Subscribe to the gold package and get unlimited access to Shamra Academy
Register a new userSystematical study of optical potential strengths in reactions involving strongly, weakly bound and exotic nuclei on $^{120}$Sn
105
0
0.0
(
0
)
Ask ChatGPT about the research
No Arabic abstract
We present new experimental angular distributions for the elastic scattering of $^6$Li$+^{120}$Sn at three bombarding energies. We include these data in a wide systematic involving the elastic scattering of $^{4,6}$He, $^7$Li, $^9$Be, $^{10}$B and $^{16,18}$O projectiles on the same target at energies around the respective Coulomb barriers. Considering this data set, we report on optical model analyses based on the double-folding Sao Paulo Potential. Within this approach, we study the sensitivity of the data fit to different models for the nuclear matter densities and to variations in the optical potential strengths.
rate research
Read More
Complete fusion excitation functions of reactions involving breakup are studied by using the empirical coupled-channel (ECC) model with breakup effects considered. An exponential function with two parameters is adopted to describe the prompt-breakup probability in the ECC model. These two parameters are fixed by fitting the measured prompt-breakup probability or the complete fusion cross sections. The suppression of complete fusion at energies above the Coulomb barrier is studied by comparing the data with the predictions from the ECC model without the breakup channel considered. The results show that the suppression of complete fusion are roughly independent of the target for the reactions involving the same projectile.
The optical potential of halo and weakly bound nuclei has a long range part due to the coupling to breakup that damps the elastic scattering angular distributions. In order to describe correctly the breakup channel in the case of scattering on a heavy target, core recoil effects have to be taken into account. We show here that core recoil and nuclear breakup of the valence nucleon can be consistently taken into account. A microscopic absorptive potential is obtained within a semiclassical approach and its characteristics can be understood in terms of the properties of the halo wave function and of the reaction mechanism. Results for the case of medium to high energy reactions are presented.
An experimental overview of reactions induced by the stable, but weakly-bound nuclei 6Li, 7Li and 9Be, and by the exotic, halo nuclei 6He, 8He, 8B, and 11Be on medium-mass targets, such as 58Ni, 59Co or 64Zn, is presented. Existing data on elastic scattering, total reaction cross sections, fusion processes, breakup and transfer channels are discussed in the framework of a CDCC approach taking into account the breakup degree of freedom.
An introduction to nucleosynthesis, the creation of the elements in the big bang, in interstellar matter and in stars is given. The two--step process $^4$He(2n,$gamma$)$^6$He and the reverse photodisintegration $^6$He($gamma$,2n)$^4$He involving the halo nucleus $^6$He could be of importance in the $alpha$--process in type--II supernovae. The reaction rates for the above processes are calculated using three--body methods and show an enhancement of more than three orders of magnitude compared to the previous adopted value. Direct--capture calculations give similar values for the above reaction rates. Therefore, this method was also used to calculate the reaction rates of the two--step processes $^6$He(2n,$gamma$)$^8$He and $^9$Li(2n,$gamma$)$^{11}$Li and the reverse photodisintegration of $^8$He and $^{11}$Li that could be also of importance in the $alpha$-process.
The yields of evaporation residues, fusion-fission and quasifission fragments in the $^{48}$Ca+$^{144,154}$Sm and $^{16}$O+$^{186}$W reactions are analyzed in the framework of the combined theoretical method based on the dinuclear system concept and advanced statistical model. The measured yields of evaporation residues for the $^{48}$Ca+$^{154}$Sm reaction can be well reproduced. The measured yields of fission fragments are decomposed into contributions coming from fusion-fission, quasifission, and fast-fission. The decrease in the measured yield of quasifission fragments in $^{48}$Ca+$^{154}$Sm at the large collision energies and the lack of quasifission fragments in the $^{48}$Ca+$^{144}$Sm reaction are explained by the overlap in mass-angle distributions of the quasifission and fusion-fission fragments. The investigation of the optimal conditions for the synthesis of the new element $Z$=120 ($A$=302) show that the $^{54}$Cr+$^{248}$Cm reaction is preferable in comparison with the $^{58}$Fe+$^{244}$Pu and $^{64}$Ni+$^{238}$U reactions because the excitation function of the evaporation residues of the former reaction is some orders of magnitude larger than that for the last two reactions.
Log in to be able to interact and post comments
comments
Fetching comments
Sign in to be able to follow your search criteria
