source, we investigated the effect of a solenoidal magnetic field on the charge-state distribution of ions in laser ion sources with a solenoid
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Advancing the study of hybrid-drive inertial fusion ignition and high energy density physics - Teller medal lecture at IFSA2019 High Energy Density Phys. (IF 1.192) Pub Date : 2020-05-20 X.T. He
The inertial confinement fusion (ICF) program toward ignition in China has made great progress since 1993. After research work on SG series with laser energy of tens kJ, SG-III laser facility with energy output of hundreds kJ is being used to study target physics prior to ignition. A new hybrid drive (HD) approach combined indirect drive (ID) and direct drive (DD) provides the HD pressure far greater
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Anomalous absorption due to development of return current instability High Energy Density Phys. (IF 1.192) Pub Date : 2020-05-14 S.I. Glazyrin, A.V. Brantov, M.A. Rakitina, V.Yu Bychenkov
We examine the anomalous absorption effect due to ion–acoustic turbulence (IAT) driven by the return current instability in a plasma corona in relation to relevant conditions of the direct-drive inertial confinement fusion scheme of the Russian megajoule-energy level laser facility. We find that for the plasma corona created by a carbon ablator, the IAT contributes not more than 10% to absorption for
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PIC simulation for dense high Z plasma formation with ultrashort petawatt laser including radiation processes High Energy Density Phys. (IF 1.192) Pub Date : 2020-05-07 K. Sugimoto, N. Higashi, N. Iwata, A. Sunahara, T. Sano, Y. Sentoku
Creation of hot dense highly charged plasma is key to realizing novel radiation sources, e.g., high Z ion beams and intense hard X-rays. We study the formation of dense silver plasma driven by an ultrashort petawatt laser using one-dimensional Particle-in-Cell (PIC) simulations take into account physics of collisional energy transport, ionizations, and radiations byproducts. For this purpose, we implemented
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Control of intense-laser ion acceleration High Energy Density Phys. (IF 1.192) Pub Date : 2020-05-07 T. Nishiura, H. Satou, S. Kawata, Y.J. Gu, Q. Kong, Y.Y. Ma, P.X. Wang
An ion beam has a unique feature to deposit its main energy inside a human body to kill cancer cells or inside material. In this paper, a future intense laser ion accelerator is discussed to make the laser-based ion accelerator compact and controllable. The issues in the laser ion accelerator include the energy efficiency from the laser to the ions, the ion beam collimation, the ion energy spectrum
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Direct observation of density gradients in ICF capsule implosions via streaked Refraction Enhanced Radiography (RER) High Energy Density Phys. (IF 1.192) Pub Date : 2020-05-07 E.L. Dewald, O.L. Landen, D. Ho, L. Berzak Hopkins, Y. Ping, L. Masse, D. Thorn, J. Kroll, A. Nikroo
We have performed refraction enhanced radiography (RER) measurements of indirect drive layered high density carbon capsule implosions relevant for inertial confinement fusion. Streaked RER data using a 5 µm wide imaging slit, backlit by a 7.8 keV Ni He-α laser driven x-ray source, shows features due to inflight density gradients in the ablator and fuel ice that are not visible in absorption only radiographs
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A numerical study on the pulse duration dependence of a magnetic field generated using a laser-driven capacitor-coil target High Energy Density Phys. (IF 1.192) Pub Date : 2020-05-07 Toru Sasaki, Kazumasa Takahashi, Takashi Kikuchi, Atsushi Sunahara, Hideo Nagatomo, Shinsuke Fujioka
Herein, a two-dimensional magnetohydrodynamic (MHD) simulation has been performed to understand the MHD and the generated magnetic field (B-field) behaviors of a capacitor-coil target. The results showed that a peak B-field strength was generated in the capacitor-coil target, followed by a current peak. This B-field depends on a peak current with a pulse duration of 2 ns. For a peak current of 2 ns
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