Thermal stability and long term hydrogen/deuterium release from soft to hard amorphous carbon layers analyzed using in-situ Raman spectroscopy. Comparison with Tore Supra deposits

TL;DR

This study investigates the thermal stability and hydrogen/deuterium release of amorphous carbon layers using in-situ Raman spectroscopy, comparing laboratory samples with deposits from the Tore Supra tokamak to understand their long-term behavior.

Contribution

It provides a detailed analysis of the thermal stability and isotopic effects in amorphous carbon layers, including long-term release behavior, using in-situ Raman spectroscopy.

Findings

Correlations between Raman spectrometric parameters and thermal treatment were established.

Isotopic substitution affects the G band shift and absorption evolution during heating.

Long-term thermal behavior of plasma-deposited amorphous carbon layers was characterized.

Abstract

The thermal stability of 200 nm thick plasma enhanced chemical vapor deposited a-C:H and a-C:D layers ranging from soft to hard layers has been studied and compared to that of deposits collected on the Tore Supra tokamak plasma facing components by means of in-situ Raman spectroscopy. Linear ramp heating and long term isotherms (from several minutes to 21 days) have been performed and correlations between spectrometric parameters have been found. The information obtained on the sp 2 clustering has been investigated by comparing the G band shift and the 514 nm photon absorption evolution due to the thermal treatment of the layer. The effects of isotopic substitution have also been investigated.