Effect of helium on defect structure formation in molybdenum under alpha-particle irradiation

The method of luminescent electron microscopy has been used to investigate the effect of helium on formation of accumulation of radiation defects in the polycrystalline molybdenum both in the alloying process and for the case of preliminary introduction of helium under irradiation by α-particles with 50 MeV initial energy at high temperatures (500 and 700 deg C). It is shown that helium promotes essential increase of the ratio of defects preserved in the form of dislocation loops and pores. It is concluded that helium forms stable complexes with vacancies and thus decreases the degree of mutual recombination of the Frenkel pores