Measurements of fission cross-sections and anisotropies were also made to finalise the data set for some other reactions studied previously.

Hydrogen flow cooled the moderator first allowing to keep very low neutron energy and high fission cross-section, then it was heated by the direct contact to the fuel rods.

While uranium-238 has a small probability for spontaneous fission or even induced fission with fast neutrons, uranium-235 and to a lesser degree uranium-233 have a much higher fission cross-section for slow neutrons.

The critical mass of a fissionable material depends upon its nuclear properties (specifically, the nuclear fission cross-section), its density, its shape, its enrichment, its purity, its temperature, and its surroundings.

Application of glass solid state nuclear track detectors in the measurement of the particle fission cross-section of uranium, by Samar Mubarakmand, K. Rashid, P. Chaudhry and Hameed Ahmad Khan, Methods of Nuclear Instrumentation.