Sensitivity analysis of multiplication rate for subcritical systems

Sensitivity coefficients of the fission neutron multiplication rate k_f with respect to the change of cross-sections and an external source are derived for subcritical systems using the generalized perturbation theory (GPT). It is confirmed that the sensitivity coefficients derived using the GPT for a simple geometry where analytic solutions can be derived, give the same values as those derived by the direct numerical differentiation. These equations may be used to analyze the experimental values for the subcritical systems such as acceleration driven subcritical systems.