Question

Calculate the fluxes and the currents in the following geometries, in a diffusing medium with a diffusion coefficient D and diffusion length L:

1. At the center of a line of length ‘x’ with two sources of strength S at each end.

2. A square of edge length ‘a’ at the center and at the midpoint of one edge, where neutron sources of strengths S [neutrons/second] are placed at each one of the vertices.

Hint: Consider that the neutron flux is a scalar quantity, whereas the neutron current is a vector quantity following Fick’s law.

Answer 1