This article describes a series of studies on the effect of the rotation of the fissile 236U nucleus in the^(235)U(n,f)process induced by monochromatic polarized neutrons with energies of 62 meV and 270 meV.The studie...This article describes a series of studies on the effect of the rotation of the fissile 236U nucleus in the^(235)U(n,f)process induced by monochromatic polarized neutrons with energies of 62 meV and 270 meV.The studied effect is expressed as a shift in the anisotropic angular distribution ofγ-rays emitted by excited fission fragments by a small angle relative to the deformation axis of the fissile nucleus when the neutron beam polarization direction is reversed.All measurements were performed at the Heinz Mayer-Leibniz research neutron source(FRM Ⅱ reactor)of the Munich Technical University in Garching on the polarized neutron beam of the POLI instrument.To generalize all results obtained on ROT effects for fissionγ-rays,the results of earlier studies by the ITEP group for cold neutrons are re-processed,and the result obtained by the PNPI group for thermal neutrons is also presented.展开更多
Purpose The performance of a scintillation detector based on an MAPD-type SiPM and LaBr_(3)(Ce)for detecting gamma rays over a wide energy range is investigated.Methods This paper proposes the use of an MAPD-type SiPM...Purpose The performance of a scintillation detector based on an MAPD-type SiPM and LaBr_(3)(Ce)for detecting gamma rays over a wide energy range is investigated.Methods This paper proposes the use of an MAPD-type SiPM with a pixel pitch of 15μm,a total pixel number of 1,063,877 pixels and a PDE of 30% for the preparation of scintillation detectors operating in a wide energy range.The scintillation detectors prepared with this method can theoretically detect gamma rays with an energy of 25 MeV.Results The performance of a LaBr_(3)(Ce)-based scintillation detector with a 16-element MAPD array was characterized for gamma-ray spectroscopy in the 0.1-7 MeV range.The detector exhibited excellent linearity and high energy resolution,successfully resolving the 1.173 MeV,1.332 MeV,and 1.460 MeV gamma lines with resolutions of 3.45%,3.11%,and 1.99%,respectively.It also identified multiple gamma-ray peaks from thermal neutron capture reactions induced by an AmBe source,detecting emissions from hydrogen,sodium,chlorine,and carbon.Despite challenges related to scintillator size and low gamma-ray intensity,the detector effectively provided spectral information on various elements.Conclusion The study demonstrates the potential of the LaBr_(3)(Ce)-MAPD scintillation detector for high-resolution gamma-ray spectroscopy over a broad energy range.The detector's excellent linearity,high light output,and ability to resolve multiple gamma-ray peaks make it a promising candidate for applications in industry,space exploration,and security.Future improvements,such as increasing the LaBr_(3)(Ce)scintillator size and investigating higher-density scintillators like BGO and LSO,could further enhance its performance,enabling even more precise and efficient gamma-ray detection.展开更多
基金Supported by the Committee of Science of the Ministry of Science and Higher Education of the Republic of Kazakhstan(BR21881930)by the Russian Ministry for Science and Education,German Ministry for Education and Research BMBF through the project 05K13PA3.
文摘This article describes a series of studies on the effect of the rotation of the fissile 236U nucleus in the^(235)U(n,f)process induced by monochromatic polarized neutrons with energies of 62 meV and 270 meV.The studied effect is expressed as a shift in the anisotropic angular distribution ofγ-rays emitted by excited fission fragments by a small angle relative to the deformation axis of the fissile nucleus when the neutron beam polarization direction is reversed.All measurements were performed at the Heinz Mayer-Leibniz research neutron source(FRM Ⅱ reactor)of the Munich Technical University in Garching on the polarized neutron beam of the POLI instrument.To generalize all results obtained on ROT effects for fissionγ-rays,the results of earlier studies by the ITEP group for cold neutrons are re-processed,and the result obtained by the PNPI group for thermal neutrons is also presented.
基金supported by the Azerbaijan Science Foundation-Grant №AEF-MGC-2024-2(50)-16/04/1-M-04received funding from the European Union’s Horizon 2021 Research and Innovation Programme under the Marie Sklodowska-Curie’s INNMEDSCAN project(grant agreement ID 101086178).
文摘Purpose The performance of a scintillation detector based on an MAPD-type SiPM and LaBr_(3)(Ce)for detecting gamma rays over a wide energy range is investigated.Methods This paper proposes the use of an MAPD-type SiPM with a pixel pitch of 15μm,a total pixel number of 1,063,877 pixels and a PDE of 30% for the preparation of scintillation detectors operating in a wide energy range.The scintillation detectors prepared with this method can theoretically detect gamma rays with an energy of 25 MeV.Results The performance of a LaBr_(3)(Ce)-based scintillation detector with a 16-element MAPD array was characterized for gamma-ray spectroscopy in the 0.1-7 MeV range.The detector exhibited excellent linearity and high energy resolution,successfully resolving the 1.173 MeV,1.332 MeV,and 1.460 MeV gamma lines with resolutions of 3.45%,3.11%,and 1.99%,respectively.It also identified multiple gamma-ray peaks from thermal neutron capture reactions induced by an AmBe source,detecting emissions from hydrogen,sodium,chlorine,and carbon.Despite challenges related to scintillator size and low gamma-ray intensity,the detector effectively provided spectral information on various elements.Conclusion The study demonstrates the potential of the LaBr_(3)(Ce)-MAPD scintillation detector for high-resolution gamma-ray spectroscopy over a broad energy range.The detector's excellent linearity,high light output,and ability to resolve multiple gamma-ray peaks make it a promising candidate for applications in industry,space exploration,and security.Future improvements,such as increasing the LaBr_(3)(Ce)scintillator size and investigating higher-density scintillators like BGO and LSO,could further enhance its performance,enabling even more precise and efficient gamma-ray detection.
