Adjoint Versus Forward Solution of Anisotropic Transport Problems

The sensitivity of the accuracy of the forward space and adjoint space calculation of a detector response in a source driven system to the order of the angular quadrature used is investigated. It is found that for problems characterized by a localized source and extended detector distributions, the adjoint space calculation may require a significantly lower order of angular quadrature than the forward space calculation. The reciprocal situation prevails for problems characterized by an extended source and localized detector distributions.