Monte Carlo Particle Transport Methods: Neutron and Photon - gnssn

74 Monte Carlo Particle Transport Methods: Neutron and Photon Calculations' Method 02 NSelect p ;, p,. p,, p 4 ayesp, < exp -a : (2x - 1)" /Select P 1j y c sq = a(2x - 1),- (P + a£Pi1-I 2ayesq = p*( Method P2Select P 1. p,Computez = max(p,, p,)j PI a(X + 1) J jFIGURE 3B.2 (continued).The azimuth is practieally exclusively assumed to be uniformly distributed over (0,2ir),thus either direct angle sampling or the two dimensional random orientation sampling ofvon Neumann (see Section 2.1.J) can be applied.The energy of the outgoing particle can be determined from Equation (3.11) for elasticscatterings and Equation (3.21) is to be used for inelastic scattering — if the angle (and theexcitation energy, in the second case) is known.Therefore, in the conventional method of energy and angle selection one samples the(cosine of the) angle and then compute the energy.Many different methods have been developed, four methods are cited here.