Discrete Ordinates Calculations of the Importance Factor of a Neutron Source

In the frame of the transport theory, the importance of an extraneous neutron source is calculated by using several methods. One of them, which was developed in a previous paper, requires only standard calculations, while the adjoint fluxes must be supplemented in the conventional approach. The spherical plutonium-metal assembly JEZEBEL is chosen as a benchmark problem for numerical comparisons. All calculations are performed with the ANISN code by using several options and various degrees of approximation.