Über das Fermialter verzögerter Neutronen

Abstract

For the first time the migration areas of four single groups of delayed neutrons resulting from the fission of²³⁵U have been measured. The following values for the migration areaM ², the age τ_{φ, 1.46} at the indium resonance, and the age τ_{φ, th} for the slowing down to thermal energies have been determined.

Group	M2[cm2]	τφ,1.46 [cm2]	τφ, th [cm2]
1	15.30±0.6	7.1±0.7	7.6±0.6
2	18.37±0.6	10.2±0.7	10.7±0.6
3	16.32±0.9	8.1±0.9	8.7±0.9
4	17.69±0.8	9.5±0.9	10.0±0.8
Average over all groups	17.58±0.5	9.4±0.6	99.±0.5

The values for the age are in good agreement with theoretical values of the literature, which use the spectra measured by Batchelor and McK Hyder, and with own Monte Carlo calculations by means of Bonner type neutron spectra using the mean energies of Batchelor and McK Hyder.