Phys.Rev. C 106, L031301 (2022)

Yu.Ts.Oganessian, V.K.Utyonkov, N.D.Kovrizhnykh, F.Sh.Abdullin, S.N.Dmitriev, D.Ibadullayev, M.G.Itkis, D.A.Kuznetsov, O.V.Petrushkin, A.V.Podshibiakin, A.N.Polyakov, A.G.Popeko, R.N.Sagaidak, L.Schlattauer, I.V.Shirokovski, V.D.Shubin, M.V.Shumeiko, D.I.Solovyev, Yu.S.Tsyganov, A.A.Voinov, V.G.Subbotin, A.Yu.Bodrov, A.V.Sabelnikov, A.V.Khalkin, V.B.Zlokazov, K.P.Rykaczewski, T.T.King, J.B.Roberto, N.T.Brewer, R.K.Grzywacz, Z.G.Gan, Z.Y.Zhang, M.H.Huang, H.B.Yang

First experiment at the Super Heavy Element Factory: High cross section of ²⁸⁸Mc in the ²⁴³Am + ⁴⁸Ca reaction and identification of the new isotope ²⁶⁴Lr

NUCLEAR REACTIONS ²⁴³Am(⁴⁸Ca, 2n)²⁸⁹Mc, (⁴⁸Ca, 3n)²⁸⁸Mc, (⁴⁸Ca, 4n), E=239.1, 240.9, 243.9 MeV; measured evaporation residues (ER), α, and fission fragments (SF), (ER)α-coin, αα-coin, α(SF)-coin, ER(SF)-coin, production σ(E) for superheavy nuclei using gas-filled separator DGFRS-2, two double-sided strip detectors (DSSD), two multiwire proportional chambers (MWPC) at the DC280 cyclotron facility of the Super Heavy Element Factory of JINR-Dubna.

RADIOACTIVITY ^288,289Mc, ^284,285Nh, ^280,281Rg, ²⁷⁶Mt, ²⁷²Bh, ²⁶⁸Db(α); ²⁸¹Rg, ²⁷⁷Mt, ²⁶⁸Db, ²⁶⁴Lr(SF)[from ²⁴³Am(⁴⁸Ca, xn)]; measured Eα, E_SF, (ER)α-coin, αα-coin, α(SF)-coin, ER(SF)-coin, T_1/2. ²⁶⁸Db; deduced α/SF branching ratio. ²⁶⁴Lr; deduced new isotope, T_1/2, average decay properties. ²⁸⁸Mc, ²⁸⁴Nh(EC), (β⁺); discussed upper limit for decay mode. History of 55 correlated events observed for ²⁸⁸Mc and six for ²⁸⁹Mc is listed by authors in the Supplemental material of the paper.

doi: 10.1103/PhysRevC.106.L031301