scholarly journals γ-ray strength function for astrophysical applications in the IAEA-CRP

2020 ◽  
Vol 239 ◽  
pp. 07005
Author(s):  
Hiroaki Utsunomiya ◽  
Stephane Goriely ◽  
Therese Renstrøm ◽  
Gry M. Tveten ◽  
Takashi Ari-izumi ◽  
...  

The γ-ray strength function (γSF) is a nuclear quantity that governs photoabsorption in (γ, n) and photoemission in (n, γ) reactions. Within the framework of the γ-ray strength function method, we use (γ, n) cross sections as experimental constraints on the γSF from the Hartree-Fock-Bogolyubov plus quasiparticle-random phase approximation based on the Gogny D1M interaction for E1 and M1 components. The experimentally constrained γSF is further supplemented with the zero-limit M1 and E1 strengths to construct the downward γSF with which (n, γ) cross sections are calculated. We investigate (n, γ) cross sections in the context of astrophysical applications over the nickel and barium isotopic chains along the s-process path.

2011 ◽  
Vol 20 (10) ◽  
pp. 2143-2151 ◽  
Author(s):  
ESRA YUKSEL ◽  
KUTSAL BOZKURT

We investigate tensor effects in pygmy dipole excitations for the case of neutron-rich nuclei 68 Ni and 124 Sn using effective nucleon–nucleon Skyrme interaction. We use the Hartree–Fock–Bogoliubov (HFB) theory and employ the quasiparticle random phase approximation (QRPA). We calculate and compare the PDR and also GDR strength in the PDR–GDR energy region for QRPA calculations with and without tensor correlations. The most obvious results for the dipole excitations calculations are strongly dependent on the tensor terms. We see that the tensor correlations are more active at around 14–20 MeV , especially for the neutron-rich nuclei 68 Ni . We also compare the PDR calculations with their experimental results for the different proton–neutron tensor coupling constants.


2002 ◽  
Vol 09 (02) ◽  
pp. 1155-1160 ◽  
Author(s):  
M. YA. AMUSIA ◽  
L. V. CHERNYSHEVA ◽  
Z. FELFLI ◽  
A. Z. MSEZANE

Compton ionization of krypton and xenon outer and intermediate subshells is investigated. Results are presented covering the energy transferred to the atoms from their ionization thresholds up to 30 Ry and momentum transferred up to 4 a.u. Calculations are performed in the one-electron Hartree–Fock approximation and with many-electron effects taken into account in the random phase approximation with exchange. It is demonstrated that many-electron correlations play an important role not only in dipole but also in monopole and quadrupole transitions, significantly modifying the cross sections as well as leading to new maxima and minima.


2010 ◽  
Vol 81 (2) ◽  
Author(s):  
Myung-Ki Cheoun ◽  
Eunja Ha ◽  
Su Youn Lee ◽  
K. S. Kim ◽  
W. Y. So ◽  
...  

1995 ◽  
Vol 09 (28) ◽  
pp. 3725-3733
Author(s):  
NGUYEN HONG QUANG ◽  
NGUYEN MINH KHUE

The dynamical aspects of the phonoriton state in highly-photoexcited semiconductors is studied theoretically. The effect of the exciton–exciton interaction and nonbosonic character of high-density excitons are taken into account. Using Green's function method and within the Random Phase Approximation it is shown that the phonoriton dispersion and damping are very sensitive to the exciton density, characterizing the excitation degree of semiconductors.


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