Inverse reactions and the statistical evaporation model: Ingoing-wave boundary-condition and optical models

Alexander, J.; Magda, M.T.; Landowne, S.

doi:10.1103/physrevc.42.1092

Cited by 31 publications

(24 citation statements)

References 30 publications

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“…As already pointed out in Ref. [15], this difference is due to the treatment of absorption. The radial tail of the imaginary potential causes reactive Taking into account the physica1 description provided by the IWBCM together with the better overall agreernent obtained, we can conclude that these transmission coefficients are more appropriate for the description of particle evaporation in this system.…”

Section: Discussionmentioning

confidence: 85%

“…[12], for the system 120-MeV Si+ Si, transmission coefficients derived from fusion systematics [14] produce alpha energy spectra harder than those obtained from optical model transmission coefficients. An important contribution to this subject is given in a recent paper [15] where the ingoing-wave boundary-condition model (IWBCM) and optical model (OM) transmission coefficients are compared. The authors pointed out that the special effects of the imaginary part of the optical potential, responsible for transparency, shape resonances, and peripheral absorption, can be misleading in the context of the evaporation model, as they include nonfusion reactions in the inverse process.…”

Section: Introductionmentioning

confidence: 99%

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H1,2,3,
Kildir
¹
,
Rana
²
,
Moro
³

et al. 1992
Phys. Rev. C

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A detailed comparison between measured energy spectra and cross sections of ' 'H and He, evaporated from the composite system Ru (E =113 MeV), and the predictions of the statistical model, has been carried out. Results obtained with transmission coefficients derived from optical model (OM), ingoing-wave boundary-condition model (IWBCM) and fusion systematics (FS) are presented. The best overa11 description of the data is obtained using IWBCM transmission coeScients, with reduced s-wave barriers, including, in the level density, deformations slightly larger than those predicted by the rotating liquid drop model (RLDM). ' H yields are we11 reproduced by IWBCM transmission coeScients, while they are largely overestimated by the OM ones; the failure is found to be related to the imaginary part of the optical potential which accounts for the absorption of nonfusion reactions, in peripheral collisions. No combination of phase space and transmission coeScients is able to reproduce, simultaneously, the low emission barrier and the cross section observed for protons. PACS number(s): 25.70.Gh, 25.70.Jj

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Section: Discussionmentioning

confidence: 85%

Section: Introductionmentioning

confidence: 99%

H1,2,3,
Kildir
¹
,
Rana
²
,
Moro
³

et al. 1992
Phys. Rev. C

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“…The transmission coefficients T l (E α ) are calculated from the ingoing wave boundary condition (IWBC) model [22] using a prescription for the nuclear potential which reproduces the Coulomb barriers in this mass region [14]. Sierk's macroscopic model was used for the calculation of the binding and rotational plus deformation energies as well as fission barriers [23].…”

Section: Statistical-model Calculationsmentioning

confidence: 99%

Search for the fade out of a collective enhancement of the nuclear level density

et al. 2007

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The fade out of a collective enhancement of the nuclear level density is predicted (by an SU3 shell model) to give rise to a clear signature in the evolution of the spectral shape of evaporated charged particles with excitation energy. We have searched for this signature in the spectra of α particles emitted from 178 Hf compound nuclei, with excitation energies between 54 and 124 MeV, formed in 18 O+ 160 Gd fusion reactions. The Gammasphere spectrometer provided us with the ability to construct channel-specific α-particle spectra that could be compared to statistical-model calculations on a channel-by-channel basis. The expected clear signature of a rapid fade out of a collective enhancement was not found. The data are best reproduced by calculations that do not explicitly consider a collective enhancement and its fade out.

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“…to describe the elastic scattering of the incident particle by ground-state nuclei. The transmission coefBcients that result include, in a natural way, shape resonances, peripheral absorption, as well as transparency effects [8,9]. On the contrary, the ingoing-wave boundarycondition model (IWBCM) [10] uses only a real potential to describe the transmission probability of particles.…”

Section: Introductionmentioning

confidence: 99%

Ingoing-wave boundary condition versus optical model transmission coefficients: A systematic comparison with particle emission data

Kildir

Moro

et al. 1995

Phys. Rev. C

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Evaporative' ' H and He yields and energy spectra have been analyzed in the framework of the statistical model in ten heavy-ion reactions, spanning composite systems with 20 & Z & 56. Transmission coefficients derived from the ingoing-wave boundary condition (IWBCM) or optical models (OM) have been used in the calculations. The effect of using different values of deformation parameters, level-density parameter a, and radii of the real part of the transmission coefficient potentials has been investigated. Except for the low-energy side of the proton spectra, the shape of energy spectra are reasonably well reproduced by both sets of transmission coefficients. While the two models are essentially equivalent for H and He cross sections, they differ significantly in the prediction of H and H cross sections. OM transmission coefficients fail in reproducing ' H cross sections, unless no standard parameters are used, while IWBCM transmission coefficients provide a good overall agreement. The failure of the OM is ascribed to the inclusion of nonfusion reactions in the inverse process. PACS number(s): 25.70.Gh, 25.70.Jj

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Inverse reactions and the statistical evaporation model: Ingoing-wave boundary-condition and optical models

Cited by 31 publications

References 30 publications

H1,2,3,
Kildir
¹
,
Rana
²
,
Moro
³

et al. 1992
Phys. Rev. C

H1,2,3,
Kildir
¹
,
Rana
²
,
Moro
³

et al. 1992
Phys. Rev. C

Search for the fade out of a collective enhancement of the nuclear level density

Ingoing-wave boundary condition versus optical model transmission coefficients: A systematic comparison with particle emission data

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Inverse reactions and the statistical evaporation model: Ingoing-wave boundary-condition and optical models

Cited by 31 publications

References 30 publications

H1,2,3,Kildir1, Rana2, Moro3 et al. 1992Phys. Rev. C

H1,2,3,Kildir1, Rana2, Moro3 et al. 1992Phys. Rev. C

Search for the fade out of a collective enhancement of the nuclear level density

Ingoing-wave boundary condition versus optical model transmission coefficients: A systematic comparison with particle emission data

Contact Info

Product

Resources

About

H1,2,3,
Kildir
¹
,
Rana
²
,
Moro
³

et al. 1992
Phys. Rev. C

H1,2,3,
Kildir
¹
,
Rana
²
,
Moro
³

et al. 1992
Phys. Rev. C