Direct and non-direct contributions to projectile fragmentation at 20 MeV/nucleon

doi:10.1016/0370-2693(81)90978-3

Physics Letters B

Volume 98, Issue 3, 8 January 1981, Pages 162-165

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Abstract

The spectrum of projectile-like fragments in the scattering of ¹⁶O on ²⁰⁸Pb at 315 MeV is analyzed in terms of direct and non-direct contributions. The direct contribution comes from a one-step breakup process whereas the non-direct contributions consist of two terms: inelastic scattering following breakup and complex multi-step processes.

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Cited by (14)

Contributions of complete fusion and break-up-fusion to intermediate mass fragment production in the low energy interaction of 12C and 27Al
2007, Nuclear Physics A
The measured spectra of a large number of intermediate mass fragments produced at a CM energy of about 110 MeV in the ²⁷Al(¹²C, x) reaction as well as in its inverse reaction, ¹²C(²⁷Al, x), are presented. The analysis of these data suggests that, at this energy, the main reaction mechanisms which contribute to the intermediate mass fragment emission are two-nucleus complete fusion and break-up–fusion reactions.
Interplay of mean field and nucleon-nucleon interactions in the production of carbon fragments in 16O induced reactions at incident energies up to 25 MeV/amu
2002, Nuclear Physics A
Two different reaction mechanisms (which both occur at very short interaction times) contribute to the emission of intermediate mass fragments in reactions induced by a light nucleus such as ¹⁶O. They are the binary fragmentation of the projectile and the coalescence of nucleons during the course of the nucleon–nucleon interaction cascade which starts as soon as the two ions (or part of them) come into contact. These two mechanisms are easily distinguished from each other because their contributions to measured emission spectra have different energy dependence, the first peaking at an energy not far from that corresponding to the beam velocity, the other to a much smaller energy about equal to the Coulomb barrier between the observed fragment and an heavy residue with mass and charge near to those of the target nucleus. These features are clearly observed in the spectra of carbon fragments produced in the interaction of ¹⁶O ions with ⁵⁹Co and ⁹³Nb at incident energies between 100 and 400 MeV. In this paper we discuss these reaction mechanisms and suggest a theoretical interpretation which satisfactorily reproduces the experimental results.
A distorted-wave Born-approximation theory of heavy-ion-induced projectile breakup reactions
1985, Annals of Physics
A distorted-wave Born-approximation (DWBA) formalism is developed to describe the “elastic” and “inelastic” breakup of the projectile in the heavy-ion-induced reasctions. Using a “local momentum approximation” and the surface localization property of these reactions expressions for the DWBA transition amplitude are derived. One of the attractive features of the present formulation is the fact that the radial integrals involved in it are the same as those contained in the transition amplitude evaluated with a zero range approximation. The validity of the approximations used in these derivations has been tested and it is shown that these approximations are well fulfilled.
Incomplete deep-inelastic heavy-ion collisions
1985, Nuclear Physics, Section A
A phenomenological two-step reaction model is proposed, in which a direct projectile fragmentation in the initial stage is succeeded by a binary dissipative interaction between the heavy projectile fragment and the target in the final state. Multi-differential cross sections are estimated by folding the fragmentation cross section given in the local plane-wave Born approximation with the cross section for deep-inelastic collisions calculated within the classical friction model, including statistical fluctuations and mass transfer. For forward angles satisfactory results are obtained in comparison with the experimental data on inclusive spectra, angular distributions, angular correlations, γ-multipliciites, and element distributions in ²⁰Ne-induced reactions for bombarding energies of 10–20 MeV/nucleon.
Search for incomplete deep inelastic collision
1988, Nuclear Physics, Section A
The relevance of a reaction mechanism involving projectile break-up or fragmentation followed by a dissipative interaction of one of the remnants with the target is discussed. This type of reaction mechanism is commonly refered to as incomplete deep inelastic collisions (INDIC). Details of an experimental study of the system ²⁰Ne + ²⁷Al at 10.8 MeV/u are given. In this study light particle detectors were fixed at forward angles and the complete distribution of the associated projectile-like fragments were measured. As INDIC with neon projectiles are expected to occur via break-up into Oxygen and an α-particle, reactions involving the emission of a fast α-particle in coincidence with a deep inelastic projectile-like fragment provide an estimate for the cross section for INDIC. From this measurement an upper limit of 100 mb is estimated.
Direct and dissipative modes in heavy-ion reactions: Incomplete deep inelastic collisions
1982, Physics Letters B

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^☆: Supported in part by the Tinker Foundation, the US-NSF, the CNPq-Brazil, FAPESP-Brazil.

¹: On leave from the University of São Paulo, Brazil.

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Physics Letters B

Abstract

References (9)

Phys. Rep.

Phys. Rev. Lett.

MSUCL Report

Cited by (14)

Contributions of complete fusion and break-up-fusion to intermediate mass fragment production in the low energy interaction of <sup>12</sup>C and <sup>27</sup>Al

Interplay of mean field and nucleon-nucleon interactions in the production of carbon fragments in <sup>16</sup>O induced reactions at incident energies up to 25 MeV/amu

A distorted-wave Born-approximation theory of heavy-ion-induced projectile breakup reactions

Incomplete deep-inelastic heavy-ion collisions

Search for incomplete deep inelastic collision

Direct and dissipative modes in heavy-ion reactions: Incomplete deep inelastic collisions

Direct and non-direct contributions to projectile fragmentation at 20 MeV/nucleon☆

Abstract

Phys. Rep.

Phys. Rev. Lett.

MSUCL Report