Use of radioisotopes in studying admixture distribution in zone refining

Addition distribution in high-purity metals was studied in aluminium of an initial purity of 99.99% to which 10-2% of 95Zr had been alloyed. The aluminium ingot with the active addition was in the shape of a pin of 10 mm in diameter and 300 mm in length. Zone melting was carried out using a horizontal resistance instrument in a graphite boat under a controlled atmosphere of argon. The slot method was used in measuring the course of activity and thus of concentration along the ingot length after each zone melting. A diagram is shown of the 95Zr relative distribution along the ingot length. The concentration profiles given were used for calculating the zirconium distribution coefficient in aluminium. (J.P.)