Verification of the surrogate ratio method

Journal Article · Thu Apr 15 00:00:00 EDT 2010 · Physical Review. C, Nuclear Physics

DOI:https://doi.org/10.1103/PHYSREVC.81.044604· OSTI ID:21388935

Chiba, Satoshi ^[1]; Iwamoto, Osamu ^[1]

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1. Japan Atomic Energy Agency, Tokai, Naka, Ibaraki 319-1195 (Japan)

Effects of difference in the spin and parity distributions for the surrogate and neutron-induced reactions are investigated. Without assuming specific (schematic) spin-parity distributions, it was found that the surrogate ratio method can be employed to determine neutron fission and capture cross sections if (1) weak Weisskopf-Ewing condition (defined in this paper) is satisfied, (2) there exist two surrogate reactions whose spin-parity distributions of the decaying nuclei are almost equivalent, and (3) difference of the representative spin values between the neutron-induced and surrogate reactions is no much larger than 10(Planck constant/2pi). If these conditions are satisfied, we need not know the spin-parity distributions populated by the surrogate method. Instead, we should just select a pair of surrogate reactions which will populate the similar spin-parity distributions, using targets having similar structure and reactions having the similar reaction mechanisms. Achievable accuracy is estimated to be around 5% and 10% for fission and capture channels, respectively, for nuclei of the Uranium region. The surrogate absolute method may be applicable to determination of fission cross sections with a caution. However, there will be little hope to apply this method for capture cross section measurements unless the spin-parity distributions in the neutron-induced and surrogate reactions are fairly close to each other (which is implausible) or the difference can be corrected theoretically. The surrogate ratio method was shown also to be a robust method in the presence of breakup reactions without assuming specific breakup reaction mechanisms.

• OSTI ID: 21388935
• Journal Information: Physical Review. C, Nuclear Physics, Vol. 81, Issue 4; Other Information: DOI: 10.1103/PhysRevC.81.044604; (c) 2010 The American Physical Society; ISSN 0556-2813
• Country of Publication: United States
• Language: English

Related Subjects

73 NUCLEAR PHYSICS AND RADIATION PHYSICS
ACCURACY
BREAKUP REACTIONS
CAPTURE
CROSS SECTIONS
DISTRIBUTION
FISSION
NEUTRON REACTIONS
NEUTRONS
NUCLEI
PARITY
REACTION KINETICS
SPIN
URANIUM
VERIFICATION
ACTINIDES
ANGULAR MOMENTUM
BARYON REACTIONS
BARYONS
ELEMENTARY PARTICLES
ELEMENTS
FERMIONS
HADRON REACTIONS
HADRONS
KINETICS
METALS
NUCLEAR REACTIONS
NUCLEON REACTIONS
NUCLEONS
PARTICLE PROPERTIES