A Useful Analogy for Single-Group Neutron Diffusion Theory

It is shown that an analogy exists between the neutron flux as predicted by single-group neutron diffusion theory and the axial component of the electric field intensity in a field excited as a plane transverse-magnetic wave in a cylindrical cavity. The buckling of a homogeneous bare core could be determined using simple microwave devices to an accuracy on the same order as the uncertainty of the cavity dimensions. Experimental techniques are described for measuring control rod worth for fully extended cylindrical control rods of arbitrary cross section and illustrative solutions are shown for circular, hexagonal, square, cruciform, “Y” and sheet cross sections located at the center and at radial positions in a circular core. A method is described for predicting the flux distribution in the core region and experimental examples are shown.