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

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°C the D content seems to be roughly uniform with D/D+C 1 20%.

Hydrogen trapping in carbon film: From laboratories studies to tokamak applications

“…6 means that, in eroded zone, the restructuration is more advanced than in deposit zone. This is again consistent with Raman observation [11].…”

“…3) in the eroded sample compared with that of deposited samples reflects the fact that a higher probability of potential trapping exists on the amorphous surface of the deposited film. This is consistent with an increase of local disorder in deposit layer seen with Raman experiment [11]. As it can be seen on Fig.…”

Long-term H-release of hard and intermediate between hard and soft amorphous carbon evidenced by in situ Raman microscopy under isothermal heating

“…Note that this type of thick film is known to easily delaminate, which might also play a role on the H-release, this analysis being beyond the scope of this paper.  G and  G are known to give similar information [22] and we will use only  G in what follows. We now focus on the long term evolutions at different temperatures.…”

Raman spectroscopy investigation of the H content of heated hard amorphous carbon layers

“…)-H modes [19]. B 1 and B 2 frequencies are in the range of the phonon density of states of graphite (350 -900 cm -1 [16]), and, although hard layers are far from pure graphite, these bands may correspond to phonons. B 1 and B 2 evolution with heating also differs from that of B 3 with respect to intensity, position and shape.…”