Transfer measurements for the Ti plus Ni systems at near barrier energies

Large enhancements have been observed in the sub-barrier fusion cross sections for Ti + Ni systems in our previous studies. Coupled channel calculations incorporating couplings to 2(+) and 3(-) states failed to explain these enhancements completely. A possibilty of transfer channels contributing to the residual enhancements had been suggested. In order to investigate the role of relevant transfer channels, measurements of one- and two-nucleon transfer were carried out for Ti-46,Ti-48 + Ni-64 systems. The present paper gives the results of these studies

Magnetic Moment of the Fragmentation Aligned 61Fe(9/2)+ Isomer

We report on the g factor measurement of the isomer in $^{61}Fe$ ($E^{*}=861 keV$). The isomer was produced and spin-aligned via a projectile-fragmentation reaction at intermediate energy, the Time Dependent Perturbed Angular Distribution (TDPAD) method being used for the measurement of the g factor. For the first time, due to significant improvements of the experimental technique, an appreciable residual alignment of the isomer has been observed, allowing a precise determination of its g factor: $g=-0.229(2)$. Comparison of the experimental g factor with shell-model and mean field calculations confirms the $9/2^+$ spin and parity assignments and suggests the onset of deformation due to the intrusion of Nilsson orbitals emerging from the $\nu g_{9/2}$.Comment: 4 figures. Submitted to Phys. Rev. Let

Asymptotic normalization coefficients for 8B->7Be+p from a study of 8Li->7Li+n

Asymptotic normalization coefficients (ANCs) for 8Li->7Li+n have been extracted from the neutron transfer reaction 13C(7Li,8Li)12C at 63 MeV. These are related to the ANCs in 8B->7Be+p using charge symmetry. We extract ANCs for 8B that are in very good agreement with those inferred from proton transfer and breakup experiments. We have also separated the contributions from the p_1/2 and p_3/2 components in the transfer. We find the astrophysical factor for the 7Be(p,gamma)8B reaction to be S_17(0)=17.6+/-1.7 eVb. This is the first time that the rate of a direct capture reaction of astrophysical interest has been determined through a measurement of the ANCs in the mirror system.Comment: 5 pages, 3 figures, 2 table

High-spin spectrum of 24Mg studied through multiparticle angular correlations

We describe the investigation of high-spin states in 24Mg populated with the 12C(16O,α)24Mg reaction at 62- and 68-MeV beam energy. The excited states were established through the coincident detection of up to four α and γ particles in complete decay cascades toward a final state of angular momentum zero, the ground state of either 20Ne or 16O. We describe a new analysis method for the angular correlations in such events and apply it with the goal to assign spin and parity to α-unbound states in 24Mg. We establish a number of high-spin, natural-parity states between spins 6 and 12, including the lowest known 10+ and 12 + levels. The energy systematics of positive- and negative-parity high-spin states are compared to the predictions of modern shell-model calculations

Transfer and higher-order phonon coupling effects in the sub-barrier fusion of {sup 28}Si and {sup 93}Nb

Measurements have been carried out for the fusion excitation function and one and two nucleon transfer probabilities at energies near and below the Coulomb barrier for the system 28 Si 93 Nb. The recoil mass separator HIRA at the Nuclear Science Center, New Delhi, has been used for these measurements. A coupledchannels formalism has been employed for explaining the observed enhancement in the sub-barrier fusion cross section. Present results support the significance of positive Q-value transfer channel in the sub-barrier enhancement. The possible role of higher-order multiphonon coupling effects in the reaction mechanism have also been investigated. S0556-28139703910-

Role of 28Si excitations in the sub-barrier fusion of 28Si+ 120Sn

Fusion cross sections were measured for the systems 16O and 28Si+ 120Sn in order to understand the role of specific channels involved in sub-barrier fusion. Fusion cross sections were measured by direct detection of the evaporation residues. Extracted fusion barrier distributions were analyzed using the exact coupled-channel code CCFULL as well as the simplified code CCMOD. These calculations show that the observed fusion barrier distribution for the Si+Sn system is reproduced only if the rotational excitation in 28Si is taken into account

Lowest I = 0 Proton Resonance in 26Si and Implications for Nucleosynthesis of 26 Al

Using a beam of the radioactive isotope 25Al, produced with the new RESOLUT facility, we measured the direct (d,n) proton-transfer reaction leading to low-lying proton resonances in 26Si. We observed the lowest l=0 proton resonance, identified with the 3+ state at 5.914-MeV excitation energy. This result eliminates the largest uncertainty in astrophysical reaction rates involved in the nucleosynthesis of 26Al

Transfer and higher-order phonon coupling effects in the sub-barrier fusion of 28Si and 93Nb

Measurements have been carried out for the fusion excitation function and one and two nucléon transfer probabilities at energies near and below the Coulomb barrier for the system 28Si+93Nb. The recoil mass separator HIRA at the Nuclear Science Center, New Delhi, has been used for these measurements. A coupled-channels formalism has been employed for explaining the observed enhancement in the sub-barrier fusion cross section. Present results support the significance of positive Q-value transfer channel in the sub-barrier enhancement. The possible role of higher-order multiphonon coupling effects in the reaction mechanism have also been investigated