Publications (16)9.74 Total impact
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Article: Fusion of 124,132 Sn with 40,48 Ca
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ABSTRACT: Fusion excitation functions for the reactions of 124,132 Sn with 40,48 Ca were measured at energies near and below the Coulomb barrier. Weak sub-barrier fusion enhancement accounted for by coupling to the first 2 + and 3 − states in the target and projectile was observed for 124,132 Sn + 48 Ca. However, the 124,132 Sn + 40 Ca fusion cross sections are very strongly enhanced below the barrier and this difference survives even after correcting for trivial size effects. Although the enhancement appears to be related to the existence of large positive Q values for neutron transfer reactions, it is not proportional to the magnitudes of those Q values, which are much larger for 132 Sn + 40 Ca than for 124 Sn + 40 Ca.Physical Review C 01/2012; 05460385. · 3.31 Impact Factor -
Article: T= 3/2 states in^{13} C
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ABSTRACT: Background: Experimental information on the structure of low-lying levels with isospin 3/2 in systems with 13 nucleons can be used to evaluate the quality of modern theoretical predictions for the light exotic systems. This level structure is poorly known at present. Purpose: Search for T=3/2 states in 13C was performed in this work. Method: These states were observed in the resonance elastic scattering of radioactive beam 12B on protons using the thick target inverse kinematics technique. Results: Six new states in 13C were identified as T=3/2 states. Tentative spin-parity assignments are suggested. Comparison to the previous knowledge of the level structure of T=3/2 A=13 system and to shell-model predictions is given. Conclusion: The elastic scattering of neutron-rich beams on proton target is a convenient tool for isobaric analog states search. The observed 12B+p excitation function is determined by the T=3/2 states and no features associated with T=1/2 states were found. Although the level scheme of T=3/2 states in A=13 systems is still far from being complete the emerging picture shows significant disagreements with predictions of contemporary shell models.Phys. Rev. C. 10/2008; 78(4). -
Article: Measurements of fusion reactions induced by radioactive 132Sn on 64Ni
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ABSTRACT: Evaporation residue and fission cross sections of radioactive 132Sn on 64Ni were measured. Statistical model calculations using parameters simultaneously fitting stable Sn+64Ni data reproduce the 132Sn induced reaction very well. A large sub-barrier fusion enhancement was observed. The enhancement can be accounted for by coupled-channels calculations including inelastic excitation of the projectile and target, and neutron transfer.The European Physical Journal Special Topics 10/2007; 150(1):35-36. · 1.56 Impact Factor -
Article: 7Be-induced α -transfer reaction on 12C
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ABSTRACT: The reaction 12C(7Be,3He) has been studied at E(7Be) = 34 MeV. Angular distributions to levels with excitation energies up to 21 MeV in the residual 16O have been measured at θlab = 13–50 degrees. This reaction selectively populates states known to have a large 12C+α component in their structure, implying that direct processes dominates at this energy.The European Physical Journal Special Topics 10/2007; 150(1):1-4. · 1.56 Impact Factor -
Article: Fusion of radioactive $^{132}$Sn with $^{64}$Ni
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ABSTRACT: Evaporation residue and fission cross sections of radioactive $^{132}$Sn on $^{64}$Ni were measured near the Coulomb barrier. A large sub-barrier fusion enhancement was observed. Coupled-channel calculations including inelastic excitation of the projectile and target, and neutron transfer are in good agreement with the measured fusion excitation function. When the change in nuclear size and shift in barrier height are accounted for, there is no extra fusion enhancement in $^{132}$Sn+$^{64}$Ni with respect to stable Sn+$^{64}$Ni. A systematic comparison of evaporation residue cross sections for the fusion of even $^{112-124}$Sn and $^{132}$Sn with $^{64}$Ni is presented.05/2007; -
Article: Neutron transfer reactions induced by^{8} Li on^{9} Be
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ABSTRACT: Angular distributions for the elastic scattering of 8Li on 9Be and the neutron transfer reactions 9Be(8Li,7Li)10Be and 9Be(8Li,9Li)8Be were measured with a 27 MeV 8Li radioactive nuclear beam. Spectr- oscopic factors for 8Li ⊗n= 9Li and 7Li ⊗n= 8Li bound systems were obtained from the comparison between the experimental differential cross section and finite-range distorted-wave Born approximation calculations with the code FRESCO. The spectroscopic factors obtained were compared to shell model calculations and to other experimental values from (d,p) reactions. Using the present values for the spectroscopic factor, cross sections for the direct neutron-capture reactions 7Li(n,γ)8Li and 8Li(n,γ)9Li were calculated in the framework of a potential model.Phys. Rev. C. 05/2007; 75(5). -
Article: Fusion of radioactive Sn132 with Ni64
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ABSTRACT: Evaporation residue and fission cross sections of radioactive Sn132 on Ni64 were measured near the Coulomb barrier. A large subbarrier fusion enhancement was observed. Coupled-channel calculations, including inelastic excitation of the projectile and target, and neutron transfer are in good agreement with the measured fusion excitation function. When the change in nuclear size and shift in barrier height are accounted for, there is no extra fusion enhancement in Sn132+Ni64 with respect to stable Sn+Ni64. A systematic comparison of evaporation residue cross sections for the fusion of even Sn112-124 and Sn132 with Ni64 is presented.Physical Review C 04/2007; 75(5):54607. · 3.31 Impact Factor -
Article: Neutron Transfer reactions induced by 8Li on 9Be
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ABSTRACT: Angular distributions for the elastic scattering of 8Li on 9Be and the neutron transfer reactions 9Be(8Li,7Li)10Be and 9Be(8Li,9Li)8Be have been measured with a 27 MeV 8Li radioactive nuclear beam. Spectroscopic factors for 8Li|n=9Li and 7Li|n=8Li bound systems were obtained from the comparison between the experimental differential cross section and finite-range DWBA calculations with the code FRESCO. The spectroscopic factors obtained are compared to shell model calculations and to other experimental values from (d,p) reactions. Using the present values for the spectroscopic factor, cross sections for the direct neutron-capture reactions 7Li(n,g)8Li and 8Li(n,g)9Li were calculated in the framework of a potential model.02/2007; -
Article: Lowest excited states of^{13} O
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ABSTRACT: An excitation function for resonance elastic scattering of p+12N was measured in the center of mass energy range of 0.8–2.7 MeV. Measurements were performed using inverse kinematics and the thick-target techniques. The data were analyzed in the framework of the R-matrix formalism. A definitive spin and parity assignment was possible for the first excited state of 13O at an excitation energy of 2.69 MeV as Jπ=1/2+. An indication of the presence of a new level in 13O at an excitation energy of 3.29 MeV with tentative spin-parity assignment Jπ=1/2- or 3/2- was obtained. We evaluate the impact of this measurement on the reaction rate of 12N(p,γ)13O for nucleosynthesis in low-metallicity stars.Phys. Rev. C. 02/2007; 75(2). -
Article: Neutron transfer reactions induced by Li8 on Be9
Physical Review C. 01/2007; 75(5). -
Chapter: Sub-barrier fusion induced by neutron-rich radioactive 132Sn
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ABSTRACT: Evaporation residue cross-sections measured with short-lived 132Sn on 64Ni at energies near and below the Coulomb barrier were found to be enhanced as compared to those measured with stable Sn isotopes on 64Ni. Subsequent measurements of fission following fusion of 132Sn with 64Ni and extending the measurement of evaporation residues to higher energies were carried out.12/2004: pages 239-240; -
Chapter: Measurement of evaporation residue cross sections from reactions with radioactive neutron-rich beams
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ABSTRACT: Evaporation residue cross sections for 132Sn, 134Te and 124Sn with 64Ni were measured. A compact system to measure these cross sections to values as low as 1 mb is described and a sample of data acquired with this system is shown.12/2004: pages 241-242; -
Article: The^{9} Be (^{8} Li,^{9} Be)^{8} Li elastic-transfer reaction
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ABSTRACT: Angular distributions for the 9Be(8Li,9Be)8Li elastic-transfer reaction have been measured with a 27-MeV 8Li radioactive nuclear beam. Spectroscopic factors for the 〈9Be|8Li+p〉 bound system were obtained from the comparison between the experimental differential cross sections and finite-range distorted-wave Born approximation calculations made with the code FRESCO. The spectroscopic factors so obtained are compared with shell-model calculations and other experimental values. Using the present value for the spectroscopic factors, cross sections and reaction rates for the 8Li(p,γ)9Be direct proton-capture reaction of astrophysical interest were calculated in the framework of the potential model.Phys. Rev. C. 78(3). -
Article: Lowest excited states of <sup>13</sup>O
Nuclear Physics Group. -
Article: Breakup of^{6} He incident on^{209} Bi near the Coulomb barrier
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ABSTRACT: A neutron-α-particle coincidence experiment was performed to study breakup of 6He on a 209Bi target at an incident energy of 22.5 MeV. Direct breakup, as well as breakup through the 2+ excited state of 6He and also the 5He+n channel, could be distinguished. A total breakup cross section of 205±65 mb was measured. The data compare well with a coupled-channels calculation that assumes a 50% reduction in the B(E1) computed from a pure 4He+2n cluster configuration, in agreement with results obtained at much higher energies. A value of B(E2⇑)=5.4±0.7e2fm4 is deduced for the 2+ state in 6He.Phys. Rev. C. 75(3). -
Conference Proceeding: Radioactive nuclear beams studies using deuterated liquid scintillators
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ABSTRACT: With over 6000 nuclides of which more than 2000 have been synthesized, the information we have about the atomic nucleus for the most part still rests in the vicinity of beta stability. With the introduction of shortlived radioactive nuclear beams (RNB) as a tool to study nuclear reactions, many doors have been opened to allow the studies of nuclei far from stability. In this study, we used a novel deuterated liquid scintillator (BC537) as a neutron detector for the study of low-energy nuclear reactions with short-lived RNBs.Nuclear Science Symposium Conference Record, 2007. NSS '07. IEEE;
Top Journals
Institutions
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2007–2012
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University of Michigan
- Department of Physics
Ann Arbor, MI, USA
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2004
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University of Notre Dame
- Department of Physics
USA
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