Publications (5)0 Total impact
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Article: High-energy two-neutron removal from^{10} Be
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ABSTRACT: A kinetically complete measurement of the 12C(10Be, α+α+n) and (10Be, α+α) reactions has been performed at a beam energy of 30 MeV/nucleon. The charged beam velocity particles were detected in an array of Si-CsI detectors placed at zero degrees, and the neutrons in an 81-element neutron array. The coincident detection of the final-state particles, produced in the breakup of 10Be, allowed the reconstruction of the excitation energy in the 8Be and 9Be systems. States in 8Be were identified, in particular the ground and first-excited states; and in 9Be, states at 1.68, 2.43, and (2.78, 3.05) MeV were observed. The population of these levels, in particular the 2.43 MeV 5/2- level, suggests that collective excitations play an important role in the neutron removal process. Distorted wave Born approximation and Glauber-type calculations have been used to model the direct neutron removal from the 10Be ground state and the two-step removal via inelastic excitations of the 10Be(2+) and 9Be(5/2-) excited states.Phys. Rev. C. 08/2005; 72(2). -
Article: Measurements of the breakup and neutron removal cross sections for^{16} C
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ABSTRACT: Measurements of the breakup and the neutron removal reactions of 16C have been made at 46 MeV∕A and the decay cross sections measured. A correlation between the cluster breakup channels and the reaction Q value suggests that the reaction mechanism is strongly linked to quasielastic processes. No enhancement of the two-body cluster breakup cross section is seen for 16C. This result would indicate that 16C does not have a well developed cluster structure in the ground state, in agreement with recent calculations.Phys. Rev. C. 12/2004; 70(6). -
Article: Neutron removal and cluster breakup of^{14} B and^{14} Be
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ABSTRACT: Measurements of the neutron removal and cluster breakup cross sections for the neutron-rich nuclei 14Be and 14B have been performed at 34.4 and 40.8 MeV∕nucleon, respectively. Enhancement of the first chance cluster breakup cross section for 14Be compared to that of 14B provides evidence for a well-developed He cluster structure of the ground state of 14Be. Measurements of both the cross sections and decay-particle velocities suggest that multistep processes play an important role in the excitation and decay of both 14B and 14Be.Phys. Rev. C. 08/2004; 70(2). -
Article: Breakup reaction studies of^{10} Be and^{10, 11} B using a^{10} Be beam
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ABSTRACT: The structure of 10Be has been investigated by inelastic scattering to states above the breakup threshold using the reaction 12C(10Be,10Be*→6He+4He)12C at Ebeam=302 MeV. Excited states in 10Be were observed at 9.6±0.1 and 10.2±0.1 MeV. No evidence was observed for the population of the 4+ member of the ground-state band of 10Be indicating the shell-model-like structure of the ground state. In addition, the decay of 8Be, 10B, and 11B, populated in the two-neutron, proton pickup, breakup and 1p pickup reactions, was reconstructed through the detection of coincident 4He+4He, 4He+6Li, and 4He+7Li particles. Cross sections for the formation of the 8Be, 9Be, 10B, and 11B were also deduced. Contrary to expectations, the two-neutron removal results in the production of 8Be predominantly (80%) in the first excited (2+) state. This suggests that dynamical excitations play an important role in the neutron removal process.Phys. Rev. C. 02/2004; 69(2). -
Article: Helium clustering in neutron-rich Be isotopes
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ABSTRACT: Measurements of the helium-cluster breakup and neutron removal cross-sections for neutron-rich Be isotopes 10–12,14Be are presented. These have been studied in the 30 to 42 MeV/nucleon energy range where reaction measurements are proposed to be sensitive to the cluster content of the ground-state wave-function. These measurements provide a comprehensive survey of the decay processes of the Be isotopes by which the valence neutrons are removed revealing the underlying α–α core-cluster structure. The measurements indicate that clustering in the Be isotopes remains important up to the drip-line nucleus 14Be and that the dominant helium-cluster structure in the neutron-rich Be isotopes corresponds to α–Xn–α.Physics Letters B.
Institutions
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2004–2005
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Joint Institute for Nuclear Research
Dubna, Moskovskaya, Russia
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