Callis, R. W.*; Doane, J. L.*; Grunloh, H. J.*; Kajiwara, Ken; Kasugai, Atsushi; Moeller, C. P.*; Oda, Yasuhisa; Olstad, R. A.*; Sakamoto, Keishi; Takahashi, Koji
Fusion Engineering and Design, 84(2-6), p.526 - 529, 2009/06
Takahashi, Koji; Ishitsuka, Etsuo; Moeller, C. P.*; Hayashida, Kazunori*; Kasugai, Atsushi; Sakamoto, Keishi; Hayashi, Kenichi*; Imai, Tsuyoshi
Fusion Engineering and Design, 66-68, p.473 - 479, 2003/09
For the purpose to confirm the reliability of the front steering concept, tests of the front steering launcher mock-up and neutron irradiation tests of bearings for a movable mirror were carried out under the ITER conditions. The max. stress of the flexible pipes for the movable mirror was measuerd to be 60MPa, much less than the allowable stress and agree with the calculation. No degradation on the performance of bearings was obtained for the assumed fluence of ITER. The mock-up of remote steering(RS) launcher was tested and RF radiation of 0.5MW-3sec and 0.2MW-10sec over 0-10 were performed. No degradation was obseved, either. The new launcher which has the capability of wider range rf beam steering and the corrugated square waveguide with four miter bends that yield the dog-legged structure has been designed, based on the test results. It has been fabricating for high power experiments.
Takahashi, Koji; Moeller, C. P.*; Sakamoto, Keishi; Hayashi, Kenichi*; Imai, Tsuyoshi
Fusion Engineering and Design, 65(4), p.589 - 598, 2003/07
High power radiation experiments of a remote steering launcher for an EC H&CD system were carried out to study the characteristic of the rf beam steering and transmission. The remote steering launcher consists of a 4.632m corrugated square waveguide (45.7 45.7mm) and a movable flat mirror which is placed at the input of the waveguide. Measurements were made in the range 0-10 at a frequency of 170GHz. The measured radiation pattern is clearly a Gaussian-like distribution, which is in agreement with the low power measurements. A steering capability of up to 10 was experimentally confirmed. Transmission and radiation of 0.5 MW-3.0 sec and 0.2 MW-10.0 sec pulses were successfully demonstrated over a steering angle range of 0-10. No arcing was observed during the experiments and no damage to the waveguide was found after the experiments were finished. We confirmed that remote steering was a possibly alternative scheme of rf beam steering for EC H&CD.
Takahashi, Koji; Moeller, C. P.*; Kasugai, Atsushi; Minami, Ryutaro; Sakamoto, Keishi; Imai, Tsuyoshi
Proceedings of 28th International Conference on Infrared and Millimeter Waves, p.385 - 386, 2003/00
no abstracts in English
Takahashi, Koji; Sakamoto, Keishi; Imai, Tsuyoshi; Kasugai, Atsushi; Heidinger, R.*; Thumm, M.*; Moeller, C. P.*
Proceedings of IAEA TM on ECRH Physics and Technology for ITER (CD-ROM), 7 Pages, 2003/00
A front steering (FS) launcher and a remote steering (RS) one have been studied for ITER. In the analysis of a mirror(Cu alloy) for FS launcher, max. temperature of 333C and max. induced stress of 136MPa, less than allowable stress(200MPa), were obtained at the mirror surface under 1MW/1line in CW operation. The efficient transmission (95%) at -1212 and 170GHz was performed for both polarizations in the experiments of a square corrugated waveguide for the RS launcher. RF and pressure tests of the diamond window irradiated by neutron were carried under JA/EU(FZK) collaboration. Neutron fluence of the window was 10n/m, whereas the estimated annual fluence at the window position is 1010n/m. Transmission of 0.48MW-30sec and 0.2MW-132sec were performed. It was successfully demonstrated that the irradiated window withstood 0.4MPa, which was twice higher than the ITER requirement. Diamond windows are applicable for ITER.
Ogawa, Toshihide; Hoshino, Katsumichi; Kanazawa, Sadayoshi*; Saigusa, Mikio*; Ido, Takeshi*; Kawashima, Hisato; Kasuya, N.*; Takase, Yuichi*; Kimura, Haruyuki; Miura, Yukitoshi; et al.
Nuclear Fusion, 41(12), p.1767 - 1775, 2001/12
no abstracts in English