UNIVERSITY OF BUCHAREST
FACULTY OF PHYSICS

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Conference: Bucharest University Faculty of Physics 2016 Meeting


Section: Nuclear and Elementary Particles Physics


Title:
Isomeric states in photoneutron reactions on natural Sn


Authors:
C. OPREA, A. OPREA


Affiliation:
FLNP, Joint Institute for Nuclear Research, Dubna 141980, RF


E-mail
coprea2005@yahoo.co.uk


Keywords:
photo-neutron reactions, cross section, Sn, compound mechanism, isomer ratio


Abstract:
In this study the photoneutron reactions on Sn nucleus which has ten natural isotopes were analyzed. For all isotopes the (gamma,xn) cross section (x=1,2,3,4) and the isomeric ratio in the (gamma,n) reaction for incident photons energy from the neutron threshold (8-9 MeV) up to 36 MeV were evaluated. Also an analysis of the contribution of compound, direct and preequlibrium processes to the cross section as well as of discrete and continuum states was accomplished. Cross sections and isomeric ratios evaluations are compared with experimental data from literature. This theoretical evaluation of cross sections is in a very good agreement with experimental data. For many isotopes of Sn the isomeric ratios in (gamma,n) reactions were not measured in the experiment in the Great Dipole Resonance (GDR) region. Because the cross sections are known from Talys it is possible to estimate the isomeric ratio in the GDR region starting from the threshold up to some maximal energy determined by the Brehmsstrahlung X-ray source.


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Acknowledgement:
This reasearch was supported by the Program of Cooperation between JINR and Romanian Universities leaded by Romanian Plenipotentiary Representative to JINR Dubna.