Structural peculiarities of fracture of tungsten-base cathode materials

Structural peculiarities of failure of tungsten cathodes in the sources of multiply charged ions (MCI) are studied. It is shown that sintered tungsten materials may be used in ion sources for production of MCI on condition of their high density, formation of large-grain structure in them as well as the most ample removal of admixtures from grain boundaries. It is established that under diffusion interaction of the cathode material with CO2-plasma the cathode is damaged more actively because of the carbon diffusion on the grain boundaries and formation of fusible carbides