Towards saturation of the electron-capture delayed fission probability: The new isotopes Es-240 and Bk-236

Konki, J; Khuyagbaatar, J; Uusitalo, J; Greenlees, T; Auranen, K; Badran, H; Block, M; Briselet, R; Cox, DM; Dasgupta, M; Di Nitto, A; Duellmann, Ch E; Grahn, T; Hauschild, K; Herzan, A; Herzberg, R-D; Hessberger, FP; Hinde, DJ; Julin, R; Juutinen, S; Jaeger, E; Kindler, B; Krier, J; Leino, M; Lommel, B; Lopez-Martens, A; Luong, DH; Mallaburn, M; Nishio, K; Pakarinen, J; Papadakis, P; Partanen, J; Peura, P; Rahkila, P; Rezynkina, Kseniia; Ruotsalainen, P; Sandzelius, M; Saren, J; Scholey, C; Sorri, J; Stolze, S; Sulignano, B; Theisen, Ch; Ward, A; Yakushev, A; Yakusheva, V

doi:10.1016/j.physletb.2016.11.038

Towards saturation of the electron-capture delayed fission probability: The new isotopes Es-240 and Bk-236

Author:

Konki, J

Khuyagbaatar, J ; Uusitalo, J ; Greenlees, T ; Auranen, K ; Badran, H ; Block, M ; Briselet, R ; Cox, DM ; Dasgupta, M ; Di Nitto, A ; Duellmann, Ch E ; Grahn, T ; Hauschild, K ; Herzan, A ; Herzberg, R-D ; Hessberger, FP ; Hinde, DJ ; Julin, R ; Juutinen, S ; Jaeger, E ; Kindler, B ; Krier, J ; Leino, M ; Lommel, B ; Lopez-Martens, A ; Luong, DH ; Mallaburn, M ; Nishio, K ; Pakarinen, J ; Papadakis, P ; Partanen, J ; Peura, P ; Rahkila, P ; Rezynkina, Kseniia ; Ruotsalainen, P ; Sandzelius, M ; Saren, J ; Scholey, C ; Sorri, J ; Stolze, S ; Sulignano, B ; Theisen, Ch ; Ward, A ; Yakushev, A ; Yakusheva, V

Keywords:

Isotopes with mass 236-240, Es-240, Bk-236, alpha decay, Electron-capture delayed fission, Fusion-evaporation reactions, Science & Technology, Physical Sciences, Astronomy & Astrophysics, Physics, Nuclear, Physics, Particles & Fields, Physics, TOTAL DATA READOUT, 0105 Mathematical Physics, 0201 Astronomical and Space Sciences, 0202 Atomic, Molecular, Nuclear, Particle and Plasma Physics, Nuclear & Particles Physics, 49 Mathematical sciences, 51 Physical sciences

Abstract:

The new neutron-deficient nuclei 240Es and 236Bk were synthesised at the gas-filled recoil separator RITU. They were identified by their radioactive decay chains starting from 240Es produced in the fusion–evaporation reaction 209Bi(34S,3n)240Es. Half-lives of View the MathML source6(2)s and View the MathML source22−6+13s were obtained for 240Es and 236Bk, respectively. Two groups of α particles with energies View the MathML sourceEα=8.19(3)MeV and View the MathML source8.09(3)MeV were unambiguously assigned to 240Es. Electron-capture delayed fission branches with probabilities of 0.16(6)0.16(6) and 0.04(2)0.04(2) were measured for 240Es and 236Bk, respectively. These new data show a continuation of the exponential increase of ECDF probabilities in more neutron-deficient isotopes.