Showing papers by "A. Bracco published in 1992"
TL;DR: In this paper, the authors studied the properties of the isoscalar monopole resonance in 208 Pb, within the framework of a self-consistent model employing a Skyrme force.
57 citations
TL;DR: A statistical method to analyze the gamma decay of excited, rapidly rotating nuclei is presented, based on the fact that the cooling path of these systems goes through regions of both suppressed and enhanced fluctuations typical of large and low level density.
Abstract: A statistical method to analyze the gamma decay of excited, rapidly rotating nuclei is presented It is based on the fact that the cooling path of these systems goes through regions of both suppressed and enhanced fluctuations typical of large and low level density, respectively The method is applied to the study of the high-spin quasicontinuum of $^{167,168}\mathrm{Yb}$
43 citations
TL;DR: A comparison between the predictions of a theoretical model describing the giant dipole resonance in hot nuclei and experimental data on the cross section and the angular distribution associated with the dipole decay of {sup 92}Mo{sup *} is presented.
Abstract: A comparison between the predictions of a theoretical model describing the giant dipole resonance in hot nuclei, which includes the coupling to time-dependent thermal fluctuations of the nuclear surface, and experimental data on the cross section and the angular distribution associated with the dipole decay of {sup 92}Mo{sup *} is presented. Effects of different time scales for fluctuuations in the deformation and orientation degrees of freedom are observed.
26 citations
TL;DR: In this article, a consistent picture of the giant dipole resonance in hot nuclei is presented, in terms of general arguments of sum rules, and of the interplay with the fluctuations of the nuclear surface.
16 citations
TL;DR: The angular distribution of high energy gamma rays emitted in the decay of the giant dipole resonance built on excited states, in mainly 162Yb, has been measured using a differential technique to enhance decays originating from the highest region of nuclear temperatures.
9 citations
TL;DR: The angular distribution of high energy gamma rays emitted in the decay of the giant dipole resonance from hot rotating atomic nuclei of 109,110Sn has been determined as a function of the angular momentum of the compound nucleus as mentioned in this paper.
8 citations
TL;DR: Axial and planar blocking patterns in thin Si single crystals have been measured for the products of the reaction {sup 28}Si(150 MeV)+{sup 28]Si at {theta}{sub {ital L}}=15{degree} and 12{degree}.
Abstract: Axial and planar blocking patterns in thin Si single crystals have been measured for the products of the reaction {sup 28}Si(150 MeV)+{sup 28}Si at {theta}{sub {ital L}}=15{degree} and 12{degree}. Reaction times of the order 10{sup {minus}18--}10{sup {minus}17} s have been observed for fusion-evaporation and fusion-fission processes.
4 citations
TL;DR: In this paper, the average shapes and fluctuations of the shapes of excited nuclei from studies of the angular distribution of the high energy gamma rays emitted when giant dipole Resonances in nuclei with large thermal energy decay are discussed.
4 citations
1 citations
10 May 1992-Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment
TL;DR: In this paper, the energy resolution of a high purity Ge detector with an efficiency of 70% was measured after it was exposed to increasing integrated fluxes of fast neutrons, produced by the reaction p+natCu → Zn+n at an incident laboratory energy of 6 MeV.
Abstract: The energy resolution of a high purity Ge detector with an efficiency of 70% was measured after it was exposed to increasing integrated fluxes of fast neutrons. The latter were produced by the reaction p+natCu → Zn+n at an incident laboratory energy of 6 MeV. The energy resolution was found to be increased by ∼ 30% after irradiation by an integrated flux of 3 × 109 neutrons/cm2.
05 Jul 1992
TL;DR: In this paper, the properties of the isoscalar giant monopole resonance in 208Pb at zero temperature are studied in a self-consistent model which employs a Skyrme-type force and compared with experimental data.
Abstract: In the first part of this contribution, the properties of the isoscalar giant monopole resonance in 208Pb at zero temperature are studied in a self‐consistent model which employs a Skyrme‐type force and compared with experimental data. The coupling with the continuum is taken into account, as well as the coupling to two‐particle—two‐hole (2p‐2h) configurations containing a collective vibration. We extract the strength function of the mode and the branching ratios for the direct decay by neutron emission.In the second part, the experimental evidence testifying to the existence of a limiting temperature for the observation of gamma decay from the giant dipole resonance in hot nuclei is interpreted as indicating a remarkable constancy with temperature of the width with which the giant resonance couples to the compound nucleus.