Positron and positronium diffusion in nanomaterials

Some problems of positron (positronium) diffusion in powder nanoparticles of solid and nanoparticles of nanomaterials (index g ) separated by voids in the case of powders and by interfaces, vacancies, and empty volumes at grain junctions of a nanomaterial (index v ) have been considered. It has been shown that the validity of the diffusion approach to describe positron and positronium transformation and the conclusions of diffusion theory can be checked by varying the particle sizes of nanopowder and solid nanomaterials, and the diffusion coefficients D can be rather simply determined.