Measurements of cross sections and decay properties of the isotopes of elements 112, 114, and 116 produced in the fusion reactionsU<mml:mprescripts/><mml:none/>233,238,Pu<mml:mprescripts/><mml:none/>242, andCm<mml:mprescripts/><mml:none/>248+Ca<mml:mprescripts/><mml:none/>48

2004/12/17 by Yu. Ts. Oganessian, V. K. Utyonkov, Yu. V. Lobanov +27 · 22 citations
Physics and Astronomy · #Nuclear physics research studies #Astronomical and nuclear sciences #Atomic and Molecular Physics #Fusion #Isotope #Physics #Nuclear fusion #Nuclear physics #Philosophy

paper · pdf · doi:10.1103/physrevc.70.064609

openalex publication_date 2004/12/17 · openalex created_date 2017/01/26 · openalex updated_date 2026/08/01

Abstract

We have studied the dependence of the production cross sections of the isotopes ^282,283112 and ^286,287114 on the excitation energy of the compound nuclei ²⁸⁶112 and ²⁹⁰114. The maximum cross section values of the xn-evaporation channels for the reaction ²³⁸U(⁴⁸Ca,xn)^286\ensuremath-x112 were measured to be \ensuremathσ_3n=2.5_\ensuremath-1.1^+1.8\phantom\rule0.3em0expb and \ensuremathσ_4n=0.6_\ensuremath-0.5^+1.6\phantom\rule0.3em0expb; for the reaction ²⁴²Pu(⁴⁸Ca,xn)^290\ensuremath-x114: \ensuremathσ_2n\ensuremath∼0.5\phantom\rule0.3em0expb, \ensuremathσ_3n=3.6_\ensuremath-1.7^+3.4\phantom\rule0.3em0expb, and \ensuremathσ_4n=4.5_\ensuremath-1.9^+3.6\phantom\rule0.3em0expb. In the reaction ²³³U(⁴⁸Ca,2--4n)^277--279112 at E*=34.9\ifmmode±\else\textpm\fi2.2\phantom\rule0.3em0exMeV we measured an upper cross section limit of \ensuremathσ_xn\ensuremath\leqslant0.6\phantom\rule0.3em0expb. The observed shift of the excitation energy associated with the maximum sum evaporation residue cross section \ensuremathσ_ER(E*) to values significantly higher than that associated with the calculated Coulomb barrier can be caused by the orientation of the deformed target nucleus in the entrance channel of the reaction. An increase of \ensuremathσ_ER in the reactions of actinide targets with ⁴⁸Ca is consistent with the expected increase of the survivability of the excited compound nucleus upon closer approach to the closed neutron shell N=184. In the present work we detected 33 decay chains arising in the decay of the known nuclei ²⁸²112, ²⁸³112, ²⁸⁶114, ²⁸⁷114, and ²⁸⁸114. In the decay of ²⁸⁷114(\ensuremathα)\ensuremath→²⁸³112(\ensuremathα)\ensuremath→²⁷⁹110(SF), in two cases out of 22, we observed decay chains of four and five sequential \ensuremathα transitions that end in spontaneous fission of ²⁷¹Sg\phantom\rule0.3em0ex(T_\ensuremathα∕SF=2.4_\ensuremath-1.0^+4.3\phantom\rule0.3em0exmin) and ²⁶⁷Rf\phantom\rule0.3em0ex(T_SF\ensuremath∼2.3\phantom\rule0.3em0exh), longer decay chains than reported previously. We observed the new nuclide ²⁹²116\phantom\rule0.3em0ex(T_\ensuremathα=18_\ensuremath-6⁺¹⁶\phantom\rule0.3em0exms,E_\ensuremathα=10.66\ifmmode±\else\textpm\fi0.07\phantom\rule0.3em0exMeV) in the irradiation of the ²⁴⁸Cm target at a higher energy than in previous experiments. The observed nuclear decay properties of the nuclides with Z=104--118 are compared with theoretical nuclear mass calculations and the systematic trends of spontaneous fission properties. As a whole, they give a consistent pattern of decay of the 18 even-Z neutron-rich nuclides with Z=104--118 and N=163--177. The experiments were performed with the heavy-ion beam delivered by the U400 cyclotron of the FLNR (JINR, Dubna) employing the Dubna gas-filled recoil separator.

Citations

• Synthesis of nuclei of the superheavy element 114 in reactions induced by 48Ca
• The discovery of the heaviest elements
• Fission barriers of neutron-rich and superheavy nuclei calculated with the ETFSI method
• New results on elements 111 and 112
• Properties of the hypothetical spherical superheavy nuclei
• Observation of the decay of292116
• Synthesis of superheavy nuclei in 48Ca+244Pu interactions
• Synthesis of Superheavy Nuclei in the48Ca<mml:mspace/>+244PuReaction
• Measurements of cross sections for the fusion-evaporation reactionsPu<mml:mprescripts/><mml:none/>244(Ca<mml:mprescripts/><mml:none/>48,xn)292−x114andCm<mml:mprescripts/><mml:none/>245(Ca<mml:mprescripts/><mml:none/>48,xn)293−x116

Cited by

• Synthesis of superheavy nuclei: A search for new production reactions
• Doubly Magic NucleusHs162<mml:none/><mml:mprescripts/>108270
• DECAY PROPERTIES AND STABILITY OF HEAVIEST ELEMENTS
• α decay chains from element 113
• Quantum Tunneling in277112 and Its α-Decay Chain
• Systematic study of decay properties of heaviest elements
• Prospects for the discovery of the next new element: Influence of projectiles withZ> 20
• Is E112 a relatively inert element? Benchmark relativistic correlation study of spectroscopic constants in E112H and its cation
• Thermochemical and Physical Properties of Element 112
• Possible Way to Synthesize Superheavy Element Z = 117
• HOW CAN ONE SYNTHESIZE THE ELEMENT Z = 120?
• Is Eka‐Mercury (Element 112) a Group 12 Metal?
• Exclusively Relativistic: Periodic Trends in the Melting and Boiling Points of Group 12
• Experiments on the synthesis of superheavy nucleiFl<mml:mprescripts/><mml:none/>284andFl<mml:mprescripts/><mml:none/>285in thePu<mml:mprescripts/><mml:none/>239,240+Ca<mml:mprescripts/><mml:none/>48reactions
• Calculation ofα-decay energies of superheavy nuclei in a hybrid method
• Effects of nuclear structure on quasi-fission
• Copernicium: A Relativistic Noble Liquid
• Synthesis and decay process of superheavy nuclei with Z=119-122 via hot-fusion reactions
• Flerovium [wikipedia]
• Livermorium [wikipedia]
• Nihonium [wikipedia]
• Oganesson [wikipedia]