Measurement of alpha coefficient, fission and capture cross sections for 235U and 239Pu for neutron energies from 10 to 80 KeV

The value of alpha, neutron fission and capture cross-. sections of 235U and 239Pu have been measured on a spectrometer for incident neutron energies between 10 and 80 KeV using a pulsed Van-de-Graaff accelerator as a neutron source and the time-of-flight technique. The resolution of the measurement was 20 ns/m. The capture and fission events were detected with a large scintillation counter loaded with cadmium. The alpha value was measured absolutely and the fission cross-section measured relative to the cross-section of the reaction 10B(n,αγ). The obtained results are accurate for alpha within 10 to 12 % and in reasonable agreement with the earlier results and other published data