Ponente
Descripción
We propose conducting measurements where fast neutrons will induce fission in both stable and radioactive actinide targets. The reaction products, which reside in exotic regions of the nuclear chart, will be separated using a gas-filled magnet (GFM) spectrometer, while the emitted gamma rays will be recorded using high-purity germanium (HPGe) or lanthanum bromide (LaBr3) detectors. Detailed information about the technique can be found in the “Report on possible complementary experiments to be developed in DONES using deuterons” delivered within the DONES Preparatory Phase project [1].
A high-intensity neutron beam induced by a pulsed beam of deuterons, if available at the DONES facility, will be crucial for providing high-statistics spectroscopy data on fission fragment nuclei. These neutrons can be produced using a 40-MeV pulsed deuteron beam directed onto a graphite converter. This approach presents attractive possibilities for studying the nuclear structure of many neutron-rich isotopes. Data collected during spontaneous fission experiments with 248Cm and 252Cf sources have significantly expanded our knowledge of nuclear properties on the neutron-rich side of the stability valley. Additionally, experiments studying fission products induced by thermal or cold neutrons, such as those recently conducted at the Institut Laue-Langevin (Grenoble) [e.g., 2, 3], have contributed to the field. However, this method has limitations, as the number of possible targets for fission induced by thermal neutrons is limited to a few odd isotopes. In contrast, fast neutrons provide new opportunities for nuclear structure studies of neutron-rich species. They can induce fission in many actinide nuclei, including radioactive targets like 236U, 232Th etc. Furthermore, the pulsing neutron beam will enable the use of a gas-filled spectrometer for fission fragment identification. A key advantage of such a spectrometer is the short flight time of the fission fragments through the device, approximately 100-200 ns, allowing unprecedented studies of short-lived isomer decays in the focal plane of the spectrometer.
During the talk, the conceptual design of the experimental setup will be described, showing the possibilities for extensive study of neutron-rich nuclei produced in fast neutron-induced fission reactions. Special attention will be devoted to the feasibility of such measurements and their uniqueness at the DONES facility.
References:
[1] Ł.W. Iskra, B. Fornal, D. Cano-Ott, E. Mendoza et al., „Report on possible complementary experiments to be developed in DONES using deuterons”
[2] Ł. W. Iskra et al., Phys. Rev. C 102, 054324 (2020).
[3] S. Leoni, C. Michelagnoli, and J. N. Wilson Riv. Nuovo Cim. (2022).
