1. Spectroscopy along Flerovium Decay Chains: Discovery of Ds280 and an Excited State in Cn282
- Author
-
Såmark-Roth, A, Cox, DM, Rudolph, D, Sarmiento, LG, Carlsson, BG, Egido, JL, Golubev, P, Heery, J, Yakushev, A, Åberg, S, Albers, HM, Albertsson, M, Block, M, Brand, H, Calverley, T, Cantemir, R, Clark, RM, Düllmann, Ch E, Eberth, J, Fahlander, C, Forsberg, U, Gates, JM, Giacoppo, F, Götz, M, Götz, S, Herzberg, R-D, Hrabar, Y, Jäger, E, Judson, D, Khuyagbaatar, J, Kindler, B, Kojouharov, I, Kratz, JV, Krier, J, Kurz, N, Lens, L, Ljungberg, J, Lommel, B, Louko, J, Meyer, C-C, Mistry, A, Mokry, C, Papadakis, P, Parr, E, Pore, JL, Ragnarsson, I, Runke, J, Schädel, M, Schaffner, H, Schausten, B, Shaughnessy, DA, Thörle-Pospiech, P, Trautmann, N, and Uusitalo, J
- Subjects
Nuclear and Plasma Physics ,Synchrotrons and Accelerators ,Physical Sciences ,Mathematical Sciences ,Engineering ,General Physics ,Mathematical sciences ,Physical sciences - Abstract
A nuclear spectroscopy experiment was conducted to study α-decay chains stemming from isotopes of flerovium (element Z=114). An upgraded TASISpec decay station was placed behind the gas-filled separator TASCA at the GSI Helmholtzzentrum für Schwerionenforschung in Darmstadt, Germany. The fusion-evaporation reactions ^{48}Ca+^{242}Pu and ^{48}Ca+^{244}Pu provided a total of 32 flerovium-candidate decay chains, of which two and eleven were firmly assigned to ^{286}Fl and ^{288}Fl, respectively. A prompt coincidence between a 9.60(1)-MeV α particle event and a 0.36(1)-MeV conversion electron marked the first observation of an excited state in an even-even isotope of the heaviest man-made elements, namely ^{282}Cn. Spectroscopy of ^{288}Fl decay chains fixed Q_{α}=10.06(1) MeV. In one case, a Q_{α}=9.46(1)-MeV decay from ^{284}Cn into ^{280}Ds was observed, with ^{280}Ds fissioning after only 518 μs. The impact of these findings, aggregated with existing data on decay chains of ^{286,288}Fl, on the size of an anticipated shell gap at proton number Z=114 is discussed in light of predictions from two beyond-mean-field calculations, which take into account triaxial deformation.
- Published
- 2021