Eur. Phys. J. A

**13**, 143-148 (2002)

## Reaction dynamics of synthesis of superheavy elements

**Y. Abe**

Yukawa Institute for Theoretical Physics, Kyoto University, Kyoto 606-8502, Japan

(Received: 1 May 2001 / Revised version: 7 August 2001)

** Abstract **

Based on the theory of the compound nucleus reaction, a brief review
is given on the special aspects of the reaction dynamics in the synthesis of the
superheavy elements (SHE), where the fusion probability is the most
unknown factor.
A new viewpoint of the fusion reaction is proposed that it consists of
two processes; the first process up to the contact of two nuclei of the
incident channel and the second one of a dynamical evolution to the spherical
compound nucleus from the contact configuration.
The fusion probability is, thus, given as a product of a
contact probability and a formation probability.
Analytic studies of the latter probability are discussed in the
one-dimensional model, where a simple expression is given to the so-called
extra-push energy in terms of the reduced friction, the curvature
parameter of the conditional saddle point and the nuclear
temperature. Preliminary results of numerical analyses of
the contact probability are given, using the surface friction model (SFM).
Remarks are given on the present status of our knowledge and
for future developments.

**PACS**

24.10.Pa - Thermal and statistical models.

25.70.Gh - Compound nucleus.

25.70.Jj - Fusion and fusion-fission reactions.

27.90.+b - .

**©**

*Società Italiana di Fisica, Springer-Verlag 2002*