Showing papers by "Carlos A. Bertulani published in 1992"
TL;DR: In this article, a fragment separator was used as an energy-loss spectrometer to make the first measurements of the parallel momentum distributions of the nuclei produced in the breakup of a projectile.
Abstract: A new method, use of a fragment separator as an energy-loss spectrometer, has been developed and used to make the first measurements of the parallel momentum distributions of $^{9}\mathrm{Li}$ nuclei produced in the breakup of $^{11}\mathrm{Li}$ Measurements were made for 66-MeV/nucleon $^{11}\mathrm{Li}$ projectiles on $^{9}\mathrm{Be}$, $^{93}\mathrm{Nb}$, and $^{181}\mathrm{Ta}$ targets Distributions with Gaussian width of ${\mathrm{\ensuremath{\sigma}}}_{\mathrm{\ensuremath{\parallel}}}$\ensuremath{\approxeq}19 MeV/c were observed for all targets---the first time such a narrow structure has been observed for medium and high mass targets From the weak dependence of width on breakup target it appears that the paralell momentum distributions are relatively insensitive to the interaction governing the breakup and reflect an extended neutron distribution for $^{11}\mathrm{Li}$
105 citations
TL;DR: In this article, the Coulomb break-up probability of loosely bound nuclei is calculated using a coupled-channels method, and it is shown that a non-perturbative calculation may reduce the cross section by 20% in collisions at intermediate energies.
51 citations
TL;DR: It is shown that the width of the narrow peak of the longitudinal momentum distribution is insensitive to the details of the collision and the size of the target nucleus, and so makes the transverse distribution less reliable than the longitudinal one for measuring thesize of the original neutron halo.
Abstract: We investigate the longitudinal and transverse momentum distributions of charged fragments originating from reactions with radioactive, neutron-rich beams. It is shown that the width of the narrow peak of the longitudinal momentum distribution is insensitive to the details of the collision and the size of the target nucleus. In contrast, the width of the peripheral region from which transversely moving particles originate is significantly narrowed via absorption of the outgoing neutrons. This diffractively broadens the width of their transverse momentum distribution, in a manner which depends on details of the collision, and so makes the transverse distribution less reliable than the longitudinal one for measuring the size of the original neutron halo.
45 citations
TL;DR: In this article, the effects of higher-order electromagnetic interactions in the dissociation of fast particles, especially 11Li, were studied using a classical approach, where a "breakup radius" is introduced.
43 citations
TL;DR: It is shown that, even in the most favorable cases, electric dipole excitations are by far more dominant and the contributions from higher order multipolarities will be less than the presently attainable experimental uncertainties.
Abstract: We investigate the electric multipole response of {sup 11}Li which could be tested in reactions with secondary beams at intermediate and high energies. We use simple arguments to show that, even in the most favorable cases, electric dipole excitations are by far more dominant. The contributions from higher order multipolarities will be less than the presently attainable experimental uncertainties.
23 citations
TL;DR: The cross section for the elastic scattering of {alpha} particles from {sup 11}Li at {ital E}{sub lab}=26 MeV/nucleon is calculated and it is found that the angular distribution is farside dominated.
Abstract: The cross section for the elastic scattering of {alpha} particles from {sup 11}Li at {ital E}{sub lab}=26 MeV/nucleon is calculated. The single-folding potential plus second-order rescattering correction is used as an optical potential. It is found that the angular distribution is farside dominated. The second-order correction, which contains the short-range correlation effects, merely adds to absorption. Comparison to the {alpha}+{sup 12}C system is made.
6 citations
TL;DR: In-plane angular correlations were measured for the 27Al, 28Si (16,18O, C-α) reactions at E/A=4.0, 3.5 and 3.0 MeV.
3 citations
TL;DR: A separable approximation proposed in a previous paper is applied to the reaction {sup 16}O+{sup 28}Si+{r arrow}{alpha}+ {sup 12}C+{Sup 28]Si, and the results are shown to agree with the experimental data.
Abstract: We investigate the breakup process in light heavy ion reactions. With the help of a separable approximation proposed in a previous paper and using closed forms for radial integrals, we obtain simple expressions for the breakup cross section. The theory is applied to the reaction {sup 16}O+{sup 28}Si{r arrow}{alpha}+{sup 12}C+{sup 28}Si, and the results are shown to agree with the experimental data.
3 citations