Photon strength functions, level densities, and isomeric ratio in 168Er from the radiative neutron capture measured at the DANCE facility

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216208%3A11320%2F23%3A10474965" target="_blank" >RIV/00216208:11320/23:10474965 - isvavai.cz</a>

Výsledek na webu

<a href="https://verso.is.cuni.cz/pub/verso.fpl?fname=obd_publikace_handle&handle=aR9Jb~ut9j" target="_blank" >https://verso.is.cuni.cz/pub/verso.fpl?fname=obd_publikace_handle&handle=aR9Jb~ut9j</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1103/PhysRevC.107.044313" target="_blank" >10.1103/PhysRevC.107.044313</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Photon strength functions, level densities, and isomeric ratio in 168Er from the radiative neutron capture measured at the DANCE facility

Popis výsledku v původním jazyce

Background: The statistical approach is usually applied for the description of electromagnetic decay of the nucleus with the exception of the lowest excitation energies as well as for the calculation of the interaction of photons with nuclei, in particular the reaction cross sections. This concept employs nuclear level density (NLD) and photon strength functions (PSFs).Purpose: While PSFs and NLD of some well-deformed rare-earth nuclei were measured by several methods, sometimes with conflicting results, the PSFs of 168Er were addressed only by (gamma , gamma&apos;) experiments. On the other hand, the low-lying levels of 168Er are well studied, including the isomeric state at 1094 keV, which enables various tests of the statistical approach.Methods: The gamma rays following radiative neutron capture on a 167Er sample were measured with the highly segmented gamma-ray calorimeter Detector for Advanced Neutron Capture Experiments at the Los Alamos Neutron Science Center. The gamma-ray energy spectra for different multiplicities (multistep cascade, or MSC, spectra) were gathered for many s-wave resonances of both possible spins. Moreover, we were able to detect the decay of the short-lived isomer and deduce the isomeric ratio for a few resonances.Results: Analysis of the MSC spectra within the statistical model enabled us to draw conclusions about dipole PSFs, in particular on the properties of the scissors mode, and NLD. The spectra can be well reproduced with phenomenological PSFs models but not with any of several models based on quasiparticle random-phase approximation (QRPA) calculations with different interactions. We showed that nonstatistical effects in feeding of the isomeric state play a role up to excitation energies of at least about 2 MeV. Conclusions: Deduced parameters of the scissors mode were found to be similar to those of neighbor well -deformed even-even Gd and Dy nuclei. Models like that of Kadmenskij, Markushev, and Furman (KMF) or like the modified generalized Lorentzian (MGLO) model provide a good description of experimental spectra. In contrast to several previous analyses of well-deformed rare-earth isotopes, we were able to match the experimental isomeric ratio with statistical model simulations.

Název v anglickém jazyce

Photon strength functions, level densities, and isomeric ratio in 168Er from the radiative neutron capture measured at the DANCE facility

Popis výsledku anglicky

Background: The statistical approach is usually applied for the description of electromagnetic decay of the nucleus with the exception of the lowest excitation energies as well as for the calculation of the interaction of photons with nuclei, in particular the reaction cross sections. This concept employs nuclear level density (NLD) and photon strength functions (PSFs).Purpose: While PSFs and NLD of some well-deformed rare-earth nuclei were measured by several methods, sometimes with conflicting results, the PSFs of 168Er were addressed only by (gamma , gamma&apos;) experiments. On the other hand, the low-lying levels of 168Er are well studied, including the isomeric state at 1094 keV, which enables various tests of the statistical approach.Methods: The gamma rays following radiative neutron capture on a 167Er sample were measured with the highly segmented gamma-ray calorimeter Detector for Advanced Neutron Capture Experiments at the Los Alamos Neutron Science Center. The gamma-ray energy spectra for different multiplicities (multistep cascade, or MSC, spectra) were gathered for many s-wave resonances of both possible spins. Moreover, we were able to detect the decay of the short-lived isomer and deduce the isomeric ratio for a few resonances.Results: Analysis of the MSC spectra within the statistical model enabled us to draw conclusions about dipole PSFs, in particular on the properties of the scissors mode, and NLD. The spectra can be well reproduced with phenomenological PSFs models but not with any of several models based on quasiparticle random-phase approximation (QRPA) calculations with different interactions. We showed that nonstatistical effects in feeding of the isomeric state play a role up to excitation energies of at least about 2 MeV. Conclusions: Deduced parameters of the scissors mode were found to be similar to those of neighbor well -deformed even-even Gd and Dy nuclei. Models like that of Kadmenskij, Markushev, and Furman (KMF) or like the modified generalized Lorentzian (MGLO) model provide a good description of experimental spectra. In contrast to several previous analyses of well-deformed rare-earth isotopes, we were able to match the experimental isomeric ratio with statistical model simulations.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10300 - Physical sciences

Projekt

<a href="/cs/project/GA23-06439S" target="_blank" >GA23-06439S: Kolektivní dynamika jaderných elektromagnetických excitací</a><br>

Návaznosti

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Rok uplatnění

2023

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

Physical Review C

ISSN

2469-9985

e-ISSN

2469-9993

Svazek periodika

107

Číslo periodika v rámci svazku

4

Stát vydavatele periodika

US - Spojené státy americké

Počet stran výsledku

17

Strana od-do

044313

Kód UT WoS článku

000974624600001

EID výsledku v databázi Scopus

2-s2.0-85152775082