Measurement of Radon Concentration in Super-Kamiokande's Buffer Gas
Measurement of Radon Concentration in Super-Kamiokande's Buffer Gas
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DOI：
10.1016/j.nima.2017.04.037
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发表时间：
2017-04
影响因子：
1.4
通讯作者：
Y. Nakano;H. Sekiya;H. Sekiya;S. Tasaka;Y. Takeuchi;Y. Takeuchi;R. Wendell;R. Wendell;M. Matsubara;M. Nakahata;M. Nakahata
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文献类型：
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作者：
Y. Nakano;H. Sekiya;H. Sekiya;S. Tasaka;Y. Takeuchi;Y. Takeuchi;R. Wendell;R. Wendell;M. Matsubara;M. Nakahata;M. Nakahata
为了精确测量作为缓冲气体供应给 Super-Kamiokande 探测器的净化空气中的氡气浓度，我们开发了一种高灵敏度氡气探测器，其固有背景低至 0. 33±0. 07 mBq∕ m 3. 在本文中，我们讨论了该探测器的构造和校准，以及其在 Super-Kamiokande 上方缓冲气体层测量和监测中的应用结果。 2013年3月，对用于去除输入缓冲气体中氡气的冷冻活性炭系统进行了升级。经过这一改进后，供应气体的氡气浓度急剧降低至0. 08±0. 07 mBq∕ m 3. 另外，测量了原位缓冲气体的 Rn 浓度 28. 8±1. 07 mBq∕ m 3。 7 mBq∕ m 3 使用新的氡气探测器。根据这些测量，我们确定缓冲气体中 Rn 的主要来源来自 Super-Kamiokande 罐本身的污染。
To precisely measure radon concentrations in purified air supplied to the Super-Kamiokande detector as a buffer gas, we have developed a highly sensitive radon detector with an intrinsic background as low as 0. 33±0. 07 mBq∕ m 3. In this article, we discuss the construction and calibration of this detector as well as results of its application to the measurement and monitoring of the buffer gas layer above Super-Kamiokande. In March 2013, the chilled activated charcoal system used to remove radon in the input buffer gas was upgraded. After this improvement, a dramatic reduction in the radon concentration of the supply gas down to 0. 08±0. 07 mBq∕ m 3. Additionally, the Rn concentration of the in-situ buffer gas has been measured 28. 8±1. 7 mBq∕ m 3 using the new radon detector. Based on these measurements we have determined that the dominant source of Rn in the buffer gas arises from contamination from the Super-Kamiokande tank itself.