Diffusion of trace amounts of some rare earths, Ba,Sr,Cs and Rb in hafnium

Diffusion of some uniformly distributed spallation products in hafnium irradiated with protons having an energy of 660 meV has been studied in the temperature range of 1700-2300 K. The values of the effective diffusion coefficients decrease in the following order: Sr > Ba > r.e.e. > Rb > Cs. It is shown that the phase transition in hafnium at 2033 K increases considerably the diffusion of rare-earth and alkaline-earth elements and does not affect the diffusion of alkaline elements. It is proposed to use heated metal hafnium as on-line target for producing short-lived radionuclides on installations operating on-line with a mass-separator