Delayed-neutron energy spectra following thermal-neutron-induced fission of Pu-239

Thesis/Dissertation · Thu Jan 01 04:00:00 EST 1987

OSTI ID:5389015

Haghighi, M H

Delayed-neutron (DN) energy spectra following thermal neutron induced fission of /sup 239/Pu as a function of time after fission have been measured, using the beta-neutron time-of-flight (TOF) spectrometer at the University of Lowell. Thermal/epithermal neutrons were produced on the 5.5-MV Van de Graaff accelerator using the /sup 7/Li(p,n)/sup 7/Be reaction. Time spectra over the neutron energy range of 0.01-4.0 MeV were measured for seven different time intervals after fission, each interval containing varying contributions from the six delayed neutrons groups. The DN energy spectra following induced thermal fission of /sup 239/Pu are compared to those resulting from induced thermal fission of /sup 235/U for each of the seven delay time intervals. Decomposition of the measured spectra into six-group DN spectra was accomplished employing an iterative least-squares method, incorporating a constraint requiring all six-group spectra remain positive for all neutron energies and have shapes similar to initial comparison spectra.

• Research Organization: Lowell Univ., MA (USA)
• OSTI ID: 5389015
• Country of Publication: United States
• Language: English

Related Subjects

652020* -- Nuclear Properties & Reactions
A=220 & above
Experimental
73 NUCLEAR PHYSICS AND RADIATION PHYSICS
BARYON REACTIONS
BARYONS
DATA
DELAYED NEUTRONS
ELEMENTARY PARTICLES
EXPERIMENTAL DATA
FERMIONS
FISSION
FISSION NEUTRONS
HADRON REACTIONS
HADRONS
INFORMATION
LEAST SQUARE FIT
MAXIMUM-LIKELIHOOD FIT
NEUTRON REACTIONS
NEUTRON SPECTRA
NEUTRONS
NUCLEAR REACTIONS
NUCLEON REACTIONS
NUCLEONS
NUMERICAL DATA
NUMERICAL SOLUTION
PLUTONIUM 239 TARGET
SPECTRA
TARGETS
THERMAL NEUTRONS
TIME DEPENDENCE
TIME-OF-FLIGHT METHOD