include/Geant4/G4WeightWindowAlgorithm.hh

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0025 //
0026 // G4WeightWindowAlgorithm
0027 //
0028 // Class description:
0029 //
0030 // Implementation of a weight window algorithm.
0031 // The arguments in the constructor configure the algorithm:
0032 //   - upperLimitFactor: the factor defining the upper weight limit
0033 //      W_u = upperLimitFactor * W_l (W_l lower weight bound)
0034 //   - survivalFactor: used in calculating the survival weight
0035 //      W_s = survivalFactor * W_l
0036 //   - maxNumberOfSplits: the maximal number of splits allowed
0037 //     to be created in one go, and the reciprocal of the minimal
0038 //     survival probability in case of Russian roulette
0039 //
0040 // In case of upperLimitFactor=survivalFactor=1 the algorithm becomes
0041 // the expected weight algorithm of the importance sampling technique.
0042 //
0043 // See also G4VWeightWindowAlgorithm.
0044
0045 // Author: Michael Dressel (CERN), 2003
0046 // ----------------------------------------------------------------------
0047 #ifndef G4WEIGHTWINDOWALGORITHM_HH
0048 #define G4WEIGHTWINDOWALGORITHM_HH 1
0049
0050 #include "G4Nsplit_Weight.hh"
0051 #include "G4VWeightWindowAlgorithm.hh"
0052
0053 class G4WeightWindowAlgorithm : public G4VWeightWindowAlgorithm
0054 {
0055   public:  // with description
0056
0057     G4WeightWindowAlgorithm(G4double upperLimitFactor = 5,
0058                             G4double survivalFactor = 3,
0059                             G4int maxNumberOfSplits = 5);
0060
0061     ~G4WeightWindowAlgorithm() override;
0062
0063     G4Nsplit_Weight Calculate(G4double init_w,
0064                                       G4double lowerWeightBound) const override;
0065       // calculate number of tracks and their weight according
0066       // to the initial track weight and the lower energy bound
0067
0068   private:
0069
0070     G4double fUpperLimitFactor = 0.0;
0071     G4double fSurvivalFactor = 0.0;
0072     G4int fMaxNumberOfSplits = 0;
0073 };
0074
0075 #endif