抄録
For the purpose of estimating the degree of evaporation loss of cosmogenic nuclides in the ablation products of materials by atmospheric heatings, a few laboratory ablation experiments were performed. Small Fe and Ni metal chips in which radioactive 54Mn, 51Cr and 58Co were induced by fast neutron irradiation, were heated to 10–20°C above the melting point under 40mtorr air pressure. Gamma ray activities of the radionuclides measured before and after the heating show that 54Mn evaporates much faster than Fe, 51Cr and 58Co evaporate much slower than 54Mn, but faster than the major elements, Fe and Ni.
