A CR-39 based method was developed for measuring the ultra-trace alpha radio activities in aqueous samples having curie levels of γ/β-radio activities. The chemical etching method was optimized to reveal the alpha tracks in CR-39. This new chemical etching method involved the use of a phase transfer catalyst tetraethylammonium bromide which reduced the track revelation induction time without deteriorating the track-etch parameters. The alpha track-etch parameters such as bulk-etch rate, track-etch rate, induction time, and the critical angle of alpha track registration were measured at 60 and 70 °C, with and without using a phase transfer catalyst in the chemical etching for the comparison and optimization. The track registration efficiency of CR-39 in the solution medium was measured using the samples having known alpha activity of mix Pu, and value obtained was found to be (4.42 ± 0.12) × 10 −4 cm. The registration efficiency value thus obtained was corroborated with the expected efficiency expected from the calculated range of alpha particles in the solution. This CR-39 based method was employed to quantify the alpha activity, as low as 0.2 Bq mL −1 , in the aqueous radiopharmaceutical samples having the curie levels of γ/β radio activities.

中文翻译：

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使用新蚀刻方法在 CR-39 中进行 Alpha 轨道注册和揭示，用于溶液介质中的超痕量 alpha 放射性定量

开发了一种基于 CR-39 的方法，用于测量具有居里水平的 γ/β 放射性活度的水性样品中的超痕量 α 放射性活度。优化化学蚀刻方法以显示 CR-39 中的 alpha 轨迹。这种新的化学蚀刻方法涉及使用相转移催化剂四乙基溴化铵，它在不降低轨道蚀刻参数的情况下减少了轨道显露诱导时间。在 60°C 和 70°C 下测量了 alpha 轨迹蚀刻参数，例如体蚀刻速率、轨迹蚀刻速率、诱导时间和 alpha 轨迹配准的临界角，在化学蚀刻中使用和不使用相转移催化剂用于比较和优化。CR-39 在溶液介质中的轨迹记录效率是使用具有已知混合 Pu α 活性的样品测量的，得到的值为(4.42±0.12)×10 -4 cm。如此获得的配准效率值与根据溶液中 α 粒子的计算范围预期的预期效率相一致。这种基于 CR-39 的方法用于量化具有居里水平的 γ/β 放射性活度的水性放射性药物样品中的 α 活度，低至 0.2 Bq mL -1 。