Gamma-ray strength functions and their relation to astrophysics
3rd International Conference on Frontiers in Nuclear Structure, Astrophysics and Reactions (FINUSTAR), Rhodes, Yunanistan, 23 - 27 Ağustos 2010, cilt.1377, ss.239-246, (Tam Metin Bildiri)
- Yayın Türü: Bildiri / Tam Metin Bildiri
- Cilt numarası: 1377
- Doi Numarası: 10.1063/1.3628386
- Basıldığı Şehir: Rhodes
- Basıldığı Ülke: Yunanistan
- Sayfa Sayıları: ss.239-246
- Eskişehir Osmangazi Üniversitesi Adresli: Evet
Özet
The nuclear gamma-ray strength function is one of the indispensable inputs needed for reaction-rate calculations, and is particularly important for the neutron-capture cross section. The nuclear physics group at the Oslo Cyclotron Laboratory has developed a method to extract simultaneously nuclear level density and gamma-ray strength function from particle-gamma coincidence measurements. Data on the strength functions of Sn nuclei as well as for lighter elements are presented. The Sn isotopes all display a resonance-like structure close to the neutron threshold, that could possibly be due to the neutron-skin oscillation mode. This so-called pygmy dipole resonance greatly influences the neutron-capture rates. In the lighter nuclei, an enhancement of the strength function at low gamma energies is observed. The possible impact of this increase on Maxwellian-averaged reaction rates has been investigated.