Development of B 4 C Thin Films for Neutron Detection

gas has been used for neutron monitors as the neutron converter owing to its advantages such as high sensitivity, good -discrimination capability, and long-term stability. However, is becoming more difficult to obtain in last few years due to a global shortage of gas. Accordingly, the cost of a neutron monitor using gas as a neutron converter is becoming more expensive. Demand on a neutron monitor using an alternative neutron conversion material is widely increased. has many advantages among various alternative materials, as a neutron converter. In order to develop a neutron converter using (actually ), we calculated the optimal thickness of a neutron converter with a Monte Carlo simulation using MCNP6. In addition, a neutron converter was fabricated by the Ar sputtering method and the neutron signal detection efficiencies were measured with respect to various thicknesses of fabricated a neutron converter. Also, we developed a 2-dimensional multi-wire proportional chamber (MWPC) for neutron beam profile monitoring using the fabricated a neutron converter, and performed experiments for neutron response of the neutron monitor at the 30 MW research reactor HANARO at the Korea Atomic Energy Research Institute. The 2-dimensional MWPC with boron () neutron converter was proved to be useful for neutron beam monitoring, and can be applied to other types of neutron imaging.