Phys.Rev. C 87, 064304 (2013)

J.Uusitalo, J.Saren, S.Juutinen, M.Leino, S.Eeckhaudt, T.Grahn, P.T.Greenlees, U.Jakobsson, P.Jones, R.Julin, S.Ketelhut, A.-P.Leppanen, M.Nyman, J.Pakarinen, P.Rahkila, C.Scholey, A.Semchenkov, J.Sorri, A.Steer, M.Venhart

α-decay studies of the francium isotopes ¹⁹⁸Fr and ¹⁹⁹Fr

RADIOACTIVITY ^198,199Fr(α)[from ¹⁴¹Pr(⁶⁰Ni, xn), E=268 MeV]; measured Eα, Iα, Eγ, time-of-flight, recoil energy deposit, half-lives using RITU separator and GREAT spectrometer at JYFL facility. ^198,199Fr; deduced levels, J, π, isomers, reduced α widths, speculative decay schemes. ^190,191Bi, ^194,195,196At, ²⁰⁰Fr(α); measured Eα, half-lives of ground states and isomers; deduced reduced α widths, speculative decay schemes. Comparison with calculated half-lives. ^186,187Tl, ^190,191Bi, ^194,195At, ^198,199Fr; deduced possible levels, isomers, J, π. ^198,199Rn, ¹⁹²Bi(α); observed α spectra. ^190,191Bi(β⁺), (EC); deduced EC+β⁺ branching ratio. Systematics of Eα for α transitions in A=190-212 At and Fr isotopes. Evidence of ground state deformation at N=112 in Fr isotopes.

NUCLEAR REACTIONS ¹⁴¹Pr(⁶⁰Ni, X)¹⁹⁸Rn/¹⁹⁹Rn/¹⁹⁸Fr/¹⁹⁹Fr, E=268 MeV; measured production σ using RITU separator at JYFL facility.

doi: 10.1103/PhysRevC.87.064304