T. N. van der Walt

Carbon radioactivity of 223Ac and a search for nitrogen emission

A very intense 227Pa source was produced in order to study the possible 14C and 15N spontaneous emission from 223Ac. After the irradiation of a hemispherical, highly efficient array of nuclear track detectors, about 350 Carbon events were found leading to a branching ratio with respect to alpha decay B = 3.2 10−11. Comparison with other 14C emitters allows the study of the influence of even-odd effects on cluster radioactivity.

Cyclotron production of 68Ge with a Ga2O target

Systematic information of exchange behavior of Ge(IV) and Ga(III) in varying oxalic acid (0.05M and 0.25M) and sulphuric acid (0.005M-2M range) mixtures is presented. These findings were used to develop a separation involving 68Ge from a Ga2O target material. A method based on acid dissolution of the target and chromatography on an anion exchange resin (Bio-RadÒ AG1-X8) was developed. The separated 68Ge has high radionuclidic purity and an acceptable chemical purity.

Separation of 103Pd from Rh and Ag by the macroporous AG MP-1 anion exchange resin in Ag targets

A radiochemical process is reported for the production of 103Pd from Ag targets for use in brachytherapy. The procedure, which is based on anion exchange chromatography, separates Pd from a large amount of target material (16 g Ag), as well as Rh radioisotopes (mainly 101Rh and 100Rh), which are produced from decays of their Pd parents. The AG MP-1 anion exchange resin was used for the process. For elution of Rh and Ag, 3M nitric acid solution was used and 5% ammonia solution was used to elute the Pd. The average recovery of Pd was 97.4%. An elution curve for Pd was set up and a panel for the radiochemistry designed and installed in a hot cell.

Isolation of Cu radionuclides with dithizone impregnated XAD-8

Abstract A novel separation method for Cu radionuclides from proton bombardment of natZn is presented. A solid phase extraction procedure using a modified dithizone (diphenylthiocarbazone) XAD-8 chelating resin was used for the purification of the Cu radionuclides from up to 5 g of natZn and other radionuclides. More than 95% of the Cu radionuclides was recovered.

Production of 111In from an In/In2O3 target

Summary A method was developed to produce 111In from an In/In2O3 target, whereby the parent 111Sn was separated from the target material by means of ion exchange, using AG1-X4 and AG MP-1 anion exchange resins. The chemical separation had to be performed as quickly as possible, to ensure the highest possible yield of the final product (111Sn has a half-life of 35.3 minutes). The 111Sn is left on the resin to decay to 111In, which is then eluted from the column. This method ensures that impurities in the final product are kept to a minimum.