Level densities and $\gamma$-ray strength functions in ${}^{170,171,172}$Yb

Abstract

Level densities and radiative strength functions in ${}^{171}$Yb and ${}^{170}$Yb nuclei have been measured using the ${}^{171}$Yb(${}^3$He,${}^3$He${}^{\prime }\gamma$)${}^{171}$Yb and ${}^{171}$Yb(${}^3$He,$\alpha \gamma$)${}^{170}$Yb reactions. New data on ${}^{171}$Yb are compared to a previous measurement for ${}^{171}$Yb from the ${}^{172}$Yb(${}^3$He,$\alpha \gamma$)${}^{171}$Yb reaction. Systematics of level densities and radiative strength functions in ${}^{170,171,172}$Yb are established. The entropy excess in ${}^{171}$Yb relative to the even-even nuclei ${}^{170,172}$Yb due to the unpaired neutron quasiparticle is found to be approximately 2$k_B$. Results for the radiative strength function from the two reactions lead to consistent parameters characterizing the ``pygmy'' resonances. Pygmy resonances in the ${}^{170,172}$Yb populated by the (${}^3$He,$\alpha$) reaction appear to be split into two components for both of which a complete set of resonance parameters are obtained.

8 pages, 7 figures

References in corpus (10)

• Extraction of level density and gamma strength function from primary gamma spectra
• Critical temperature for quenching of pair correlations
• Odd-even staggering of binding energies as a consequence of pairing and mean-field effects
• Gamma-ray strength function and pygmy resonance in rare earth nuclei
• Thermal properties and radiative strengths in 160,161,162Dy
• Entropy of thermal quasiparticles in nuclei
• Free energy and criticality in the nucleon pair breaking process
• Evolution of level density step structures from 56,57-Fe to 96,97-Mo
• Level density and gamma strength function in 162-Dy from inelastic 3-He scattering
• Level density and $\gamma$-ray strength in ${}^{27,28}$Si

Cited by in corpus (20)

• Analysis of possible systematic errors in the Oslo method
• Radiative strength functions in 93-98Mo
• Level densities and thermodynamical quantities of heated 93-98Mo isotopes
• Nuclear level densities and gamma-ray strength functions in 44,45Sc
• Transitional $\gamma$ strength in Cd isotopes
• First observation of low-energy γ-ray enhancement in the rare-earth region
• Consolidating the concept of low-energy magnetic dipole decay radiation
• Pairing phase transition: A Finite-Temperature Relativistic Hartree-Fock-Bogoliubov study
• Evidence for the pair-breaking process in 116,117Sn
• Influence of complete energy sorting on the characteristics of the odd-even effect in fission-fragment element distributions
• The energy response of the Oslo Scintillator Array OSCAR
• Establishment of M1 multipolarity of a 6.5 mu_N^2 resonance in 172-Yb at E_gamma=3.3 MeV
• Nuclear Level Density and Gamma-Ray Strength Function of 43Sc
• Observation of a first-order pairing phase transition in atomic nuclei
• Experimental signature of collective enhancement in nuclear level density
• Calculation of microscopic nuclear level densities based on covariant density functional theory
• Statistical properties of the well deformed ${}^{153,155}$Sm nuclei and the scissors resonance
• Microscopic model for the collective enhancement of nuclear level densities
• Experimentally constrained ${}^{165,166}\text{Ho}(n,\gamma )$ rates and implications for the $s$ process
• Inference of Parameters for Back-shifted Fermi Gas Model using Feedback Neural Network