Isolation of lanthanide and hafnium radioisotopes from a massive Ta-target

Production of radioactive isotopes of rare Earth elements (REE) is relevant for their application in systematic chemical, environmental and nuclear medical investigations. In particular, among the lanthanides the number of isotopes with different nuclear characteristics is very high, while their chemical properties are quite similar. As a source of radiolanthanides, in this experiment a massive 195 g tantalum target was used, which has been irradiated with 1 GeV protons at CERN accelerator in 2002, totally receiving about 1019 protons. A rough estimate of the overall REE mass in the target yielded 100 μg. Due to significant radiation dose (200 μSv at 100 cm distance), excess of the chemical matrix (Ta) and the complex radioelement distribution in the target, a sophisticated radiochemical separation procedure was developed. (orig.)