Nuclear level densities and $\gamma$-ray strength functions of ${}^{87}\mathrm{Kr}$ -- First application of the Oslo Method in inverse kinematics

Abstract

The $\gamma$-ray strength function ($\gamma$SF) and nuclear level density (NLD) have been extracted for the first time from inverse kinematic reactions with the Oslo Method. This novel technique allows measurements of these properties across a wide range of previously inaccessible nuclei. Proton-$\gamma$ coincidence events from the $\mathrm{d}{(}^{86}\mathrm{Kr},\mathrm{p}\gamma {)}^{87}\mathrm{Kr}$ reaction were measured at iThemba LABS and the $\gamma$SF and NLD in ${}^{87}\mathrm{Kr}$ obtained. The low-energy region of the $\gamma$SF is compared to Shell Model calculations which suggest this region to be dominated by M1 strength. The $\gamma$SF and NLD are used as input parameters to Hauser-Feshbach calculations to constrain $(\mathrm{n},\gamma )$ cross sections of nuclei using the TALYS reaction code. These results are compared to ${}^{86}\mathrm{Kr}(n,\gamma )$ data from direct measurements.

arXiv commentSubmitted to EpJ A Letters

References in corpus (24)

• The Shell Model as Unified View of Nuclear Structure
• The r-process of stellar nucleosynthesis: Astrophysics and nuclear physics achievements and mysteries
• Nuclear Level Density and the Determination of Thermonuclear Rates for Astrophysics
• Microscopic HFB+QRPA predictions of dipole strength for astrophysics applications
• Extraction of level density and gamma strength function from primary gamma spectra
• Reference Database for Photon Strength Functions
• Analysis of possible systematic errors in the Oslo method
• Novel technique for constraining r-process (n,$\gamma$) reaction rates
• Radiative strength functions in 93-98Mo
• Low-energy enhancement of magnetic dipole radiation
• Impact of a low-energy enhancement in the gamma-ray strength function on the radiative neutron-capture
• Gamma-ray strength function and pygmy resonance in rare earth nuclei
• Evidence for dipole nature of the low-energy $\gamma$ enhancement in ${}^{56}$Fe
• Transitional $\gamma$ strength in Cd isotopes
• Cross-Section Measurements of the 86Kr(g,n) Reaction to Probe the s-Process Branching at 85Kr
• First observation of low-energy γ-ray enhancement in the rare-earth region
• Microcanonical entropies and radiative strength functions of ${}^{50,51}$V
• Understanding the Low-Energy Enhancement of the $\gamma$-ray Strength Function of ${}^{56}$Fe
• Low-energy enhancement in the γ-ray strength functions of ${}^{73,74}$Ge
• Experimentally constrained ($p,\gamma$)${}^{89}$Y and ($n,\gamma$)${}^{89}$Y reaction rates relevant to the $p$-process nucleosynthesis
• Low-energy enhancement and fluctuations of $\gamma$-ray strength functions in ${}^{56,57}$Fe: test of the Brink-Axel hypothesis
• Quasicontinuum $\gamma$-decay of ${}^{91,92}$Zr: benchmarking indirect ($n,\gamma$) cross section measurements for the $s$-process
• ${}^{137,138,139}$La($n$, $\gamma$) cross sections constrained with statistical decay properties of ${}^{138,139,140}$La nuclei
• Extraction of thermal and electromagnetic properties in 45Ti