An electrochemical route to prepare planar ²⁰⁴Tl sources for the calibration of beta surface contamination monitors

Abstract

Tl / Autoradiography / Electrodeposition / Leachability / Polymer coating / Radioactive sourceSummary. This paper describes the utility of the electrochemical technique for the preparation of a circular planar 204 Tl source required for the calibration of beta surface contamination monitors. The electrolytic cell, the experimental set up used and the process of deposition are described. The factors that influence the electrodeposition of 204 Tl onto the circular copper substrate were investigated and a careful control has been exercised to ensure an optimum deposition of the 204 Tl activity onto the substrate. The morphology of the deposited layer was examined by SEM, AFM and EDS analyses. Sources containing ∼ 3.7 MBq (∼ 0.1 mCi) 204 Tl on a copper sheet of 20 mm diameter working area were prepared and housed in a holder. Quality control tests on the leachability, distribution of activity and stability of the source were performed to ensure compliance with regulatory safety requirements.

An electrochemical pathway to prepare circular planar 90Sr/90Y sources for the calibration of surface contamination monitors

“…The activity deposited on the anodic titanium substrate was therefore kept 5 % more than the required activity based on the experimental results, in order to compensate the attenuation effects of the coating material. The concentration of the polystyrene in benzene was kept at 150 mg/mL based on the information derived from the reported procedure [5,6,10,12,16]. As seen from the results, polymer coating of the radioactive source was found to be effective in retarding the leachability to 0.0049 ± 0.0017 %, which is well within the limit prescribed by AERB, India [22].…”

“…The active area of the source was coated with polystyrene by the dip-pull method following the reported procedure [5,6,10,12,16]. The 90 Sr/ 90 Y deposited source was immersed into a solution of polystyrene in benzene solution (150 mg/mL), stirred using magnetic stirrer, for 3 min and taken out with a tweezers.…”

“…In pursuit of a pragmatic approach to undertake routine preparation of circular planar 90 Sr/ 90 Y source for the above application, various radioactive source preparation strategies explored in our laboratory [4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21] were scrupulously evaluated. Among the various options exploited, the scope of using electrodeposition technique is enticing from the viewpoints of technical simplicity, scalability, rapidity and reproducibility [4][5][6][7][8][9][10][11].…”

“…Among the various options exploited, the scope of using electrodeposition technique is enticing from the viewpoints of technical simplicity, scalability, rapidity and reproducibility [4][5][6][7][8][9][10][11]. While the electrodeposition technique constitutes a successful paradigm for the preparation of broad panoply of radioactive sources of different radionuclides and achieved considerable success [4][5][6][7][8][9][10][11], electrodeposition of 90 Sr from ionic state to metallic state from an aqueous solution is precluded owing to the low solution potentials and difficulty encountered in controlling the electrolytic-deposition of 90 Sr on a metallic cathode. In order to circumvent such limitation, the scope of using chemically modified conductive electrode containing oxide/hydroxide films similar to that used in the preparation of 133 Ba source [9] seems to be an interesting proposition owing to the similar chemical properties of Ba and Sr.…”