The work focuses on sorption of radium-223 and polonium-210 by a thin-layer MnO2-CTA sorbent. The maximal sorption of Ra (≈ 80%) and Po (≈ 12%) was achieved after 1 day of sorption. For Ra, decrease of quality of alpha spectrum was observed during sorption that can be explained by its diffusion into MnO2 and support layers. The average thickness of the sorption layer was determined to be 456 nm, whereas the energy loss of 5 MeV α-particles in MnO2 is approximately 270 keV μm−1. Scanning electronic microscopy and optical microphotographs confirmed flat morphology of the sorbent’s surface and no morphology changes as a result of sorption. In contrast to radium, the values of full width at half maximum (FWHM) of the 210Po alpha peak just slightly increased from ≈ 40 to ≈ 80 keV after 2 weeks of sorption that can be explained by larger ionic radius of polonium and another sorption mechanism, which is probably a partial replacement of manganese by polonium in the manganese dioxide crystal lattice. The observed phenomenon of increasing FWHM of alpha peaks from flat sorbents was suggested as an instrument for study the diffusion of alpha emitters in flat sorption-active layers.

中文翻译：

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薄层MnO2-CTA吸附剂对镭和钋的吸附研究

这项工作的重点是通过薄层 MnO2-CTA 吸附剂吸附镭 223 和钋 210。Ra (≈ 80%) 和 Po (≈ 12%) 在吸附 1 天后达到最大吸附。对于 Ra，在吸附过程中观察到 α 光谱质量下降，这可以通过其扩散到 MnO2 和支撑层来解释。吸附层的平均厚度确定为 456 nm，而 5 MeV α-粒子在 MnO2 中的能量损失约为 270 keV μm-1。扫描电子显微镜和光学显微照片证实了吸附剂表面的平坦形态，并且没有吸附导致的形态变化。与镭相比，吸附 2 周后，210Po α 峰的半峰全宽 (FWHM) 从 ≈ 40 keV 略微增加到 ≈ 80 keV，这可以通过较大的钋离子半径和另一种吸附机制来解释，这可能是在二氧化锰晶格中用钋部分替代锰。观察到的来自平坦吸附剂的 α 峰的 FWHM 增加的现象被建议作为研究 α 发射体在平坦吸附活性层中扩散的工具。