Электронный каталог

Книга (аналит. описание)

Mullins, S.
Two-Neutron-Transfer to *1*7*8Yb and Population of &sup(178m2)Hf Via In-Complete Fusion / S.Mullins, S.Bogolomov, A.Efremov, [a.o.] // The 2nd International African Symposium on Exotic Nuclei IASEN2024, Cape Town, 09 - 13 December 2024 : Book of Abstracts [Electronic resource]. – Cape Town, 2024. – P. 31-32. – URL: http://inis.jinr.ru/sl/NTBLIB/IASEN-2024-P31.pdf.

The DIAMANT light-charged-particle detector from ATOMKI was coupled with the AFRODITE gamma-ray spectrometer at iThemba LABS in a collaboration enabled by a bilateral agreement between the governments of South Africa and Hungary. This facilitated the study of incomplete fusion reactions in the bombardment of a Ytterbium-176 target with a beam of 50 MeV Lithium-7 ions. The beam was generated as a collaborative effort between ion source experts at iThemba LABS and the Flerov Laboratory for Nuclear Reactions (FLNR) of the Joint Institute for Nuclear Reactions (JINR), Dubna. Particle-Identification (PID) spectra from DIAMANT generated from the ATOMKI custom-built VXI electronics clearly show the detection of protons, tritons and alpha particles, which, when gated on, allowed the selection of gamma-ray coincidences detected with AFRODITE when the respective complementary Helium-6, Helium-4 (*a) and triton fragments fused with the target. Analysis of the charged-particle-selected gamma-ray coincidence data enabled the identification of Hafnium-180 in the proton-gated Eγ -Eγ correlation matrix, as well as Hafnium-178, including the band based on the T&sub(1/2) = 31a, K&sup(*p) = 16&sup(+) four-quasiparticle state. Hafnium-178 is also evident in the triton-gated matrix, which suggests that this nucleus is populated via two incomplete fusion channels, this one in which the fused fragment is Helium-4, and the other in which a Helium-6 neutron-rich fragment fuses with the Ytterbium-176 target. The relative contribution from the (&sup(7)Li,p4n) fusion evaporation channel is unclear, but there is other evidence for Helium-6-induced reactions in the population of neutron-rich Ytterbium-178 whereby two neutrons have been transferred to the target. The ground-state band of Ytterbium-178 can be clearly observed in both the proton-gated and alpha-gated matrices, which supports the assignment of the &sup(176)Yb(&sup(7)Li,*ap)&sup(178)Yb reaction. The deuteron yield is comparatively weak which has hampered the unambiguous confirmation of the &sup(176)Yb(&sup(7)Li, *ad)&sup(177)Yb reaction. The comparatively strong population of Hafnium-178 via the two reaction channels discussed above has allowed the population ratio I*g(proton-gated)/ I*g(triton-gated) of the ground-state, two-quasiparticle K&sup(*p) = 8&sup(−) and four-quasiparticle K&sup(*p) = 14&sup(−) and K&sup(*p) = 16&sup(+) bands to be extracted as function of spin . There is evidence for a marked increase in relative population of the K&sup(*p) = 16&sup(+) band when compared to the other lower-spin band structures.



Спец.(статьи,препринты) = С 343 е1 - Взаимодействие тяжелых ионов с ядрами
Спец.(статьи,препринты) = С 343 г3 - Гамма-излучение радиационного захвата нейтронов
ОИЯИ = ОИЯИ (JINR)2024