Import Geant4 0.0.0 source tree

source/processes/hadronic/models/generator/util/include/G4FermiMomentum.hh

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+// This code implementation is the intellectual property of
+// the RD44 GEANT4 collaboration.
+//
+// By copying, distributing or modifying the Program (or any work
+// based on the Program) you indicate your acceptance of this statement,
+// and all its terms.
+//
+// $Id: G4FermiMomentum.hh,v 1.2 1998/10/30 16:40:09 gunter Exp $
+// GEANT4 tag $Name: geant4-00 $
+//
+#ifndef G4FermiMomentum_h
+#define G4FermiMomentum_h 1
+
+#include "globals.hh"
+#include "G4ThreeVector.hh"
+#include "Randomize.hh"
+
+class G4FermiMomentum 
+{
+
+  public:
+    G4FermiMomentum();
+    ~G4FermiMomentum();
+    
+    inline void Init(G4double anA, G4double aZ) {theA = anA; theZ = aZ;}
+    
+    inline G4double GetFermiMomentum(G4double density)
+    {
+	return constofpmax * cbrt(density * theA);
+    }
+    
+    inline G4ThreeVector GetMomentum(G4double density)
+    { 
+	G4ThreeVector p;
+	
+	do {
+	    p=G4ThreeVector(2.*G4UniformRand()-1.,
+	    		    2.*G4UniformRand()-1.,
+	    		    2.*G4UniformRand()-1.);
+	    } while ( p.mag() > 1. );
+	return p*GetFermiMomentum(density); 
+     }
+    
+  private:
+  
+    G4double theA;
+    G4double theZ;
+      // pmax= hbar * c * ( 3* pi**2 * rho )**(1/3) =
+      //       hbar * c * ( 3* pi**2 )**(1/3) * rho**(1/3)=
+      //       constofpmax * rho**(1/3)
+    G4double constofpmax;
+  
+};
+
+#endif
+