STRONG ABSORPTION ANALYSIS OF ELASTIC SCATTERING REACTIONS USING McINTYRE AND FRAHN–VENTER MODELS

Abstract

The Frahn–Venter and McIntyre models are employed to analyze the experimental data of a set of elastic scattering reactions for heavy ions. The existence of semi-classical phenomena such as Fresnel and Fraunhofer diffraction patterns has been obtained by analyzing the experimental data of a set of elastic scattering reactions 12 C + 28 Si at laboratory energies 24.0, 49.3, 70.0, 83.5, and 186.4 MeV, 16 O + 28 Si at laboratory energies 72.0, 141.5, and 215.0 MeV, 16 O + 16 O at laboratory energies 145.0 and 350.0 MeV, 16 O + 12 C at laboratory energies 128.0 and 168.0 MeV; 12 C + 12 C at laboratory energies 89.7, 93.8, 105.0, 112.0, 117.1, 121.6, 126.7, and 158.8 MeV. The theoretical models can reasonably reproduce the general pattern of the data, thus allowing us to extract important parameters from elastic scattering processes. Deviations of some reproduced results from experimental data may be attributed to weak absorption. It is found that interpretation of the diffraction features of the data is model-independent. The values of extracted parameters, from both models, are found comparable to each other and to those of others. The correlation between the total reaction cross-section and the incident laboratory energy for each scattering is discernible and comparable with those of others.

An Analysis of Heavy-Ion Elastic Scattering Processes Using Numerical Model Based on the Partial Wave Parameterised S-Matrix with Regge Pole Factor

“…The value of the total reaction cross section obtained for 8 He + 208 Pb system is larger than that of 6 He + 208 Pb and 4 He + 208 Pb. This is again attributed to nuclear halo properties, The value of θ Νucl is obtained when λ = Λ is substituted into the formula of θ Ν (λ) [17] as mentioned earlier in Subsection 3.1. Here, our values of the interaction radii, as obtained from Eq.…”

“…In particular, the nuclear scattering amplitude depends on the function F[(Δ(θ R − θ)], namely [17]:…”

“…However, the far-side branch of the scattering amplitude in a region called the shadow region (at θ ≥ θ R ) is purely diffractive and is represented by the nuclear part only. The Fraunhofer diffraction nature of the scattering is embodied by the nuclear part only [1,[17][18][19]. Thus, the interference between these two components may result in Fresnel oscillation pattern.…”

“…This analysis will also allow the determination of several useful parameters and physical quantities, such as the grazing angular momentum Λ, the width of the ℓ-space window that contributes to elastic scattering, Δ, the nuclear phase shift, μ, the total reaction cross section σ r , etc. [17][18][19][20][21]. For an attempt to improve the fits and search for possibly existing Regge poles, which may be responsible for structures in the angular distribution, especially at backward angles, the numerical combined model will be employed using seven adjustable parameters (three SAM plus four Regge pole parameters) [17,31].…”

“…[17][18][19][20][21]. For an attempt to improve the fits and search for possibly existing Regge poles, which may be responsible for structures in the angular distribution, especially at backward angles, the numerical combined model will be employed using seven adjustable parameters (three SAM plus four Regge pole parameters) [17,31]. The theoretical elastic angular distributions in collisions of different isotopes with the same target and the same laboratory energy are obtained for a full range of centre of mass angles (0-180°), using the combined model.…”