Neutron-neutron angular correlations in spontaneous fission of Cf252 and Pu240

Verbeke, J. M.; Nakae, L. F.; Vogt, R.

doi:10.1103/PhysRevC.97.044601

Neutron-neutron angular correlations in spontaneous fission of ${}^{252}{Cf}$ and ${}^{240}{Pu}$

Journal Article · Sun Apr 01 00:00:00 EDT 2018 · Physical Review C

DOI:https://doi.org/10.1103/PhysRevC.97.044601· OSTI ID:1488798

Verbeke, J. M. ^[1]; Nakae, L. F. ^[1]; Vogt, R. ^[2]

Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States). Nuclear and Chemical Sciences Division
Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States). Nuclear and Chemical Sciences Division; Univ. of California, Davis, CA (United States). Dept. of Physics

Background: Angular anisotropy has been observed between prompt neutrons emitted during the fission process. Such an anisotropy arises because the emitted neutrons are boosted along the direction of the parent fragment. Purpose: To measure the neutron-neutron angular correlations from the spontaneous fission of ²⁵²Cf and ²⁴⁰Pu oxide samples using a liquid scintillator array capable of pulse-shape discrimination. To compare these correlations to simulations combining the Monte Carlo radiation transport code MCNPX with the fission event generator FREYA. Method: Two different analysis methods were used to study the neutron-neutron correlations with varying energy thresholds. The first is based on setting a light output threshold while the second imposes a time-of-flight cutoff. The second method has the advantage of being truly detector independent. Results: The neutron-neutron correlation modeled by FREYA depends strongly on the sharing of the excitation energy between the two fragments. The measured asymmetry enabled us to adjust the FREYA parameter x in ²⁴⁰Pu , which controls the energy partition between the fragments and is so far inaccessible in other measurements. The ²⁴⁰Pu data in this analysis was the first available to quantify the energy partition for this isotope. The agreement between data and simulation is overall very good for ²⁵²Cf ( sf ) and ²⁴⁰Pu ( sf ). Conclusions: The asymmetry in the measured neutron-neutron angular distributions can be predicted by FREYA. The shape of the correlation function depends on how the excitation energy is partitioned between the two fission fragments. Lastly, experimental data suggest that the lighter fragment is disproportionately excited.

View Accepted Manuscript (DOE)

Research Organization:: Lawrence Livermore National Laboratory (LLNL), Livermore, CA (United States)

Sponsoring Organization:: USDOE National Nuclear Security Administration (NNSA); USDOE National Nuclear Security Administration (NNSA), Office of Defense Nuclear Nonproliferation; USDOE National Nuclear Security Administration (NNSA), Office of Defense Nuclear Nonproliferation (NA-20)

Grant/Contract Number:: AC52-07NA27344

OSTI ID:: 1488798

Alternate ID(s):: OSTI ID: 1430782

Report Number(s):: LLNL-JRNL--731534; 878683

Journal Information:: Physical Review C, Journal Name: Physical Review C Journal Issue: 4 Vol. 97; ISSN PRVCAN; ISSN 2469-9985

Publisher:: American Physical Society (APS)Copyright Statement

Country of Publication:: United States

Language:: English

References (31)

Improved predections of neutron detection efficiency for hydrocarbon scintillators from 1 MeV to about 300 MeV Cecil, R. A.; Anderson, B. D.; Madey, R. Nuclear Instruments and Methods, Vol. 161, Issue 3 https://doi.org/10.1016/0029-554X(79)90417-8	journal	May 1979
Angular correlation of neutrons from thermal-neutron fission of 235U Franklyn, C. B.; Hofmeyer, C.; Mingay, D. W. Physics Letters B, Vol. 78, Issue 5 https://doi.org/10.1016/0370-2693(78)90640-8	journal	October 1978
Simultaneous investigation of fission fragments and neutrons in 252Cf (SF) Budtz-Jørgensen, C.; Knitter, H. -H. Nuclear Physics A, Vol. 490, Issue 2 https://doi.org/10.1016/0375-9474(88)90508-8	journal	December 1988
Determination of light output function and angle dependent correction for a stilbene crystal scintillation neutron spectrometer Hansen, W.; Richter, D. Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Vol. 476, Issue 1-2 https://doi.org/10.1016/S0168-9002(01)01430-9	journal	January 2002
TRIPOLI-4®, CEA, EDF and AREVA reference Monte Carlo code Brun, E.; Damian, F.; Diop, C. M. Annals of Nuclear Energy, Vol. 82 https://doi.org/10.1016/j.anucene.2014.07.053	journal	August 2015
Fission Reaction Event Yield Algorithm, FREYA — For event-by-event simulation of fission Verbeke, J. M.; Randrup, J.; Vogt, R. Computer Physics Communications, Vol. 191 https://doi.org/10.1016/j.cpc.2015.02.002	journal	June 2015
Fission Reaction Event Yield Algorithm FREYA 2.0.2 Verbeke, J. M.; Randrup, J.; Vogt, R. Computer Physics Communications, Vol. 222 https://doi.org/10.1016/j.cpc.2017.09.006	journal	January 2018
MCNP-PoliMi: a Monte-Carlo code for correlation measurements Pozzi, Sara A.; Padovani, Enrico; Marseguerra, Marzio Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Vol. 513, Issue 3 https://doi.org/10.1016/j.nima.2003.06.012	journal	November 2003
Facility for neutron multiplicity measurements in fission Dushin, V. N.; Hambsch, F. -J.; Jakovlev, V. A. Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Vol. 516, Issue 2-3 https://doi.org/10.1016/j.nima.2003.09.029	journal	January 2004
Total characterization of neutron detectors with a 252Cf source and a new light output determination Kornilov, N. V.; Fabry, I.; Oberstedt, S. Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Vol. 599, Issue 2-3 https://doi.org/10.1016/j.nima.2008.10.032	journal	February 2009
Verification and validation of the MCNPX-PoliMi code for simulations of neutron multiplicity counting systems Clarke, S. D.; Miller, E. C.; Flaska, M. Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Vol. 700 https://doi.org/10.1016/j.nima.2012.10.025	journal	February 2013
Neutron light output response and resolution functions in EJ-309 liquid scintillation detectors Enqvist, Andreas; Lawrence, Christopher C.; Wieger, Brian M. Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Vol. 715 https://doi.org/10.1016/j.nima.2013.03.032	journal	July 2013
Neutron crosstalk between liquid scintillators Verbeke, J. M.; Prasad, M. K.; Snyderman, N. J. Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Vol. 794 https://doi.org/10.1016/j.nima.2015.04.019	journal	September 2015
Method for measuring multiple scattering corrections between liquid scintillators Verbeke, J. M.; Glenn, A. M.; Keefer, G. J. Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Vol. 825 https://doi.org/10.1016/j.nima.2016.04.003	journal	July 2016
Neutron angular distribution in plutonium-240 spontaneous fission Marcath, Matthew J.; Shin, Tony H.; Clarke, Shaun D. Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Vol. 830 https://doi.org/10.1016/j.nima.2016.05.064	journal	September 2016
Velocity and Angular Distributions of Prompt Neutrons from Spontaneous Fission of Cf 252 Bowman, Harry R.; Thompson, Stanley G.; Milton, J. C. D. Physical Review, Vol. 126, Issue 6 https://doi.org/10.1103/PhysRev.126.2120	journal	June 1962
Monte Carlo approach to sequential neutron emission from fission fragments Lemaire, S.; Talou, P.; Kawano, T. Physical Review C, Vol. 72, Issue 2 https://doi.org/10.1103/PhysRevC.72.024601	journal	August 2005
Monte Carlo approach to sequential γ-ray emission from fission fragments Lemaire, S.; Talou, P.; Kawano, T. Physical Review C, Vol. 73, Issue 1 https://doi.org/10.1103/PhysRevC.73.014602	journal	January 2006
Calculation of fission observables through event-by-event simulation Randrup, Jørgen; Vogt, Ramona Physical Review C, Vol. 80, Issue 2 https://doi.org/10.1103/PhysRevC.80.024601	journal	August 2009
Event-by-event study of prompt neutrons from Pu 239 ( n , f ) Vogt, R.; Randrup, J.; Pruet, J. Physical Review C, Vol. 80, Issue 4 https://doi.org/10.1103/PhysRevC.80.044611	journal	October 2009
Event-by-event study of neutron observables in spontaneous and thermal fission Vogt, R.; Randrup, J. Physical Review C, Vol. 84, Issue 4 https://doi.org/10.1103/PhysRevC.84.044621	journal	October 2011
Event-by-event evaluation of the prompt fission neutron spectrum from 239 Pu ( n , f ) Vogt, R.; Randrup, J.; Brown, D. A. Physical Review C, Vol. 85, Issue 2 https://doi.org/10.1103/PhysRevC.85.024608	journal	February 2012
New prompt spectral γ -ray data from the reaction 252 Cf(sf) and its implication on present evaluated nuclear data files Billnert, R.; Hambsch, F. -J.; Oberstedt, A. Physical Review C, Vol. 87, Issue 2 https://doi.org/10.1103/PhysRevC.87.024601	journal	February 2013
Event-by-event study of photon observables in spontaneous and thermal fission Vogt, R.; Randrup, J. Physical Review C, Vol. 87, Issue 4 https://doi.org/10.1103/PhysRevC.87.044602	journal	April 2013
Refined treatment of angular momentum in the event-by-event fission model freya Randrup, J.; Vogt, R. Physical Review C, Vol. 89, Issue 4 https://doi.org/10.1103/PhysRevC.89.044601	journal	April 2014
Neutron angular correlations in spontaneous and neutron-induced fission Vogt, R.; Randrup, J. Physical Review C, Vol. 90, Issue 6 https://doi.org/10.1103/PhysRevC.90.064623	journal	December 2014
Angular Correlation of Neutrons from Spontaneous Fission of Cf 252 Pringle, J. S.; Brooks, F. D. Physical Review Letters, Vol. 35, Issue 23 https://doi.org/10.1103/PhysRevLett.35.1563	journal	December 1975
Correlated Neutron Emissions from ²⁵² Cf Pozzi, Sara A.; Wieger, Brian; Enqvist, Andreas Nuclear Science and Engineering, Vol. 178, Issue 2 https://doi.org/10.13182/NSE13-96	journal	October 2014
Prompt Neutron Emission Probabilities Following Spontaneous and Thermal Neutron Fission Boldeman, J. W.; Hines, M. G. Nuclear Science and Engineering, Vol. 91, Issue 1 https://doi.org/10.13182/NSE85-A17133	journal	September 1985
Initial MCNP6 Release Overview Goorley, T.; James, M.; Booth, T. Nuclear Technology, Vol. 180, Issue 3 https://doi.org/10.13182/NT11-135	journal	December 2012
Neutron-neutron angular correlations in spontaneous fission of 252Cf Gagarski, A. M.; Guseva, I. S.; Sokolov, V. E. Bulletin of the Russian Academy of Sciences: Physics, Vol. 72, Issue 6 https://doi.org/10.3103/S1062873808060130	journal	June 2008

Cited By (2)

Review on the progress in nuclear fission—experimental methods and theoretical descriptions Schmidt, Karl-Heinz; Jurado, Beatriz Reports on Progress in Physics, Vol. 81, Issue 10 https://doi.org/10.1088/1361-6633/aacfa7	journal	September 2018
High resolution measurement of tagged two-neutron energy and angle correlations in Cf 252 (sf) Schuster, P. F.; Marcath, M. J.; Marin, S. Physical Review C, Vol. 100, Issue 1 https://doi.org/10.1103/physrevc.100.014605	journal	July 2019

Similar Records

Related Subjects

73 NUCLEAR PHYSICS AND RADIATION PHYSICS