Development of pellet injector using screw type pellet extruder; Improvement of pellet extruder for high frequency and long duration, and its test results

Ichige, Hisashi; Honda, Masao; Sasaki, Shunichi; Takenaga, Hidenobu; Matsuzawa, Yukihiro; Haga, Saburo; Ishige, Yoichi

JAEA-Technology 2007-037, 16 Pages, 2007/07

JAEA-Technology-2007-037.pdf:2.91MB

In JT-60U, pellet injector has been developed for improvement of density controllability and long operation duration consistent with a long pulse discharge (65 s) started from FY2003. The injection frequency and operation duration were limited by extrusion speed and volume of the piston type pellet extruder, respectively, in the previous system. The screw type pellet extruder made in Russian company was newly installed in the system, which can continuously extrude the pellet at high speed and has been used in other fusion devices. After parts of the pellet injector system moved from JT-60 torus hall for efficient work, the previous piston type pellet extruder was changed to the new screw type pellet extruder and the tests for continuous pellet extrusion were performed. In the extrusion test using deuterium gas as a working gas, continuous pellet extrusion up to 330s was achieved, which is sufficient performance for applying it to JT-60U experiments.

Fabrication of 8Cr-2W ferritic steel tile for reduction in toroidal magnetic field ripple on JT-60U

Kudo, Yusuke; Sawai, Tomotsugu; Sakurai, Shinji; Masaki, Kei; Suzuki, Yutaka; Sasajima, Tadayuki; Hayashi, Takao; Takahashi, Ryukichi*; Honda, Masao; Jitsukawa, Shiro; et al.

Journal of the Korean Physical Society, 49(96), p.S297 - S301, 2006/12

http://www.kps.or.kr/jkps/abstract_view.asp?articleuid=71E58E92-124F-41B0-899D-B0C585DA073B&globalmenu=3&localmenu=10

Installation of ferritic steel tiles was proposed in JT-60U to reduce the toroidal magnetic field ripple and to improve the fast ion loss, which degrades heating efficiency and increases heat load on plasma facing component under large volume plasma operations. We selected a 8Cr-2W-0.2V ferritic steel with the cost-effectiveness, in which concentration limits of activation elements in F82H were relaxed because of the less number of neutron generations from deuterium operations on JT-60U. The fabricated ferritic steel has clear tempered martensitic microstructure, and sufficient magnetic and mechanical properties. The saturated magnetization was estimated to 1.7 Tesla at 573 K, lower than expected, but effectiveness in JT-60U was confirmed by numerical analyses. To research the effect of material conditions, such as microstructure and heat treatment, on saturated magnetization of the ferritic steel based on 8-9Cr is important for the future fusion reactors which will be planned to install the ferritic steel as the in-vessel components.

Insulation resistance measurement for the toroidal field coils of JT-60

Nishiyama, Tomokazu; Arai, Takashi; Miyo, Yasuhiko; Hiratsuka, Hajime; Honda, Masao; Miya, Naoyuki

Heisei-14-Nendo Tokyo Daigaku Sogo Gijutsu Kenkyukai Gijutsu Hokokushu, p.2_28 - 2_30, 2003/03

no abstracts in English

Gas and pellet injection systems for JT-60 and JT-60U

Kizu, Kaname; Hiratsuka, Hajime; Miyo, Yasuhiko; Ichige, Hisashi; Sasajima, Tadayuki; Nishiyama, Tomokazu; Masaki, Kei; Honda, Masao; Miya, Naoyuki; Hosogane, Nobuyuki

Fusion Science and Technology (JT-60 Special Issue), 42(2-3), p.396 - 409, 2002/09

https://doi.org/10.13182/FST02-A236

Designs and operations of the gas system and pellet injection systems for JT-60 were described. A gas injection valve that is a key component of the gas injection system was developed using a multi layer piezoelectric element. The maximum flow rate of this system is 43.3 Pam3/s. The valve has mechanism for adjustment at atmospheric side meaning that a repair and an adjustment can be conducted without ventilation inside a vacuum vessel. Two systems of pellet injector; one is pneumatic drive and another is centrifugal one were developed. The pneumatic type attained a pellet velocity of 2.3 km/s, which was the world record at the time in 1988. On the other hand, the centrifugal one was developed in 1998. This injector can eject trains of up to 40 cubic (2.1 mm)3 pellets at frequencies of 1~10 Hz and speed of 0.1~1.0 km/s. A guide tube for a magnetic high field side top injection HFS(top)) was also developed in 1999. The pellet injection experiment with the HFS system started in 2000. In addition, another guide tube for HFS(mid) injection was newly developed and installed in March 2001.

Development of the guide tube for magnetic high field side pellet injection

Kizu, Kaname; Sasajima, Tadayuki; Masaki, Kei; Hiratsuka, Hajime; Ichige, Hisashi; Honda, Masao; Miya, Naoyuki

Journal of Plasma and Fusion Research SERIES, Vol.5, p.446 - 449, 2002/00

no abstracts in English

Development of the centrifugal pellet injector for JT-60U

Kizu, Kaname; Hiratsuka, Hajime; Ichige, Hisashi; Iwahashi, Takaaki*; Sasajima, Tadayuki; Masaki, Kei; Sasaki, Noboru*; Honda, Masao; Miya, Naoyuki; Hosogane, Nobuyuki

JAERI-Tech 2001-022, 20 Pages, 2001/03

JAERI-Tech-2001-022.pdf:1.34MB

no abstracts in English

Development of the centrifugal pellet injector in JT-60U

Hiratsuka, Hajime; Kizu, Kaname; Ichige, Hisashi; Honda, Masao; Iwahashi, Takaaki*; Sasaki, Noboru*; Miya, Naoyuki; Hosogane, Nobuyuki; Oda, Yasushi*; Yoshida, Kazuto*

Purazuma, Kaku Yugo Gakkai-Shi, 76(11), p.1189 - 1197, 2000/11

http://ci.nii.ac.jp/naid/110003825480

no abstracts in English

Stress analysis for the crack observation in cooling channels of the toroidal field coils in JT-60U

Tamai, Hiroshi; Kikuchi, Mitsuru; Arai, Takashi; ; *; Saido, Masahiro; Kimura, Toyoaki; Nagami, Masayuki; Shimizu, Masatsugu; *; et al.

Fusion Engineering and Design, 38(4), p.429 - 439, 1998/00

https://doi.org/10.1016/S0920-3796(97)00121-X

no abstracts in English

Achievement of high fusion triple product in the JT-60U high H mode

Mori, Masahiro; Ishida, Shinichi; Ando, Toshiro; ; Asakura, Nobuyuki; Azumi, Masafumi; A.A.E.van-Blokland*; G.J.Frieling*; Fujii, Tsuneyuki; Fujita, Takaaki; et al.

Nuclear Fusion, 34(7), p.1045 - 1053, 1994/00

https://doi.org/10.1088/0029-5515/34/7/I09

no abstracts in English

JT-60 operation results after its modification for higher plasma current with single null open divertor

; Horiike, Hiroshi; Neyatani, Yuzuru; Matsukawa, Makoto; Ando, Toshiro; Yoshino, Ryuji; Arai, Takashi; Ninomiya, Hiromasa; Yamamoto, Masahiro; ; et al.

Proc. of the 14th Symp. on Fusion Engineering,Vol. 1, p.177 - 180, 1992/00

no abstracts in English