Ядерна фізика та енергетика Nuclear Physics and Atomic Energy   ISSN: 1818-331X (Print), 2074-0565 (Online)   Publisher: Institute for Nuclear Research of the National Academy of Sciences of Ukraine   Languages: Ukrainian, English   Periodicity: 4 times per year   Open access peer reviewed journal

Full text (en)

Yu. E. Penionzhkevich, R. A. Astabatyan, N. A. Demekhina, R. Kalpakchieva, A. A. Kulko, S. P. Lobastov, S. M. Lukyanov, E. R. Markaryan, V. A. Maslov, Yu. A. Muzychka, Yu. Ts. Oganessian, D. N. Rassadov, N. K. Skobelev, Yu. G. Sobolev, T. Zholdybaev^*

Flerov Laboratory of Nuclear Reactions, JINR, Dubna, Russia
^*Institute of Nuclear Physics, Almaty, Kazakhstan

Abstract: Excitation functions for evaporation residues in the reactions ¹⁹⁷Au(⁶He, xn)^203-xnTl, where x = 2 - 7, and ²⁰⁶Pb(⁶He, ²n)²¹⁰Po, as well as for neutron transfer reactions for the production of ¹⁹⁶Au and ¹⁹⁸Au in the interaction of ⁶He with ¹⁹⁷Au were measured. ⁶He beam was obtained from the accelerator complex for radioactive beams DRIBs (JINR). The energy of the incident beam was about 10 MeV/A and the intensity reached 2 · 10⁷ pps. The stacked foil technique was used directly in the beam extracted from the cyclotron or in the focal plane of the magnetic spectrometer MSP-144. The identification of the reaction products was done by their radioactive γ- or α-decay. Unusually large cross section was observed below the Coulomb barrier for the production of ¹⁹⁸Au in the interaction of ⁶He with ¹⁹⁷Au. Possible mechanisms of formation and decay of transfer reaction products are discussed. An increase in the cross section was observed for the fusion reaction with the evaporation of two neutrons compared to statistical model calculations. The analysis of the data in the framework of the statistical model for the decay of excited nuclei, which took into account the sequential fusion of ⁶He has shown good agreement between the experimental and the calculated values of the cross sections for the case of sub-Coulomb-barrier fusion in the ²⁰⁶Pb + ⁶He reaction.

1. Penionzhkevich Yu. E. et al. Nucl. Phys. A 588 (1995) c259; https://doi.org/10.1016/0375-9474(95)00149-U

Fomichev A. S. et al. Z. Phys. A 351 (1995) 129. https://doi.org/10.1007/BF01289520

2. Hussein M. S. et al. Phys. Rev. C 46 (1992) 377; https://doi.org/10.1103/PhysRevC.46.377

Nucl. Phys. A 588 (1995) c85. https://doi.org/10.1016/0375-9474(95)00104-9

3. Dasso C. et al. Nucl. Phys. A 597 (1996) 473. https://doi.org/10.1016/0375-9474(95)00459-9

4. Stelson P. H. Phys. Rev. C 41 (1990) 1584. https://doi.org/10.1103/PhysRevC.41.1584

5. Kolata J. J. et al. Phys. Rev. Lett. 81 (1998) 4580. https://doi.org/10.1103/PhysRevLett.81.4580

6. Trotta M. et al. Phys. Rev. Lett. 84 (2000) 2342. https://doi.org/10.1103/PhysRevLett.84.2342

7. Raabe R., Sida J. L., Trotta M. et al. Nature 431 (2004) 823. https://doi.org/10.1038/nature02984

8. Di Pietro A. et al. Phys. Rev. C 69 (2004) 044613. https://doi.org/10.1103/PhysRevC.69.044613

9. Navin A. et al. Phys. Rev. C 70 (2004) 044601. https://doi.org/10.1103/PhysRevC.70.044601

10. Oganessian Yu. Ts., Gulbekian G. G. Proc. of the Int. Conf. "Nuclear Shells - 50 Years". Ed. by Yu. Ts. Oganessian, W. von Oertzen, R. Kalpakchieva (Singapore: World Scientific, 2000) p. 61.

11. Penionzhkevich Yu. E. et al. Particle and Nuclei, Lett. 3 (2006) 38.

12. Kuznetsov V. D. et al. Scientific report FLNR 2001-2002. Ed. by A. G. Popeko (Dubna: JINR, 2003) p. 223, 224.

13. Astabatyan R. A. et al. Scientific report FLNR 2001-2002. Ed. by A. G. Popeko (Dubna: JINR, 2003) p. 212;

Astabatyan R. A. et al. Scientific report FLNR 2003-2004. Ed. by A. G. Popeko (Dubna: JINR, 2005).

14. Skobelev N. K. et al. Nucl. Instr. Meth. B 227 (2005) 471. https://doi.org/10.1016/j.nimb.2004.10.077

15. Information from website: http://dnr080.jinr.ru/lise/

16. Frana J. Radioanal. and Nucl. Chem. 257 (2003) 583. https://doi.org/10.1023/A:1025448800782

17. Information from website: http://nucleardata.nuclear.lu.se/NuclearData/toi/

18. Gritchenko Z. G. et al. Physics of Atomic Nuclei 10 (1969) 929 (Rus).

19. Muzychka Yu. A., Pustylnik B. I. Physics of Atomic Nuclei 45 (1987) 90.

20. Penionzhkevich Yu. E. et al. Physics of Atomic Nuclei 65 (2002) 1563. https://doi.org/10.1134/1.1508687

21. Lanzafame F. M., Blann M. Nucl. Phys. A 142 (1970) 545. https://doi.org/10.1016/0375-9474(70)90811-0

22. Kulko A. A. et al. Preprint JINR R7-2006-14 (2006).

23. Zagrebaev V. I. Phys. Rev. C 67 (2003) 061601(R); https://doi.org/10.1103/PhysRevC.67.061601

Progr. Theor. Phys. Suppl. 154 (2004) 122. https://doi.org/10.1143/PTPS.154.122

24. Oppenheimer J. R., Phillips M. Phys. Rev. 48 (1935) 500. https://doi.org/10.1103/PhysRev.48.500

25. Keeley N. et al. Phys. Rev. C 68 (2003) 054601. https://doi.org/10.1103/PhysRevC.68.054601

26. Dasso C. H. et al. Proc. of the 2nd Japan - Italy Joint Symp.'95 "Perspective in Heavy Ion Physics", Riken, Japan (Singapore: World Scientific, 1996) p. 42.