Fission Product Yield Data for the Transmutation of Minor Actinide ...

(1) Read the value plotted in Fig. 2.2.7, i.e. 25
± 2 mb from the 10–50 MeV bin;
(2) Apply the branching ratio correction to give
25 ± 2 × 1/(1 × 0.84) = 29.8 ± 2.4 mb.
The data are compared to the systematics by
Wahl [2.2.7] in green. At energies above 14 MeV,
Wahl uses data from 238 U(p,f) and 232 Th(p,f). The
evolution of the fragment production cross-section
as a function of neutron energy (excitation
function) exhibits correlations with the thresholds
of fission chances. However, for a given element,
the behaviour differs strongly from one isotope to
another.
2.2.4. Conclusions
New data on prompt photon emission during
the intermediate energy neutron induced fission of
238 U have been obtained. Gamma ray measurements
have enabled the extraction of individual
post-neutron emission fragment production
excitation functions. From X ray measurements, the
primary fragment Z distribution has been extracted
for different incident neutron energies. Although
these last results have to be finalized, they agree
quite well with calculations and other
measurements.
REFERENCES TO SECTION 2.2
[2.2.1] NELSON, R., et al., Nuclear Data for Science
and Technology, Italian Physics Society (1997)
445.
[2.2.2] ETHVIGNOT, Th., et al., A fission-fragmentsensitive
target for X-ray spectroscopy in
neutron-induced fission, Nucl. Instrum. Methods
Phys. Res. A 490 (2002) 559–565.
[2.2.3] GRANIER, Th., et al., CEA Bruyères-le-
Chatel, personal communication, 2003.
[2.2.4] BEARDEN, J.A., X-ray wavelengths, Rev. Mod.
Phys. 39 (1967) 78–124.
[2.2.5] REISDORF, W., et al., Fission fragment K X-ray
emission and nuclear charge distribution for
thermal neutron fission of 233 U, 235 U, 239 Pu and
spontaneous fission of 252 Cf, Nucl. Phys. A 177
(1971) 337–378.
[2.2.6] BREISMEISTER, J., Ed., MCNP — A Monte-
Carlo N-particle Transport Code, Rep. LA-
12625-M, Los Alamos National Laboratory, NM
(1997).
[2.2.7] WAHL, A.C., Contribution to Compilation and
Evaluation of Fission Yields Nuclear Data, Rep.
LA-13928, Los Alamos National Laboratory,
NM (2002).
[2.2.8] ZÖLLER, C.M., Fission Fragment Properties in
the 238 U(n,f) Reaction at Incident Neutron
Energies from 1 MeV to 500 MeV, Rep. IKDA-
95/25, Technische Hochschule Darmstadt (1995).
[2.2.9] CHEIFETZ, E., et al., Determination of the
charge and mass distribution in the fission of
252 Cf, Phys. Rev. C 4 (1971) 1913–1926.
[2.2.10] CASOLI, P., Étude de la Production de
Fragments dans la Fission Induite par Neutrons
sur l’Uranium-238, PhD thesis, Université de
Bordeaux (2003).
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