Fission of 239Pu by resonance neutrons

Gamma-ray spectra from the 239Pu(n,f) reaction were measured with a gamma spectrometer on the pulsed reactor IBR-30. The fission gamma-rays within the 32-ns time window were measured using a Ge(Li) detector. Based on the measured gamma-ray spectrum in the 0.1 - 1.8 MeV interval, the total number of emitted γ-quanta (multiplicity) av and the total energy av of γ quanta per fission event were calculated. The results were 7.0±0.6 γ/fission and 6.8±0.5 MeV/fission, respectively. The yields of light and heavy fragments were determined. In this paper, the authors evaluate and discuss the experimental charge dispersion σz2=0.36±0.03 (ch.u)2 and other quantities that can be deduced from it. Based on the experimental results, they discuss the competition between the (n, γf) and (n, fγ) processes. They estimate the prescission with bar Γγf+ to be (4.8±2.5) meV. 35 refs., 5 figs., 3 tabs