Algorithms for calculation of the transport tensor components in the generalized first collision probability method

The first collision probability (FCP) method allows generalization by introducing several angular modes in each zone. Algorithms are proposed for calculating the components of the corresponding first collision tensor. These algorithms do not increase the computational complexity beyond that of the matrix calculation algorithm in the traditional FCP method and allow calculating a system described in terms of combinatorial geometry. Fourfold integrals are numerically taken in calculation of a three-dimensional system and twofold integrals are taken for two-dimensional geometry. The geometrical capabilities are ensured by using the standard geometrical module of the Monte Carlo method.