Gas desorption behavior of carbon fiber composite/copper brazed components as a nuclear fusion reactor

The international thermonuclear experimental reactor (ITER) being developed by the international cooperation of Japan, USA, EC and Russia entered the engineering design stage now. In the ITER, for removing the ash and impurities in plasma, removing thermal load and particle control, a diverter is arranged. The diverter is a kind of pump well, which leads impurity ions to the diverter plate by external magnetic flux lines and neutralize them, then exhausts them to outside the reactor with a pump. Accordingly, the diverter is exposed to high thermal and particle loads. In this research, as for the diverter, in which carbon fiber composite and oxygen-free copper are joined, and which was developed by Japan Atomic Energy Research Institute, the gas emission characteristics were systematically investigated. The diverter used for this research is described. The gas emission characteristics were studied by elevated temperature desorption spectrometry. The mass spectra at the joint at 800k, at which the gas emission was the most, are shown. The desorbed gases were H2, H2O, CO and CO2. The TDS spectra of the gases released form the carbon fiber composite, MFC-1, the oxygen-free copper and the joint part are shown. The pressure rise due to gas release in the diverter of the ITER was estimated. (K.I.)