Activation Measurements of Cross Sections for Ground and Isomeric States Production in Neutron Threshold Reactions on Y and Au

Abstract

The paper describes cross-section measurements consisting of neutron activation using a ⁷Li(p,n) quasi mono-energetic neutron source and gamma-ray spectrometry performed at the Nuclear Physics Institute of the Czech Academy of Sciences in Řež, Czech Republic. The analysis of the excitation functions of neutron-induced threshold reactions for the energy range from 17 up to 34 MeV is presented. The cross sections for the population of both ground and isomeric states were measured in yttrium and gold. A comprehensive comparison of the measured cross sections with earlier experimental data from the EXFOR database, TALYS calculations, and evaluated nuclear data libraries is presented.

Keywords:

• Neutron
• (n,xn) reactions
• cross section

Acknowledgments

We would like to thank the cyclotron staff at the NPI for excellent services and beam quality. This work was supported by the ERINDA program. The research has been conducted at the Center of Accelerators and Nuclear Analytical Methods (LM2011019) infrastructure with funding from the Ministry of Education, Youth and Sports of the Czech Republic.

Notes

^a The level corresponding to the second isomer is 596 keV with a rather high spin and M4 multipolarity of the gamma-ray emission.²² The levels of Au are known up to about 1700 keV, however, none of them has such a high spin that could feed this level. Apparently, a much higher level must be responsible for that, perhaps rotational structures.