Электронный каталог

Статья

Kessaci, K.
Cascade of High-K Isomers in *2*5*5&sub(102)No&sub(153) / K.Kessaci, M.L.Chelnokov, V.I.Chepigin, A.V.Isaev, A.A.Kuznetsova, O.N.Malyshev, A.V.Yeremin, [a.o.] // Physical Review C [Electronic resource]. – 2024. – Vol. 110, No. 5. – P. 054310. – URL: https://doi.org/10.1103/PhysRevC.110.054310. – Bibliogr.: 42.

This study of isomeric states in *2*5*5No was performed with the GABRIELA detector array at the focal plane of the SHELS recoil separator. The *2*0*8Pb(*4*8Ca, xn)&sup(256-x)No fusion-evaporation reaction was used to produce nobelium isotopes with a beam energy optimized for the one-neutron and two-neutron evaporation channels. These nobelium isotopes were studied by decay spectroscopy leading to the identification of isomeric states in *2*5*5No by means of the calorimetric method. In order to isolate the radioactive decays of *2*5*5No from the more numerous decays of *2*5*4No, the characteristic signal of the internal decay of the daughter *2*5*1Fm was used as a tag. Under these conditions, the decay of four isomeric states was observed. They are interpreted as high-K structures decaying in cascade. The first isomeric state is assigned to a ν[725]*1*1*-/2 neutron one quasiparticle (qp) configuration, in good agreement with the trend of this state in the neighboring isotones. The second and the third ones were attributed to three-qp 21/2*+ and 27/2*+ states and are interpreted as resulting from the coupling of the same ν[725]*1*1*-/2 one-qp configuration with the π2{[624]9*+/2 ⊗ [521]*1*1*-/2}&sub(5*−) and with the π2{[624]*9*+/2⊗[514]*7*-/2}&sub(8*-) two-qp configurations, respectively. According to its excitation energy E**> 2.5 MeV, the fourth isomeric state should have a five-qp structure, which requires more statistics to be detailed.



ОИЯИ = ОИЯИ (JINR)2024