How well do we understand the synthesis of heavy elements by heavy-ion induced fusion?

Abstract

Experimental cross sections to synthesize heavy ion induced fusion reactions are confronted with calculations using the conventional picture of complete fusion after passing the barrier plus statistical deexcitation after complete equilibration. The sensitivity of the calculations to some of the parameters is demonstrated. Despite this sensitivity, a single parameter set is found that reproduces well the large body of data from experiments using actinide targets. By comparison, for the more symmetric entrance channels using targets around 2~we find a fusion hindrance that increases steeply with increasing compound nuclear charge. Predictions for a few reactions of future interest for the synthesis of heavy elements are also presented.

In-beam Fission Study at JAEA

“…Figure 5 (left) summarizes the capture cross sections, fusion cross sections and evaporation residue cross sections for 30 Si + 238 U. The cross sections for 263,264 Sg were compared with a statistical model calculation, where the obtained fusion probabilities were used as input for the HIVAP code [16]. It is evident from Fig.5 that the measured cross sections agree with the calculation.…”

“…In order to see the influence of nuclear properties on the capture cross-sections, we performed a coupled-channel calculation using the computer code CCDEGEN [5]. We used the same parameters for the nuclear potential as in our previous work for the reactions 16 O+ 238 U [6]. The dashed curve in Fig.1 is the result without considering any collective properties of target and projectile (one-dimensional barrier penetration model).…”

In-beam fission study for Heavy Element Synthesis

“…Figure 5 (left) summarizes the capture cross sections, fusion cross sections and evaporation residue cross sections for 30 Si + 238 U. The cross sections for 263,264 Sg were compared with a statistical model calculation, where the obtained fusion probabilities were used as input for the HIVAP code [16]. It is evident from Figure 5 that the measured cross sections agree with the calculation.…”

“…In order to see the influence of nuclear properties on the capture cross-sections, we performed a coupled-channel calculation using the computer code CCDEGEN [5]. We used the same parameters for the nuclear potential as in our previous work for the reactions 16 O + 238 U [6]. The dashed curve in Figure 1 is the result without considering any collective properties of target and projectile (one-dimensional barrier penetration model).…”

Time-dependent Hartree-Fock studies of the dynamical fusion threshold

“…The energy difference between fusion barrier and fission barrier is known as extra push energy. Recently, the experimental evidence [38][39][40] indicates that the extra push energy, needed in the formation of heavy and superheavy systems, is smaller than the prediction with macroscopic model [36].…”