Strong coupled-channel effects in the barrier distributions of 16,18O+58Ni

Simões, R. F.; Monteiro, D. S.; Ono, Luis K.; Jacob, Alexsandro Machado; Shorto, J. M. B.; Added, N.; Crema, Eduardo

doi:10.1016/s0370-2693(02)01171-1

Cited by 31 publications

(61 citation statements)

References 27 publications

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“…The sensitivity of the representation D qel (E) to the fusion barrier distribution at energies below the average fusion barrier has been confirmed by experiments for a variety of systems with widely different fusion dynamics and coupling interactions [9,10,11,12,13,14,15]. It has, however, also become clear that at energies above the average fusion barrier the representation D qel (E) rapidly looses this sensitivity with increasing energy.…”

Section: Alternative Representations Of the Fusion Barrier Distrimentioning

confidence: 79%

Probing fusion dynamics with scattering experiments

Timmers

2003

Braz. J. Phys.

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The fusion of heavy nuclei at energies spanning the Coulomb barrier involves the coupling of their relative motion to the internal degrees of freedom of the binary system formed by them. The fusion process is thus a realisation of the fundamental problem of surmounting a potential barrier in an environment of many other degrees of freedom. In the nuclear binary system the number, strength, and nature of the coupling interactions can be widely varied by selecting specific projectile-target combinations. Strong coupling interactions result in a distribution of fusion barriers. These strong couplings can often be clearly identified by extracting representations of this fusion barrier distribution from precision measurements of the excitation function. Alternative representations of the fusion barrier distribution can be obtained from scattering experiments, which generally involve less experimental effort. Since they are not sensitive to the fusion barrier distribution at energies above the average fusion barrier, these alternative representations can only reveal coupling interactions with signatures in the low energy part of the distribution, such as coupling to positive Q-value neutron transfer channels.

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Section: Alternative Representations Of the Fusion Barrier Distrimentioning

confidence: 79%

Probing fusion dynamics with scattering experiments

Timmers

2003

Braz. J. Phys.

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“…As mentioned before, all calculations were performed using the average nuclear matter diffuseness (a = 0.56 fm) obtained from a large systematic that successfully described reaction mechanisms of hundreds of different systems [11]. Nevertheless, there are experimental indications that the 18 O nucleus presents a larger nuclear matter diffuseness (a = 0.60 fm) compared to this systematic value, whereas 16 O follows this systematic [5]. So, it is reasonable to suspect that 17 O also has a large diffuseness, because its unpaired neutron is relatively weakly bound in the double-closed shell core, extending the nuclear matter far from the core.…”

Section: Derivation Of the Nuclear Matter Diffuseness Of The 17 Omentioning

confidence: 99%

“…It is already well established that heavy ion fusion can be investigated by the measurement of its complementary process, the so-called quasi-elastic scattering (QES), at backward angles [1][2][3][4][5]. At energies near the Coulomb barrier, QES is defined as the sum of elastic scattering, inelastic scattering, and all other direct transfer reactions.…”

Section: Introductionmentioning

confidence: 99%

“…Quasi-elastic barrier distributions (QEBDs) are obtained from the first derivative of the ratio of the quasi-elastic differential cross section, dσ qel , to the Rutherford differential cross section, dσ Ruth , with respect to energy, −d(σ qel /σ Ruth )/dE [3]. It has been shown [3][4][5] that QEBD and FBD are similar at energies around the Coulomb barrier for tightly bound systems.…”

Section: Introductionmentioning

confidence: 99%

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Quasi-elastic barrier distribution of theO17 +
Huiza
¹
,
Crema
²
,
Barioni
³

et al. 2010
Phys. Rev. C
17
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14
0
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The quasi-elastic excitation function for the 17 O + 64 Zn system was measured at energies near and below the Coulomb barrier, at the backward angle θ lab = 161 • . The corresponding quasi-elastic barrier distribution was derived. The excitation function for the neutron stripping reactions was also measured, at the same angle and energies, and the experimental values of the spectroscopic factors were deduced by fitting the data. A reasonably good agreement was obtained between the experimental quasi-elastic barrier distribution with the coupled-channel calculations including a very large number of channels. Of the channels investigated, three dominated the coupling matrix: two inelastic channels, 64 Zn(2 + 1 ) and 17 O(1/2 + ), and one-neutron transfer channel, particularly the first one. On the other hand, a very good agreement is obtained when we use a nuclear diffuseness for the 17 O nucleus larger than the one for 16 O. We verify that quasi-elastic barrier distribution is a sensitive tool for determining nuclear matter diffuseness.

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“…Quasielastic barrier distributions [1][2][3] are obtained by differentiation of the high precision quasielastic excitation function in respect to the energy. Quasielastic processes include elastic and inelastic scattering and transfer channels.…”

Section: Quasielastic Excitacion Function and Quasielastic Barrier DImentioning

confidence: 99%