Absorption of neutrons in the unresolved region
It is the purpose of this thesis to provide a usable theoretical description of the high energy neutron absorption region, known as the unresolved region, for mixtures containing one absorbing element. Although the theoretical development contained herein is presented in general form so as to be applicable to any hypothetical homogeneous reactor system containing a dilute mixture of absorber in some moderating system, the specific goal is that of applying the results to a moderating mixture of oxygen, hydrogen and nitrogen containing thorium fuel. By utilizing the results in the form of an expression giving the absorption cross section 6a.(E) for 1 = 0 neutrons in the energy range 1000 ev. to 14 mev. of the unresolved region, a computer program can be set up to yield the fraction of neutrons absorbed in the given energy region. This computer subroutine is cast in such a form as to make it easily included in an overall program for resonance escape probability calculation.