Assessment of the measurement performance of the in-vessel system of gap 6 of the ITER plasma position reflectometer using a finite-difference time-domain Maxwell full-wave code

F da Silva; S Heuraux; E Ricardo; P Quental; J Ferreira

doi:10.1063/1.4962356

Assessment of the measurement performance of the in-vessel system of gap 6 of the ITER plasma position reflectometer using a finite-difference time-domain Maxwell full-wave code

Rev Sci Instrum. 2016 Nov;87(11):11E727. doi: 10.1063/1.4962356.

Authors

F da Silva¹, S Heuraux², E Ricardo¹, P Quental¹, J Ferreira¹

Affiliations

¹ Instituto de Plasmas e Fusão Nuclear, Instituto Superior Técnico, Universidade de Lisboa, 1049-001 Lisboa, Portugal.
² Institut Jean Lamour, UMR 7198 CNRS-University of Lorraine, F-54506 Vandœuvre, France.

PMID: 27910506
DOI: 10.1063/1.4962356

Abstract

We conducted a first assessment of the measurement performance of the in-vessel components at gap 6 of the ITER plasma position reflectometry with the aid of a synthetic Ordinary Mode (O-mode) broadband frequency-modulated continuous-wave reflectometer implemented with REFMUL, a 2D finite-difference time-domain full-wave Maxwell code. These simulations take into account the system location within the vacuum vessel as well as its access to the plasma. The plasma case considered is a baseline scenario from Fusion for Energy. We concluded that for the analyzed scenario, (i) the plasma curvature and non-equatorial position of the antenna have neglectable impact on the measurements; (ii) the cavity-like space surrounding the antenna can cause deflection and splitting of the probing beam; and (iii) multi-reflections on the blanket wall cause a substantial error preventing the system from operating within the required error margin.