Direct neutron-multiplicity sorting with a flat-efficiency detector

• Published in: Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment Accelerators, spectrometers, detectors and associated equipment, 2017-11, Vol.871, p.135-141
• Main Authors: Utsunomiya, Hiroaki, Gheorghe, Ioana, Filipescu, Dan M., Glodariu, Tudor, Belyshev, Sergey, Stopani, Konstantin, Varlamov, Vladimir, Ishkhanov, Boris, Katayama, Seitarou, Takenaka, Daiki, Ari-izumi, Takashi, Amano, Sho, Miyamoto, Shuji
• Format: Article
• Language: English
• Subjects: Flat-efficiency neutron detector; Neutron-multiplicity sorting; Partial photoneutron cross sections
• ISSN: 0168-9002; 1872-9576
• DOI: 10.1016/j.nima.2017.08.001

A novel technique of direct neutron-multiplicity sorting with a flat-efficiency detector is proposed to resolve the long-standing discrepancy between the Livermore and Saclay data of partial photoneutron cross sections. A flat-response neutron detector with the detection efficiency of 36.5±1.6% over a neutron energy range 0.01–5.0 MeV was developed by optimizing triple-ring configurations of He proportional counters embedded in a polyethylene moderator. The technique forms a foundation of measuring cross sections with x=1−3 for the photonuclear data project of the International Atomic Energy Agency. The methodology of direct neutron-multiplicity sorting and key experimental elements are presented.