Dynamic Amplification Factor of the ITER Diagnostic Upper Port Plug

Author

Pak, S. ; Udintsev, V. ; Maquet, Ph ; Pitcher, C.S. ; Mun-Seong Cheon ; Chang Rae Seon ; Hyeon Gon Lee

Author_Institution

Nat. Fusion Res. Inst., Daejeon, South Korea

Volume

42

Issue

7

fYear

2014

fDate

Jul-14

Firstpage

1977

Lastpage

1981

Abstract

The diagnostic upper port plug in ITER is a long metal box cantilevered to the vacuum vessel port with 42 × M52 studs and nuts. The plug structure has a heavy payload at the front, such as the diagnostic first wall and the diagnostic shield module to protect the diagnostic components from plasma and neutron fluxes. This kind of structural configuration is susceptible to a resonance with the transient external load. For the upper port plug, the design-driving load is electromagnetic (EM) forces due to plasma disruptions. In this paper, the dynamic amplification factor (DAF) of the structure is calculated for such EM loads. The bolted joint at the back flange of the plug structure is also considered together with the port extension of the vacuum vessel and its influence on the dynamic behavior is investigated. The analysis results show that the bolted joint reduces the DAF as well as the natural frequency of the structure.

Keywords

Tokamak devices; cantilevers; plasma diagnostics; plasma instability; plasma toroidal confinement; plasma-wall interactions; ITER; bolted joint; design-driving load; diagnostic first wall; diagnostic shield module; diagnostic upper port plug; dynamic amplification factor; electromagnetic forces; heavy payload; long metal box cantilever; natural frequency; neutron fluxes; plasma diagnostic components; plasma disruptions; plug structure; structural configuration; transient external load; vacuum vessel port; Damping; Dynamics; Joints; Plasmas; Plugs; Ports (Computers); Transient analysis; Dynamic amplification factor (DAF); ITER; electromagnetic (EM) loads; upper port plug (UPP); upper port plug (UPP).;

fLanguage

English

Journal_Title

Plasma Science, IEEE Transactions on

Publisher

ieee

ISSN

0093-3813

Type

jour

DOI

10.1109/TPS.2014.2327126

Filename

6837512