Calculated Radioactivity Yields of Gallium-67 using Matlab Codes

In nuclear medicine, gallium-67 (67Ga) is potentially applied for imaging a certain type of tissue. In this investigation, 67Ga is theoretically studied in terms of its potential radioactivity yields at the end of various energetic proton bombardments. Nuclear cross-sections derived from the Talys Evaluated Nuclear Data Library (TENDL) 2017 were used as the input files, while a Matlab code was developed to perform the yield calculations of 67Zn(p,n)67Ga and 68Zn(p,2n)67Ga nuclear reactions to produce 67Ga. Two different targets – enriched 67Zn and natZn targets – were simulated in the calculations. The calculated yields suggested that a maximum of 27.37 MBq/µAh could be achieved when enriched 67Zn target was irradiated with 15-MeV protons, whereas 46.99 MBq/µAh could be generated following a 30 MeV proton bombardment of enriched 68Zn target. Various radioactive gallium impurities, i.e. 63,64,65,66,68,70Ga and stable 69Ga isotope were also expected to be generated mostly via (p,n) and (p,2n) reactions when natZn target was used in the 67Ga production. In contrast, radioactive 66Ga and 68Ga impurities were mainly produced following bombardment of enriched 67Zn and 68Zn targets. This study can be used as a reference for future 67Ga radionuclide production.

Enhancement and Validation of a 3D-Printed Solid Target Holder at a Cyclotron Facility in Perth, Australia

A 3D-printed metal solid target using additive manufacturing process is a cost-effective production solution to complex and intricate target design. The initial proof-of-concept prototype solid target holder was 3D-printed in cast alloy, Al–7Si–0.6Mg (A357). However, given the relatively low thermal conductivity for A357 (max, 160 W/m·K), replication of the solid target holder in sterling silver (SS925) with higher thermal conductivity (max, 361 W/m·K) was investigated. The SS925 target holder enhances the cooling efficiency of the target design, thus achieving higher target current during irradiation. A validation production of 64Cu using the 3D-printed SS925 target holder indicated no loss of enriched 64Ni from proton bombardment above 80 µA, at 11.5 MeV.