Skip to main content
OSTI.GOVU.S. Department of Energy Office of Scientific and Technical Information
U.S. Department of Energy
Office of Scientific and Technical Information
 

Measurement of pre- and post-fission neutron emission at moderate excitation energies

Journal Article · · Phys. Rev., C, v. 12, no. 6, pp. 1809-1825
; ; ; ;
Fission fragment mass-energy distributions and the coincident neutron velocity distributions have been measured for $sup 209$Bi, $sup 232$Th, $sup 233$U, $sup 238$U, and $sup 239$Pu bombarded with 45 MeV $alpha$ particles and $sup 226$Ra bombarded with 16 MeV protons. The number of pre-fission neutrons and the number of post-fission neutrons were obtained as a function of fragment mass and total fragment kinetic energy. The average number of pre-fission neutrons emitted is 2.9plus-or-minus0.9 for the $sup 232$Th target, 3.3plus-or- minus1.5 for $sup 233$U, 3.6plus-or-minus1.6 for $sup 238$U, and 2.7plus-or- minus0.8 for $sup 239$Pu. The average number of post-fission neutrons emitted by these systems is 4.4plus-or-minus0.3, 4.2plus-or-minus0.7, 4.6plus-or-minus0.7, and 5.1plus-or-minus0.3, respectively. (The values reported for pre-fission neutrons include also contributions from scission neutrons.) The number of pre- fission neutrons from the $sup 226$Ra+16 MeV proton system is 0.5plus-or-minus0.3. The number of post-fission neutrons is 3.6plus-or-minus0.4. The number of neutrons emitted from the $sup 209$Bi+45 MeV $alpha$ particle system is 3.6plus- or-minus0.2. The number of post-fission neutrons as a function of fragment mass and total kinetic energy which were obtained by the direct neutron measurements are more consistent with calculated total energy balances than the values obtained by the indirect method. The agreement between the calculated results and our experimental results is satisfactory. However, the calculations predict spallation cross sections which are much larger than those obtained experimentally. (AIP)
Research Organization:
Argonne National Laboratory, Argonne, Illinois 60439 and Weizmann Institute of Science, Rehovot, Israel
Sponsoring Organization:
USDOE
NSA Number:
NSA-33-019123
OSTI ID:
4091484
Journal Information:
Phys. Rev., C, v. 12, no. 6, pp. 1809-1825, Journal Name: Phys. Rev., C, v. 12, no. 6, pp. 1809-1825; ISSN PRVCA
Country of Publication:
United States
Language:
English

Similar Records

Measurement of the average number of prompt neutrons emitted in fission at high energy
Technical Report · Mon Mar 19 23:00:00 EST 1956 · OSTI ID:4459970
ANGULAR DISTRIBUTIONS IN FISSION INDUCED BY ALPHA PARTICLES, DEUTERONS, AND PROTONS
Journal Article · Wed Oct 15 00:00:00 EDT 1958 · Physical Review (U.S.) Superseded in part by Phys. Rev. A, Phys. Rev. B: Solid State, Phys. Rev. C, and Phys. Rev. D · OSTI ID:4267965
AVERAGE NUMBER AND SPECTRUM OF PROMPT NEUTRONS IN FAST NEUTRON-INDUCED FISSION
Technical Report · Fri Oct 30 23:00:00 EST 1959 · OSTI ID:4264662

Related Subjects

643406*
ALPHA REACTIONS-- BISMUTH 209-- BISMUTH 209 TARGET-- PLUTONIUM 239-- PLUTONIUM 239 TARGET-- THORIUM 232-- THORIUM 232 TARGET-- URANIUM 233-- URANIUM 233 TARGET-- URANIUM 238-- URANIUM 238 TARGET
FISSION FRAGMENTS
FISSION NEUTRONS
KINETIC ENERGY
MASS SPECTRA
MEV RANGE 10-100
MULTIPLICITY
N68961 --Physics (Nuclear
Experimental)--Nuclear Properties & Reactions
190 <= A <= 219 Nuclear Reactions & Scattering--Spontaneous & Induced Fission
N69161* --Physics (Nuclear
Experimental)--Nuclear Properties & Reactions
A >= 220--Nuclear Reactions & Scattering--Spontaneous & Induced Fission:734
VELOCITY PROTON REACTIONS-- RADIUM 226-- RADIUM 226 TARGET