Chemical analysis of flakes from the Joint European Torus

Measurements were performed on flakes from the JET with the Mark IIa divertor installed during the 1996 operation period by wavelength dispersive X-ray microanalysis in the element range from Be to the actinides and by X-ray diffraction. Metallic and ceramic particles up to 0.5 mm diameter were observed consisting of Al, Al2O3, Al–Mg alloys, austenitic steel, Mg2Si and Ni base alloys. The major phase is stratified graphite up to 50 μm thickness with layers of Al and Fe up to 2 μm thickness on the surface and inside the redeposited flakes. The graphite contains further about 3% oxygen. The carbon fraction is higher than 80% of the total material. The origin of the redeposits is explained.