Pairing effects in actinide (n,2n) reaction cross sections

Conference · Fri Dec 30 23:00:00 EST 1994

OSTI ID:68343

Maslov, V M ^[1]

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1. Radiation Physics and Chemistry Problems Institute, Minsk-Sosny (Belarus)

The well-known discrepancy between measured data on {sup 239}Pu(n,2n) reaction cross section and convenient statistical model calculation is resolved. Near-threshold behaviour of the reaction cross section is interpreted as being due to jump-like excitation of two quasi-particle states in the residual {sup 238}Pu nucleus. The factorized contribution of intrinsic quasi-particle and collective states to the total level density enables fitting of (n,2n) and fission data. The detailed shape of intrinsic two-quasi-particle state density is derived. With obtained level density we maintain prediction of (n,2n) reaction for Z-even, N-odd actinide targets. The data on {sup 235}U(n,2n) reaction cross section are analyzed. The calculated {sup 233}U(n,2n) reaction cross section, governing the {sup 232}U niclide build-up in U-Th fuel cycle is different from the current evaluations.

• OSTI ID: 68343
• Report Number(s): CONF-940507--Vol.1; CNN: Contract 7207/RB
• Country of Publication: United States
• Language: English

Related Subjects

66 PHYSICS
CROSS SECTIONS
FISSION
MEV RANGE 01-10
MEV RANGE 10-100
NEUTRON REACTIONS
PLUTONIUM 239
URANIUM 233
URANIUM 235