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Kawachi, Tetsuya; Hasegawa, Noboru; Iwamae, Atsushi*; Yoneda, Hitoki*
Journal of Physics; Conference Series, 548(1), p.012038_1 - 012038_7, 2014/11
Times Cited Count:0 Percentile:0.00(Physics, Applied)Polarization is a fundamental property of light, and the effective use provides us powerful tools for probing materials and for plasma diagnostics. In plasmas, alignment of emission shows the plasma anisotropy, and Zeeman splitting informs us the magnetic field strength. We took the plasma-based soft X-ray laser as an example and observed the Zeeman splitting under the external magnetic field. A grazing incidence spectrograph, HIREFS, with the resolution of 15000 was used to observe the X-ray laser line. A magnetic coil driven by an electrical pulsed power supply provided the external magnetic field of 1035 T along the direction of the plasma column, and the left-handed and right-handed circular polarization components were obtained separately. The experimental result indicated that the magnetic field was larger by a factor of 4 than that of the applied field, which implied that the magnetic field compression occurred in the dynamics of the intense laser-plasma interaction.
Iwamae, Atsushi*; Ogawa, Hiroaki; Sugie, Tatsuo; Kusama, Yoshinori
JAEA-Research 2011-045, 11 Pages, 2012/02
In order to investigate reflection properties on plasma-facing material in ITER, the bi-directional reflectance distribution function (BRDF) of a tungsten block sample has been measured. On the machining surface of the block, one-directional machining lines are engraved. Two laser diodes 652 nm and
473 nm were used to simulate H
and H
emissions, respectively. The reflected light is affected by the machining surface. The reflected light traces a line when the incident light is injected in the perpendicular direction to the engraved line. On the other hand the reflected light traces an arc shape when the incident light is injected in the parallel direction to the engraved lines. Ray tracing simulation qualitatively explains the experimental results.
Iwamae, Atsushi; Sugie, Tatsuo; Ogawa, Hiroaki; Kusama, Yoshinori
Plasma Physics and Controlled Fusion, 53(4), p.045005_1 - 045005_17, 2011/04
Times Cited Count:5 Percentile:22.26(Physics, Fluids & Plasmas)Iwamae, Atsushi; Ogawa, Hiroaki; Sugie, Tatsuo; Kusama, Yoshinori
Review of Scientific Instruments, 82(3), p.033502_1 - 033502_4, 2011/03
Times Cited Count:3 Percentile:17.47(Instruments & Instrumentation)Shoji, Mamoru*; Masuzaki, Suguru*; Kobayashi, Masahiro*; Goto, Motoshi*; Morisaki, Tomohiro*; Yamada, Hiroshi*; Komori, Akio*; Iwamae, Atsushi; Sakaue, Atsushi*; LHD Experimental Group*
Fusion Science and Technology, 58(1), p.208 - 218, 2010/07
Times Cited Count:9 Percentile:51.35(Nuclear Science & Technology)Yanagibayashi, Jun*; Nakano, Tomohide; Iwamae, Atsushi; Kubo, Hirotaka; Hasuo, Masahiro*; Itami, Kiyoshi
Journal of Physics B; Atomic, Molecular and Optical Physics, 43(14), p.144013_1 - 144013_6, 2010/07
Times Cited Count:28 Percentile:74.70(Optics)We observe the vacuum ultraviolet spectra of highly charged tungsten ions in plasmas at electron temperatures of 8 keV and 14 keV. The observed emission lines in a wavelength range of 2.6 3.2 nm for the plasma at 8 keV are identified to be the
transitions of
. The observed emission lines at 2.0 nm and 2.3 nm at 14 keV are identified to be the
transitions of
and
transitions of
, respectively.
Iwamae, Atsushi; Sakaue, Atsushi*; Atake, Makoto*; Sawada, Keiji*; Goto, Motoshi*; Morita, Shigeru*
Plasma Physics and Controlled Fusion, 51(11), p.115004_1 - 115004_15, 2009/11
Times Cited Count:6 Percentile:22.92(Physics, Fluids & Plasmas)Iwamae, Atsushi; Sugie, Tatsuo; Ogawa, Hiroaki; Kusama, Yoshinori
Plasma and Fusion Research (Internet), 4, p.042_1 - 042_11, 2009/10
Hasegawa, Noboru; Sasaki, Akira; Yamatani, Hiroshi; Kishimoto, Maki; Tanaka, Momoko; Ochi, Yoshihiro; Nishikino, Masaharu; Kunieda, Yuichi; Kawachi, Tetsuya; Yoneda, Hitoki*; et al.
Journal of the Optical Society of Korea, 13(1), p.60 - 64, 2009/03
Times Cited Count:5 Percentile:28.79(Optics)The precise knowledge about the spectral width of the X-ray laser line is important to generate the circularly polarized X-ray laser. There are three magnetic sub-levels at lower state of the collisional excitation X-ray laser transition of the nickel-like ion X-ray laser medium. The polarization of each transition is circular or linear. Therefore the circularly polarized X-ray laser could be extracted by the influence of the Zeeman effect if the X-ray laser medium was under the external magnetic field. The strength of the magnetic field required for the circularly polarized X-ray laser is determined by the spectral width of the X-ray laser. Only a few measurements of the spectral width of the laser line have been reported, because the spectral width of the X-ray laser is so narrow that the required spectral resolution is quite high. In this study, we took the nickel-like molybdenum X-ray laser as an example and succeeded the measurement of the spectral width of the X-ray laser.
Maehara, Tsunehiro*; Kawashima, Ayato*; Iwamae, Atsushi; Mukasa, Shinobu*; Takemori, Toshihiko*; Watanabe, Takashi*; Kurokawa, Kenya*; Toyota, Hiromichi*; Nomura, Shinfuku*
Physics of Plasmas, 16(3), p.033503_1 - 033503_5, 2009/03
Times Cited Count:14 Percentile:46.06(Physics, Fluids & Plasmas)Iwamae, Atsushi; Ogawa, Hiroaki; Sugie, Tatsuo; Kasai, Satoshi*; Kusama, Yoshinori
Proceedings of 18th International Toki Conference on Development of Physics and Technology of Stellarator/Heliotrons en route to Demo (ITC-18) (CD-ROM), p.450 - 453, 2008/12
Maehara, Tsunehiro*; Miyamoto, Ippei*; Kurokawa, Kenya*; Hashimoto, Yukio*; Iwamae, Atsushi; Kuramoto, Makoto*; Yamashita, Hiroshi*; Mukasa, Shinobu*; Toyota, Hiromichi*; Nomura, Shinfuku*; et al.
Plasma Chemistry and Plasma Processing, 28(4), p.467 - 482, 2008/08
Times Cited Count:54 Percentile:87.03(Engineering, Chemical)Kim, J.*; Kim, D. E.*; Kawachi, Tetsuya; Hasegawa, Noboru; Sukegawa, Kota*; Iwamae, Atsushi*; Fujimoto, Takashi*
Journal of the Optical Society of Korea, 7(3), p.145 - 149, 2003/09
The anistropy of electron energy distribution in oxygen plasmas produced by a high intensinty laser was investigated by using polarization spectroscopy. An ultra-short pulsed laser with a pulse duration of 66.5 fs and a power density of 110
W/cm
was used. At this power density and pulse duration, the plasma was generated predominantly by optical field ionization. The degree of polarization of OVI 1s
2p
P
-1s
4d
D
(J=1/2-3/2 and J=3/2-5/2) transition line at 129.92
の1s
2p
P
-1s
4s
S
(J=1/2-1/2 and J=3/2-1/2) transition line at 132.26 AA was used to calibrate the sensitivity of the optical system. The dependencies of the degree of polarization on the initial gas density and on the laser polarization were investigated. When the laser polarization was changed from a linear to a circlar polarization was decreased. When the initial gas density was increased, the degree of polarization was decreased.
Hasegawa, Noboru; Kawachi, Tetsuya; Sasaki, Akira; Kishimoto, Maki; Tanaka, Momoko; Ochi, Yoshihiro; Nishikino, Masaharu; Kunieda, Yuichi; Iwamae, Atsushi*; Yoneda, Hitoki*
no journal, ,
We tried to generate the circularly polarized X-ray laser by use of the high power pulse magnet system. There are three magnetic sub-levels at lower state of the collisional excitation X-ray laser transition. For example, nickel-like X-ray laser transition (4d (m = 0) - 4p (m = -1, 0, +1)), the polarization from each transitions are right-handed circular (m = -1), left-handed circular (
m = +1), and linear (
m = 0) along to the quantization axis. If the quantization axis were decided by the magnetic field from the outside of the X-ray laser medium, the circularly polarized X-ray laser can be extracted. In this study, we tried to generate the circularly polarized X-ray laser by using the nickel-like molybdenum X-ray laser medium (18.9 nm) with 20 Tesla magnetic field generated by the pulse power magnet system.
Kawano, Yasunori; Kondoh, Takashi; Ishikawa, Masao; Hatae, Takaki; Hayashi, Toshimitsu; Ono, Takehiro; Ogawa, Hiroaki; Sugie, Tatsuo; Iwamae, Atsushi; Kusama, Yoshinori; et al.
no journal, ,
Progress in ITER diagnostics development in Japan is presented. (1) Micro Fission Chamber: A bending test of the mineral insulated cable has been carried out since its smallest bending radius would be 12 cm in the vacuum vessel. It has been confirmed that no damage has been observed even at the bending radius is small as 10 cm. (2) Thomson Scattering (Edge): It has been confirmed that the prototype YAG laser amplifier satisfies the target performance of ITER requirement. (3) Poloidal Polarimeter: Study of retro-reflectors in the first wall modules and the divertor cassette has been progressed. (4) Impurity Influx Monitor (Divertor): Mechanical designs of mirror box and optical shutter in the divertor cassette have been designed. (5) Upper Port Plug: For the generic design of the upper port plug (UPP), mesh modeling of UPP has been performed for the E-M analysis. Application of HIP (Hot Isostatic Press) method for manufacturing of UPP has been proposed.
Kawano, Yasunori; Iwamae, Atsushi; Ogawa, Hiroaki; Sugie, Tatsuo; Hatae, Takaki; Yatsuka, Eiichi; Kondoh, Takashi; Ishikawa, Masao; Sato, Kazuyoshi; Hayashi, Toshimitsu; et al.
no journal, ,
no abstracts in English
Iwamae, Atsushi; Ogawa, Hiroaki; Sugie, Tatsuo; Kusama, Yoshinori
no journal, ,
no abstracts in English
Kusama, Yoshinori; Ishikawa, Masao; Kondoh, Takashi; Ogawa, Hiroaki; Iwamae, Atsushi; Sugie, Tatsuo; Takeuchi, Masaki
no journal, ,
no abstracts in English
Ogawa, Hiroaki; Iwamae, Atsushi; Sugie, Tatsuo; Kasai, Satoshi*; Katsunuma, Atsushi*; Hara, Hirotsugu*; Takeyama, Norihide*; Kusama, Yoshinori
no journal, ,
no abstracts in English
Ogawa, Hiroaki; Iwamae, Atsushi; Sugie, Tatsuo; Takeuchi, Masaki; Kusama, Yoshinori
no journal, ,
no abstracts in English