Plasma and Fusion Research

Volume 14, 3405080 (2019)

Regular Articles

Mechanical Design and Structural Analysis for Lower Port Optics of ITER Divertor Impurity Monitor
Toshiyuki MARUYAMA, Toshihiro OIKAWA1), Sin-iti KITAZAWA1), Kimihiro IOKI, Saori MERA, Ikuma NOMURA, Hiroaki OGAWA1), Suguru TANAKA1) and Takaki HATAE1)
TOYAMA Co. Ltd., Yamakita-machi, Ashigarakami-gun, Kanagawa 258-0112, Japan
Naka Fusion Institute, National Institutes for Quantum and Radiological Science and Technology, Naka, Ibaraki 311-0193, Japan
(Received 4 January 2019 / Accepted 17 March 2019 / Published 25 April 2019)


The Divertor Impurity Monitor (DIM) for ITER is a spectroscopic diagnostic that measures the parameters of impurities and isotopes of hydrogen in the divertor plasmas. The DIM systems are installed in upper port, equatorial port, lower port (LP) and the divertor cassette. The LP systems consist of the side-upper/lower optical systems and the central optical system. In the central system, the front-end optics (optical mirrors) are located under the divertor-dome and this optics is required to have a structure that can withstand extremely high thermal loads in terms of establishing a sensitive optical structure. This paper presents a mechanical design of the optics with taking manufacturability into account and structural integrity assessment according to ITER load conditions (thermal and electro-magnetic loads, etc.) and design criteria specified in the RCC-MR code. The mechanical design of the optics forms a box-shaped optics and the structural analysis results indicate the mirror box satisfies design criteria in the RCC-MR code, except for the inner support part interfacing with the divertor cassette.


ITER, plasma diagnostics, lower port, divertor cassette, structural analysis

DOI: 10.1585/pfr.14.3405080


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