Isomer production studied with simultaneous decay curve analysis for alpha-particle induced reactions on natural platinum up to 29 MeV

Abstract

The isomeric ratios of ${}^{198}$Au, ${}^{197}$Hg and ${}^{195}$Hg produced by $\alpha$-particle induced reactions on natural platinum were investigated experimentally up to 29 MeV by using the standard stacked foil activation technique and $\gamma$-ray spectrometry. The isomeric ratios of ${}^{197}$Hg and ${}^{195}$Hg determined by the conventional activation cross section formula showed strong cooling time dependence. The time dependence was resolved by adjusting the isomeric transition branching ratios for the two isotopes within a simultaneous decay curve analysis framework. Our analysis suggests 94.5$\pm$0.7% and 48.9$\pm$1.8% as the isomeric transition branching ratios of ${}^{197m}$Hg (24 h) and ${}^{195m}$Hg (42 h), respectively. The isomeric ratios and independent production cross sections of ${}^{198}$Au, ${}^{197}$Hg, ${}^{195}$Hg and some other Hg, Au and Pt isotopes were also measured down to 6 MeV with these corrected isomeric transition branching ratios, and compared with predictions of statistical and pre-equilibrium models by TALYS-2.0 to discuss spin cuto? parameter dependence. We found the measured isomeric ratios are better predicted if we reduce the spin cuto? parameter to half or less from that estimated with the rigid body moment of inertia.

arXiv commentSubmitted to European Physical Journal A

References in corpus (5)

• Towards a More Complete and Accurate Experimental Nuclear Reaction Data Library (EXFOR): International Collaboration Between Nuclear Reaction Data Centres (NRDC)
• Spallation reactions. A successful interplay between modeling and applications
• Cross sections for nuclide production in 1 GeV proton-irradiated 208-Pb
• Mass number and excitation energy dependence of the ${\Theta }_{eff}/{\Theta }_{rig}$ parameter of the spin cut-off factor in the formation of an isomeric pair
• Compilation of isomeric ratios of light particle induced nuclear reactions

Cited by in corpus (2)

• Energy dependence of isomeric ratios for alpha-particle-induced reactions on natural platinum up to 50 MeV studied by simultaneous decay curve analysis
• Influence of secondary neutrons on alpha-particle induced reaction cross section measurement below the Coulomb barrier