Skip to main content
U.S. Department of Energy
Office of Scientific and Technical Information

Nonstatistical fluctuations in the 35Cl(n,p)35S reaction cross section at fast-neutron energies from 0.6 to 6 MeV

Journal Article · · Physical Review C

The lack of experimental data on the 35Cl(n,p)35S reaction above 100 keV has led to nuclear data evaluations that are relatively unconstrained at fast neutron energies. As a result, efforts to explore, develop, and potentially certify next generation reactor designs that incorporate chloride salts as a coolant material have been hindered. Here, we report partial cross section data for the 35Cl(n,p)35S and 35Cl(n,α)32P reactions at incident neutron energies between 0.6 MeV and 6 MeV. The measurement was performed using the pulsed beam of neutrons at the unmoderated WNR spallation neutron source at the Los Alamos Neutron Science Center, with the outgoing charged particles detected by the LENZ experimental setup, consisting of annular silicon detectors. Nonstatistical fluctuations in the 35Cl(n,p0) cross section were observed up to around 3 MeV, and the magnitude of the cross section was systematically lower than all available data evaluations at energies above 1 MeV. Modifications to the ENDF/B-VIII.0 data evaluation are suggested to better reproduce the energy averaged experimental data.

Research Organization:
Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)
Sponsoring Organization:
USDOE National Nuclear Security Administration (NNSA); USDOE Laboratory Directed Research and Development (LDRD) Program
Grant/Contract Number:
89233218CNA000001
OSTI ID:
1711388
Report Number(s):
LA-UR--20-22546
Journal Information:
Physical Review C, Journal Name: Physical Review C Journal Issue: 2 Vol. 102; ISSN 2469-9985
Publisher:
American Physical Society (APS)Copyright Statement
Country of Publication:
United States
Language:
English

References (36)

Nuclear Ground-State Masses and Deformations journal March 1995
(n, p) Cross sections for27Al,28Si,31P,35Cl,39K, and52Cr at 14.1 MeV journal August 1975
Some activation cross sections for 14 MeV neutrons journal July 1965
A fission ionization detector for neutron flux measurements at a spallation source
  • Wender, S. A.; Balestrini, S.; Brown, A.
  • Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Vol. 336, Issue 1-2 https://doi.org/10.1016/0168-9002(93)91102-S
journal November 1993
The 37Cl(3He, α)36Cl reaction and the 36S ground state analog journal May 1968
Determination of the 35Cl(n, p)35S reaction cross section and its astrophysical implications journal June 1994
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
Local and global nucleon optical models from 1 keV to 200 MeV journal January 2003
Complementary optical-potential analysis of -particle elastic scattering and induced reactions at low energies journal July 2009
Nuclear ground-state masses and deformations: FRDM(2012) journal May 2016
Excitation function for 63Cu(n,p)63Ni reaction in neutron energy range up to 15MeV journal October 2008
Nuclear Data Sheets for A = 32 journal September 2011
Nuclear Data Sheets for A = 35 journal November 2011
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
Fourth-generation spallation neutron target-moderator-reflector-shield assembly at the Manuel Lujan Jr. neutron scattering center journal March 2013
Fast neutron response of 6Li-depleted CLYC detectors up to 20MeV
  • D׳Olympia, N.; Chowdhury, P.; Jackson, E. G.
  • Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Vol. 763 https://doi.org/10.1016/j.nima.2014.06.074
journal November 2014
Fast neutron measurements using Cs2LiYCl6:Ce (CLYC) scintillator
  • Smith, M. B.; Achtzehn, T.; Andrews, H. R.
  • Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Vol. 784 https://doi.org/10.1016/j.nima.2014.09.021
journal June 2015
A new measurement of the 6 Li(n, α )t cross section at MeV energies using a 252Cf fission chamber and 6 Li scintillators
  • Kirsch, Leo E.; Devlin, M.; Mosby, S. M.
  • Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Vol. 874 https://doi.org/10.1016/j.nima.2017.08.046
journal December 2017
Applications of C 7 LYC scintillators in fast neutron spectroscopy
  • Brown, T.; Chowdhury, P.; Doucet, E.
  • Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Vol. 954 https://doi.org/10.1016/j.nima.2018.08.082
journal February 2020
New evaluation on angular distributions and energy spectra for neutron-induced charged-particle measurements
  • Kim, H. I.; Lee, H. Y.; Kawano, T.
  • Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Vol. 963 https://doi.org/10.1016/j.nima.2020.163699
journal May 2020
SRIM – The stopping and range of ions in matter (2010)
  • Ziegler, James F.; Ziegler, M. D.; Biersack, J. P.
  • Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, Vol. 268, Issue 11-12 https://doi.org/10.1016/j.nimb.2010.02.091
journal June 2010
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
JENDL-4.0: A New Library for Nuclear Science and Engineering journal January 2011
Odd-Even Dependence of Nuclear Level Density Parameters journal July 1960
The Inelastic Scattering of Neutrons journal July 1952
Neutron Total Cross Sections, 2.5-15 MeV. I. Experimental journal February 1971
Elastic deuteron scattering and optical model parameters at energies up to 100 MeV journal September 1988
Cl 35 ( n , p ) 35 S cross section from 25 meV to 100 keV journal October 1991
R -matrix analysis of Cl neutron cross sections up to 1.2 MeV journal April 2006
Hauser-Feshbach Theory and Ericson Fluctuations in the Presence of Direct Reactions journal September 1973
Random-matrix approach to the statistical compound nuclear reaction at low energies using the Monte Carlo technique 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
Possible evidence of nonstatistical properties in the Cl 35 ( n ,   p ) S 35 cross section journal April 2019
The Angular Distribution of Scattering and Reaction Cross Sections journal October 1952
Fast Neutron–Induced Fission Cross Sections of 233, 234, 236, 238 U up to 200 MeV journal September 2014
The Los Alamos National Laboratory Spallation Neutron Sources journal October 1990

Similar Records

Status of the n+35Cl Cross Sections [Slides]
Conference · Wed Nov 06 23:00:00 EST 2019 · OSTI ID:1922036

Quantification of the 35Cl($\textit{n, p}$) reaction channel
Journal Article · Wed Jan 11 23:00:00 EST 2023 · Progress in Nuclear Energy · OSTI ID:1909132

Measurement of the energy-differential 35Cl(n, p0) 35S cross section via the ratio with 6Li(n, α) 3H
Journal Article · Thu Sep 12 00:00:00 EDT 2024 · Physical Review. C · OSTI ID:2472516