Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Shiwaku, Hideaki; Marushita, Motoharu*
JAEA-Research 2022-015, 39 Pages, 2023/05
JAEA-Research-2022-015.pdf:2.74MB
We designed the hard X-ray undulator beamline BL22XU, which is dedicated to Japan Atomic Energy Research Institute (JAERI) at SPring-8 (now Japan Atomic Energy Agency (JAEA)). BL22XU is used for XAFS (X-ray Absorption Fine Structure) analysis experiments to develop separation and extraction materials for radioactive waste treatment and to elucidate their chemical behavior, magnetic research experiments using a diffractometer, and experiments under extreme conditions using a high-pressure press and a diamond anvil cell. The available X-ray energy range was set from 3 to 70 keV. To design the optics of the beamline, the reflectivity of the mirrors, the diffraction width of the monochromatic crystal, and the absorptance of the Be window were calculated. In addition, ray tracing was performed to optimize the materials for optics, dimensions, and location. The delay time of the ADL (Acoustic Delay Line) was also examined to ensure the safety in the use of radioactive materials. The operation of BL22XU "JAEA Actinide Science I" has already started. By collaborating BL22XU and BL23SU "JAEA Actinide Science II," which uses a soft X-ray undulator as a light source, we solve the problems to promote nuclear sciences. Since the monochromator was upgraded in 2018-2019, initial planning and measured data are documented here again.
Sato, Yuki
Physics Open (Internet), 7, p.100070_1 - 100070_8, 2021/05
Tamura, Itaru; Kashima, Yoichi; Soyama, Kazuhiko
JAEA-Research 2014-029, 12 Pages, 2015/03
JAEA-Research-2014-029.pdf:1.89MB
Neutron guide tubes, which are installed near reactor cores, are damaged by neutrons and 
rays irradiation. Those glass substrates which contain boron material are affected by (n, 
) reaction, and ionization effect of rays on material strength decrease duration of use of neutron guide tubes. In order to increase resistance to radiation, we have fabricated a supermirror with Ni-P metallic substrate. The substrate roughness with 0.2 - 0.3 nm (rms) was produced by super- polishing. The neutron reflectivity reached 76 % for an m=3 supermirror.
Hatae, Takaki; Naito, Osamu; Kitamura, Shigeru; Sakuma, Takeshi*; Hamano, Takashi*; Nakatsuka, Masahiro*; Yoshida, Hidetsugu*
Journal of the Korean Physical Society, 49, p.S160 - S164, 2006/12
no abstracts in English
Maruyama, Ryuji; Yamazaki, Dai; Ebisawa, Toru*; Hino, Masahiro*; Soyama, Kazuhiko
Physica B; Condensed Matter, 385-386(2), p.1256 - 1258, 2006/11
Times Cited Count：25 Percentile：70.33(Physics, Condensed Matter)Neutron supermirror has become an important device to transport, bending and focusing a neutron beam. We have developed it using ion beam sputtering (IBS) instrument since it enables us to produce good quality layers with high density and small grain size. We have also investigated ion-polishing technique, which suppresses the interface roughness of multilayers. We have now installed new IBS instrument with effective deposit area of 500 mm in diameter for the realization of supermirror guide and bender with large effective critical angle. In this presentation, the performance of the supermirrors fabricated with it and the future development of neutron optical devices using supermirrors will be discussed.
Kashiwa, Yoshinori*; Saigusa, Mikio*; Takahashi, Koji; Kasugai, Atsushi; Sakamoto, Keishi
Fusion Engineering and Design, 81(19), p.2249 - 2256, 2006/09
Times Cited Count：4 Percentile：30.64(Nuclear Science & Technology)High efficiency ECCD operations need an obliquely propagating electromagnetic wave with a specified elliptical polarization in magnetized plasma. The polarizer is necessary in order to excite the specified polarization. In the ITER design for ECCD system, the transmitted power per one waveguide is planned to be 1 MW as CW operation. The ohmic loss evaluation code for grooved mirror polarizers which calculates tangential magnetic field to the material at exterior to the groove and inside of that was developed. Calculation results were made sure of agreement with high power experiment qualitatively, and validity of the evaluation code has been confirmed.
Takahashi, Koji; Kobayashi, Noriyuki*; Kasugai, Atsushi; Sakamoto, Keishi
Fusion Engineering and Design, 81(1-7), p.281 - 287, 2006/02
Times Cited Count：5 Percentile：36.24(Nuclear Science & Technology)In the ITER, an EC H&CD steering antenna mirror was designed to reflect eight or nine 1MW-wave beams. The cross-section and thickness of the mirror are 250
360 mm
and 50mm, respectively. The thermal and stress analysis under the ITER condition show that the copper alloy(DSCu) mirror with stainless steel cooling tubes inside is considered acceptable. The EC H&CD antenna system for the ITER must have a dog-legged transmission lines so as to protect the diamond windows or superconducting magnets of a tokamak. A 90
miter bend, which consists of waveguides and a reflection mirror, is required to make the structure. The mock-up of the mirror based on the ITER design was fabricated and the high power transmission experiment was carried out. The mm-wave transmission with power/pulse length 450kW/5.0sec, was demonstrated. The ohmic loss is estimated to be 
0.2%, which agrees with the calculation based on electrical resistivity of DSCu 2.010
m.
Moriyama, Shinichi; Kajiwara, Ken*; Takahashi, Koji; Kasugai, Atsushi; Seki, Masami; Ikeda, Yoshitaka; Fujii, Tsuneyuki; JT-60 Team
Review of Scientific Instruments, 76(11), p.113504_1 - 113504_6, 2005/11
Times Cited Count：6 Percentile：33.42(Instruments & Instrumentation)A compact antenna has been designed and fabricated to enable millimeter wave beam scan in the toroidal and the poloidal directions of the JT-60U Tokamak, for electron cyclotron heating (ECH) and current drive (ECCD) experiments. It consists of fast movable flat mirror mounted on the Tokamak vacuum vessel, and rotary focusing mirror attached at the end of the waveguide supported from outside of the vacuum vessel. This separate support concept enables compact structure in the shallow port (0.68 m 0.54 m 0.2m) sharing with a sub-port for an independent diagnostic system. The flat mirror is driven during a shot by a servo-motor with a 3 m long drive shaft to refuse influence of the high magnetic field to the motor. The focusing mirror is rotated by a simple mechanism with a push rod and an air cylinder. The antenna has been operated reliably for 3 years after small improvement in the rotary mechanism. It has been contributing ECH and ECCD experiments especially current profile control, in JT-60U.
Kiriyama, Hiromitsu; Yamakawa, Koichi; Kageyama, Nobuto*; Miyajima, Hirofumi*; Kan, Hirofumi*; Yoshida, Hidetsugu*; Nakatsuka, Masahiro*
Japanese Journal of Applied Physics, Part 1, 44(10), p.7464 - 7471, 2005/10
Times Cited Count：2 Percentile：9.28(Physics, Applied)no abstracts in English
Hatae, Takaki; Kondoh, Takashi; Naito, Osamu; Nakatsuka, Masahiro*; Yoshida, Hidetsugu*
Proceedings of 12th International Symposium on Laser-Aided Plasma Diagnostics (LAPD-12) (CD-ROM), 6 Pages, 2005/09
no abstracts in English
Osakabe, Toyotaka; Soyama, Kazuhiko
Review of Scientific Instruments, 76(7), p.073102_1 - 073102_5, 2005/07
Times Cited Count：4 Percentile：25.5(Instruments & Instrumentation)Neutron focusing is an indispensable technique used to compensate for weak signals in experiments under extreme conditions with tiny samples. We describe the development of a thermal neutron focusing device for a typical triple-axis neutron spectrometer. The device has a length of 400 mm and is placed between the second collimator and the sample position. The focal length is 150 mm from the downstream end of the device. The optic has 18 pieces of the circular blade consisting of 3m NiC/Ti neutron supermirrors. The extensions of the end of each blade meet at the sample position, namely the focal point. Neutrons undergo successive reflection through the same angle from the inner surface of each blade and arrive at the sample position. The test results show that the gain of the neutron intensity at the sample position increases by a factor of two or more for the neutron energy below 30.5 meV.
Takahashi, Koji; Kobayashi, Noriyuki*; Kasugai, Atsushi; Sakamoto, Keishi
Journal of Physics; Conference Series, 25, p.75 - 83, 2005/00
Recent progress of the development on the ITER equatorial EC launcher components, such as the steering mirrors, its drive system, the waveguide components and the diamond vacuum windows, is reported. Thermmo-mechanical analysis of the recent mirror design shows that maximum temperature increase of 187C at the reflecting surface and maximum stress of 242MPa at the inner surface of the cooling tube are obtained. In the cyclic test of the spiral tube mock-up, the cyclic number of 1.310
is succeeded without failure. In the window development, the fabrication of the Cu-coated edge diamond window and the high power transmission test were done. The Cu-coating on the disk edge can avoid water ingress in the launcher (vessel) under the assumption of the crack formation toward edge. Transmission experiment indicative to 1.2MW, was carried out. Temperature increase of 50C agrees with the calculation. It concludes that the Cu-coated window is capable of MW-level transmission and improves its reliability.
Hatae, Takaki; Nakatsuka, Masahiro*; Yoshida, Hidetsugu*
Purazuma, Kaku Yugo Gakkai-Shi, 80(10), p.870 - 882, 2004/10
A high performance phase conjugate mirror by stimulated Brillouin scattering (SBS-PCM) is applied to Thomson scattering diagnostics in JT-60U for the first time. To improve the measurement performance, two developments were performed with SBS-PCM. First, we developed a new optical design to provide a double-pass scattering scheme with SBS-PCM. A laser beam passing through the plasma is reflected by the SBS-PCM, and a reflected beam returned back through the same path as coming one by the phase conjugate effect, and passed through the plasma again. The double path Thomson scattering scheme demonstrated in JT-60U plasma that a factor of 1.6 increase of the scattered light in contrast with single-pass scattering. Second, an improvement of the output power of YAG laser system using the SBS-PCM was performed. As a result, average power was increased over 8 times in contrast with conventional system, and was achieved up to 368 W (7.4 J 50 Hz). A multi-pass Thomson scattering scheme is also proposed based on the results of double-pass scattering.
Sugie, Tatsuo; Kasai, Satoshi; Taniguchi, Masaki; Nagatsu, Masaaki*; Nishitani, Takeo
Journal of Nuclear Materials, 329-333(2), p.1481 - 1485, 2004/08
Times Cited Count：30 Percentile：85.88(Materials Science, Multidisciplinary)In ITER, the effect of lower energy particle bombardment is important for mirrors located near the divertor where the low temperature plasma is formed. The test pieces of molybdenum mirrors and a tungsten mirror were irradiated by high flux and low energy (67-80 eV) deuterium ions using SLEIS (Super Low Energy Ion Source with High Ion Flux) facility at the temperature of around 100 C. The molybdenum mirror manufactured by sintering and melting the thin layer of the surface by electron beam in order to eliminate holes on the surface has a higher reflectivity before irradiation than the mirrors without melting the surface, but the reflectivity decreases rapidly with the irradiation fluence due to the generation of blisters on the mirror surface. The reflectivity of molybdenum mirror manufactured by sintering only did not decrease so significantly (less than 10 % at the fluence of 1.3 10
m
). The molybdenum and tungsten mirrors manufactured by sintering without melting the surface have a potential for plasma facing mirrors in ITER.
Tamura, Itaru; Suzuki, Masatoshi; Hazawa, Tomoya; Moriai, Atsushi; Hori, Naohiko; Sasajima, Fumio; Soyama, Kazuhiko
Nuclear Instruments and Methods in Physics Research A, 529(1-3), p.234 - 237, 2004/08
Times Cited Count：4 Percentile：30.85(Instruments & Instrumentation)Thermal neutron guides at JRR-3 reactor have been upgraded from Nickel mirrors to Ni/Ti multilayer supermirrors. We performed the characteristics experiment of neutron beams transmitted through supermirror neutron guides. Neutron fluxes at the end of the thermal neutron guides were measured by the gold foil activation method on March 2003. We have confirmed that neutron fluxes at the end of thermal neutron guide increases by 6 times. The neutron spectra were also measured at the end of the thermal neutron guides by the time-of-flight method. The wavelength range for the neutron beam is extended and the shorter wavelength neutrons, which had been filtered by the characteristics of curved neutron guides before upgrade, were observed. In this paper, we have performed several Monte Carlo simulation codes using the McStas package in the consideration of the performance of fabricated supermirrors and its alignment errors for the purpose of estimation of instruments performance. We discuss the comparison of the experimental results with results of simulation.
-Qc supermirror by ion polishingSoyama, Kazuhiko; Tsunoda, Haruhiko*; Murakami, Katsuhiko*
Nuclear Instruments and Methods in Physics Research A, 529(1-3), p.73 - 77, 2004/08
Times Cited Count：5 Percentile：36.35(Instruments & Instrumentation)An ion polishing technique has been applied to supermirror coating in order to enhance neutron reflectivity. A Ni/Ti supermirror with a critical value of 3Qc and the total number of layers of 407 was coated in combination with ion polishing. The dependencies of Ar
ion polishing time, ion acceleration energy and incidence angle on the interface roughness were studied and optimized by using X-ray and neutron reflectometry. The reflectivity of the supermirror was measured at the JRR-3 reflectometer of cold beam line. It has reached 90% at the external critical angle, although the non polished one has the reflectivity of 80%.
Saigusa, Mikio*; Takahashi, Koji; Oishi, Shimpei*; Kashiwa, Yoshitada*; Hoshi, Yuki*; Kobayashi, Yuki*; Kasugai, Atsushi; Sakamoto, Keishi; Imai, Tsuyoshi
Proceedings of IAEA TM on ECRH Physics and Technology for ITER (CD-ROM), 7 Pages, 2003/00
The specified elliptical polarization which is necessary to excite a pure ordinary or extraordinary mode, when rf waves obliquely propagate in plasma, for electron cyclotron current drive(ECCD) can be produced by a grooved mirror polarizer. The Joule loss of deeped groove mirrors has been experimentally investigated at a frequency of 170 GHz. The strange dependence of the Joule loss of groove mirror on the mirror rotation angle was obtained. In addition, maximum loss of 0.8% in regard to the injection rf power to the mirrors was estimated. The calculation code to estimate the Joule loss of grooved mirror is developed for the structure analysis. The dependence of the mirror on its rotation angle can be explained by the calculation results, clearly.
Takizuka, Tomonori; Hojo, Hitoshi*; Hatori, Tadatsugu*
Purazuma, Kaku Yugo Gakkai-Shi, 78(9), p.857 - 912, 2002/09
Transport along field lines in magnetic confinement plasmas is reviewed. Collisionless and collisional-diffusive transports are discussed. Because of their fast transport, features of plasmas along field lines are apt to behave nonlocally. A nonlocal phenomenon of scrape-off layer (SOL) and divertor plasmas in a tokamak is introduced, whose asymmetry along field lines is induced by the thermoelectric instability related to the SOL current. A local phenomenon called MARFE can be brought by the strong radiation cooling. The "snake" with nonlocal feature along field lines but with local structure perpendicular to the field is observed in a tokamak core plasma. For mirror-confined plasmas, axial particle losses from the mirror ends, especially pitch-angle-sattering losses into the loss cone and nondiabatic losses due to the breakdown of adiabaticity of the magnetic moment, are also discussed in the relation to nonlocal axial transport.
Uruga, Tomoya*; Tanida, Hajime*; Yoneda, Yasuhiro; Takeshita, K.*; Goto, Shunji*; Ishikawa, Tetsuya*
Nuclear Instruments and Methods in Physics Research A, 467-468(Part1), p.782 - 784, 2001/07
Times Cited Count：8 Percentile：52.3(Instruments & Instrumentation)no abstracts in English
Bin, C.; Soyama, Kazuhiko
JAERI-Conf 2001-002, p.592 - 599, 2001/03
no abstracts in English
