Abstract
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Objectives To investigate the electrodeposition of nickel from all nickel chloride (NiCl2) solutions using boric acid (H3BO3) and to evaluate the performance of the targets for the production of high specific activity 64Cu
Methods Bath solution was prepared using a mixture of natural NiCl2 and H3BO3 [Wesley & Carey 1939, J Electrochem Soc] and the electrolytic cell consisted of a Pyrex tube with a Teflon insert using a gold disk as cathode and a platinum wire as anode. Experiments were carried out using 2 ml of solution and parameters studied were concentration of H3BO3 (15-60 mg/ml), temperature (room and °55C), and current (10-55 mA). All plated targets were irradiated with 11 MeV protons
Results Table 1 show the results of time-current controlled experiments. Additional experiments were performed at lower and higher density currents keeping the electrodeposition process for longer time. Deposition efficiencies were >90% in 2-3 h, reaching almost quantitative plating in 10-20 h, depending on the current density. The finish of the plated targets was different within the ranges of the investigated variables. However, regardless of the appearance and finish all plated targets withstood proton irradiations up to 40 µA for 2 h. Specific activity and reactivity was evaluated with bis(thiosemicarbazone) complexes and DOTA conjugates and was comparable to the 64Cu produced using the typical electrodeposition method with alkaline solution [Avila-Rodriguez et al. 2007, Appl Radiat Isot]. Recovered nickel solution was successfully recycled with an efficiency >95%
Conclusions This simple and efficient method produces harder and stronger targets more suitable for the cyclotron production of high specific activity 64Cu at high power irradiations
Research Support CONACYT Grant 179218