G4WeightWindowAlgorithm.hh

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// $Id$
//
// ----------------------------------------------------------------------
// Class G4WeightWindowAlgorithm
// 
// Class description:
// Implementation of a weight window algorithm. 
// The arguments in the constructor configure the algorithm:
//   - upperLimitFaktor: the factor defining the upper weight limit 
//      W_u = upperLimitFaktor * W_l (W_l lower weight bound)
//   - survivalFaktor: used in calculating  the survival weight
//      W_s = survivalFaktor * W_l
//   - maxNumberOfSplits: the maximal number of splits allowed
//     to be created in one go, and the reciprocal of the minimal
//     survival probability in case of Russian roulette
//
// In case of upperLimitFaktor=survivalFaktor=1 the algorithm
// becomes the expected weight algorithm of the importance sampling 
// technique.
//
// see also G4VWeightWindowAlgorithm.
//
 
// Author: Michael Dressel ([email protected])
// ----------------------------------------------------------------------
#ifndef G4WeightWindowAlgorithm_hh
#define G4WeightWindowAlgorithm_hh G4WeightWindowAlgorithm_hh 
 
#include "G4Nsplit_Weight.hh"
#include "G4VWeightWindowAlgorithm.hh"
 
class G4WeightWindowAlgorithm : public G4VWeightWindowAlgorithm
{
 
public:  // with description
  
  G4WeightWindowAlgorithm(G4double upperLimitFaktor = 5,
              G4double survivalFaktor = 3,
              G4int maxNumberOfSplits = 5);
  
  virtual ~G4WeightWindowAlgorithm();
 
  virtual G4Nsplit_Weight Calculate(G4double init_w,
                    G4double lowerWeightBound) const;
    // calculate number of tracks and their weight according
    // to the initial track weight and the lower energy bound
 
private:
  G4double fUpperLimitFaktor;
  G4double fSurvivalFaktor;
  G4int fMaxNumberOfSplits;
};
 
#endif