Effect of preequilibrium spin distribution on {sup 48}Ti +n cross sections
- North Carolina State University, Raleigh, North Carolina 27695 (United States)
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)
- Lawrence Livermore National Laboratory, Livermore, California 94551 (United States)
Nuclear model calculations of discrete {gamma}-ray production cross sections produced in {sup 48}Ti(n,n{sup '}{gamma}{sub i}){sup 48}Ti and {sup 48}Ti(n,2n{gamma}{sub i}){sup 47}Ti reactions were made as a function of incident neutron energy from E{sub n}=1 MeV to 35 MeV and compared with new experimental results using the large-scale Compton-suppressed germanium array for neutron induced excitations (GEANIE) at LANSCE. The Hauser-Feshbach reaction code GNASH, incorporating the spin distribution for the preequilibrium process calculated with the Feshbach-Kerman-Koonin (FKK) quantum-mechanical preequilibrium theory, was used to calculate partial {gamma}-ray transition cross sections. The comparisons of calculated and experimental data demonstrate that, the FKK model for preequilibrium leads a better overall reproduction of the experimental data above E{sub n}=10 MeV, where preequilibrium processes are important. The FKK calculation predicts a strong reduction in the high-spin state population in {sup 48}Ti by inelastic scattering. Population of low-spin states was also affected, however the change in the low-lying 983.5-keV (2{sup +}) state production is small because almost all {gamma}-ray decay cascades feed this transition. In addition, the FKK calculation has a significant impact on the partial {gamma}-ray transition cross sections for the (n,2n) reaction above E{sub n}=15 MeV. The calculated cross sections for high-spin states in {sup 47}Ti are reduced, and those from the low-spin states are enhanced, in agreement with the experimental cross section data.
- OSTI ID:
- 20995298
- Journal Information:
- Physical Review. C, Nuclear Physics, Vol. 75, Issue 5; Other Information: DOI: 10.1103/PhysRevC.75.054612; (c) 2007 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); ISSN 0556-2813
- Country of Publication:
- United States
- Language:
- English
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