Determination of trace levels of uranium and thorium in high purity gadolinium sulfate using the ICP-MS with solid-phase chromatographic extraction resin
Determination of trace levels of uranium and thorium in high purity gadolinium sulfate using the ICP-MS with solid-phase chromatographic extraction resin
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采用固相色谱萃取树脂 ICP-MS 测定高纯硫酸钆中的痕量铀和钍
DOI：
10.1093/ptep/ptx145
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发表时间：
2017
期刊：
影响因子：
--
通讯作者：
Y. Kishimoto
中科院分区：
文献类型：
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作者：
S. Ito;Y. Takaku;M. Ikeda;Y. Kishimoto
新的Super-Kamiokande-Gadolinium（SK-Gd）项目是Super-Kamiokande（SK）探测器的升级。在SK-Gd计划中，将0.2%的Gd（SO）装入SK的50 kton水箱中，该计划的主要目的之一是发现超新星遗迹中微子。中微子测量和质子衰变搜索也将在SK-Gd中进行。为了在SK-Gd装置上测量3.5MeV的低能太阳中微子，在装载前应尽量减少Gd（SO）_8HO中的主要放射性污染物U和Th。铀和钍的最大水平分别为5 mBq（U）/kg（Gd（SO）8HO）和0.05 mBq（Th）/kg（Gd（SO）8HO）。为了测量Gd（SO）_8HO中如此低浓度的U和Th，我们开发了固相萃取技术。用这种方法，约90%或更多的U和Th可以有效地提取，而Gd被减少了约1倍。这使得这些放射性污染能够精确测量，U为0.04 mBq/kg（Gd（SO）8 HO），Th为0.01 mBq/kg（Gd（SO）8 HO）。我们用这种方法测量了三个纯Gd（SO）_8HO样品，用ICP-MS估计最纯的样品中Gd（SO）_8HO的含量为mBq（U）/kg和0.060.01mBq（Th）/kg。
The new Super-Kamiokande-Gadolinium (SK-Gd) project is an upgrade of the Super-Kamiokande (SK) detector. In the SK-Gd project, 0.2% Gd(SO)is loaded into the 50 kton water tank of the SK. One of the main purposes of the project is to discover supernova relic neutrinos. Neutrino measurements and proton decay searches will also be performed in the SK-Gd. In order to measure solar neutrinos with a low energy threshold of3.5 MeV in the SK-Gd, the main radioactive contaminations,U andTh, in Gd(SO)8HO, should be minimized before loading. Our maximum levels for U and Th are 5 mBq (U)/kg (Gd(SO)8HO) and 0.05 mBq (Th)/kg (Gd(SO)8HO). In order to measure such low concentrations of U and Th in Gd(SO)8HO, we developed the solid-phase extraction technique. Using this method, about 90% or more U and Th could be efficiently extracted while Gd was reduced by a factor of about. This allowed these radioactivity contaminations to be measured precisely as 0.04 mBq/kg (Gd(SO)8HO) for U and 0.01 mBq/kg (Gd(SO)8HO) for Th. We measured three pure Gd(SO)8HO samples using this method and estimated that the purest one containedmBq (U)/kg (Gd(SO)8HO) and 0.060.01 mBq (Th)/kg (Gd(SO)8HO) by the ICP-MS.