Differential and integral comparisons of three representations of the prompt neutron spectrum for the spontaneous fission of /sup 252/Cf

Conference · Thu Nov 01 04:00:00 EST 1984

OSTI ID:6205330

Madland, D G; LaBauve, R J; Nix, J R

Because of their importance as neutron standards, we present comparisons of measured and calculated prompt fission neutron spectra N(E) and average prompt neutron multiplicities anti nu/sub p/ for the spontaneous fission of /sup 252/Cf. In particular, we test three representations of N(E) against recent experimental measurements of the differential spectrum and threshold integral cross sections. These representations are the Maxwellian spectrum, the NBS spectrum, and the Los Alamos spectrum of Madland and Nix. For the Maxwellian spectrum, we obtain the value of the Maxwellian temperature T/sub M/ by a least-squares adjustment to the experimental differential spectrum of Poenitz and Tamura. For the Los Alamos spectrum, a similar least-squares adjustment determines the nuclear level-density parameter a, which is the single unknown parameter that appears. The NBS spectrum has been previously constructed by adjustments to eight differential spectra measured during the period 1965 to 1974. Among these three representations, we find that the Los Alamos spectrum best reproduces both the differential and integral measurements, assuming ENDF/B-V cross sections in the calculation of the latter. Although the NBS spectrum reproduces the integral measurements fairly well, it fails to satisfactorily reproduce the new differential measurement, and the Maxwellian spectrum fails to satisfactorily reproduce the integral measurements. Additionally, we calculate a value of anti nu/sub p/ from the Los Alamos theory that is within approximately 1% of experiment. 25 references.

• Research Organization: Los Alamos National Lab., NM (USA)
• DOE Contract Number: W-7405-ENG-36
• OSTI ID: 6205330
• Report Number(s): LA-UR-84-3557; CONF-8411118-1; ON: DE85003728
• Country of Publication: United States
• Language: English

Related Subjects

652016* -- Nuclear Properties & Reactions
A=220 & above
Theoretical-- Spontaneous & Induced Fission-- (-1987)
652026 -- Nuclear Properties & Reactions
A=220 & above
Experimental-- Spontaneous & Induced Fission-- (-1987)
73 NUCLEAR PHYSICS AND RADIATION PHYSICS
ACTINIDE ISOTOPES
ACTINIDE NUCLEI
ALPHA DECAY RADIOISOTOPES
BARYONS
CALIFORNIUM 252
CALIFORNIUM ISOTOPES
DATA
DECAY
ELEMENTARY PARTICLES
EVEN-EVEN NUCLEI
EXPERIMENTAL DATA
FERMIONS
FISSION
FISSION NEUTRONS
HADRONS
HEAVY NUCLEI
INFORMATION
ISOTOPES
LEAST SQUARE FIT
MAXIMUM-LIKELIHOOD FIT
MULTIPLICITY
NEUTRON SPECTRA
NEUTRONS
NUCLEAR REACTIONS
NUCLEI
NUCLEONS
NUMERICAL DATA
NUMERICAL SOLUTION
PROMPT NEUTRONS
RADIOISOTOPES
SPECTRA
SPONTANEOUS FISSION
STANDARDS
THEORETICAL DATA
YEARS LIVING RADIOISOTOPES