RIKEN Nuclear Physics Seminar
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Lecturer: Dr. S.M. Lukyanov
	 (Flerov Laboratory of Nuclear Reactions,
          Joint Institute for Nuclear Research,
          Dubna, Russia)

Title:  "FUSION ENHANCEMENT ABOVE THE BARRIER FOR THE 6He+209Bi-REACTION"

Date:    29th Nov. 2001 (Thu.) 16:00 -

Place:  RIKEN Main Bldg. 2F Seminar Room

Abstract:
The experimentally measured excitation functions for the fission
and 4n-evaporation channels are  presented for the 6He + 209Bi-reaction.
The secondary 6He beam was produced using the standard beam-transport line
of the U400M accelerator at FLNR, JINR.
The comparison of the obtained experimental data with similar results for
the 4He + 209Bi-reaction shows that in the case of the 6He + 209Bi-reaction
a significant enhancement of the cross section is observed for energies
above the barrier. In order to get an agreement between the experimental
data and the theoretical calculations it is necessary to reduce the Coulomb
barrier by 15-20%, which corresponds to an increase of the parameter ro of
the nuclear potential up to 1.5-1.6 Fm. The future experiments are planned
and described.

Host reseacher: H. Sakurai (Univ. of Tokyo/RIKEN)
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        Contact persons of Nuclear Physics Seminar
        Y. Fukuyama, Y. Nishi, and T. Wakui (RI Beam Science Lab.)
        (email) seminar@rarfaxp.riken.go.jp 
	(FAX)   048-462-4689
        (WWW)   http://rarfaxp.riken.go.jp/~seminar/    
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