4. METHOD OF SOLUTION
Monte Carlo methods are used to solve the forward and the adjoint transport equations. Quantities of interest are then obtained by summing the contributions over all collisions, and frequently over most of phase space.
Standard multigroup cross sections such as those used in discrete ordinates codes may be used as input; either ANISN, DTF-4 or DOT cross section formats are acceptable.
Anisotropic scattering is treated for each group-to-group transfer by utilizing a generalized Gaussian quadrature technique.
The MORSE code is organized into functional modules with simplified interfaces such that new modules may be incorporated with reasonable ease. The modules are (1) random walk, (2) cross section, (3) geometry, (4) analysis, and (5) diagnostic.
While the basic MORSE code assumes the analysis module is user-written, a general analysis package, SAMBO, has been developed. SAMBO handles most of the drudgery associated with the analysis of random walks and minimizes the amount of user-written coding. An arbitrary number of detectors, energy-dependent response functions, energy bins, time bins, and angle bins are allowed. Analysis is divided for each detector as follows - uncollided and total response, fluence versus energy, time-dependent response, fluence versus time and energy, and fluence versus angle and energy. Each of these quantities is listed as output. The diagnostic module provides an easy means of printing out, in useful form, the information in the various labelled common and any part of blank common. This module is very useful to debug a problem and to gain further insight into the physics of the random walk.
MORSE-H uses in a weighted-tracking scheme a track-length as next- event event estimation of neutron and photon fluxes.