The effect of level density and reaction mechanisms on the reaction cross-section calculations at intermediate energies

Lunev, V.P.; Shubin, Yu.N.; Grandi, C.; Poli, B.; Ventura, A.

doi:10.1007/bf03035883

Cited by 4 publications

(4 citation statements)

References 37 publications

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“…According to this consideration the incident proton generates a cascade of sequential nucleon-nucleon collisions, and highenergy particles escape from the nucleus. There may also be a contribution of the competitive process of precompound cluster emission [16]. The angular momentum of the final nucleus is a result of the transfer of orbital angular momentum from the incident proton plus its coupling with the spin of the target nucleus.…”

Section: Discussionmentioning

confidence: 99%

Production of high-spin isomers in proton induced reactions at100–500MeVonTa181
Жуйков
¹
,
Mebel
²
,
Kokhanyuk³
et al. 2003
Phys. Rev. C
21
0
11
0
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Cross sections for production of a broad variety of high-spin isomers, i.e., 177 Hf m2 ͑37/2 − ͒, 179 Hf m2 ͑25/2 − ͒, 177 Lu m ͑23/2 − ͒, 180 Hf m ͑8 − ͒, and 178 Ta m ͑7 − ͒ from 181 Ta targets irradiated with 100, 145, 200, 350, and 500 MeV protons have been measured by off-line ␥-spectroscopy. A radiochemical procedure was used to achieve high sensitivity. Isomer ratios in products ranging down to 10 −3 were based on experimentally measured and theoretically calculated cross sections. It was demonstrated that the isomer ratio does not depend essentially on proton energy in the given range. Regularities in formation of isomeric states in different nuclear reactions are discussed.

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Section: Discussionmentioning

confidence: 99%

Production of high-spin isomers in proton induced reactions at100–500MeVonTa181
Жуйков
¹
,
Mebel
²
,
Kokhanyuk³
et al. 2003
Phys. Rev. C
21
0
11
0
View full text Add to dashboard Cite

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“…Owing to the 7+3 additional degrees of freedom, the dynamical algebra is enlarged to U (16). 3,4) However, p bosons play a minor role in reproducing the energies of low-lying states of negative parity and are thus neglected in the present work.…”

Section: The Boson Partition Functionmentioning

confidence: 98%

“…In these phenomenological approaches, the parameters defining the intrinsic densities are adjusted on the basis of level density systematics, mainly at excitation energies of the order of the neutron binding energy, B n , where data exist on the s-wave neutron resonance spacings. 14 ) The vibrational enhancement factor commonly used in the generalized superftuid model 15) of nuclear level densities, can be written in the form 15,16) !J.U Kvib(U(T)) = exp (!J.S -T)' (4) where the variations of entropy, !J.S, and excitation energy, …”

Section: K=klk>omentioning

confidence: 99%

Collective Degrees of Freedom in Nuclear Level Densities

Mengoni

Ventura

Masetti³

et al. 2002

Journal of Nuclear Science and Technology

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A finite temperature extension of the interacting boson model is developed and applied to the calculation of the collective partition function of transitional even-even Sm isotopes. The effective boson number decreases with increasing temperature, leading to a natural damping of collectivity. Positive and negative parity contributions to the boson partition function are computed and compared to rotational and vibrational enhancement factors commonly used in the generalized superftuid model.

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“…The average number of type-i phonons is given by a Bose distribution corrected for damping effects [28]:…”

Section: Collective Enhancementmentioning

confidence: 99%

Combinatorial level densities from a relativistic structure model

Pezer¹,

Ventura²,

Vretenar³

2003

Nuclear Physics A

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A new model for calculating nuclear level densities is investigated. The singlenucleon spectra are calculated in a relativistic mean-field model with energy-dependent effective mass, which yields a realistic density of single-particle states at the Fermi energy. These microscopic single-nucleon states are used in a fast combinatorial algorithm for calculating the non-collective excitations of nuclei. The method, when applied to magic and semi-magic nuclei, such as 60 Ni, 114 Sn and 208 Pb, reproduces the cumulative number of experimental states at low excitation energy, as well as the s-wave neutron resonance spacing at the neutron binding energy. Experimental level densities above 10 MeV are reproduced by multiplying the non-collective level densities by a simple vibrational enhancement factor. Problems to be solved in the extension to open-shell nuclei are discussed.

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The effect of level density and reaction mechanisms on the reaction cross-section calculations at intermediate energies

Cited by 4 publications

References 37 publications

Production of high-spin isomers in proton induced reactions at100–500MeVonTa181
Жуйков
¹
,
Mebel
²
,
Kokhanyuk³
et al. 2003
Phys. Rev. C
21
0
11
0
View full text Add to dashboard Cite

Production of high-spin isomers in proton induced reactions at100–500MeVonTa181
Жуйков
¹
,
Mebel
²
,
Kokhanyuk³
et al. 2003
Phys. Rev. C
21
0
11
0
View full text Add to dashboard Cite

Collective Degrees of Freedom in Nuclear Level Densities

Combinatorial level densities from a relativistic structure model

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The effect of level density and reaction mechanisms on the reaction cross-section calculations at intermediate energies

Cited by 4 publications

References 37 publications

Production of high-spin isomers in proton induced reactions at100–500MeVonTa181Жуйков1, Mebel2, Kokhanyuk3 et al. 2003Phys. Rev. C210110View full textAdd to dashboardCite

Production of high-spin isomers in proton induced reactions at100–500MeVonTa181Жуйков1, Mebel2, Kokhanyuk3 et al. 2003Phys. Rev. C210110View full textAdd to dashboardCite

Collective Degrees of Freedom in Nuclear Level Densities

Combinatorial level densities from a relativistic structure model

Contact Info

Product

Resources

About

Production of high-spin isomers in proton induced reactions at100–500MeVonTa181
Жуйков
¹
,
Mebel
²
,
Kokhanyuk³
et al. 2003
Phys. Rev. C
21
0
11
0
View full text Add to dashboard Cite

Production of high-spin isomers in proton induced reactions at100–500MeVonTa181
Жуйков
¹
,
Mebel
²
,
Kokhanyuk³
et al. 2003
Phys. Rev. C
21
0
11
0
View full text Add to dashboard Cite