Measurement of Prompt Neutron Spectra for exp 233 U, exp 235 U and exp 239 Pu Thermal-Neutron-Induced Fission in the 0.01-5 MeV Energy Region and for exp 252 Cf Spontaneous Fission in the 0.01-10 Mev Region

摘要

The authors give the results of measurements of prompt neutron spectra for exp 233 U, exp 235 U and exp 239 Pu thermal-neutron-induced fission in the 0.01-5 MeV region, and for exp 252 Cf spontaneous fission in the 0.01-10 MeV region. The spectra exceed the Maxwellian distributions in the region E<0.4MeV. The average excess is approximately 20% over the range E = 0.05-0.15 MeV and 5%-7% over the range 0.15-0.4 MeV for the exp 252 Cf fission neutron spectrum. The spectra were analysed after they and the corresponding Maxwellian distributions had been normalized to the same area. In the 0.05-0.22 MeV region the exp 235 U + n/sub T/ fission neutron yield exceeds the exp 252 Cf and exp 239 Pu + n/sub T/ fission neutron yields by approximately 8% and approximately 15%, respectively. In the 0.3-1.2 MeV region, the exp 235 U + n/sub T/ yield exceeds the exp 239 Pu + n/sub T/ yield by 8%. There is no difference in the exp 235 U + n/sub T/ and exp 233 U + n/sub T/ fission neutron spectra in the 0.05-0.6 MeV region. (Atomindex citation 12:634143)