Presentation on theme: "Surface modification of tungsten due to carbon ion implantation A. Martinavičius."— Presentation transcript:
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 Target Not all atoms are immediately sputtered. Some atoms are activated and relocate. Other atoms after relocation also are sputtered.
Model 123K123K I i – flux of arriving ions, Y i – sputtering yield α ij – sticking coefficient
Calculations K. Krieger, J. Roth / J. Nucl. Mater. 290-293 (2001) 107-111 C+C+ Y W = 0.37Y C = 0.34α CW =0.61α CC =1α WW =?α WC =? C+C+ Y W = 0.37Y C = 0.34α CW =0.61α CC =0.8α WW =0.4α WC =0.3 CH 3 + Y W = 0.37Y C = 0.68α CW =0.61α CC =1α WW =?α WC =? CH 3 + Y W = 0.37Y C = 0.68α CW =0.61α CC =0.72α WW =0.5α WC =0.4