Phys.Rev. C 101, 024306 (2020)

K.Auranen, U.Jakobsson, H.Badran, T.Grahn, P.T.Greenlees, A.Herzan, R.Julin, S.Juutinen, J.Konki, M.Leino, A.-P.Leppanen, G.O'Neill, J.Pakarinen, P.Papadakis, J.Partanen, P.Rahkila, P.Ruotsalainen, M.Sandzelius, J.Saren, C.Scholey, L.Sinclair, J.Sorri, S.Stolze, J.Uusitalo, A.Voss

Isomeric 13/2⁺ state in ²⁰¹Fr

RADIOACTIVITY ²⁰¹Fr(IT)[from ¹⁶⁹Tm(³⁶Ar, 4n)²⁰¹Fr, E=178-187 MeV, followed by separation of residues using RITU separator at the University of Jyvaskyla accelerator laboratory]; measured evaporation residues, E(ce), I(ce), Eγ, Iγ and half-life of the 13/2+ isomer in ²⁰¹Fr using the GREAT spectrometer and three clover-type Ge detectors. ²⁰¹Fr; deduced energy, J, π of the 13/2+ isomer, K/(L+M) ratio and multipolarity of the isomeric transition, B(M2). Discussed systematics of energies, B(M2) and deformation of the 13/2+ isomers in N(even)=104-124 Bi, At and Fr isotopes. ^201mFr(α)[from ¹⁶⁹Tm(³⁶Ar, 4n)²⁰¹Fr, E=178-187 MeV]; measured Eα and half-life of the 1/2+ isomer of ²⁰¹Fr; deduced reduced α-decay width using Rasmussen formalism. Comparison with previous experimental results.

doi: 10.1103/PhysRevC.101.024306