Written from the viewpoint of the applied physicist, this monograph codifies a general formalism for obtaining mathematically tractable approximations to multivariable systems by means of modal expansions. Methods for assessing the mathematical and/or physical significance of the approximate solutions are presented. The general formalism, together with physical insight, is applied to obtain calculation models for the space-energy distribution of neutrons in fast reactors.
Stacey's work is unique in two respects, for it codifies a general approximation formalism (including many well-known techniques such as moments expansions and vibrational procedures as special cases) and develops models for fast-reactor physics calculations that embody new conceptual approaches to this complex problem. These models are both more computationally economical and more amenable to direct comparison with experiment than are currently used multigroup models. Although this application is primarily concerned with the neutron space-energy problem, a chapter is also devoted to analytical solutions for the spectra and importance function in spatially independent media.
Intended for applied physicists and engineers, especially those engaged in neutron-reactor physics research, Modal Approximations will prove valuable to graduate students as well as practicing professionals. The treatment of the mathematical formalism is sufficiently extensive that the applied physicist or engineer interested in obtaining a tractable, meaningful approximation or in finding a basis of comparison among alternate approximations will find this work a useful reference.