Shell effects in cold fusion reactions

Influence of the target and projectile deformation changes within the overlapping region of the fusion configuration is studied. A deformed two-center shell model for ellipsoidal nuclei partners is presented. The model produces the level scheme of the two partially superposed deformed nuclei all along the fusion path towards the synthesized element. Shell corrections are calculated in fusion reactions as functions of target or projectile deformation changes and also for different mass asymmetries. It is shown that lower shell correction values are obtained when the initial deformation of a partner nucleus is modified within the overlapping region. Studies are performed for light and superheavy nuclei synthesis reactions.

Figure 1

Fusionlike shape parametrization for two ellipsoidal overlapped nuclei.

Figure 2

Matching potential energy surface ${\rho }_m\left(z\right)$ between $V_1(\rho ,z)$ generated by the $O_1$ centered partner and $V_2(\rho ,z)$ (acting within the shadowed region).

Figure 3

Occupation probability transition $\mid Z_{\nu }\left(z\right){\mid }^2$ along the symmetry axis $Oz$ for four distances between centers $R$, on the first energy levels. Calculations are made for the fusion reaction ${}^{42}\mathrm{Ca}+{}^{210}\mathrm{Pb}\to {}^{252}\mathrm{No}$.

Figure 4

Target deformation effects on the level schemes (upper figure) and on the proton and total shell corrections for three fusion reactions leading to Ar isotope synthesis.

Figure 5

Target deformation effects on the level schemes (upper figure) and on the proton and total shell corrections for three fusion reactions in the synthesis of Ca isotopes.

Figure 6

Projectile deformation effects on the level schemes and on the proton and total shell corrections for three isotopic-isobaric reactions in the synthesis of ${}^{266}\mathrm{Hs}$.

Figure 7

Target deformation effects on the level scheme (upper figure) and on the proton and total shell corrections for four isotopic reactions in the synthesis of $Z=112$.

Figure 8

Shell correction variation with the mass and charge asymmetry for the synthesis of the superheavy nucleus ${}^{296}116$.