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169Tm (n, γ) cross section and statistical decay properties from measurements at the DANCE facility

Journal Article · · Physical Review. C
DOI:https://doi.org/10.1103/5sjr-vyjv· OSTI ID:2572563
 [1];  [2];  [1];  [1];  [3];  [1];  [1];  [2];  [1];  [1];  [1];  [1];  [1];  [2]
  1. Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)
  2. Charles Univ., Prague (Czech Republic)
  3. Commissariat a l'Energie Atomique et aux Energies Alternatives (CEA-Saclay), Gif-sur-Yvette (France). Institut de Recherche sur les lois Fondamentales de l'Univers (IRFU); Univ. Paris-Saclay, Gif-sur-Yvette (France)
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Background: Radiative neutron capture on thulium, which is a monoisotopic element, plays a role in different applications such as nuclear astrophysics or nuclear burning environments. Considerable discrepancies—reaching 20%—exist between evaluations in the unresolved-resonance region. Furthermore, experimental data on statistical 𝛾 decay in odd-odd rare-earth nuclei is scarce. There are still open questions about the systematics of the so-called scissors mode in the 𝑀⁢1 photon strength function, especially in odd-odd nuclei. Purpose: This work is focused on two main topics—deriving experimental 169Tm ⁢(𝑛,𝛾) cross section and studying statistical 𝛾 decay of 170Tm, in particular properties of the scissors mode. Methods: The capture experiments to obtain experimental cross section were performed at the Los Alamos Neutron Science Center using the time-of-flight technique and employing the Detector for Advanced Neutron Capture Experiments. Measured coincident 𝛾-ray spectra were also compared with statistical simulations using the dicebox code to test different models of level density and photon strength functions. Results: The capture cross section was determined from 1.8 eV to 0.97 MeV, the broadest neutron-energy range ever measured for this isotope. Several new resonances have been observed. The statistical 𝛾 decay of 170 Tm cannot be reproduced without a scissors mode resonance centered at ≈ 3.3MeV. Conclusions: The measured cross section in the unresolved-resonance region is generally lower than the latest evaluations. The derived 169Tm 𝑠-process abundance is expected to increase by a factor of 1.26, while the changes of the abundances of elements heavier than 169Tm are in the order of 0.2%. The scissors mode properties in 170Tm are similar to those deduced in previous analyses of neighboring nuclei 168Er and 166Ho .
Research Organization:
Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)
Sponsoring Organization:
USDOE National Nuclear Security Administration (NNSA), Office of Defense Programs (DP)
Grant/Contract Number:
89233218CNA000001
OSTI ID:
2572563
Report Number(s):
LA-UR--25-21688; 10.1103/5sjr-vyjv; 2469-9993
Journal Information:
Physical Review. C, Journal Name: Physical Review. C Journal Issue: 1 Vol. 112; ISSN 2469-9985; ISSN 2469-9993
Publisher:
American Physical Society (APS)Copyright Statement
Country of Publication:
United States
Language:
English

References (51)

Nuclear Ground-State Masses and Deformations journal March 1995
Investigation of nuclear structure by resonance fluorescence scattering journal January 1996
Further evidence for the new collective magnetic dipole mode in heavy deformed nuclei journal November 1984
Détermination du spin et des paramètres des résonances pour 107, 109Ag+n, 169Tm+n, Pt+n de 4 eV À 830 eV journal June 1969
A detector for (n,γ) cross-section measurements at a spallation neutron source
  • Heil, M.; Reifarth, R.; Fowler, M. M.
  • Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Vol. 459, Issue 1-2 https://doi.org/10.1016/S0168-9002(00)00993-1
journal February 2001
Geant4—a simulation toolkit
  • Agostinelli, S.; Allison, J.; Amako, K.
  • Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Vol. 506, Issue 3 https://doi.org/10.1016/S0168-9002(03)01368-8
journal July 2003
Simulation of γ cascades in complex nuclei with emphasis on assessment of uncertainties of cascade-related quantities journal November 1998
Local and global nucleon optical models from 1 keV to 200 MeV journal January 2003
Nuclear ground-state masses and deformations: FRDM(2012) journal May 2016
RIPL – Reference Input Parameter Library for Calculation of Nuclear Reactions and Nuclear Data Evaluations journal December 2009
The Karlsruhe Astrophysical Database of Nucleosynthesis in Stars Project – Status and Prospects journal June 2014
Nuclear Data Sheets for A = 182 journal December 2015
ENDF/B-VIII.0: The 8 th Major Release of the Nuclear Reaction Data Library with CIELO-project Cross Sections, New Standards and Thermal Scattering Data journal February 2018
Nuclear Data Sheets for A=170 journal November 2018
Background identification and suppression for the measurement of (n,γ) reactions with the DANCE array at LANSCE
  • Reifarth, R.; Bredeweg, T. A.; Alpizar-Vicente, A.
  • Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Vol. 531, Issue 3 https://doi.org/10.1016/j.nima.2004.05.096
journal October 2004
Evaluation of theoretical conversion coefficients using BrIcc
  • Kibédi, T.; Burrows, T. W.; Trzhaskovskaya, M. B.
  • Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Vol. 589, Issue 2 https://doi.org/10.1016/j.nima.2008.02.051
journal May 2008
Fourth-generation spallation neutron target-moderator-reflector-shield assembly at the Manuel Lujan Jr. neutron scattering center journal March 2013
Physics design of the next-generation spallation neutron target-moderator-reflector-shield assembly at LANSCE
  • Zavorka, Lukas; Mocko, Michael J.; Koehler, Paul E.
  • Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Vol. 901 https://doi.org/10.1016/j.nima.2018.06.018
journal September 2018
Erratum to “Simulation of gamma cascades in complex nuclei with emphasis on assessment of uncertainties of cascade-related quantities” [Nucl. Instrum. Methods A 417 (1998) 434–449] journal August 2019
GEANT4 simulations of the DANCE array
  • Jandel, M.; Bredeweg, T. A.; Couture, A.
  • Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, Vol. 261, Issue 1-2 https://doi.org/10.1016/j.nimb.2007.04.252
journal August 2007
Plasma stopping-power measurements reveal transition from non-degenerate to degenerate plasmas journal March 2020
Japanese evaluated nuclear data library version 5: JENDL-5 journal January 2023
Phenomenological Nuclear Level Densities using the KTUY05 Nuclear Mass Formula for Applications Off-Stability journal January 2006
Coupled-channels Optical Model Analyses of Nucleon-induced Reactions for Medium and Heavy Nuclei in the Energy Region from 1 keV to 200 MeV journal June 2007
Evolution and Nucleosynthesis in Low‐Mass Asymptotic Giant Branch Stars. II. Neutron Capture and the s ‐Process journal April 1998
Neutron capture cross section of 169Tm measured at the CSNS Back-n facility in the energy region from 30 to 300 keV * journal April 2022
Chemical evolution with rotating massive star yields II. A new assessment of the solar s- and r- process components journal November 2019
Average Radiative Capture Cross Sections for 7- to 170-kev Neutrons journal April 1961
Observation of a candidate for theM1scissors resonance in odd-oddHo166 journal March 2023
Photon strength functions, level densities, and isomeric ratio in Er168 from the radiative neutron capture measured at the DANCE facility journal April 2023
Neutron Total Cross Sections, 2.5-15 MeV. I. Experimental journal February 1971
Systematics of nuclear level density parameters journal October 2005
Hauser-Feshbach Theory and Ericson Fluctuations in the Presence of Direct Reactions journal September 1973
Experimental energy-dependent nuclear spin distributions journal November 2009
Strength of the scissors mode in odd-mass Gd isotopes from the radiative capture of resonance neutrons journal September 2013
Further explorations of the α -particle optical model potential at low energies for the mass range A ≈ 45 –209 journal October 2014
Random-matrix approach to the statistical compound nuclear reaction at low energies using the Monte Carlo technique journal October 2015
Ni 63 ( n , γ ) cross sections measured with DANCE journal October 2015
Statistical Hauser-Feshbach theory with width-fluctuation correction including direct reaction channels for neutron-induced reactions at low energies journal July 2016
Cu 63 ( n , γ ) cross section measured via 25 keV activation and time of flight journal January 2017
Estimation of M 1 scissors mode strength for deformed nuclei in the medium- to heavy-mass region by statistical Hauser-Feshbach model calculations journal August 2017
Examination of photon strength functions for Dy 162 , 164 from radiative capture of resonance neutrons journal November 2017
Synthesis of the Elements in Stars journal October 1957
Origin of the heaviest elements: The rapid neutron-capture process journal February 2021
A Composite Nuclear-Level Density Formula with Shell Corrections journal August 1965
Reference database for photon strength functions journal October 2019
The joint evaluated fission and fusion nuclear data library, JEFF-3.3 journal July 2020
TALYS: modeling of nuclear reactions journal June 2023
PHOTON STRENGTH FUNCTIONS OF 160 Tb FROM THE TWO-STEP GAMMA CASCADE MEASUREMENT journal February 2011
Cross Sections of the 169Tm(n,γ) Reaction from 2.6 keV to 2 MeV journal October 1982
The Los Alamos National Laboratory Spallation Neutron Sources journal October 1990

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