Examinando por Autor "Di Gregorio, D. E."

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  • Miniatura
    ÍtemAcceso Abierto
    10B + 17O fusion cross sections
    (American Institute of Physics, 1982) Chan, Y. D.; Di Gregorio, D. E.; Ford, jr., J. L. C.; Gomez del Campo, J.; Ortiz, M. E.; Shapira, D.
    The fusion cross section for 10B + 17O has been measured at four excitation energies in 27Al of E*=48.4, 55.1, 66.9, and 74.4 MeV in order to study possible compound nucleus limitation effects on fusion for light heavy-ion systems at intermediate excitation energies. Comparing this data with other measurements for different entrance channels populating the same compound nucleus it is found that for E*60 MeV the bands tend to converge indicating a possible compound nucleus limitation effect. The data are compared with existing models for entrance channel and statistical yrast line limitations. NUCLEAR REACTIONS 17O + 10B, E(17O)=54, 72, 104, and 124 MeV; measured d2sigmadOmegadE for reaction products from Z=3 to 12. Extracted sigmafusion.
  • Miniatura
    ÍtemAcceso Abierto
    14n + 13c fusion cross sections and compound nucleus limitation in 27al
    (American Institute of Physics, 1982) Di Gregorio, D. E.; Gomez del Campo, J.; Chan, Y. D.; Ford, Jr. J. L. C.; Shapira, D.; Ortiz, M. E.
    Fusion cross sections for the 14N + 13C system have been measured by detecting the evaporation residues at five bombarding energies which correspond to high excitation energies in the compound nucleus: E∗(27Al)=64−110 MeV. The 27Al nucleus can be populated by four different heavy-ion entrance channels—15N + 12C, 16O + 11B, 14N + 13C, and 17O + 10B—which are accessible to experimental measurements. Comparing the present data with those already existing for the above channels, it is found that for E∗>60 MeV the curves E∗ vs Jcr for each system converge, which may be indicative of a limitation imposed by the compound nucleus. The data are discussed in terms of existing models for entrance channel and statistical yrast line limitations. The highest energy point also suggests the existence of a maximum absolute angular momentum limit of ∼28ℏ. Las secciones transversales de fusión para el sistema 14N + 13C se midieron detectando los residuos de evaporación a cinco energías de bombardeo que corresponden a altas energías de excitación en el núcleo compuesto: E∗(27Al)=64−110 MeV. El núcleo de 27Al puede estar poblado por cuatro canales de entrada de iones pesados ​​diferentes: 15N + 12C, 16O + 11B, 14N + 13C y 17O + 10B, que son accesibles para mediciones experimentales. Comparando los datos actuales con los ya existentes para los canales anteriores, se encuentra que para E∗>60 MeV convergen las curvas E∗ vs Jcr para cada sistema, lo que puede ser indicativo de una limitación impuesta por el núcleo compuesto. Los datos se analizan en términos de los modelos existentes para el canal de entrada y las limitaciones estadísticas de la línea yrast. El punto de energía más alto también sugiere la existencia de un límite máximo de momento angular absoluto de ∼28ℏ.
  • Miniatura
    ÍtemAcceso Abierto
    Fusion, direct and total reaction cross sections of the ¹°B+¹⠴N system up to E/sub 14N/ = 180 MeV
    (American Institute of Physics, 1982) Ortiz, M. E.; Gomez del Campo, J.; Chan, Y. D.; Di Gregorio, D. E.; Ford, J. L. C.; Shapira, D.
    The fusion cross section of the ¹°B+¹⠴N system has been measured at five energies covering the range E/sub 14N/ = 86-180 MeV. Angular distributions of fusion and direct reaction components for products from Z = 3 to Z = 11 have been determined. Hauser-Feshbach calculations of the Z distributions, energies and angular distributions of the evaporation residues are presented and compared to the data. The fusion cross section decreases slowly with increasing energy and reaches a maximum angular momentum of about 21 +- 1 h. The fusion cross section is discussed in terms of entrance channel models and compound nucleus formation and is compared to that of the ¹²C+¹²C system. The experimental total reaction cross sections are in good agreement with optical model calculations with parameters deduced from elastic scattering