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| Design of an improved multisphere neutron spectrometer based on boron-doped moderator |
| CHEN Ran, CHEN Jun, XU Yongjun, WU Jianhua, LIU Senlin |
| China Institute of Atomic Energy, P. O. Box 275-15, Beijing 102413 China |
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Abstract Objective A modification of the multisphere neutron spectrometer is proposed in order to improve the energy resolution at low and intermediate energies around some radiation fields, and then to provide information for the calibration of radiation protection instruments.Methods The spectrometer is a set of detector assemblies made of spherical moderators of different sizes, which the polyethylene spheres are surrounded by layers of neutron moderators and absorbers (Boron-containing-PE), each one with a 3He proportional counter placed at the center. By adjusting the thickness and content of the boron shell, the response of the multisphere spectrometer in lower energy has been changed, then a series of response functions with different threshold values are obtained. By this way a set of improved multisphere spectrometer with good resolving power is acquired.Results This design improves the energy resolution of the multisphere neutron spectrometer in the energy range from 1 eV to 10 MeV significantly has been proved by comparing with the conventional multisphere spectrometers.Conclusion The theoretical calculation results indicate that the principle of response functions with different threshold values has greatly improved the energy resolution at low and intermediate energies.
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Received: 09 November 2017
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