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Surface modification of tungsten due to carbon ion implantation. A. Martinavičius. Introduction. The first wall of future fusion devices will be made from the materials W, C and Be.
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Surface modification of tungsten due to carbon ion implantation A. Martinavičius
Introduction • The first wall of future fusion devices will be made from the materials W, C and Be. • The W tiles in the divertor chamber are exposed to high heat and carbon impurity fluxes which will lead to high C concentrations in the W.
Schematic view of model • Not all atoms are immediately sputtered. • Some atoms are activated and relocate. • Other atoms after relocation also are sputtered. Target
1 2 3 K Model Ii – flux of arriving ions, Yi – sputtering yield αij – sticking coefficient
Calculations K. Krieger, J. Roth / J. Nucl. Mater. 290-293 (2001) 107-111
Diffusion data D = 0 m2/s, T = 3.66 (103 K-1) D = 5 10-23 m2/s, T = 1.29 (103 K-1) D = 1.5 10-22 m2/s, T = 1.03 (103 K-1) D = 5 10-21 m2/s, T = 0.93 (103 K-1)