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Nakanishi, Ryuzo; Oba, Hironori; Saeki, Morihisa; Wakaida, Ikuo; Tanabe, Rie*; Ito, Yoshiro*
Optics Express (Internet), 29(4), p.5205 - 5212, 2021/02
Times Cited Count：13 Percentile：83.13(Optics)Laser-induced breakdown spectroscopy (LIBS) combined with liquid jets was applied to the detection of trace sodium (Na) in aqueous solutions. The sensitivities of two types of liquid jets were compared: a liquid cylindrical jet with a diameter of 500 
m and a liquid sheet jet with a thickness of 20 m. Compared with the cylindrical jet, the liquid sheet jet effectively reduced the splash from the laser-irradiated surface and produced long-lived luminous plasma. The limit of detection (LOD) of Na was determined to be 0.57 g/L for the sheet jet and 10.5 g/L for the cylindrical jet. The LOD obtained for the sheet jet was comparable to those obtained for commercially available inductively coupled plasma emission spectrometers.
Matsumoto, Ayumu
Reza Kako Gakkai-Shi, 23(3), p.222 - 231, 2016/10
no abstracts in English
Nakano, Tomohide; Shumack, A.*; Maggi, C. F.*
Journal of Physics B; Atomic, Molecular and Optical Physics, 2 Pages, 2016/01
Collaboration of researchers from Japan Atomic Energy Agency and EUROfusion Consortium (Dutch Institute For Fundamental Energy Research, Max-Planck-Institut f
r Plasmaphysik and so on) successfully led to determination of tungsten ion density in high temperature plasmas in Joint European Torus (JET) with an upgraded X-ray spectrometer. The researchers used the FAC code and successfully identified 
, 
and 
spectral lines. The line identification was confirmed experimentally by Mo injection to the plasma. From the measured absolute intensity of these spectral lines, tungsten and molybdenum ion densities in the plasma core were determined.
Sugie, Tatsuo
Purazuma Shindan No Kiso To Oyo, p.116 - 131, 2006/03
Radiation from the plasma degrades the performance of energy confinement. In addition, the efficiency of fusion reaction will be decreased by the fuel dilution due to the impurity ions in the plasma. Therefore, the impurity control (generation, reduction of the contamination, exhaust) becomes an important research subject. Spectroscopic diagnostics is the one of the most important methods to study such subjects. On the other hand, it is also utilized for the measurements of plasma parameters such as ion temperature, plasma current distribution etc. In this section, the radiation behavior and the spectroscopic diagnostics of high temperature plasma are described.
Eidmann, K.*; Kawachi, Tetsuya; Marcinkevicius, A.*; Bartlome, R.*; Tsakiris, G.*; Witte, K.*; Teubner, U.*
Physical Review E, 72(3), p.036413_1 - 036413_9, 2005/09
Times Cited Count：33 Percentile：77.37(Physics, Fluids & Plasmas)In order to clarify the mechanism of high-order harmonics generation from solid target, we investigated the emission from rear side of the foil target irradiated by an intense Ti:S laser pulse, duration of 150 fs. The comparison of the exprimental result with our Particle-in-Cell simulation implies that rear side emission is caused by energetic electron bunches which is generated at the front side by resonance absorption.
Kawachi, Tetsuya; Nagashima, Keisuke; Kishimoto, Maki; Hasegawa, Noboru; Tanaka, Momoko; Ochi, Yoshihiro; Nishikino, Masaharu; Kawazome, Hayato; Tai, R.; Namikawa, Kazumichi*; et al.
Proceedings of SPIE's International Symposium on Optics and Photonics 2005, Vol.5919, p.59190L_1 - 59190L_11, 2005/09
Recent results of the X-ray laser research in Advanced Photon Research (APR) Center in JAERI are reported. In the application of the nickel-like silver laser at a wavelength of 13.9 nm, we report the observation of the microscopic polarization clusters in ferroelectrics material such as BaTi03 by use of the X-ray speckle technique, and other experiments such as photo-ionization of inner-shell electrons are intoroduced. In the development of high quality X-ray laser beam, recently we demonstrated temporally coherent X-ray beam at 23.6 nm, in which the high-order harmonics light was injected into the Ne-like Mn X-ray amplifier. We also mention about the development of new X-ray laser driver laser, which is based on 2 beams of zig-zag slab Nd:glass lasers with 0.1 Hz repetition-rate, and each beam line can provide 10 J output energy, and 1 ps duration.
Kubo, Hirotaka; Takenaga, Hidenobu; Sawada, Keiji*; Nakano, Tomohide; Kobayashi, Shinji*; Higashijima, Satoru; Asakura, Nobuyuki; Shimizu, Katsuhiro
Journal of Nuclear Materials, 337-339, p.161 - 165, 2005/03
Times Cited Count：16 Percentile：71.86(Materials Science, Multidisciplinary)no abstracts in English
Oba, Hironori; Saeki, Morihisa; Yokoyama, Atsushi
Proceedings of Plasma Science Symposium 2005/22nd Symposium on Plasma Processing (PSS-2005/SPP-22), p.331 - 332, 2005/01
A plasma produced by a XeCl laser ablation of boron compound was investigated using ion probes and a quadrupole mass spectrometer. Although the ablated neutral boron atoms had a natural abundance ratio, the isotope ratio of singly ionized boron atoms having a greatly different from the natural abundance ratio was observed. The observed isotope ratio of boron ions was different from the natural abundance.
spectral bands for hydrocarbon-loss-events measured in JT-60U divertor plasmasNakano, Tomohide; Tsuzuki, Kazuhiro; Higashijima, Satoru; Kubo, Hirotaka; Asakura, Nobuyuki
Europhysics Conference Abstracts (CD-ROM), 29C, 4 Pages, 2005/00
Emission rates of CH and C
spectral bands for CH
, CD
_2
loss events due to dissociation, ionization and transport were measured in JT-60U divertor plasmas. The obtained data were used for estimating the chemical sputtering yields by a spectroscopic technique. The CH loss events over one CH photon emission was about 200 at electron temperatures between 30 eV and 70 eV. These values fell within the confidential band of the CD one. The CH
loss events over one CH and one C photon emission were, respectively, between 200 - 300 and between 600 - 1800, and their ratio between 3 - 6. On the assumption that only CH among hydrocarbons generated by chemical sputtering emits the C spectral bands, the intensity of the CH spectral bands originating from CH is inferred from the intensity of C spectral bands multiplied by the obtained ratio, resulting in higher than the measured CH intensity. This result indicates that dominant hydrocarbons generated by the chemical sputtering is not CH but CH.
Kubo, Hirotaka; Takenaga, Hidenobu; Nakano, Tomohide; Higashijima, Satoru; Shimizu, Katsuhiro; Sawada, Keiji*; Kobayashi, Shinji*; JT-60 Team
Nuclear Fusion Research; Springer Series in Chemical Physics, Vol.78, p.121 - 134, 2004/11
no abstracts in English
Kawachi, Tetsuya
Physical Review E, 67(1), p.016409_1 - 016409_8, 2003/01
Times Cited Count：3 Percentile：18.75(Physics, Fluids & Plasmas)A collisional-radiative model for the lithium-like and beryllium-like ions has been constructed. In this model, virtually all the doubly excited levels of the beryllium-like ions are taken into account. Time-differential coupled rate equatios for the level populations of the liyjium-like and beryllium-like ions are solved under a recombining plasma condition, and the population kinetics of these ions, especially for the validity of quasi-steady state(QSS) approximation and the population flux into and out of excited levels, is discussed. Temporal evolution of gains of the lithium-like aluminum laser is also calculated, and the result indicates the gain is generated before the establishment of the QSS condition.
Lu, P.; Kawachi, Tetsuya; Kishimoto, Maki; Sukegawa, Kota*; Tanaka, Momoko; Hasegawa, Noboru; Suzuki, Masayuki; Tai, R.; Kado, Masataka; Nagashima, Keisuke; et al.
Optics Letters, 27(21), p.1911 - 1913, 2002/11
Times Cited Count：8 Percentile：39.8(Optics)We demonstrate a high gain nickel-like xenon ion x-ray laser using a gas puff target. The elongated x-ray laser plasma column was produced by irradiating the gas puff target with line-focused double picosecond laser pulses with a total energy of 18 J in a travelling-wave excitation scheme. Strong lasing at 9.98 nm was observed, and a high gain coefficient of 17.4 1/cm was measured on the transient collisionally excited 4d ミ 4p, J=0-1 transition for nickel-like xenon ion with target lengths up to 0.45 cm long. A weak nickel-like lasing line at a shorter wavelength of 9.64 nm was also observed with a gain coefficient of 5.9 1/cm.
Kawachi, Tetsuya; Kado, Masataka; Tanaka, Momoko; Sasaki, Akira; Hasegawa, Noboru; Kilpio, A.*; Namba, Shinichi; Nagashima, Keisuke; Lu, P.; Takahashi, Kenjiro; et al.
Physical Review A, 66(3), p.033815_1 - 033815_7, 2002/09
Times Cited Count：85 Percentile：93.03(Optics)A silver and tin slab targets were irradiated by a line-focused CPA glass laser light. In this experiment, the laser pulses consisted of two pulses with 4 ps duration, separated by 1.2 ns. Strong amplification in the nickel-like silver and tin x-ray lasers at the wavelengths of 13.9nm and 12.0nm was demonstrated with a pumping energy of 12 J and 14 J, respectively, and gain-saturation behaviors could be seen. A hydro-dynamics simulation coupled with a collisional-radiative model was performed under the present experimental condition, and the calculated result was compared with the experimental results.
Department of Fusion Plasma Research
JAERI-Conf 2000-007, p.161 - 0, 2000/03
JAERI-Conf-2000-007.pdf:9.11MB
no abstracts in English
Sugie, Tatsuo; Ogawa, Hiroaki; *; *; Ebisawa, Katsuyuki*; Ando, Toshiro; *; Kasai, Satoshi; Nishitani, Takeo
Review of Scientific Instruments, 70(1), p.351 - 354, 1999/01
Times Cited Count：10 Percentile：58.84(Instruments & Instrumentation)no abstracts in English
Kato, Takako*; *; Murakami, Izumi*; *; Kubo, Hirotaka; Shimizu, Katsuhiro
Proc. of 1996 Int. Conf. on Plasma Physics, 1, p.730 - 733, 1996/00
no abstracts in English
JAERI-Conf 95-005, 1035 Pages, 1995/03
no abstracts in English
Yoda, Osamu; Miyashita, Atsumi; *; *; *
Excimer Lasers and Applications III, p.463 - 466, 1991/00
no abstracts in English
Baba, Yuji
JAERI 1304, 76 Pages, 1987/02
no abstracts in English
Itakura, Ryuji
no journal, ,
In this study, we propose and demonstrate a new methodology based on time-resolved vacuum-ultraviolet (VUV) reflection spectroscopy for monitoring plasma formation induced by an intense laser pump pulse. The temporal waveform of a VUV probe pulse is also retrieved simultaneously.
