Late Gamma Rays from
Neutron-Induced Fission and Capture
from 235 U
G. Rusev, J. M. O’Donnell, I. Stetcu, M. Jandel, P. Talou , B. Baramsai,
T. A. Bredeweg, E. Bond, A. Couture, S. Mosby, C. J. Prokop, J. L. Ullmann,
and C. L. Walker
1 235 U+n Experiment
The late emission γ rays from the 235 U(n, γ ) and 235 U(n, f ) reactions were studied
in an experiment with a 26-mg/cm 2 thick target enriched to 235 U. The experiment
was performed at flight path 14 of the Lujan Center using neutrons produced via
spallation reaction of 800-MeV protons striking a tungsten target with a repetition
rate of 20 Hz [1]. A 1 in. thick water moderator increases the neutron flux at low
energies. The γ -rays were measured with the DANCE array, which consists of
160 BaF 2 detectors in a 4π configuration [2]. Pictures of DANCE are shown in
Fig. 1. DANCE was equipped with the NEUANCE array [3] serving as a fission
trigger by measuring the prompt fission neutrons. NEUANCE consists of 21 stilbene
detectors in a cylindrical configuration located in the central cavity of DANCE (cf.
Fig. 1). The signals from all DANCE and NEUANCE detectors were digitized by
CAEN VX1730B cards (14-bit, 500 MHz). In offline analysis, coincidence events
of detectors fired within 5 ns were built and ordered in time relative to the beginning
of the neutron spill (T 0 ).
G. Rusev () · J. M. O’Donnell · I. Stetcu · P. Talou · T. A. Bredeweg · E. Bond · A. Couture ·
S. Mosby · C. J. Prokop · J. L. Ullmann · C. L. Walker
Los Alamos National Laboratory, Los Alamos, NM, USA
e-mail: rusev@lanl.gov
M. Jandel
Los Alamos National Laboratory, Los Alamos, NM, USA
University of Massachusetts Lowell, Lowell, MA, USA
B. Baramsai
Los Alamos National Laboratory, Los Alamos, NM, USA
NASA Glenn Research Center, Brook Park, OH, USA
© This is a U.S. government work and not under copyright protection
in the U.S.; foreign copyright protection may apply 2021
J. Escher et al. (eds.), Compound-Nuclear Reactions, Springer Proceedings in
Physics 254, https://doi.org/10.1007/978-3-030-58082-7_41
323
Neutron-Induced Fission and Capture
from 235 U
G. Rusev, J. M. O’Donnell, I. Stetcu, M. Jandel, P. Talou , B. Baramsai,
T. A. Bredeweg, E. Bond, A. Couture, S. Mosby, C. J. Prokop, J. L. Ullmann,
and C. L. Walker
1 235 U+n Experiment
The late emission γ rays from the 235 U(n, γ ) and 235 U(n, f ) reactions were studied
in an experiment with a 26-mg/cm 2 thick target enriched to 235 U. The experiment
was performed at flight path 14 of the Lujan Center using neutrons produced via
spallation reaction of 800-MeV protons striking a tungsten target with a repetition
rate of 20 Hz [1]. A 1 in. thick water moderator increases the neutron flux at low
energies. The γ -rays were measured with the DANCE array, which consists of
160 BaF 2 detectors in a 4π configuration [2]. Pictures of DANCE are shown in
Fig. 1. DANCE was equipped with the NEUANCE array [3] serving as a fission
trigger by measuring the prompt fission neutrons. NEUANCE consists of 21 stilbene
detectors in a cylindrical configuration located in the central cavity of DANCE (cf.
Fig. 1). The signals from all DANCE and NEUANCE detectors were digitized by
CAEN VX1730B cards (14-bit, 500 MHz). In offline analysis, coincidence events
of detectors fired within 5 ns were built and ordered in time relative to the beginning
of the neutron spill (T 0 ).
G. Rusev () · J. M. O’Donnell · I. Stetcu · P. Talou · T. A. Bredeweg · E. Bond · A. Couture ·
S. Mosby · C. J. Prokop · J. L. Ullmann · C. L. Walker
Los Alamos National Laboratory, Los Alamos, NM, USA
e-mail: rusev@lanl.gov
M. Jandel
Los Alamos National Laboratory, Los Alamos, NM, USA
University of Massachusetts Lowell, Lowell, MA, USA
B. Baramsai
Los Alamos National Laboratory, Los Alamos, NM, USA
NASA Glenn Research Center, Brook Park, OH, USA
© This is a U.S. government work and not under copyright protection
in the U.S.; foreign copyright protection may apply 2021
J. Escher et al. (eds.), Compound-Nuclear Reactions, Springer Proceedings in
Physics 254, https://doi.org/10.1007/978-3-030-58082-7_41
323