Preparation of isotopically enriched targets and of thin metal foils with high melting temperature using an electron gun

Thin metal oxide targets are useful in experiments with heavy ion beams of high current densities, because these targets can stand higher temperatures than metal foils. With commercial electron guns we prepared isotopically enriched CaO, Nd2O3, Sm2O3, Gd2O3 and SiO2 targets of thicknesses from 80 to 250 μg cm-2 with yields of about 20% of the isotope materials consumed. Self-supporting W and Mo foils of thicknesses from 100 to 500 μg cm-2 with surface areas of about 3 cm2 were produced with an electron gun. The thermal behaviour of the W foils in an electron beam has been studied. A device for reductive evaporation with an electron beam is described. (orig.)