Two-Group Theory of the Feynman-Alpha Method for Reactivity Measurement in ADS

<table>The possible reactions which the three different particles can undergo. Fast neutrons (red circle) can be detected (yellow), absorbed (white), and thermalized (green). Thermal neutrons (green) can be absorbed, and through fission lead to a random number of delayed neutron precursors (grey) and fast neutrons (red). Delayed neutron precursors decay into a fast neutron.</table>

Science and Technology of Nuclear Installations

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Figure 1

Figure 1: Two-Group Theory of the Feynman-Alpha Method for Reactivity Measurement in ADS 