Browsing by Author "Nemulodi, F."

Now showing 1 - 4 of 4
  • Thumbnail Image
    Item
    Characterization of the proposed 4−α cluster state candidate in ¹⁶O
    (American Physical Society, 2017) Li, K. C. W.; Neveling, R.; Adsley, P.; Papka, P.; Smit, F. D.; Brummer, J. W.; Diget, C. Aa.; Freer, M.; Harakeh, M. N.; Kokalova, Tz.; Nemulodi, F.; Pellegri, L.; Rebeiro, B.; Swartz, J. A.; Triambak, S.; Van Zyl, J. J.; Wheldon, C.
    The 0¹⁶O(α,α′) reaction was studied at θlab=0∘ at an incident energy of Elab=200 MeV using the K600 magnetic spectrometer at iThemba LABS. Proton decay and α decay from the natural parity states were observed in a large-acceptance silicon strip detector array at backward angles. The coincident charged-particle measurements were used to characterize the decay channels of the 0⁺₆ state in ¹⁶O located at Ex=15.097(5) MeV. This state is identified by several theoretical cluster calculations to be a good candidate for the 4−α cluster state. The results of this work suggest the presence of a previously unidentified resonance at Ex≈15 MeV that does not exhibit a 0⁺ character. This unresolved resonance may have contaminated previous observations of the 0⁺₆ state.
  • Thumbnail Image
    Item
    Deformation dependence of the isovector giant dipole resonance : the neodymium isotopic chain revisited
    (Elsevier, 2018) Donaldson, L. M.; Bertulani, C. A.; Carter, J.; Nesterenko, V. O.; Von Neumann-Cosel, P.; Neveling, R.; Ponomarev, V. Yu; Reinhard, P. G.; Usman, I. T.; Adsley, P.; Brummer, J. W.; Buthelezi, E. Z.; Cooper, G. R. J.; Fearick, R. W.; Fortsch, S. V.; Fujita, H.; Fujita, Y.; Jingo, M.; Kleinig, W.; Kureba, C. O.; Kvasil, J.; Latif, M.; Li, K. C. W.; Mira, J. P.; Nemulodi, F.; Papka, P.; Pellegri, L.; Pietralla, N.; Richter, A.; Sideras-Haddad, E.; Smit, F. D.; Steyn, G. F.; Swartz, J. A.; Tamii, A.
    Proton inelastic scattering experiments at energy Ep=200MeV and a spectrometer scattering angle of 0° were performed on 144,146,148,150Nd and 152Sm exciting the IsoVector Giant Dipole Resonance (IVGDR). Comparison with results from photo-absorption experiments reveals a shift of resonance maxima towards higher energies for vibrational and transitional nuclei. The extracted photo-absorption cross sections in the most deformed nuclei, 150Nd and 152Sm, exhibit a pronounced asymmetry rather than a distinct double-hump structure expected as a signature of K-splitting. This behaviour may be related to the proximity of these nuclei to the critical point of the phase shape transition from vibrators to rotors with a soft quadrupole deformation potential. Self-consistent random-phase approximation (RPA) calculations using the SLy6 Skyrme force provide a relevant description of the IVGDR shapes deduced from the present data.
  • Thumbnail Image
    Item
    Search for highly excited states in ²⁸Si
    (IOP Publishing, 2017) Montanari, D.; Courtin, S.; Jenkins, D. G.; Diget, C.; Yavuzkanat, N.; Neveling, R.; Mira, J. P.; Nemulodi, F.; Smit, F. D.; Usman, I.; Papka, P.; Swartz, J. A.; Van Zyl, J. J.; Orce, N.
    The theoretical and experimental determination of superdeformed states in nuclei in the mass region A≤40 has been since a long time one of the major challenges of nuclear structure studies. Despite the considerable experimental and theoretical work dedicated to this topic, up to now superdeformed bands have been found in only two nuclei, ³⁶Ar and ⁴⁰Ca. While the experimental signature of the superdeformed nature of those states is irrefutable, their theoretical interpretation is still uncertain. In particular, it is not clear whether clusterisation is responsible of the onset of superdeformation. For this reason, we wanted to investigate an even lighter system, ²⁸Si, where a number of theoretical calculations predict the presence of superdeformation as an effect of the cluster structure of the nucleus.
  • Thumbnail Image
    Item
    Second T = 3/2 state in 9B and the isobaric multiplet mass equation
    (American Physical Society, 2018) Mukwevho, N. J.; Rebeiro, B. M.; Marin-Lambarri, D. J.; Triambak, S.; Adsley, P.; Kheswa, N. Y.; Neveling, R.; Pellegri, L.; Pesudo, V.; Smit, F. D.; Akakpo, E. H.; Brümmer, J. W.; Jongile, S.; Kamil, M.; Mabika, P. Z.; Nemulodi, F.; Orce, J. N.; Papka, P.; Steyn, G. F.; Yahia-Cherif, W.
    Recent high-precision mass measurements and shell-model calculations [M. Brodeur et al., Phys. Rev. Lett. 108, 212501 (2012)] have challenged a longstanding explanation for the requirement of a cubic isobaric multiplet mass equation for the lowest A=9 isospin quartet. The conclusions relied upon the choice of the excitation energy for the second T=3/2 state in 9B, which had two conflicting measurements prior to this work. We remeasured the energy of the state using the 9Be(3He,t) reaction and significantly disagree with the most recent measurement. Our result supports the contention that continuum coupling in the most proton-rich member of the quartet is not the predominant reason for the large cubic term required for A=9 nuclei.