First-wall materials

As discussed earlier, the first wall materials in next generation machines will receive from 0.005 to 30 displacements per atom. At the lower end of this range (<0.01 dpa) there are essentially no mechanical property changes expected in graphite materials. However, even at these low doses thermal conductivity and stored energy are of concern. For displacement levels >0.01 dpa other property... 

Fusion Machine Country Fuel System First Wall Heat Load (MW/m2) First Wall Material Divertor or Limiter Heat Load (MW/m2) Divertor of Limiter Material... 

The crystal structure of beryllium carbide is cubic, density = 2.44 g/mL. The melting point is 2250—2400°C and the compound dissociates under vacuum at 2100°C (1). This compound is not used industrially, but Be2C is a potential first-wall material for fusion reactors, one on the very limited list of possible candidates (see Fusion energy). 

The Surface Chemistry of First-Wall Materials in Magnetic Fusion Devices... 

The hydrogen-isotope retention and recycling properties of first-wall materials are also the determinant of the isotopic ratio in a multi-component plasma. Maximization of the reactivity of D-T plasmas (16) and the efficiency of minority-specie RF heating schemes require precise control of the isotopic mixtures, a task which is considerably easier in low recycling situations. Titanium sublimation over 20-40% of the vacuum vessel of the PLT tokamak was sufficient for density and isotopic mixture control for both the high power neutral beam (55) and ion cyclotron... 

R. Moormann, H.K. Hinssen, C.H. Wu, Oxidation of carbon based first wall materials of ITER, Proc. 18th IAEA Fusion Energy Conference, Sorrento, Italy, October 4-10, 2000, paper FTP1/29... 

TiC/Ni3Al-M system was chosen for the potential use as the first wall materials of thermonuclear experimental reactors. The residual thermal stresses dutti fabrication were calculated by finite element method. Based on the consideration of minimum stress, minimum ratio of stress to fi acture stret fii and proper distribution of thermal stress in pure TiC side, the optimum design wifit the distribution exponent P=1.6 was reached. According to the design result, TiC/Ni3Al-Ni FGM samples were then successfully fabricated. 

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