Detailed structure analysis of deposit layer in TEXTOR by means of TEM techniques

We examined in detail the structure of the deposit layer on the main graphite belt limiter (ALT-II) in TEXTOR by means of transmission electron microscopy (TEM), electron diffraction, electron energy-loss spectroscopy (EELS) and their combination. The layer consisted mainly of an amorphous carbon matrix and a high density of crystalline boron precipitates. The amorphous carbon matrix was characterized by the stacking of pseudo-two-dimensional graphitic planes parallel to the surface of the limiter block, containing a considerable amount of boron solved. This character of deposit seems very similar to B-doped graphite irradiated by H+.