Search

Your search keyword '"Johzaki, Tomoyuki"' showing total 10 results
Start Over Author "Johzaki, Tomoyuki" Publication Type Electronic Resources
10 results on '"Johzaki, Tomoyuki"'

1. Hot electron and ion spectra on blow-off plasma free target in GXII-LFEX direct fast ignition experiment

Author

OZAKI, Tetsuo, ABE, Yuki, ARIKAWA, Yasunobu, SENTOKU, Yasuhiko, KAWANAKA, Junji, TOKITA, Shigeki, MIYANAGA, Noriaki, JITSUNO, Takahisa, NAKATA, Yoshiki, TSUBAKIMOTO, Koji, SUNAHARA, Atsushi, JOHZAKI, Tomoyuki, MIURA, Eisuke, KOMEDA, Osamu, IWAMOTO, Akifumi, SAKAGAMI, Hitoshi, OKIHARA, Shinichiro, ISHII, Katsuhiro, HANAYAMA, Ryohei, MORI, Yoshitaka, KITAGAWA, Yoneyoshi, OZAKI, Tetsuo, ABE, Yuki, ARIKAWA, Yasunobu, SENTOKU, Yasuhiko, KAWANAKA, Junji, TOKITA, Shigeki, MIYANAGA, Noriaki, JITSUNO, Takahisa, NAKATA, Yoshiki, TSUBAKIMOTO, Koji, SUNAHARA, Atsushi, JOHZAKI, Tomoyuki, MIURA, Eisuke, KOMEDA, Osamu, IWAMOTO, Akifumi, SAKAGAMI, Hitoshi, OKIHARA, Shinichiro, ISHII, Katsuhiro, HANAYAMA, Ryohei, MORI, Yoshitaka, and KITAGAWA, Yoneyoshi

Abstract

Polystyrene deuteride shell targets with two holes were imploded by the Gekko XII laser and additionally heated by the LFEX laser in a direct fast ignition experiment. In general, when an ultra-intense laser is injected into a blow-off plasma created by the imploding laser, electrons are generated far from the target core and the energies of electrons increase because the electron acceleration distance has been extended. The blow-off plasma moves not only to the vertical direction but to the lateral direction against the target surface. In a shell target with holes, a lower effective electron temperature can be realized by reducing the inflow of the implosion plasma onto the LFEX path, and high coupling efficiency can be expected. The energies of hot electrons and ions absorbed into the target core were calculated from the energy spectra using three electron energy spectrometers and a neutron time-of-flight measurement system, Mandala. The ions have a large contribution of 74% (electron heating of 4.9 J and ion heating of 14.1 J) to target heating in direct fast ignition., source:T. Ozaki et al 2023 Nucl. Fusion 63 036009, source:https://doi.org/10.1088/1741-4326/acb44d

Published
2023

2. Hot electron and ion spectra on blow-off plasma free target in GXII-LFEX direct fast ignition experiment

Author

OZAKI, Tetsuo, ABE, Yuki, ARIKAWA, Yasunobu, SENTOKU, Yasuhiko, KAWANAKA, Junji, TOKITA, Shigeki, MIYANAGA, Noriaki, JITSUNO, Takahisa, NAKATA, Yoshiki, TSUBAKIMOTO, Koji, SUNAHARA, Atsushi, JOHZAKI, Tomoyuki, MIURA, Eisuke, KOMEDA, Osamu, IWAMOTO, Akifumi, SAKAGAMI, Hitoshi, OKIHARA, Shinichiro, ISHII, Katsuhiro, HANAYAMA, Ryohei, MORI, Yoshitaka, KITAGAWA, Yoneyoshi, OZAKI, Tetsuo, ABE, Yuki, ARIKAWA, Yasunobu, SENTOKU, Yasuhiko, KAWANAKA, Junji, TOKITA, Shigeki, MIYANAGA, Noriaki, JITSUNO, Takahisa, NAKATA, Yoshiki, TSUBAKIMOTO, Koji, SUNAHARA, Atsushi, JOHZAKI, Tomoyuki, MIURA, Eisuke, KOMEDA, Osamu, IWAMOTO, Akifumi, SAKAGAMI, Hitoshi, OKIHARA, Shinichiro, ISHII, Katsuhiro, HANAYAMA, Ryohei, MORI, Yoshitaka, and KITAGAWA, Yoneyoshi

Abstract

Polystyrene deuteride shell targets with two holes were imploded by the Gekko XII laser and additionally heated by the LFEX laser in a direct fast ignition experiment. In general, when an ultra-intense laser is injected into a blow-off plasma created by the imploding laser, electrons are generated far from the target core and the energies of electrons increase because the electron acceleration distance has been extended. The blow-off plasma moves not only to the vertical direction but to the lateral direction against the target surface. In a shell target with holes, a lower effective electron temperature can be realized by reducing the inflow of the implosion plasma onto the LFEX path, and high coupling efficiency can be expected. The energies of hot electrons and ions absorbed into the target core were calculated from the energy spectra using three electron energy spectrometers and a neutron time-of-flight measurement system, Mandala. The ions have a large contribution of 74% (electron heating of 4.9 J and ion heating of 14.1 J) to target heating in direct fast ignition.

Published
2023

3. Hot Electron and Ion Spectra in Axial and Transverse Laser Irradiation in the GXII-LFEX Direct Fast Ignition Experiment

Author

OZAKI, Tetsuo, ABE, Yuki, ARIKAWA, Yasunobu, OKIHARA, Shinichirou, MIURA, Eisuke, SUNAHARA, Atsushi, ISHII, Katsuhiro, HANAYAMA, Ryohei, KOMEDA, Osamu, SENTOKU, Yasuhiko, IWAMOTO, Akifumi, SAKAGAMI, Hitoshi, JOHZAKI, Tomoyuki, KAWANAKA, Junji, TOKITA, Shigeki, MIYANAGA, Noriaki, JITSUNO, Takahisa, NAKATA, Yoshiki, TSUBAKIMOTO, Koji, MORI, Yoshitaka, KITAGAWA, Yoneyoshi, OZAKI, Tetsuo, ABE, Yuki, ARIKAWA, Yasunobu, OKIHARA, Shinichirou, MIURA, Eisuke, SUNAHARA, Atsushi, ISHII, Katsuhiro, HANAYAMA, Ryohei, KOMEDA, Osamu, SENTOKU, Yasuhiko, IWAMOTO, Akifumi, SAKAGAMI, Hitoshi, JOHZAKI, Tomoyuki, KAWANAKA, Junji, TOKITA, Shigeki, MIYANAGA, Noriaki, JITSUNO, Takahisa, NAKATA, Yoshiki, TSUBAKIMOTO, Koji, MORI, Yoshitaka, and KITAGAWA, Yoneyoshi

Abstract

An electron spectrometer was used to measure the electron and ion spectra in two different irradiations of implosion laser to the deuterated spherical shell targets at the direct fast ignition experiments on the Gekko-LFEX facility. In the transverse irradiation against the LFEX laser axis, the low effective hot electron temperature (Teff) and huge neutron yield (Ny) could be obtained although high Teff and low Ny could be observed in the axial irradiation. In the transverse irradiation, the efficient core heating could be obtained because the laser-plasma interaction position is close to the core and the diffusive/ion drag heating may be effective., source:https://doi.org/10.1585/pfr.16.2404076

Published
2022

4. Ten hertz bead pellet injection and laser engagement

Author

MORI, Yoshitaka, ISHII, K., HANAYAMA, R., OKIHARA, S., KITAGAWA, Y., NISHIMURA, Y., KOMEDA, O., HIOKI, T., MOTOHIRO, T., SUNAHARA, Atsushi, SENTOKU, Y., IWAMOTO, Akifumi, SAKAGAMI, Hitoshi, MIURA, E., JOHZAKI, Tomoyuki, MORI, Yoshitaka, ISHII, K., HANAYAMA, R., OKIHARA, S., KITAGAWA, Y., NISHIMURA, Y., KOMEDA, O., HIOKI, T., MOTOHIRO, T., SUNAHARA, Atsushi, SENTOKU, Y., IWAMOTO, Akifumi, SAKAGAMI, Hitoshi, MIURA, E., and JOHZAKI, Tomoyuki

Abstract

source:https://doi.org/10.1088/1741-4326/ac3d69, identifier:0000-0001-7754-9171

Published
2022

5. Super-strong magnetic field-dominated ion beam dynamics in focusing plasma devices

Author

MORACE, A., ABE, Y., HONRUBIA, J.J., IWATA, N., ARIKAWA, Yasunobu, NAKATA, Y., JOHZAKI, Tomoyuki, YOGO, A., SENTOKU, Yasuhiko, MIMA, Kunioki, MA, T., MARISCAL, D., SAKAGAMI, Hitoshi, NORIMATSU, Takayoshi, TSUBAKIMOTO, Koji, KAWANAKA, Junji, TOKITA, Shigeki, MIYANAGA, Noriaki, SHIRAGA, Hiroyuki, SAKAWA, Yohichi, NAKAI, Mitsuo, AZECHI, Hiroshi, FUJIOKA, Shinsuke, KODAMA, Ryosuke, MORACE, A., ABE, Y., HONRUBIA, J.J., IWATA, N., ARIKAWA, Yasunobu, NAKATA, Y., JOHZAKI, Tomoyuki, YOGO, A., SENTOKU, Yasuhiko, MIMA, Kunioki, MA, T., MARISCAL, D., SAKAGAMI, Hitoshi, NORIMATSU, Takayoshi, TSUBAKIMOTO, Koji, KAWANAKA, Junji, TOKITA, Shigeki, MIYANAGA, Noriaki, SHIRAGA, Hiroyuki, SAKAWA, Yohichi, NAKAI, Mitsuo, AZECHI, Hiroshi, FUJIOKA, Shinsuke, and KODAMA, Ryosuke

Abstract

High energy density physics is the field of physics dedicated to the study of matter and plasmas in extreme conditions of temperature, densities and pressures. It encompasses multiple disciplines such as material science, planetary science, laboratory and astrophysical plasma science. For the latter, high energy density states can be accompanied by extreme radiation environments and super-strong magnetic fields. The creation of high energy density states in the laboratory consists in concentrating/depositing large amounts of energy in a reduced mass, typically solid material sample or dense plasma, over a time shorter than the typical timescales of heat conduction and hydrodynamic expansion. Laser-generated, high current–density ion beams constitute an important tool for the creation of high energy density states in the laboratory. Focusing plasma devices, such as cone-targets are necessary in order to focus and direct these intense beams towards the heating sample or dense plasma, while protecting the proton generation foil from the harsh environments typical of an integrated high-power laser experiment. A full understanding of the ion beam dynamics in focusing devices is therefore necessary in order to properly design and interpret the numerous experiments in the field. In this work, we report a detailed investigation of large-scale, kilojoule-class laser-generated ion beam dynamics in focusing devices and we demonstrate that high-brilliance ion beams compress magnetic fields to amplitudes exceeding tens of kilo-Tesla, which in turn play a dominant role in the focusing process, resulting either in a worsening or enhancement of focusing capabilities depending on the target geometry., source:Morace, A., Abe, Y., Honrubia, J.J. et al. Super-strong magnetic field-dominated ion beam dynamics in focusing plasma devices. Sci Rep 12, 6876 (2022). https://doi.org/10.1038/s41598-022-10829-1, source:https://doi.org/10.1038/s41598-022-10829-1

Published
2022

6. Estimation of a Plasma Mirror Reflectivity of LFEX Laser and Relevant Results Using Electron Energy Spectrometers

Author

OZAKI, Tetsuo, MIURA, Eisuke, KOJIMA, Sadaoki, ARIKAWA, Yasunobu, ABE, Yuuki, YAMANOI, Kohei, IKEDA, Tomokazu, ISHII, Katsuhiro, SUNAHARA, Atsushi, JOHZAKI, Tomoyuki, SAWADA, Hiroshi, FUJIOKA, Shinsuke, SAKAGAMI, Hitoshi, KITAGAWA, Yoneyoshi, MORI, Yoshitaka, OZAKI, Tetsuo, MIURA, Eisuke, KOJIMA, Sadaoki, ARIKAWA, Yasunobu, ABE, Yuuki, YAMANOI, Kohei, IKEDA, Tomokazu, ISHII, Katsuhiro, SUNAHARA, Atsushi, JOHZAKI, Tomoyuki, SAWADA, Hiroshi, FUJIOKA, Shinsuke, SAKAGAMI, Hitoshi, KITAGAWA, Yoneyoshi, and MORI, Yoshitaka

Abstract

In the counter-irradiation, which is one of the fast ignition schemes, higher core energy coupling can be expected when there are two hot electron flows in counter directions. Two plasma mirrors were installed for the counter irradiation at about 180 degrees. The hot electron effective temperatures (Teff) were measured by using electron energy spectrometers. Teff vs the laser intensity on a foil target followed Wilkes' scaling law. The energy incident on the target could be calculated by estimating the laser intensity on the target from Teff and estimating the focusing radius from the X-ray pinhole camera image. As a result, the reflectivity could be estimated to be 17 ± 3%., source:https://doi.org/10.1585/pfr.17.2404084

Published
2022

7. Demonstration of a spherical plasma mirror for the counter-propagating kilojoule-class petawatt LFEX laser system

Author

1000040815156, Kojima, Sadaoki, Abe, Yuki, 1000010358070, Miura, Eisuke, 1000050183033, Ozaki, Tetsuo, 1000030722813, 0000-0003-4492-4099, Yamanoi, Kohei, Ikeda, Tomokazu, Wang, Yubo, Dun, Jinyuan, Guo, Shuwang, Maekawa, Tamaki, Takizawa, Ryunosuke, Morita, Hiroki, Asano, Shoui, 1000090624255, 0000-0002-3142-3060, Arikawa, Yasunobu, Sawada, Hiroshi, 1000030311517, Ishii, Katsuhiro, 1000020418924, Hanayama, Ryohei, Okihara, Shinichiro, 1000040093405, Kitagawa, Yoneyoshi, Kajimura, Yasuhiro, 1000070724326, Morace, Alessio, Shiraga, Hiroyuki, 1000050335395, 0000-0002-3978-8427, Shigemori, Keisuke, Sunahara, Atsushi, 1000070814086, Iwata, Natsumi, 1000080362606, 0000-0001-9106-3856, Sano, Takayoshi, 1000010322653, 0000-0003-2093-7100, Sentoku, Yasuhiko, 1000010397680, Johzaki, Tomoyuki, 1000070370450, Nishikino, Masaharu, 1000000260050, Iwamoto, Akifumi, 1000020353443, Nagaoka, Kenichi, 1000030254452, Sakagami, Hitoshi, 1000040372635, 0000-0001-8406-1772, Fujioka, Shinsuke, Mori, Yoshitaka, 1000040815156, Kojima, Sadaoki, Abe, Yuki, 1000010358070, Miura, Eisuke, 1000050183033, Ozaki, Tetsuo, 1000030722813, 0000-0003-4492-4099, Yamanoi, Kohei, Ikeda, Tomokazu, Wang, Yubo, Dun, Jinyuan, Guo, Shuwang, Maekawa, Tamaki, Takizawa, Ryunosuke, Morita, Hiroki, Asano, Shoui, 1000090624255, 0000-0002-3142-3060, Arikawa, Yasunobu, Sawada, Hiroshi, 1000030311517, Ishii, Katsuhiro, 1000020418924, Hanayama, Ryohei, Okihara, Shinichiro, 1000040093405, Kitagawa, Yoneyoshi, Kajimura, Yasuhiro, 1000070724326, Morace, Alessio, Shiraga, Hiroyuki, 1000050335395, 0000-0002-3978-8427, Shigemori, Keisuke, Sunahara, Atsushi, 1000070814086, Iwata, Natsumi, 1000080362606, 0000-0001-9106-3856, Sano, Takayoshi, 1000010322653, 0000-0003-2093-7100, Sentoku, Yasuhiko, 1000010397680, Johzaki, Tomoyuki, 1000070370450, Nishikino, Masaharu, 1000000260050, Iwamoto, Akifumi, 1000020353443, Nagaoka, Kenichi, 1000030254452, Sakagami, Hitoshi, 1000040372635, 0000-0001-8406-1772, Fujioka, Shinsuke, and Mori, Yoshitaka

Abstract

Kojima S., Abe Y., Miura E., et al. Demonstration of a spherical plasma mirror for the counter-propagating kilojoule-class petawatt LFEX laser system. Optics Express 30, 43491 (2022); https://doi.org/10.1364/oe.475945., A counter-propagating laser-beam platform using a spherical plasma mirror was developed for the kilojoule-class petawatt LFEX laser. The temporal and spatial overlaps of the incoming and redirected beams were measured with an optical interferometer and an x-ray pinhole camera. The plasma mirror performance was evaluated by measuring fast electrons, ions, and neutrons generated in the counter-propagating laser interaction with a Cu-doped deuterated film on both sides. The reflectivity and peak intensity were estimated as ∼50% and ∼5 × 1018 W/cm2, respectively. The platform could enable studies of counter-streaming charged particles in high-energy-density plasmas for fundamental and inertial confinement fusion research.

Published
2022

8. Study on Thermal Responses of Dry Walls in Laser Fusion Reactors

Author

ヤマモト, ケイジ, フルカワ, ヒロユキ, ジョウザキ, トモユキ, コザキ, ヤスジ, ヒロオカ, ヨシヒコ, ウエダ, ヨシオ, ニシカワ, マサヒロ, タナカ, カズオ, Yamamoto, Keiji, Furukawa, Hiroyuki, Johzaki, Tomoyuki, Kozaki, Yasuji, Hirooka, Yoshihiko, Ueda, Yoshio, Nishikawa, Masahiro, Tanaka, Kazuo A., 山本, 敬治, 古河, 裕之, 城﨑, 知至, 神前, 康次, 廣岡, 慶彦, 上田, 良夫, 西川, 雅弘, 田中, 和夫, ヤマモト, ケイジ, フルカワ, ヒロユキ, ジョウザキ, トモユキ, コザキ, ヤスジ, ヒロオカ, ヨシヒコ, ウエダ, ヨシオ, ニシカワ, マサヒロ, タナカ, カズオ, Yamamoto, Keiji, Furukawa, Hiroyuki, Johzaki, Tomoyuki, Kozaki, Yasuji, Hirooka, Yoshihiko, Ueda, Yoshio, Nishikawa, Masahiro, Tanaka, Kazuo A., 山本, 敬治, 古河, 裕之, 城﨑, 知至, 神前, 康次, 廣岡, 慶彦, 上田, 良夫, 西川, 雅弘, and 田中, 和夫

Published
2006

9. Demonstration of a spherical plasma mirror for the counter-propagating kilojoule-class petawatt LFEX laser system

Author

Kojima, Sadaoki, Abe, Yuki, Miura, Eisuke, Ozaki, Tetsuo, Yamanoi, Kohei, Ikeda, Tomokazu, Wang, Yubo, Dun, Jinyuan, Guo, Shuwang, Maekawa, Tamaki, Takizawa, Ryunosuke, Morita, Hiroki, Asano, Shoui, Arikawa, Yasunobu, Sawada, Hiroshi, Ishii, Katsuhiro, Hanayama, Ryohei, Okihara, Shinichiro, Kitagawa, Yoneyoshi, Kajimura, Yasuhiro, Morace, Alessio, Shiraga, Hiroyuki, Shigemori, Keisuke, Sunahara, Atsushi, Iwata, Natsumi, Sano, Takayoshi, Sentoku, Yasuhiko, Johzaki, Tomoyuki, Nishikino, Masaharu, Iwamoto, Akifumi, Nagaoka, Kenichi, Sakagami, Hitoshi, Fujioka, Shinsuke, Mori, Yoshitaka, Kojima, Sadaoki, Abe, Yuki, Miura, Eisuke, Ozaki, Tetsuo, Yamanoi, Kohei, Ikeda, Tomokazu, Wang, Yubo, Dun, Jinyuan, Guo, Shuwang, Maekawa, Tamaki, Takizawa, Ryunosuke, Morita, Hiroki, Asano, Shoui, Arikawa, Yasunobu, Sawada, Hiroshi, Ishii, Katsuhiro, Hanayama, Ryohei, Okihara, Shinichiro, Kitagawa, Yoneyoshi, Kajimura, Yasuhiro, Morace, Alessio, Shiraga, Hiroyuki, Shigemori, Keisuke, Sunahara, Atsushi, Iwata, Natsumi, Sano, Takayoshi, Sentoku, Yasuhiko, Johzaki, Tomoyuki, Nishikino, Masaharu, Iwamoto, Akifumi, Nagaoka, Kenichi, Sakagami, Hitoshi, Fujioka, Shinsuke, and Mori, Yoshitaka

Abstract

Kojima S., Abe Y., Miura E., et al. Demonstration of a spherical plasma mirror for the counter-propagating kilojoule-class petawatt LFEX laser system. Optics Express 30, 43491 (2022); https://doi.org/10.1364/oe.475945., A counter-propagating laser-beam platform using a spherical plasma mirror was developed for the kilojoule-class petawatt LFEX laser. The temporal and spatial overlaps of the incoming and redirected beams were measured with an optical interferometer and an x-ray pinhole camera. The plasma mirror performance was evaluated by measuring fast electrons, ions, and neutrons generated in the counter-propagating laser interaction with a Cu-doped deuterated film on both sides. The reflectivity and peak intensity were estimated as ∼50% and ∼5 × 1018 W/cm2, respectively. The platform could enable studies of counter-streaming charged particles in high-energy-density plasmas for fundamental and inertial confinement fusion research.

10. Demonstration of a spherical plasma mirror for the counter-propagating kilojoule-class petawatt LFEX laser system

Author

Kojima, Sadaoki, Abe, Yuki, Miura, Eisuke, Ozaki, Tetsuo, Yamanoi, Kohei, Ikeda, Tomokazu, Wang, Yubo, Dun, Jinyuan, Guo, Shuwang, Maekawa, Tamaki, Takizawa, Ryunosuke, Morita, Hiroki, Asano, Shoui, Arikawa, Yasunobu, Sawada, Hiroshi, Ishii, Katsuhiro, Hanayama, Ryohei, Okihara, Shinichiro, Kitagawa, Yoneyoshi, Kajimura, Yasuhiro, Morace, Alessio, Shiraga, Hiroyuki, Shigemori, Keisuke, Sunahara, Atsushi, Iwata, Natsumi, Sano, Takayoshi, Sentoku, Yasuhiko, Johzaki, Tomoyuki, Nishikino, Masaharu, Iwamoto, Akifumi, Nagaoka, Kenichi, Sakagami, Hitoshi, Fujioka, Shinsuke, Mori, Yoshitaka, Kojima, Sadaoki, Abe, Yuki, Miura, Eisuke, Ozaki, Tetsuo, Yamanoi, Kohei, Ikeda, Tomokazu, Wang, Yubo, Dun, Jinyuan, Guo, Shuwang, Maekawa, Tamaki, Takizawa, Ryunosuke, Morita, Hiroki, Asano, Shoui, Arikawa, Yasunobu, Sawada, Hiroshi, Ishii, Katsuhiro, Hanayama, Ryohei, Okihara, Shinichiro, Kitagawa, Yoneyoshi, Kajimura, Yasuhiro, Morace, Alessio, Shiraga, Hiroyuki, Shigemori, Keisuke, Sunahara, Atsushi, Iwata, Natsumi, Sano, Takayoshi, Sentoku, Yasuhiko, Johzaki, Tomoyuki, Nishikino, Masaharu, Iwamoto, Akifumi, Nagaoka, Kenichi, Sakagami, Hitoshi, Fujioka, Shinsuke, and Mori, Yoshitaka

Abstract

Kojima S., Abe Y., Miura E., et al. Demonstration of a spherical plasma mirror for the counter-propagating kilojoule-class petawatt LFEX laser system. Optics Express 30, 43491 (2022); https://doi.org/10.1364/oe.475945., A counter-propagating laser-beam platform using a spherical plasma mirror was developed for the kilojoule-class petawatt LFEX laser. The temporal and spatial overlaps of the incoming and redirected beams were measured with an optical interferometer and an x-ray pinhole camera. The plasma mirror performance was evaluated by measuring fast electrons, ions, and neutrons generated in the counter-propagating laser interaction with a Cu-doped deuterated film on both sides. The reflectivity and peak intensity were estimated as ∼50% and ∼5 × 1018 W/cm2, respectively. The platform could enable studies of counter-streaming charged particles in high-energy-density plasmas for fundamental and inertial confinement fusion research.

Catalog

Books, media, physical & digital resources
See catalog results