Interim report on the ORNL absolute measureoffoments of anti. nu. /sub p/ for /sup 252/Cf

Technical Report · Sat Sep 01 04:00:00 EDT 1979

DOI:https://doi.org/10.2172/5938627· OSTI ID:5938627

Spencer, R. R.; Gwin, R.; Ingle, R.; Weaver, H.

An initial effort was made to measure absolutely the average number of prompt neutrons, anti ..nu../sub p/, emitted in spontaneous fission of /sup 252/Cf to an unprecedented accuracy of +- 0.25%. Fission neutrons were counted with a large, gadolinium poisoned, liquid scintillator. A white source of neutrons from the ORELA was used to calibrate the detector efficiency as a function of neutron energy. Source neutrons were scattered into the large scintillator by a thin NE-213 proton-recoil detector which employed pulse shape discrimination to eliminate unwanted ..gamma..-ray background. The resulting neutron-energy and scattering angle-dependent efficiencies were used to normalize a Monte Carlo calculation of the scintillator efficiency for fission neutrons. Under the assumptions that the effects of parasitic charged particle reactions and multiple neutron scattering in the proton-recoil counter have negligible influence on the efficiency calibration, the value of the average number of prompt neutrons emitted per /sup 252/Cf fission was found to be 3.783 +- 0.010. This report is intended as a documentary and guide for future measurements incorporating improvements suggested by the analysis of this first determination. 31 references.

• Research Organization: Oak Ridge National Lab., TN (USA)
• DOE Contract Number: W-7405-ENG-26
• OSTI ID: 5938627
• Report Number(s): ORNL/TM-6805
• Country of Publication: United States
• Language: English

Related Subjects

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
DATA FORMS
DECAY
DELAYED GAMMA RADIATION
ELECTROMAGNETIC RADIATION
ELEMENTARY PARTICLES
EVEN-EVEN NUCLEI
EXPERIMENTAL DATA
FERMIONS
FISSION
FISSION NEUTRONS
GAMMA RADIATION
HADRONS
HEAVY NUCLEI
INFORMATION
IONIZING RADIATIONS
ISOLATED VALUES
ISOTOPES
NEUTRONS
NUCLEAR REACTIONS
NUCLEI
NUCLEONS
NUMERICAL DATA
PROMPT NEUTRONS
RADIATIONS
RADIOISOTOPES
SPONTANEOUS FISSION
YEARS LIVING RADIOISOTOPES