Level Densities from Excitation Functions of Isolated Levels

Huizenga, J.R.; Vonach, H.; Katsanos, A.A.; Gorski, A.J.; Stéphan, C.

doi:10.1103/physrev.182.1149

Cited by 63 publications

(21 citation statements)

References 25 publications

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“…As we mentioned before, Vonach seems to underestimate the trend of level widths as a function of the excitation energy and as a consequence overestimates the level density; the evaluated level width of Behkami [22] calculated at the same energy of 20.4 MeV is four times greater than Vonach's width. Other evaluations of level densities in 60 Ni have been done by Huizenga [41] and Fisher [42]; their reported values agree with the systematics of Al-Quraishi [29]. Huizenga has studied reactions 59 Co͑p , ␣ 0,1,2 ͒ 56 Fe and 56 Fe͑p , ␣ 0 ͒ 59 Co with a 50 keV energy resolution, evaluating the NLD with the expression ⌫ / D 0, with a model that includes the Hausser-Feshbach equation, D J, , and the measured differential cross section to the residual nucleus d ab / d⍀.…”

Section: Comparison With Other Evaluations Level Density Systematmentioning

confidence: 99%

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Level widths and level densities inSi28,Ti46
Salas-Bacci
¹
,
Grimes
²
,
Massey
³

et al. 2004
Phys. Rev. C
12
2
9
0
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Ericson fluctuations in the differential cross sections were investigated for the compound reactions 27 Al͑p , n 0 ͒ 27 Si, 45 Sc͑p , n 4 ͒ 45 Ti, 45 Sc͑p , n 5 ͒ 45 Ti, 51 V͑p , n 0 ͒ 51 Cr, and 59 Co͑p , n 0 ͒ 59 Ni. Level widths in the compound nuclei 28 Si, 46 Ti, 52 Cr, and 60 Ni were extracted from the analysis of the differential cross sections by the Fourier method and a nonlinear fit to the ln͗A k 2 + B k 2 ͘ distribution. The neutron spectra for each reaction were measured at least at three backward angles but the coherence width ͗⌫͘ did not show a strong angular dependence. Nuclear level densities for the above nuclei were extracted by relating the average level spacing D J to the average level width ⌫ J using the fluctuation theory. Reasonable agreements were found with other level densities and level density compilations based in the Fermi gas formalism of Al-Quraishi and Huang for 28 Si, 46 Ti, and 52 Cr but the comparison diverges for 60 Ni for which additional measurements are required in order to clarify the observed discrepancies. The level density parameters that best describe the data are a = 3.5 and ␦ = 4.0, U Ͻ 25 MeV, for 28 Si, a = 4.8 and ␦ = −0.3, U Ͻ 20 MeV, for 46 Ti, and a = 4.8 and ␦ = 0.3, U Ͻ 20 MeV, for 52 Cr.

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Section: Comparison With Other Evaluations Level Density Systematmentioning

confidence: 99%

“…(15). It might have been possible that Huizenga [41] could have used the Vonach's [26] width as a reference in his evaluations of NLD in 60 Ni. If this were the case, then its level densities could be lower than the reported ones.…”

Section: Comparison With Other Evaluations Level Density Systematmentioning

confidence: 99%

Level widths and level densities inSi28,Ti46
Salas-Bacci
¹
,
Grimes
²
,
Massey
³

et al. 2004
Phys. Rev. C
12
2
9
0
View full text Add to dashboard Cite

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“…Their algebraic formulas, obtaincd by invcrsc Within the worldwide used back-shifted Fermi gas Laplace transformation of the grand canonical partition func-(BSFG) level density model [10,11] the effective excitation tion for a Fermi gas with pairing interactions (but neglecting [2] at fixed effective total excitation energies of 0, 2, 4, and 7 MeV. Different nuclear charges are indicated by different symbols.…”

Section: Effective Total Excitation Energymentioning

confidence: 99%

Cold-fission yields at effective excitation energies

Avrigeanu¹,

Florescu²,

Săndulescu³

et al. 1995

Phys. Rev. C

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The experimental cold-fission yields for the systein 2 3 '~( n , h , f ) are analyzed as function of the effective total excitation energy (TXE). The nuclear level density effect is taken into account at higher TXE, in order to benefit by the lower experimental data uncertainty as well as to avoid the quantitative account of the level densities close to fragment ground states. In this way the odd-even staggering which appears in the yields extrapolated at Zero excitatiori energy by using the level densities, vanishes. We conclude that the cold nuclear fragmentatioii theory including the dynamical model desciibes well the experimental data. PACS number(s): 25.85. Ec, 23.70.+j, 21.10.Ma

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“…In any case the observation of such effect would be difficult -when looking to excitation functions for production of spallation residues -since this process would be superimposed upon the one -of much greater intensity -corresponding to the emission of individual nucleons not bound into an particle. For evaluating the state and level densities in decay rate expressions, the parameters suggested by Gadioli et al [14] in the framework of the back-shifted Fermi Gas Model [15,16] have been employed.…”

Section: Ill the Calculationmentioning

confidence: 99%

Emission of alpha particles in the interaction of 10?85 MeV protons with48,50Ti

et al. 1981

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The excitation functions of twenty nuclear reactions induced by protons of up to 85 MeV incident upon 48Ti and S~ targets have been measured. Most of these involve the emission of one to three alpha particles. The Exciton model has been used to calculate these excitation functions. An expanded and more precise treatment of nucleon-alpha scattering has been incorporated into the model. It is presented and the implications of its predictions discussed. The agreement of experiment and calculation is very good lending support to the approach to alpha particle interactions introduced in this work.Nuclear Reactions: 48Ti(p, xnypzcO, S~ xnypze), x =0-7, y=2-6, z=0-3; measured a(E). Calculated a(E). 48Ti, 5~ enriched targets.

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Level Densities from Excitation Functions of Isolated Levels

Cited by 63 publications

References 25 publications

Level widths and level densities inSi28,Ti46
Salas-Bacci
¹
,
Grimes
²
,
Massey
³

et al. 2004
Phys. Rev. C
12
2
9
0
View full text Add to dashboard Cite

Level widths and level densities inSi28,Ti46
Salas-Bacci
¹
,
Grimes
²
,
Massey
³

et al. 2004
Phys. Rev. C
12
2
9
0
View full text Add to dashboard Cite

Cold-fission yields at effective excitation energies

Emission of alpha particles in the interaction of 10?85 MeV protons with48,50Ti

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Level Densities from Excitation Functions of Isolated Levels

Cited by 63 publications

References 25 publications

Level widths and level densities inSi28,Ti46Salas-Bacci1, Grimes2, Massey3 et al. 2004Phys. Rev. C12290View full textAdd to dashboardCite

Level widths and level densities inSi28,Ti46Salas-Bacci1, Grimes2, Massey3 et al. 2004Phys. Rev. C12290View full textAdd to dashboardCite

Cold-fission yields at effective excitation energies

Emission of alpha particles in the interaction of 10?85 MeV protons with48,50Ti

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Product

Resources

About

Level widths and level densities inSi28,Ti46
Salas-Bacci
¹
,
Grimes
²
,
Massey
³

et al. 2004
Phys. Rev. C
12
2
9
0
View full text Add to dashboard Cite

Level widths and level densities inSi28,Ti46
Salas-Bacci
¹
,
Grimes
²
,
Massey
³

et al. 2004
Phys. Rev. C
12
2
9
0
View full text Add to dashboard Cite