Neutron Importance and Fission Rate in Enriched Uranium Metal Sphere

To properly account for spatial effects in the point reactor kinetics description of Rossi-α measurement， the spatial distribution of the neutron importance in depleteduraniumreflected uranium metal sphere(CFBR-Ⅱ) was measured using ²⁵²Cf neutron source.The spatial distribution of the fission rate from enriched uranium fission chamber is presented too. The spatial-effects factor obtained from these measurements is 1.096.