- Physical Review Journals
All JournalsPhysics Magazine
Access Provided by Xinjiang University

Physical Review C

Export citation

Export citation

Choose format for download:

Download Citation
  • Access by Xinjiang University

Fusion process studied with a preequilibrium giant dipole resonance in time-dependent Hartree-Fock theory

C. Simenel1,2, Ph. Chomaz2, and G. de France2

  • 1DSM/DAPNIA/SPhN, CEA/SACLAY, F-91191 Gif-sur-Yvette Cedex, France
  • 2Grand Accélérateur National d'Ions Lourds (GANIL), CEA/DSM-CNRS/IN2P3, Boulevard Henri Becquerel, Boîte Postale 55027, F-14076 CAEN Cedex 5, France

PDF

Phys. Rev. C 76, 024609 – Published 23 August, 2007

DOI: https://doi.org/10.1103/PhysRevC.76.024609

Abstract

The equilibration of macroscopic degrees of freedom during the fusion of heavy nuclei, such as the charge and the shape, are studied in the time-dependent Hartree-Fock theory. The preequilibrium giant dipole resonance (GDR) is used to probe the fusion path. It is shown that such an isovector collective state is excited in N/Z asymmetric fusion and to a lesser extent in mass asymmetric systems. The characteristics of this GDR, such as its deformation, rotation, and vibration, are governed by the structure of the fused system in its preequilibrium phase. In particular, we show that a loweringq of the preequilibrium GDR energy is expected as compared to the statistical one. Revisiting experimental data, we extract evidence of this lowering for the first time. We also quantify the fusion-evaporation enhancement resulting from γ-ray emission from the preequilibrium GDR. This cooling mechanism along the fusion path may be suitable for synthesizing in the future superheavy elements using radioactive beams with strong N/Z asymmetries in the entrance channel.

View figure in article

Article Text

References (58)

  1. R. V. F. Janssens and T. L. Khoo, Annu. Rev. Nucl. Part. Sci. 41, 321 (1991).
  2. S. Hofmann, Rep. Prog. Phys. 61, 639 (1998).
  3. M. Dasgupta, D. J. Hinde, N. Rowley, and A. M. Stefanini, Annu. Rev. Nucl. Part. Sci. 48, 401 (1998).
  4. P. Bonche and B. Grammaticos, Phys. Lett. B95, 198 (1980).
  5. P. Bonche and N. Ngô, Phys. Lett. B105, 17 (1981).
  6. Ph. Chomaz, M. Di Toro, and A. Smerzi, Nucl. Phys. A563, 509 (1993).
  7. V. Baran, M. Colonna, M. Di Toro, A. Guarnera, and A. Smerzi, Nucl. Phys. A600, 111 (1996).
  8. V. Baran, M. Cabibbo, M. Colonna, M. Di Toro, and N. Tsoneva, Nucl. Phys. A679, 373 (2001).
  9. V. Baran, D. M. Brink, M. Colonna, and M. Di Toro, Phys. Rev. Lett. 87, 182501 (2001).
  10. C. Simenel, Ph. Chomaz, and G. de France, Phys. Rev. Lett. 86, 2971 (2001).
  11. A. Van der Woude, Prog. Part. Nucl. Phys. 18, 217 (1987).
  12. M. N. Harakeh and A. van der Woude, Giant Resonances: Fundamental High-Frequency Modes of Nuclear Excitation (Oxford Science, Oxford, 2001).
  13. J. O. Newton et al., Phys. Rev. Lett. 46, 1383 (1981).
  14. J. J. Gaardhoje, Annu. Rev. Nucl. Part. Sci. 42, 483 (1992).
  15. A. Bracco et al., Phys. Rev. Lett. 62, 2080 (1989).
  16. Ph. Chomaz, Phys. Lett. B347, 1 (1995).
  17. C. Simenel and Ph. Chomaz, Phys. Rev. C 68, 024302 (2003).
  18. M. Fallot, Ph. Chomaz, M. V. Andrès, F. Catara, E. G. Lanza, and J. A. Scarpaci, Nucl. Phys. A729, 699 (2003).
  19. Ph. Chomaz and C. Simenel, Nucl. Phys. A731, 188c (2004).
  20. E. Suraud, M. Pi, and P. Schuck, Nucl. Phys. A492, 294 (1989).
  21. C. H. Dasso, H. Sofia, and A. Vitturi, Eur. Phys. J. A 12, 279 (2001).
  22. S. Flibotte et al., Phys. Rev. Lett. 77, 1448 (1996).
  23. M. Cinausero et al., Nuovo Cimento A 111, 613 (1998).
  24. D. Pierroutsakou et al., Eur. Phys. J. A 17, 71 (2003).
  25. D. Pierroutsakou et al., Phys. Rev. C 71, 054605 (2005).
  26. F. Amorini et al., Phys. Rev. C 69, 014608 (2004).
  27. L. Campajola et al., Z. Phys. A 352, 421 (1995).
  28. F. Amorini et al., Phys. Rev. C 58, 987 (1998).
  29. M. Sandoli et al., Eur. Phys. J. A 6, 275 (1999).
  30. M. Papa et al., Eur. Phys. J. A 4, 69 (1999).
  31. D. Pierroutsakou et al., Eur. Phys. J. A 16, 423 (2003).
  32. M. Papa et al., Phys. Rev. C 68, 034606 (2003).
  33. M. Papa et al., Phys. Rev. C 72, 064608 (2005).
  34. D. R. Hartree, Proc. Cambridge Philos. Soc. 24, 89 (1928).
  35. V. A. Fock, Z. Phys. 61, 126 (1930).
  36. P. A. M. Dirac, Proc. Cambridge Philos. Soc. 26, 376 (1930).
  37. D. Vautherin and D. M. Brink, Phys. Rev. C 5, 626 (1972).
  38. Y. M. Engel, D. M. Brink, K. Goeke, S. J. Krieger, and D. Vautherin, Nucl. Phys. A249, 215 (1975).
  39. P. Bonche, S. Koonin, and J. W. Negele, Phys. Rev. C 13, 1226 (1976).
  40. J. W. Negele, Rev. Mod. Phys. 54, 913 (1982).
  41. M. Gong, M. Thoyama, and J. Randrup, Z. Phys. A 335, 331 (1990).
  42. C. Y. Wong and H. H. K. Tang, Phys. Rev. Lett. 40, 1070 (1978).
  43. D. Lacroix, S. Ayik, and Ph. Chomaz, Prog. Part. Nucl. Phys. 52, 497 (2004).
  44. O. Juillet and Ph. Chomaz, Phys. Rev. Lett. 88, 142503 (2002).
  45. Ph. Chomaz, N. V. Giai, and S. Ayik, Phys. Lett. B189, 375 (1987).
  46. C. Simenel, Ph. Chomaz, and G. de France, Phys. Rev. Lett. 93, 102701 (2004).
  47. K.-H. Kim, T. Otsuka, and P. Bonche, J. Phys. G 23, 1267 (1997).
  48. T. Skyrme, Philos. Mag. 1, 1043 (1956).
  49. J. D. Jackson, Classical Electrodynamics (Wiley, New York, 1962), Eq. (15.1).
  50. J. A. Maruhn, P. G. Reinhard, P. D. Stevenson, J. R. Stone, and M. R. Strayer, Phys. Rev. C 71, 064328 (2005).
  51. P.-G. Reinhard, P. D. Stevenson, D. Almehed, J. A. Maruhn, and M. R. Strayer, Phys. Rev. E 73, 036709 (2006).
  52. F. Calvayrac, S. El-Gammal, C. Kohl, P.-G. Reinhard, and E. Suraud, Nuovo Cimento A 110, 1175 (1997).
  53. P. M. Dinh, P. G. Reinhard, and E. Suraud, J. Phys. B 38, 1637M (2005).
  54. E. B. Balbutsev and P. Schuck, Nucl. Phys. A652, 221 (1999).
  55. D. M. Brink, Nucl. Phys. A482, 3c (1988).
  56. K. A. Snover, Annu. Rev. Nucl. Part. Sci. 36, 545 (1986).
  57. A. V. Ignatyuk, K. K. Istekov, and G. N. Smirenkin, Sov. J. Nucl. Phys. 30, 626 (1979).
  58. Y. Aritomo, T. Wada, M. Ohta, and Y. Abe, Phys. Rev. C 59, 796 (1999).

Outline

Information

Phys. Rev. C 76, 024609– Published 23 August, 2007
  • Received 3 April 2007

© 2007 American Physical Society

Sign In to Your Journals Account

Filter

Filter

Article Lookup

Enter a citation