Status of CFC development in Europe for ITER

Abstract

Carbon–carbon fibre composites (CFCs) have a unique combination of high conductivity, low Z and resistance to damage due to high heat loads. Given the demanding environmental requirements in the ITER divertor, specially developed CFCs are required as plasma facing materials. However, the manufacture of the plasma facing components, copper tubes surrounded by the CFC, and their inspection also places demands on the thermo-mechanical properties of the CFCs and their uniformity. This paper will describe, in detail, these demands and the work being undertaken to identify the appropriate thermo-mechanical properties of the CFC, since the three main demands, stability under ITER conditions, manufacturing ability of the plasma facing components and inspect-ability are not necessarily complementary. Due to the nature of CFC there are significant variations in its properties; these variations need to be limited, taking also into account cost and delivery requirements. The aim of the study undertaken is to identify the necessary CFC material properties, define their allowed range and select suitable CFC grades of material in 2008 for the European contribution to ITER.