Fusion Reactions Between Heavy Nuclei

Abstract

The most general theoretical models (1-3) of nuclear fusion reactions conceive the process as a motion of the target and projectile across a potential energy surface created by the forces between the two nuclei. The internuclear potential energy is a function of the separation of the two nuclei, the angular momentum of the system, and the deformation of the 1 Work su pported by th e US Department of Energy.

Towards a unified description of evaporation-residue fusion cross-sections above the barrier

“…From them one infers the value of the vanishing energy of incomplete fusion process at E avail = 13.2 ± 0.6 MeV/nucleon 6 . The uncertainty on the fit parameters is 4 Error on fusion cross section ∆σ F is generally in the range of 0.05 -0.15 σ F . In case of a non-reported experimental error it has been assumed to be 20 % of the corresponding σ F value.…”

“…-Since mid-seventies of the last century it is consensual that heavy-ion fusion reaction as a function of the center-of-mass energy passes through three distinct regions, that of rising (I), stagnating (II), and falling (III) cross sections, respectively. At low energies, the regions I and II have been systematically studied by confronting models with a myriad of experimental data [1][2][3][4][5][6][7][8][9][10]. In the region III, the incomplete fusion (IF) reaction mechanism opens and increasingly competes with the complete fusion (CF).…”

On the mechanism of (HI, ? x n) reactions

“…We take Bv=62.4 MeV and RF= 10.6 fm as follows from the calculations done by Birkelund and Huizenga [19] using the modified proximity potential [20] and the Coulomb potential of Bondorf et al [21].…”

Macroscopic treatment of nuclear dynamics

“…From now on it is an exercise in dimensional analysis. The assumptions a) and b) predict that a relevant dimensionless parameter measuring the relative strengths of electric and nuclear forces may be taken as the "effective fissility parameter" xe defined by (11) where 2 (Z /A)eff (12) -AlI3AlI3(AI/3 + A 113 ) 40'lfr~Yo(1 -KsI2)…”