64Zn Target Research Articles

Insights into the dynamics of breakup of the halo nucleus 11Be on a 64Zn target

We reexamine the elastic and breakup observables of the Be11+64Zn reaction at the near-barrier energy of 28.7 MeV. The measured quasi-elastic data are compared with CDCC and extended CDCC (XCDCC) calculations, the latter including the effect of the 10Be deformation.The angular distribution of emitted 10Be fragments, reported in the original analysis of this experiment, along with newly extracted 10Be energy distributions, are compared with calculations for the elastic breakup and non-elastic breakup contributions. Elastic breakup, computed with CDCC, accounts for most of the observed yields. The remaining difference (∼20%) is attributed to non-elastic breakup events (neutron absorption or target excitation) as confirmed by calculations performed with the model of Ichimura, Austern and Vincent (1985) [14].Finally, the effect of post-acceleration in the energy distribution is investigated. This effect is well accounted for by the present CDCC calculations and, according to simple kinematical considerations, is estimated to be of the order of 1 MeV, and roughly independent of the scattering angle.

Decay Analysis of Ge Isotopes Formed in Reactions Induced by Tightly and Loosely Bound Projectiles** Supported by CSIR-Scheme No. 03(1341)/15/EMR-II, and the University Grants Commission (UGC), in the form of Maulana Azad National Fellowship (MANF)

The dynamical cluster-decay model (DCM) is employed to investigate the decay of 68,70Ge* compound nuclei formed respectively via tightly (4He) and loosely (6He) bound projectiles, using 64Zn target. The study is carried out over a wide energy range (Ec.m. ∼5 MeV to 16 MeV) by including the quadrupole deformations (β2i) and optimum orientations () of the decaying fragments. The fusion cross-sections, obtained by adding various evaporation channels show nice agreement with the experimental data for 4He+64Zn reaction. The contribution from competing compound inelastic scattering channel is also analyzed particularly for 68Ge* nucleus at above barrier energies. On the other hand, the decrement in the fusion cross-sections of 70Ge* nuclear system is addressed by presuming that 65Zn ER is formed via two different modes: (i) the αn evaporation of 70Ge* nucleus, and (ii) 1n-evaporation of 66Zn* nuclear system, formed via breakup and 2n-transfer channels due to halo structure of the 6He projectile. Besides this, the suppression in 2np evaporation cross-sections suggests the contribution of another breakup and transfer process of 6He i.e. 4He+64Zn. The contribution of breakup+transfer channels for 6He+64Zn reaction is duly addressed by applying relevant energy corrections due to the breakup of “6He” projectile into 2n and 4He. In addition to this, the barrier lowering, angular momentum and energy dependence effects are also explored in view of the dynamics of chosen reactions.

Double folding model analysis of elastic scattering of halo nucleus 11Be from 64Zn

Calculations of elastic scattering cross-sections for 9,10,11Be + 64Zn at near-Coulomb barrier energy have been performed using a potential obtained from the double folding model and are compared with the experiment. In the framework of the double folding model, the nuclear matter densities of 9,10,11Be projectiles and a 64Zn target are folded with the complex energy-dependent effective M3Y interaction. The angular distributions of the differential cross-section for 9,10Be scattering from 64Zn at E c.m≈ 24.5 MeV agree remarkably well with the data, while in case of 11Be, calculations show a Coulomb–nuclear interference peak which is not observed in the data.

Heavy-ion fusion cross sections of weakly bound 9Be on 27Al, 64Zn and tightly bound 16O on 64Zn target using Coulomb and proximity potential

The total fusion cross sections for the fusion of weakly bound $^{9}$Be on $^{27}$Al and $^{64}$Zn targets at near and above the barrier have been calculated using one dimensional barrier penetration model, taking scattering potential as the sum of Coulomb and proximity potential and the calculated values are compared with experimental data. For the purpose of comparison of the fusion of weakly bound projectiles and strongly bound projectiles, the total fusion cross sections for the reaction of tightly bound nucleus $^{16}$O on $^{64}$Zn have also been computed using a similar procedure. The calculated values of total fusion cross sections in all cases are compared with coupled channel calculations using the code CCFULL. The computed cross sections using Coulomb and proximity potential explain the fusion reactions well in both cases of weakly bound and strongly bound projectiles. Reduced reaction cross sections for the systems $^{9}$Be + $^{27}$Al, $^{9}$Be+ $^{64}$Zn and $^{16}$O + $^{64}$Zn have also been described.

Elastic scattering and direct reactions of the 1n halo 11Be nucleus on 64Zn near the barrier

Elastic scattering and direct reactions have been studied for the collisions induced by the three Beryllium isotopes 9,10,11Be, on a medium mass 64Zn target at energies near the Coulomb barrier. The elastic-scattering angular distribution of the 11Be halo nucleus shows a deviation from the classical Fresnel type diffraction behavior in the Coulomb-nuclear interference peak angular region. The deduced total reaction cross-sections for the 11Be collision is more than a factor of two than the ones measured in the collisions induced by 9;10Be. Moreover, for 11Be a large contribution to the total reaction cross-section due to transfer and break-up processes has been observed.

Coupled-channel analysis for 20.4 MeV energy of p-64Zn inelastic scattering

In this study, a coupled-channel (CC) analysis of the elastic and the inelastic scattering of 20.4 MeV polarized protons from a 64Zn target leading to the deformed 2 + , 3 −, \(2_2^+\) states was performed. The CC potential parameters and the deformation parameters of the excited states corresponding to the best fit to the experimental differential cross-sections and the analysing powers data were determined. For \(2_2^+\) excited state, a mixed type was used and a good fit to the data was provided. The CC calculation results were compared to the pure distorted wave Born approximation (DWBA) calculation results which were calculated using the new parameters. All calculations were conducted using the computer code ECIS06.

Evidence of strong effects of the 11Be halo structure on reaction processes at energies around the Coulomb barrier

The collision induced by the three Beryllium isotopes, 9,10,11Be, on 64Zn target were investigated at Ec.m. ≈ 1.4 the Coulomb barrier. Elastic scattering angular distributions were measured for the 9,10Be collisions whereas, in the 11Be case the quasielastic scattering angular distribution was obtained. A strong damping of the quasielastic cross-section was observed in the 11Be case, especially in the angular range around the Coulomb-nuclear interference peak. In this latter case a large total-reaction cross-section is found, more than a factor of two larger than the ones extracted in the reactions induced by the non-halo Beryllium isotopes. A large contribution to the total-reaction cross-section in the 11Be case could be attributed to transfer and/or break-up events.

Reactions induced by11Be beam at Rex-Isolde

The collision induced by the three Beryllium isotopes, 9,10,11Be, on a 64Zn target were investigated at Ec.m. ≈ 1.4 the Coulomb barrier. The experiments with the radioactive 10,11Be beams were performed at the Rex-Isolde facility at CERN. In the case of 9,10Be, elastic scattering angular distributions were measured whereas, in the 11Be case, the quasielastic scattering angular distribution was obtained. A strong damping of the quasielastic cross-section was observed in the 11Be case, in the angular range around the Coulomb-nuclear interference peak. In this latter case a large total-reaction cross-section is found. Such a cross-section is more than a factor of two larger than the ones extracted in the reactions induced by the non-halo Beryllium isotopes. A large contribution to the total-reaction cross-section in the 11Be case could be attributed to transfer and/or break-up events.

Structure effects in the reactions 9,10,11Be+64Zn at the Coulomb barrier

Elastic scattering and direct reactions have been studied for the collisions induced by the three Beryllium isotopes 9,10,11Be, on a medium mass 64Zn target at energies around the Coulomb barrier. The elastic scattering angular distributions, measured for the three systems at the same center of mass energy, were analyzed within the Optical Model and reaction cross-sections were deduced from optical model calculations. For the 11Be induced reaction the transfer/break-up angular distribution was also extracted.

Elastic Scattering and Reaction Mechanisms of the Halo NucleusBe11around the Coulomb Barrier

Collisions induced by (9,10,11)Be on a 64Zn target at the same c.m. energy were studied. For the first time, strong effects of the 11Be halo structure on elastic-scattering and reaction mechanisms at energies near the Coulomb barrier are evidenced experimentally. The elastic-scattering cross section of the 11Be halo nucleus shows unusual behavior in the Coulomb-nuclear interference peak angular region. The extracted total-reaction cross section for the 11Be collision is more than double the ones measured in the collisions induced by (9,10)Be. It is shown that such a strong enhancement of the total-reaction cross section with 11Be is due to transfer and breakup processes.

Experimental study of excitation functions for the deuteron induced reactions 64Zn(d,2p) 64Cu and 64Zn(d,αn) 61Cu using the stacked-foil technique

There is considerable, and growing, interest in the 64Cu radioisotope for application in Nuclear Medicine for PET imaging and targeted radiotherapy of tumours. We are investigating the cyclotron production of this isotope by way of deuteron bombardment of enriched 64Zn target material. In this study, experimental excitation functions for both the 64Zn(d,2p) 64Cu and 64Zn(d,αn) 61Cu reactions up to 18.2 MeV deuteron energy have been measured using the stacked-foil technique. The deuteron energies in the various foils were calculated with the SRIM 2003 code and γ-ray spectrometry was used to measure the activities of the various radioisotopes produced. Monitor foils were used to determine the deuteron beam current on the target stack. Theoretical excitation functions, calculated both with the Empire II code and with an updated version of the Alice code, were compared with the experimental results and a reasonable agreement was found. The experimental work was performed at the MC40 Cyclotron at the European Commission's Joint Research Centre at Ispra, Italy.

Measurement of fission neutron spectrum averaged cross sections of some threshold reactions on zinc: small-scale production of no-carrier-added 64Cu in a nuclear reactor

Summary Fission neutron spectrum averaged cross sections of some threshold reactions like (n,p), (n, α) and (n,2n) on zinc were measured using the activation technique in combination with radiochemical separations and high-resolution γ-ray spectroscopy. Special attention was paid to the formation of 64Cu via the 64Zn(n,p) 64Cu reaction since 64Cu labeled compounds are potentially important radiopharmaceuticals. At a fast neutron flux density of 7.5 × 1013 cm-2s-1 and using a 100% enriched 64Zn target, 35 GBq activity of no-carrier-added 64Cu per batch could be produced. The process seems to be interesting from the medical application viewpoint, if a cyclotron is not available. A fast neutron source, on the other hand, would lead to significantly higher yield of 64Cu.