The particle sources are defined by a set of spatial, angular, energy and time distributions. By combining these distributions, the user can model virtually any kind of source according to the problem at hand.
Additionally, it is also possible to call from Tripoli-4® an external FORTRAN module previously defined for use with the MCNP code [1]. This may be done without recompiling Tripoli-4® by means of a dynamic library.
In the case of a biased simulation using an importance map pre-calculated by Tripoli-4®, source particles are sampled according to a biased distribution obtained by convoluting the unbiased source intensity with the importance function. Accordingly, the statistical weight is set to the inverse of the importance at the phase space point of emission for each source particle.