29th Symposium on Fusion Technology (SOFT 2016)

O3A.1 Topology design of the in-vessel ITER plasma-position reflectometry antennas

6 Sep 2016, 16:40

20m

Congress Hall 2nd floor (Prague Congress Centre)

Board: 1

Oral D. Diagnostics, Data Acquisition and Remote Participation O3A

Speaker

Hugo Policarpo (IPFN - Instituto de Plasmas e Fusão Nuclear)

Description

The ITER Plasma Position Reflectometry (PPR) system will be used to estimate the distance between the position of the magnetic separatrix and the first-wall at four pre-defined locations also known as gaps 3, 4, 5, and 6, complementing the information provided by the magnetic diagnostics. For gaps 4 and 6, the antennas are to be installed in-vessel between two blanket shield modules. The microwave signal is routed to/from the antennas using rectangular oversized waveguides that enter/exit the vacuum vessel through feed-outs located in upper ports 01 and 14, respectively. The antennas and adjacent waveguides are in direct sight to the plasma through cut-outs in the blanket shield modules and are subject to plasma radiation, neutronics loads, and stray-radiation from ECH that may cause excessive temperatures and stresses. Although the antenna assembly is designed in such way that it can be remotely installed and removed, it should withstand the maintenance period. Therefore, one of the initial constraints is the topology design of the antennas that arises from thermal-structural simulations. Here, we report on the topology optimization of the antennas that is conducted to find suitable material distributions in the antennas, while maintaining their internal geometry that is relevant for microwave diagnostics. The results obtained through the analysis presented here may be used as input in the global integrity analysis of the in-vessel components of the ITER PPR system.