CONVERGENCE LIMITS IN PERTURBATION THEORY

摘要

Perturbation theory is a powerful technique which is often used in reactor physics as afirst-order fast tool suitable to estimate the systemresponse to small perturbations. Thanksto recent advancements in the field of numerical evaluation of higher flux harmonics, itis possible, in principle, to increase the perturbation analysis order, allowing to improvethe estimation of system parameters and to reconstruct the flux distribution, also in thepresence of non-linear perturbations. In this respect, it is important to assess the convergenceproperties of such methodology. The aim of the present work is to investigate theconvergence behaviour of the method for perturbations of different parameters and fordifferent systems, in order to draw some conclusions on its limits of validity.