Nuclear analysis of ITER equatorial EC launcher

Takahashi, Koji; Iida, Hiromasa*; Kobayashi, Noriyuki*; Kajiwara, Ken; Sakamoto, Keishi; Omori, Toshimichi*; Henderson, M.*

Fusion Science and Technology, 63(1T), p.156 - 159, 2013/05

https://doi.org/10.13182/FST13-A16894

Nuclear analysis of the ITER equatorial EC launcher has been carried out to determine heat and/or particle loads on its components and also to evaluate the possibility of "hands-on maintainability" (personnel accessibility) to the launcher back-end. Monte Carlo code "MCNP5" is applied to simulate the radiation leak from fusion plasma to the special region around the launcher. The results indicate a significant radiation leak at the gaps between the port walls and port plug frame and at the waveguide bundles in the launcher. Another significant neutron leakage is through the port wall consisting of only stainless steel but without light isotopes such as water. The shut down dose rates was estimated at the port interspace behind the launcher at the level of the required value of 100 Sv/h. This analysis offers the potential to modify the launchers shielding layout to minimize the above leakage and further reduce the shut down dose rates in the regions of personnel access.

Control and instrumentation for the ITER magnet system

Yoshida, Kiyoshi; Takahashi, Yoshikazu; Iida, Hiromasa

IEEE Transactions on Applied Superconductivity, 16(2), p.775 - 778, 2006/06

https://doi.org/10.1109/TASC.2006.873251

The ITER superconducting coil system consists of 18 TF coils, 6 PF coils, 6 CS modules, 18 Correction Coils and their feeders. An extensive measurement and control system is required to monitor and to control these coils and feeders for safety and optimal operational availability. For each coil, both current and helium are supplied from external systems and are controlled from a central control system that manages flow distribution at each cooling pass to smooth the cryoplant loads by a virtual model of the coil thermo-hydraulic system. Quench detection is provided as stand alone system. Monitoring of the electric insulation system inside the coils is performed to detect incipient problems before serious damage. The ITER will procure directly all sensors, wires, electrical insulation breaks and cryogenic components for all the coils and feeders to a common specification. This will avoid duplication of qualification work and guarantee a common interface. This paper introduces the requirements and specifications of the control and instrumentation for the ITER magnet system.

Engineering design and control scenario for steady-state high-beta operation in national centralized tokamak

Tsuchiya, Katsuhiko; Akiba, Masato; Azechi, Hiroshi*; Fujii, Tsuneyuki; Fujita, Takaaki; Fujiwara, Masami*; Hamamatsu, Kiyotaka; Hashizume, Hidetoshi*; Hayashi, Nobuhiko; Horiike, Hiroshi*; et al.

Fusion Engineering and Design, 81(8-14), p.1599 - 1605, 2006/02

https://doi.org/10.1016/j.fusengdes.2005.08.066

no abstracts in English

Design study of national centralized tokamak facility for the demonstration of steady state high- plasma operation

Tamai, Hiroshi; Akiba, Masato; Azechi, Hiroshi*; Fujita, Takaaki; Hamamatsu, Kiyotaka; Hashizume, Hidetoshi*; Hayashi, Nobuhiko; Horiike, Hiroshi*; Hosogane, Nobuyuki; Ichimura, Makoto*; et al.

Nuclear Fusion, 45(12), p.1676 - 1683, 2005/12

https://doi.org/10.1088/0029-5515/45/12/023

Design studies are shown on the National Centralized Tokamak facility. The machine design is carried out to investigate the capability for the flexibility in aspect ratio and shape controllability for the demonstration of the high-beta steady state operation with nation-wide collaboration, in parallel with ITER towards DEMO. Two designs are proposed and assessed with respect to the physics requirements such as confinement, stability, current drive, divertor, and energetic particle confinement. The operation range in the aspect ratio and the plasma shape is widely enhanced in consistent with the sufficient divertor pumping. Evaluations of the plasma performance towards the determination of machine design are presented.

None

Kato, Masato; Sugata, Hiromasa*; Takahashi, Kuniaki; Kamimura, Katsuichiro

PNC TN8410 97-018, 38 Pages, 1997/01

PNC-TN8410-97-018.pdf:1.38MB

None

Compacting and element-quick-replaceable design of high power density fusion reactor

*; *; *; Okamoto, Yoshizo*; Hoshiya, Taiji; Takahashi, Akito*; *; *; *; *; et al.

Koshutsuryoku Mitsudo Kaku Yugoro Niokeru Yoso Kokan Gijutsu No Kiso Sekkei, 147 Pages, 1988/03

no abstracts in English

Modification of ITER equatorial EC launcher design enhancing EC H&CD function

Takahashi, Koji; Abe, Ganji; Isozaki, Masami; Ikeda, Ryosuke; Oda, Yasuhisa; Kajiwara, Ken; Sakamoto, Keishi; Kobayashi, Noriyuki*; Iida, Hiromasa*; Komatsuzaki, Manabu*; et al.

no journal, , 

It was analytically obtained that electron cyclotron current drive efficency at =0.40.6 can be doubled modifying the steering function of millimeter wave launching from the equatorial port from toroidally to poloidally. The design modification of the ITER equatorial launcher enhancing ECCD function is implemented. The millimeter wave design satisfying transmission efficiency more than 99% with the required ploidal beam steering capability is successfully obtained and reflected to the launcher structural design. The millimeter wave design optimization, BSM design modification to allow the required polidal beam steering capability and so on are reported in detail at the conference.