An unattended device for high-voltage sampling and passive measurement of thoron decay products.
An unattended device for high-voltage sampling and passive measurement of thoron decay products.
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DOI：
10.1063/1.4865163
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发表时间：
2014-02
期刊：
影响因子：
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通讯作者：
S. Gierl;O. Meisenberg;T. Haninger;M. Wielunski;J. Tschiersch
中科院分区：
文献类型：
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作者：
S. Gierl;O. Meisenberg;T. Haninger;M. Wielunski;J. Tschiersch
设计并标定了气载钍射气衰变产物浓度的积分测量装置。它也适合在有人居住的住宅中无人看管使用长达几个月。该装置由一个半球形电容器组成，该电容器具有作为接地电位上的外电极的金属丝网和作为+7.0 kV上的内电极的采样基板。带负电荷和中性的钍射气衰变产物被加速并沉积在取样基底上。作为取样基底，使用CR 39固态核径迹探测器以记录取样衰变产物的α衰变。通过用不同厚度的铝箔覆盖探测器来实现核素鉴别，铝箔仅被具有足够能量的α粒子穿透。这种类型的设备校准工作水平监测器在钍实验室。灵敏度为9.2径迹/Bq/m（3）× d。这些装置在德国南部的几座用土材料建造的房屋中使用了8个多星期，在那里测得的钍射衰变产物的平衡当量浓度为1.4-9.9 Bq/m（3）。
An integrating measurement device for the concentration of airborne thoron decay products was designed and calibrated. It is suitable for unattended use over up to several months also in inhabited dwellings. The device consists of a hemispheric capacitor with a wire mesh as the outer electrode on ground potential and the sampling substrates as the inner electrode on +7.0 kV. Negatively charged and neutral thoron decay products are accelerated to and deposited on the sampling substrates. As sampling substrates, CR39 solid-state nuclear track detectors are used in order to record the alpha decay of the sampled decay products. Nuclide discrimination is achieved by covering the detectors with aluminum foil of different thickness, which are penetrated only by alpha particles with sufficient energy. Devices of this type were calibrated against working level monitors in a thoron experimental house. The sensitivity was measured as 9.2 tracks per Bq/m(3) × d of thoron decay products. The devices were used over 8 weeks in several houses built of earthen material in southern Germany, where equilibrium equivalent concentrations of 1.4-9.9 Bq/m(3) of thoron decay products were measured.