1 - IAEA Nuclear Data Services

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Linac fission cross-sections down to below thermal
energy for a direct normalisation to the absolute
2200 m/s reference cross-section. A well-collimated
short flight-path (about 8 meter) with low repetition
rate (50 c/s) and long burst time (2 usee) of
the Linac is used. Also a run at 10 c/s was performed
to check the influence in the low energy-region of
overlap neutrons. The comparison of the induced
reaction-rates in a back-to-back
255
"U- and
10
B-foil
is made simultaneously with two sets of solid-state
detectors and registered in two halves of a 4096 channels
time-of-flight analyser. Based on the normalisation
at 2200 m/s a few resonance integrals will be
later calculated.
Scattering Cross Sections
E. Migneco, J. Theobald
Scattering Cross Section of
240
Pu
A scattering cross section measurement on
240
Pu has
been performed between 18 eV and 3 keV Till. A Bloaded
liquid scintillator has been used as detector
for scattered neutrons with a pulse shape discriminator
against Y-rays. Fig. 7 shows a time-of-flight
spectrum of the scattering yield. The analysis of
the resonance parameters is under way.
Other Measurements
Measurements of the scattering cross section on Cu,
Nd and Hf relatively to Pb are in preparation. For
determination of the scattering cross section of
fissile isotopes a big scintillator tank, to be used
as an anti-fission detector, has been constructed and
the shielding is going to be built. The B-loaded
liquid scintillator for the scattered neutron detection
has been successfully tested during the
240
Pu scattering experiment.