The ideal gas, scattering kernel for heavy nuclei with pronounced resonances was developed , proved and implemented in the data processing code NJOY from which the scattering probability tables were prepared. Those tables were introduced to the well known MCNP code via the ''mt" input cards in the same manner as it is done for light nuclei in the thermal energy range.
The authors present an alternative methodology for solving the double differential, energy dependent scattering kernel which is based solely on stochastic consideration as far as the scattering probabilities are concerned. The solution scheme is based on an alternative rejection scheme suggested by W. Rothenstein. Based on comparison with the above mentioned analytical (probability S(a,b)-tables) approach it is confirmed that the suggested rejection scheme provides accurate results. The uncertainty concerning the stochastic treatment lies within 1-2 standard deviations for all practical cases that were analysed. In the following the instruction to implement the stochastic method are presented together with the probability scattering data (Sab12.J31mp) at 1200 K to be used as a reference case.
Forschungszentrum Karlsruhe GmbH Postfach 36403 D-76021 Karlsruhe, Germany email: dagan@inr.fzk.de; bjoern.becker@inr.fzk.de
Last reviewed: 27 October 2010
