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Title: Experiments on the synthesis of superheavy nuclei Fl 284 and Fl 285 in the Pu 239 , 240 + Ca 48 reactions

Abstract

Irradiations of 239Pu and 240Pu targets with 48Ca beams aimed at the synthesis of Z=114 flerovium isotopes were performed at the Dubna Gas Filled Recoil Separator. A new spontaneously fissioning (SF) isotope 284Fl was produced for the first time in the 240Pu+ 48Ca (250 MeV) and 239Pu+ 48Ca (245 MeV) reactions. The cross section of the 239Pu( 48Ca,3n) 284Fl reaction channel was about 20 times lower than predicted by theoretical models and about 50 times lower than the maximum fusion-evaporation cross section for the 3n and 4n channels measured in the 244Pu+ 48Ca reaction. In the 240Pu+ 48Ca experiment, performed at 245 MeV in order to maximize the 3n-evaporation channel, three decay chains of 285Fl were detected. The α-decay energy of 285Fl was measured for the first time and decay properties of its descendants 281Cn, 277Ds, 273Hs, 269Sg, and 265Rf were determined with higher accuracy. The assignment of SF events observed during the irradiation of the 240Pu target with a 250 MeV 48Ca beam to 284Fl decay is presented and discussed. The cross sections at both 48Ca energies are similar and exceed that observed in the reaction with the lighter isotope 239Pu by a factor of 10. In conclusion, themore » decay properties of the synthesized nuclei and their production cross sections indicate a rapid decrease of stability of superheavy nuclei as the neutron number decreases from the predicted magic neutron number N = 184.« less

Authors:
 [1];  [2];  [1]; ORCiD logo [2];  [1];  [1]; ORCiD logo [3];  [1];  [4];  [1]; ORCiD logo [2];  [1];  [1];  [1];  [1];  [1];  [1];  [1];  [1];  [1] more »;  [5];  [6];  [7] « less
  1. Flerov Lab of Nuclear Reactions, Dubna (Russian Federation)
  2. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
  3. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Univ. of Tennessee, Knoxville, TN (United States)
  4. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Univ. of Warsaw, Warsaw (Poland)
  5. Vanderbilt Univ., Nashville, TN (United States)
  6. Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
  7. Univ. of Notre Dame, Notre Dame, IN (United States)
Publication Date:
Research Org.:
Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
Sponsoring Org.:
USDOE Office of Science (SC), Nuclear Physics (NP)
OSTI Identifier:
1493143
Alternate Identifier(s):
OSTI ID: 1215770
Grant/Contract Number:  
AC05-00OR22725; AC52-07NA27344; 08-ERD-030; FG05-88ER40407
Resource Type:
Journal Article: Accepted Manuscript
Journal Name:
Physical Review. C, Nuclear Physics
Additional Journal Information:
Journal Volume: 92; Journal Issue: 3; Journal ID: ISSN 0556-2813
Publisher:
American Physical Society (APS)
Country of Publication:
United States
Language:
English
Subject:
73 NUCLEAR PHYSICS AND RADIATION PHYSICS

Citation Formats

Utyonkov, Vladimir K., Brewer, Nathan T., Oganessian, Yuri Ts., Rykaczewski, Krzysztof P., Abdullin, F. Sh., Dmitriev, S. N., Grzywacz, Robert Kazimierz, Itkis, M. G., Miernik, Krzysztof, Polyakov, A. N., Roberto, James B., Sagaidak, R. N., Shirokovsky, I. V., Shumeiko, M. V., Tsyganov, Yu. S., Voinov, A. A., Subbotin, V. G., Sukhov, A. M., Sabel'nikov, A. V., Vostokin, G. K., Hamilton, J. H., Stoyer, M. A., and Strauss, S. Y. Experiments on the synthesis of superheavy nuclei Fl284 and Fl285 in the Pu239,240+Ca48 reactions. United States: N. p., 2015. Web. doi:10.1103/PhysRevC.92.034609.
Utyonkov, Vladimir K., Brewer, Nathan T., Oganessian, Yuri Ts., Rykaczewski, Krzysztof P., Abdullin, F. Sh., Dmitriev, S. N., Grzywacz, Robert Kazimierz, Itkis, M. G., Miernik, Krzysztof, Polyakov, A. N., Roberto, James B., Sagaidak, R. N., Shirokovsky, I. V., Shumeiko, M. V., Tsyganov, Yu. S., Voinov, A. A., Subbotin, V. G., Sukhov, A. M., Sabel'nikov, A. V., Vostokin, G. K., Hamilton, J. H., Stoyer, M. A., & Strauss, S. Y. Experiments on the synthesis of superheavy nuclei Fl284 and Fl285 in the Pu239,240+Ca48 reactions. United States. doi:10.1103/PhysRevC.92.034609.
Utyonkov, Vladimir K., Brewer, Nathan T., Oganessian, Yuri Ts., Rykaczewski, Krzysztof P., Abdullin, F. Sh., Dmitriev, S. N., Grzywacz, Robert Kazimierz, Itkis, M. G., Miernik, Krzysztof, Polyakov, A. N., Roberto, James B., Sagaidak, R. N., Shirokovsky, I. V., Shumeiko, M. V., Tsyganov, Yu. S., Voinov, A. A., Subbotin, V. G., Sukhov, A. M., Sabel'nikov, A. V., Vostokin, G. K., Hamilton, J. H., Stoyer, M. A., and Strauss, S. Y. Tue . "Experiments on the synthesis of superheavy nuclei Fl284 and Fl285 in the Pu239,240+Ca48 reactions". United States. doi:10.1103/PhysRevC.92.034609. https://www.osti.gov/servlets/purl/1493143.
@article{osti_1493143,
title = {Experiments on the synthesis of superheavy nuclei Fl284 and Fl285 in the Pu239,240+Ca48 reactions},
author = {Utyonkov, Vladimir K. and Brewer, Nathan T. and Oganessian, Yuri Ts. and Rykaczewski, Krzysztof P. and Abdullin, F. Sh. and Dmitriev, S. N. and Grzywacz, Robert Kazimierz and Itkis, M. G. and Miernik, Krzysztof and Polyakov, A. N. and Roberto, James B. and Sagaidak, R. N. and Shirokovsky, I. V. and Shumeiko, M. V. and Tsyganov, Yu. S. and Voinov, A. A. and Subbotin, V. G. and Sukhov, A. M. and Sabel'nikov, A. V. and Vostokin, G. K. and Hamilton, J. H. and Stoyer, M. A. and Strauss, S. Y.},
abstractNote = {Irradiations of 239Pu and 240Pu targets with 48Ca beams aimed at the synthesis of Z=114 flerovium isotopes were performed at the Dubna Gas Filled Recoil Separator. A new spontaneously fissioning (SF) isotope 284Fl was produced for the first time in the 240Pu+48Ca (250 MeV) and 239Pu+48Ca (245 MeV) reactions. The cross section of the 239Pu(48Ca,3n)284Fl reaction channel was about 20 times lower than predicted by theoretical models and about 50 times lower than the maximum fusion-evaporation cross section for the 3n and 4n channels measured in the 244Pu+48Ca reaction. In the 240Pu+48Ca experiment, performed at 245 MeV in order to maximize the 3n-evaporation channel, three decay chains of 285Fl were detected. The α-decay energy of 285Fl was measured for the first time and decay properties of its descendants 281Cn, 277Ds, 273Hs, 269Sg, and 265Rf were determined with higher accuracy. The assignment of SF events observed during the irradiation of the 240Pu target with a 250 MeV 48Ca beam to 284Fl decay is presented and discussed. The cross sections at both 48Ca energies are similar and exceed that observed in the reaction with the lighter isotope 239Pu by a factor of 10. In conclusion, the decay properties of the synthesized nuclei and their production cross sections indicate a rapid decrease of stability of superheavy nuclei as the neutron number decreases from the predicted magic neutron number N = 184.},
doi = {10.1103/PhysRevC.92.034609},
journal = {Physical Review. C, Nuclear Physics},
issn = {0556-2813},
number = 3,
volume = 92,
place = {United States},
year = {2015},
month = {9}
}

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    Works referencing / citing this record:

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