Exponential optical potentials for heavy-ion elastic scattering
Abstract
A detailed quantitative survey of the optical-model ambiguity in some particular cases shows a very wide range of equally good choices in the Woods-Saxon parameters and even some degree of indefiniteness in the magnitudes usually considered to be well-defined, like the strong absorption radius. In 16O + 208Pb elastic scattering we show that all the good real potentials agree over a given region rather than a point. A systematic use of (real and imaginary) exponential potentials can fit, in a less redundant form, a fairly sizable range of experimental data and lends itself to the construction of a general expression.
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Cited by (48)
Nuclear Data Sheets for A=64
2021, Nuclear Data SheetsThe evaluated experimental data are presented and evaluated for 13 known nuclides of mass 64 (Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, Ge, As, Se). For each nuclide, the best values combining all available data are recommended for spectroscopic properties. No excited states have been identified in 64Ti, 64As, and 64Se. Only one excited state in 64V as an isomer, and three in 64Cr have been identified. Data for excited states in 64Mn, 64Fe, and 64Co remain limited. 64Ni, 64Cu, and 64Zn are the most studied nuclides through various reactions and decays, followed by 64Ga and 64Ge. In the opinion of the evaluators, there are several incomplete or discrepant aspects of the high-spin portion of the level scheme for 64Zn above ≈5 MeV excitation which need to be resolved in further experiments using large γ-detector arrays. The decay schemes of 64Ti β−, 64As ε and 64Se ε are unknown, while very little information is available for 64V β− and 64Cr β−. The decay schemes of 64Mn β−, 64Fe β−, 64Co β− and 64Ge ε are somewhat better known, but still considered incomplete by evaluators. The decay scheme of 64Ga ε decay is known in detail, however there is the possibility of additional levels populated above 4713 keV, as the Q(ε) value is 7171 keV. The β−, β+ and ε decay modes of 64Cu are well known, as this radionuclide is of great importance in applications, for example, as a dosimeter for neutron flux determination in nuclear reactors, and as a radiopharmaceutical for positron emission tomography (PET). This work supersedes earlier full evaluations of A=64 by 2007Si04, 1996Si12, 1991Si03, 1979Ha35 and 1974Au04.
Nuclear Data Sheets for A=100
2021, Nuclear Data SheetsEvaluated experimental data are presented for 15 known nuclides of mass 100 (Kr, Rb, Sr, Y, Zr, Nb, Mo, Tc, Ru, Rh, Pd, Ag, Cd, In, Sn). Recommended values are given for level parameters, γ and β radiations, and other spectroscopic information. No excited states are known in 100Rb and 100Sn. Except for isotopic identification, no information is available for the decay of the 100Kr isotope, and limited information is known about the decay properties of the 100Sn isotope. According to Fig. 2 (A/Q versus counts plot) and as mentioned in the text in 2021Su01, 100Br isotope was not observed, although, discovery of 101Br was claimed in this work. In the case of 100Pd, the agreement in the orderings of the γ-ray cascades and γ-ray inventory between various studies of high-spin structures remains poor at high excitation energies (>9 MeV). For 100Y, the assignments of the two previously known half-lives to the respective states (g.s. and the 145-keV isomer) remain to be established. This work supersedes earlier full evaluations of A=100 by 2008Si01, 1997Si09, 1990Si05 and 1974Ko37.
An explanation for the anomaly problem of diffuseness parameter of the nucleus-nucleus potential in heavy-ion fusion reactions: A possible thermal solution
2019, Nuclear Physics AWe present an explanation for the abnormally large diffuseness parameter of the Woods-Saxon (WS) potential in heavy-ion fusion reactions based on the thermal considerations of the ion-ion potential. Within the framework of the temperature-dependent (TD) form of the proximity potential 2010, we systematically explored the role of the thermal effects in the fusion excitation functions of a significant number of the heavy-ion fusion reactions. The obtained results reveal that the proximity potential supplemented with temperature effects has been successful in reproducing the fusion excitation data for various considered systems. Based on the TD nucleus-nucleus potentials, we extract the equivalent diffuseness parameter of the WS potential. The extracted values are ranging between 0.63 fm and 1.09 fm. We also show the diffuseness parameter follows a regular decreasing trend with increase of the temperature T.
Nuclear Data Sheets for A = 100
2008, Nuclear Data SheetsThe evaluated experimental data are presented for 15 known nuclides of mass 100 (Kr, Rb, Sr, Y, Zr, Nb, Mo, Tc, Ru, Rh, Pd, Ag, Cd, In, Sn). High spin excitations are known for 100Sr, 100Zr, 100Mo, 100Tc, 100Ru, 100Rh, 100Pd, 100Ag, and 100Cd. The neutron capture data are available for 100Tc and 100Ru. Particle transfer data exist for structures in 100Nb, 100Mo, 100Tc and 100Ru. The two-neutrino ββ decay mode in 100Mo is fully established with measured half-life and population of the g.s. and 1130,0+ state in 100Ru. The absolute energy of the isomer in 100Nb is now well established from recent Penning-trap mass measurements.
Excited state data are nonexistent for 100Kr, 100Rb and 100Sn; and only one excited state is known in 100In. Except for isotopic identification, no information is available for the decay of the 100Kr isotope and very little is known about the decay properties of the 100Sn isotope. In the case of 100Pd, there are many recent studies of high-spin structures but the agreement in the orderings of the γ-ray cascades and γ-ray inventory between various studies remains poor at high (>9 MeV) excitation energies. The energy difference between the g.s. an isomer in 100Y has recently been precisely measured in Penning-Penning-trap mass measurements, however, the assignments of the two previously known half-lives and Jπ's to the respective states (g.s. and the 145-keV isomer) in 100Y remains to be established. Static moments in 100Y have also been recently measured for one of these states in 100Y but it is not definitely known as to which of the two states (g.s. or the isomer) is connected with these measurements.
This work supersedes earlier full evaluations of A = 100 by 1997Si09, 1990Si05 and 1974Ko37.
Nuclear Data Sheets for A = 64
2007, Nuclear Data SheetsThe evaluated spectroscopic data are presented for known nuclides of mass 64 (V,Cr,Mn,Fe,Co,Ni,Cu,Zn,Ga,Ge,As,Se). Excited-state data are nonexistent for 64V, 64Cr, 64As and 64Se. Except for half-lives, no other radioactive decay data are available for the decay of 64V, 64As and 64Se; and those for the decays of 64Cr, 64Mn, 64Fe, 64Co and 64Ge are not considered as definitive. There are several high-spin studies for 64Zn nuclide, but many inconsistencies are noted in this evaluation and complete details of data in these studies are generally lacking in the published literature. This work supersedes earlier full evaluations of A = 64 by 1996Si12, 1979Ha35, 1974Au04 and 1967Ve09; and a mid-strem evaluation by 1991Si03 published in an 'update' mode.
Nuclear Data Sheets for A = 74
2006, Nuclear Data SheetsNuclear spectroscopic information for known nuclides of mass number 74 (Co,Ni,Cu,Zn,Ga,Ge,As,Se,Br,Kr, Rb,Sr) with Z = 27 to 38 and N = 47 to 36 have been evaluated and presented together with adopted energies and Jπ of levels in these nuclei. No excited state data are yet available for 74Co, 74Cu and 74Sr. This evaluation supersedes previous full evaluations of A = 74 by 1987Si08 and 1976Ko07, and a midstream evaluation (published in update mode) by 1995Fa23 with a literature cutoff date of May 1994. Extensive new data have been included for most nuclides in the current revision of A = 74.