INVESTIGATION OF THE SHAPE OF THE 235U(n,f) CROSS-SECTION WITH VERY COLD NEUTRONS
Commission of the European Communities
Joint Research Centre - Gael-Establishment
Central Bureau for Nuclear Measurements, 2440 Geel, Belgium
W. Mampe, P. Ageron, A. Michaudon
Institut Laue-Langevin, 156X, F-38042 Grenoble, France
At the Very Cold Neutron Source of the Institut Laue-Langevin at Grenoble, the shape of the 235U(n,f) cross-section has been measured in the meV-neutron energy region. For this purpose, a slow chopper has been installed at the end of the very cold neutron guide. Very thin 235UF4 and 6LiF samples and PIPS-detectors were used for the detection of the 235U(n,f) fragments and for the determination of the neutron flux via the 6Li(n,α)t reaction. Within the experimental accuracy, the present results do not show a significant deviation of the 235U(n,f) cross-section from a 1/v-shape.
KEYWORDS: 235U, fission cross-section shape, neutron energy 6-60 μeV