The development of conductive 10B thin film for neutron monitoring

Title & Authors
The development of conductive 10B thin film for neutron monitoring
Lim, Chang Hwy; Kim, Jongyul; Lee, Suhyun; Jung, Yongju; Choi, Young-Hyun; Baek, Cheol-Ha; Moon, Myung-Kook;

Abstract
In the field of neutron detections, $\small{^3He}$ gas, the so-called "the gold standard," is the most widely used material for neutron detections because of its high efficiency in neutron capturing. However, from variable causes since early 2009, $\small{^3He}$ is being depleted, which has maintained an upward pressure on its cost. For this reason, the demands for $\small{^3He}$ replacements are rising sharply. Research into neutron converting materials, which has not been used well due to a neutron detection efficiency lower than the efficiency of $\small{^3He}$, although it can be chosen for use in a neutron detector, has been highlighted again. $\small{^{10}B}$, which is one of the $\small{^3He}$ replacements, such as $\small{BF_3}$, $\small{^6Li}$, $\small{^{10}B}$, $\small{Gd_2O_2S}$, is being researched by various detector development groups owing to a number of advantages such as easy gamma-ray discrimination, non-toxicity, low cost, etc. One of the possible techniques for the detection is an indirect neutron detection method measuring secondary radiation generated by interactions between neutrons and $\small{^{10}B}$. Because of the mean free path of alpha particle from interactions that are very short in a solid material, the thickness of $\small{^{10}B}$ should be thin. Therefore, to increase the neutron detection efficiency, it is important to make a $\small{^{10}B}$ thin film. In this study, we fabricated a $\small{^{10}B}$ thin film that is about 60 um in thickness for neutron detection using well-known technology for the manufacturing of a thin electrode for use in lithium ion batteries. In addition, by performing simple physical tests on the conductivity, dispersion, adhesion, and flexibility, we confirmed that the physical characteristics of the fabricated $\small{^{10}B}$ thin film are good. Using the fabricated $\small{^{10}B}$ thin film, we made a proportional counter for neutron monitoring and measured the neutron pulse height spectrum at a neutron facility at KAERI. Furthermore, we calculated using the Monte Carlo simulation the change of neutron detection efficiency according to the number of thin film layers. In conclusion, we suggest a fabrication method of a $\small{^{10}B}$ thin film using the technology used in making a thin electrode of lithium ion batteries and made the $\small{^{10}B}$ thin film for neutron detection using suggested method.
Keywords
$\small{^{10}B}$ thin film;Neutron;Proportional counter;MCNP6;
Language
Korean
Cited by
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