A General Method of Importance Sampling the Angle of Scattering in Monte Carlo Calculations

Methods of Monte Carlo biasing using two-dimensional discrete ordinates adjoint flux

“…The MORSE code utilizes the same multigroup cross sections used by the d.iscrete ordinates codes DOT,(11) ANISN,(l 9 ) or DTF-IV. ( 2 0) th These cross section sets employ an n -order Legendre polynomial expansion to describe the scattering distribution for each group-to ... Lrg .…”

“…of Equation (3 must be known so that the corr"esponding point values X*,(r,Q'.) can the N outgoin_g• directions effectively transforms the distribution given by Equation (3)(4)(5)(6)(7)(8)(9)(10) into…”

“…where the direct1on 11 j'' has been 5clected from the biased distribution given by Equation (3)(4)(5)(6)(7)(8)(9)(10)(11).…”

“…Equation (3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14) is also valid for particle transport through more than one material. Note that e-n is a normalized p.d.f.…”

“…However, events occur only in the interval ( 0, ne), where ne is the total number of mean free paths to the external boundary. When a path is selected from -n e ' only the (3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14) -n • -n fraction (1 -e • e) are events, and the fraction e e leak into the external void. Therefore, the leakage probability of a particle -n -ne is e e, and the nonleakage probability is (1 -e ).…”