G4ProjectileFragmentCrossSection Class Reference

#include <G4ProjectileFragmentCrossSection.hh>

Public Member Functions
	G4ProjectileFragmentCrossSection ()
G4double	doit (G4double Ap, G4double Zp, G4double At, G4double Zt, G4double A, G4double Z)
void	testMe ()

Detailed Description

Definition at line 36 of file G4ProjectileFragmentCrossSection.hh.

Constructor & Destructor Documentation

G4ProjectileFragmentCrossSection()

G4ProjectileFragmentCrossSection::G4ProjectileFragmentCrossSection ( )

inline

Definition at line 39 of file G4ProjectileFragmentCrossSection.hh.

  {
        p_S[1] = -2.38;                  // scale factor for xsect in barn    
        p_S[2] = 0.27;         
 
        p_P[1] = -2.5840E+00;            // slope of mass yield curve         
        p_P[2] = -7.5700E-03;
 
        p_Delta[1] = -1.0870E+00;        // centroid rel. to beta-stability
        p_Delta[2] = +3.0470E-02;
        p_Delta[3] = +2.1353E-04; 
        p_Delta[4] = +7.1350E+01; 
 
        p_R[1] = +0.885E+00;             // width parameter R
        p_R[2] = -9.8160E-03;
 
        p_Un[1] = 1.65;                  // slope par. n-rich ride of Z distr.
 
        p_Up[1] = 1.7880;                // slope par. p-rich ride of Z distr.  
        p_Up[2] = +4.7210E-03;   
        p_Up[3] = -1.3030E-05;   
 
        p_mn[1]  = 0.400;                // memory effect n-rich projectiles
        p_mn[2]  = 0.600;        
 
        p_mp[1] = -10.25;                // memory effect p-rich projectiles
        p_mp[2] = +10.1; 
 
        corr_d[1] = -25.0;       // correction close to proj.: centroid dzp
        corr_d[2] = 0.800;       
        corr_r[1] = +20.0;       // correction close to proj.: width R
        corr_r[2] = 0.820;
        corr_y[1] = 200.0;       // correction close to proj.: Yield_a
        corr_y[2] = 0.90;        
  }

Member Function Documentation

doit()

G4double G4ProjectileFragmentCrossSection::doit ( G4double  Ap, G4double  Zp, G4double  At, G4double  Zt, G4double  A, G4double  Z  )

inline

Definition at line 75 of file G4ProjectileFragmentCrossSection.hh.

  {
//  calculate mass yield
        G4double Ap13 = std::pow(Ap, 1./3.);
        G4double At13 = std::pow(At, 1./3.);
        G4double S = p_S[2] * (At13 + Ap13 + p_S[1]);
//  cout << "debug0 "<<S<<" "<<At13<<" "<<Ap13<<" "<<p_S[1]<<" "<<p_S[2]<<endl;
        G4double p    = std::exp(p_P[2]*Ap + p_P[1]);
        G4double yield_a = p * S * std::exp(-p * (Ap - A));
  cout << "debug1 "<<yield_a<<endl;
//   modification close to projectile
        G4double f_mod_y=1.0;
        if (A/Ap > corr_y[2])
    {
          f_mod_y=corr_y[1]*std::pow(A/Ap-corr_y[2], 2) + 1.0;
        }
        yield_a= yield_a * f_mod_y;
  cout << "debug1 "<<yield_a<<endl;
 
//   calculate maximum of charge dispersion zprob
        G4double zbeta = A/(1.98+0.0155*std::pow(A, (2./3.)));
        G4double zbeta_p = Ap/(1.98+0.0155*std::pow(Ap, (2./3.)));
        G4double delta;
    if(A > p_Delta[4]) 
    {
          delta = p_Delta[1] + p_Delta[2]*A;
        }
    else
    {
          delta = p_Delta[3]*A*A;
        }
 
//   modification close to projectile
        G4double f_mod=1.0;
        if(A/Ap > corr_d[2]) 
    {
          f_mod = corr_d[1]*std::pow(A/Ap-corr_d[2], 2) + 1.0;
        }
        delta = delta*f_mod;
        G4double zprob = zbeta+delta;
 
//   correction for proton- and neutron-rich projectiles
        G4double  dq;
    if((Zp-zbeta_p)>0) 
    {
          dq = std::exp(p_mp[1] + G4double(A)/G4double(Ap)*p_mp[2]);
      cout << "dq "<<A<<" "<<Ap<<" "<<p_mp[1]
      <<" "<<p_mp[2]<<" "<<dq<<" "<<p_mp[1] + A/Ap*p_mp[2]<<endl;
    }
        else                       
        {
      dq = p_mn[1]*std::pow(A/Ap, 2.0) + p_mn[2]*std::pow(A/Ap, 4.0);
        }
        zprob = zprob + dq * (Zp-zbeta_p);
 
//   small corr. since Xe-129 and Pb-208 are not on Z_beta line
        zprob = zprob + 0.0020*A;
    cout <<"zprob "<<A<<" "<<dq<<" "<<Zp<<" "<<zbeta_p
         <<" "<<zbeta<<" "<<delta<<endl;
 
//  calculate width parameter R
        G4double r = std::exp(p_R[1] + p_R[2]*A);
 
//  modification close to projectile
        f_mod=1.0;
        if (A/Ap > corr_r[2]) 
    {
          f_mod = corr_r[1]*Ap*std::pow(A/Ap-corr_r[2], 4.0)+1.0;
        }
        r = r*f_mod;
 
//   change width according to dev. from beta-stability
        if ((Zp-zbeta_p) < 0.0) 
    { 
          r=r*(1.0-0.0833*std::abs(Zp-zbeta_p));
        }
 
//   calculate slope parameters u_n, u_p
        G4double u_n = p_Un[1];
        G4double u_p = p_Up[1] + p_Up[2]*A + p_Up[3]*A*A;
 
//   calculate charge dispersion
        G4double expo, fract;
    if((zprob-Z) > 0) 
    {
//     neutron-rich
          expo = -r*std::pow(std::abs(zprob-Z), u_n);
          fract   =  std::exp(expo)*std::sqrt(r/3.14159);
        }
    else
    {
//     proton-rich
          expo = -r*std::pow(std::abs(zprob-Z), u_p);
          fract   =  std::exp(expo)*std::sqrt(r/3.14159);
 cout << "1 "<<expo<<" "<<r<<" "<<zprob<<" "<<Z<<" "<<u_p<<endl;
//     go to exponential slope
          G4double dfdz = 1.2 + 0.647*std::pow(A/2.,0.3);
          G4double z_exp = zprob + dfdz * std::log(10.) / (2.*r);
          if( Z>z_exp ) 
      {
            expo = -r*std::pow(std::abs(zprob-z_exp), u_p);
            fract   =  std::exp(expo)*std::sqrt(r/3.14159)
                      / std::pow(std::pow(10, dfdz), Z-z_exp);
          }
        }
 
        cout << "debug "<<fract<<" "<<yield_a<<endl;
    G4double epaxv2=fract*yield_a;
    return epaxv2;
  }

Referenced by testMe().

testMe()

void G4ProjectileFragmentCrossSection::testMe ( )

inline

Definition at line 186 of file G4ProjectileFragmentCrossSection.hh.

  {
    G4ProjectileFragmentCrossSection i;
    cout << i.doit(58, 28, 9, 4, 49, 28) << endl;
 // Sigma = 9.800163E-13 b
  }

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The documentation for this class was generated from the following file:

• G4ProjectileFragmentCrossSection.hh