Recrystallized titanium- and boron-doped graphites as well as C-C fiber composites are of interest as plasma-facing materials for fusion facilities. Recrystallized graphite possesses high strength properties, resistance to ion and thermal erosion and an extremely high thermal conductivity (exceeding 600 W/mK for some grades). It was shown that dopants of boron cause the introduction of its atoms in the crystal graphite lattice and the production of solid substitution solution bringing about a reduction in the diffusion and inventory of heavy hydrogen isotopes.

In this study, boron-doped carbon materials were investigated in a wide range of dopant concentrations using the methods of chemical and X-Ray phase analysis and the method of electron paramagnetic resonance (EPR). The possibility is demonstrated of controlling the boron concentration in recrystallized graphites by treating them thermally at increased temperatures in a chlorine medium. The concentrations of boron atoms producing solid substitution solution in the graphite lattice, as well as the degree of distribution uniformity of these atoms in micro- and macro-volumes of samples were defined on the basis of the analysis of the EPR data using the unified zone model of quasi two-dimensional graphite.

The materials samples were investigated on ion-, plasma- and electron- beam accelerators in the regimes simulating normal operation conditions of the ITER divertor plates and at plasma current disruptions. It is shown that titanium dopants increase essentially the resistance of recrystallized graphites, as compared to non-doped graphites and C-C composites, to ion and thermal erosion. Boron is postulated to considerably increase the erosion resistance with increasing the content of boron atoms in graphite in the form of a solid substitution solution. The carbide phase of boron in these processes is practically of minor importance.

The investigations of both recrystallized graphites and C-C composites revealed their relatively high neutron radiation resistance in the very wide range of temperatures (up to 1000 C) and neutron fluence (up to 6.0x10²¹ n/cm²). Though their thermal conductivity is reduced considerably in the initial irradiation period, still later it does not practically depend on the neutron fluence and the graphites retain their workability, as structural materials, practically up to the life time fluences of irradiation: that is, they preserve their integrity at the microlevel (there is no mass formation of microcracks resulting in a drastic degradation of all physico-mechanical properties of graphite materials). The same conclusions follow from the results of investigations of the thermal expansion coefficients of these materials after irradiation, which increase practically for all irradiation conditions testifying to the integrity of their structure being preserved.