Evaluation of several electrolyte mixture-cathode material combinations in electrodeposition of americium radioisotopes for alpha-spectrometric measurements

Investigation of key factors in preparation of alpha sources by electrodeposition

“…prepared by MPC method (50-63 keV FWHM). The lowest resolution for ED source preparation (from 31 keV to 41 keV FWHM) was obtained when using the sodium sulphate medium (NS), which is in agreement with the results obtained for electrodeposition of americium radioisotopes in the previous study (Krmpotić et al, 2017). The activity concentration results for 239 Pu, 241 Am and 244 Cm in a PT water sample (NPL 2015) also showed very good agreement comparing the obtained results by using different source preparation methods, and with the assigned values provided by the organizer (Table 4).…”

“…Very low yield (only 28% total) was obtained when using the ASO electrolyte for ED, which in this case cannot be attributed to the radiochemical procedure used, due to the fact that all the samples were treated with the same radiochemical procedure up to the source preparation step, but suggests that the parameters for ED in this medium (Table 2) are most probably not optimal for Pu deposition. This was somewhat expected and is in accordance with the previous reported studies ( Lee and Pimpl, 1999;Oh et al, 2014), but was tested nevertheless due to the fact that lower concentrations of the chosen electrolyte's components were studied here, which previously proved to give higher deposition yields under lower currents (Krmpotić et al, 2017). To be able to quantitatively prepare plutonium sources in this medium, higher currents would be necessary.…”

“…Additionally, ED times above 150 min were not investigated since they proved too long and inconvenient (due to decrease of the ED yield), while the 30 min time intervals were chosen to reduce the number of experiments needed to reach the satisfying conclusions, while also producing less chemical and radioactive wastes. Despite the fact that the ammonium sulphate/oxalate based electrolyte with diethylenetriaminepentaacetic acid (DTPA) as a chelating agent, used in our previous study (Krmpotić et al, 2017), was reported to give the sources of highest quality on Ag cathode, further experiments for method optimization were made on the solution without DTPA since its presence proved to significantly decrease the electrodeposition (ED) yield while not improving the source quality drastically.…”

“…The polypropylene ED cells used in this study were designed and manufactured at Jožef Stefan Institute (Ljubljana, Slovenia), as presented in our previous work (Krmpotić et al, 2017). The cells, with a total volume of 25 mL, contain a closing lid and anode insertion opening at the top, a metal backing for the cathode at the bottom, and no cooling or stirring system.…”

“…Several electrolyte solution-cathode material combinations were characterized and compared in our previous study for a conventional electrodeposition system used in order to obtain quantitative sources of americium isotopes with optimal spectral resolution for alpha-spectrometric measurements (Krmpotić et al, 2017;Trdin et al, 2012). This study is the extension of the reported findings, and focuses on the optimization of each proposed electrolyte solution-cathode material combination (for which 241 Am and 243 Am radioisotopes were again used as model solutions), and their implementation for the source preparation in determination of actinides (uranium, plutonium, americium and curium radioisotopes) in environmental samples.…”