Boron-coated straws as a replacement for 3He-based neutron detectors
Boron-coated straws as a replacement for 3He-based neutron detectors
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DOI：
10.1016/j.nima.2010.09.011
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发表时间：
2011-10
影响因子：
1.4
通讯作者：
J. Lacy;A. Athanasiades;Liang Sun;Christopher S. Martin;T. Lyons;M. A. Foss;Hallee Haygood
中科院分区：
文献类型：
--
作者：
J. Lacy;A. Athanasiades;Liang Sun;Christopher S. Martin;T. Lyons;M. A. Foss;Hallee Haygood
US and international government efforts to equip major seaports with large area neutron detectors, aimed to intercept the smuggling of nuclear materials, have precipitated a critical shortage of3He gas. It is estimated that the annual demand of3He for US security applications alone is more than the worldwide supply. This is strongly limiting the prospects of neutron science, safeguards, and other applications that rely heavily on3He-based detectors. Clearly, alternate neutron detection technologies that can support large sensitive areas, and have low gamma sensitivity and low cost must be developed. We propose a low-cost technology based on long copper tubes (straws), coated on the inside with a thin layer of10B-enriched boron carbide (10B4C). In addition to the high abundance of boron on Earth and low cost of10B enrichment, the boron-coated straw (BCS) detector offers distinct advantages over conventional3He-based detectors, and alternate technologies such as10BF3tubes and10B-coated rigid tubes. These include better distribution inside moderator assemblies, many-times faster electronic signals, no pressurization, improved gamma-ray rejection, no toxic or flammable gases, and ease of serviceability. We present the performance of BCS detectors dispersed in a solid plastic moderator to address the need for portal monitoring. The design adopts the outer dimensions of currently deployed3He-based monitors, but takes advantage of the small BCS diameter to achieve a more uniform distribution of neutron converter throughout the moderating material. We show that approximately 63 BCS detectors, each 205cm long, distributed inside the moderator, can match or exceed the detection efficiency of typical monitors fitted with a 5cm diameter3He tube, 187cm long, pressurized to 3atm.
