Raman study of CFC tiles extracted from the toroidal pump limiter of Tore Supra

TL;DR

This study uses micro-Raman spectroscopy to analyze the carbon structure and deuterium content of tiles from Tore Supra's toroidal pump limiter, revealing insights into material composition and temperature effects during plasma operation.

Contribution

It provides detailed post-mortem analysis of CFC tiles, linking surface temperature to deuterium content and characterizing the carbon structure after plasma exposure.

Findings

Carbon structure resembles plasma-deposited amorphous carbon

Deuterium content is about 20% where temperature is below 500°C

Surface temperature influences deuterium retention in tiles

Abstract

The structure of six tiles extracted from the erosion and deposition zones (thin and thick deposition) of the Tore Supra toroidal pump limiter (TPL) have been analysed in the framework of the DITS campaign using micro-Raman spectroscopy. This post-mortem analysis gives information on both carbon structure and D content. We have found that the carbon structure is most often similar to that of plasma-deposited hard amorphous carbon layers. The role of the surface temperature during the discharge in the D content is investigated: in all locations where the temperature does not reach more than 500{\degree}C the D content seems to be roughly uniform with D/D+C \approx 20%.