GeomConverter/src/org/lcsim/material

diff -u -r1.5 -r1.6
--- Material.java	1 Jul 2005 00:06:26 -0000	1.5
+++ Material.java	1 Jul 2005 21:49:10 -0000	1.6
@@ -2,23 +2,42 @@

 
 import static java.lang.Math.sqrt;
 import static java.lang.Math.abs;

+import static java.lang.Math.pow;

 import java.util.List;
 import java.util.ArrayList;
 
 /**
  * @author jeremym
  *

- * Material implementation, mostly based on G4Material.

+ * Material implementation, mostly based on Geant4's G4Material.

  *
  */
 public class Material
 {

-    /** Default temperature in kelvin = 1.0 */

+    /* Default temperature in kelvin = 1.0 */

     public static final double DEFAULT_TEMPERATURE = 273.15;
     

-    /** Default pressure in atmospheres = 1.0 */

+    /* Default pressure in atmospheres = 1.0 */

     public static final double DEFAULT_PRESSURE = 1.0;        
     

+    /* 1 mole */
+    public static final double AVOGADRO = 6.022136736e23;
+    
+    public static final double MAX_RADIATION_LENGTH = java.lang.Double.MAX_VALUE;
+    public static final double MAX_NUCLEAR_INTERACTION_LENGTH = java.lang.Double.MAX_VALUE;
+    
+    /* nuclear interaction length factor in g/cm2 */
+    public static final double LAMBDA0 = 35.0;
+    
+    /* atomic mass unit (rest mass) in MeV */
+    public static final double AMU_C2 = 931.49432;
+    
+    /* speed of light in mm/s */
+    public static final double C_LIGHT = 299.792458;
+    
+    /* atomic mass unit */
+    public static final double AMU = AMU_C2 / (C_LIGHT * C_LIGHT);
+    

     double _temp;
     double _pressure;
     double _density;

@@ -33,11 +52,22 @@

     private List<MaterialElement> _elements = new ArrayList<MaterialElement>();
     private List<Double> _massFractions = new ArrayList<Double>();
     private List<Integer> _atoms = new ArrayList<Integer>();

+    private List<Double> _nAtomsPerVolume = new ArrayList<Double>();
+   
+    /* electrons per element */
+    double _totalElectronsPerVolume;
+    
+    /* radiation length */
+    double _radiationLength;
+    
+    /* nuclear interaction length in g/cm2 */
+    double _nuclearInteractionLength;

     
     int _nComponents;
     int _nComponentsMax;
     int _nElements;
     

+    /*

     public Material()
     {
         _Z=0;

@@ -45,6 +75,7 @@

         _isElement = false;
         _name = "Vacuum";
     }

+     */

     
     /* Construct base material with all info, creating a MaterialElement, also. */
     public Material(String name,

@@ -82,6 +113,8 @@

         MaterialManager.addElement(new MaterialElement(_name, _Z, _A) );
         _massFractions.add(1.0);
         

+        computeDerivedQuantities();
+        

         MaterialManager.addMaterial(this);
     }
     

@@ -169,6 +202,8 @@

                 _massFractions.add(_atoms.get(massCnt) * ee.getA() / Amol);
                 ++massCnt;
             }

+            
+            computeDerivedQuantities();

         }
     }
     

@@ -207,6 +242,7 @@

         if ( isFilled() )
         {
             checkMassSum();

+            computeDerivedQuantities();

         }
     }
     

@@ -321,8 +357,78 @@

     public int getNElements()
     {
         return _nElements;

-    }    

+    }            
+    
+    public void computeDerivedQuantities()
+    {
+        computeNAtomsPerVolume();
+        computeRadiationLength();
+        computeNuclearInteractionLength();
+    }
+    
+    public void computeNAtomsPerVolume()
+    {
+        double Zi, Ai;
+        _totalElectronsPerVolume = 0.0;                        
+        
+        for ( int i = 0; i < _nElements; i++)
+        {
+            Zi = _elements.get(i).getZ();
+            Ai = _elements.get(i).getA();
+            double nElec = AVOGADRO * _density * _massFractions.get(i) / Ai;
+            _nAtomsPerVolume.add(i, nElec);
+            _totalElectronsPerVolume += _nAtomsPerVolume.get(i);
+            _totalElectronsPerVolume += _nAtomsPerVolume.get(i) * Zi;
+        }        
+    }                
+    
+    void computeRadiationLength()
+    {
+        double radinv = 0.0;
+        for ( int i = 0; i < _nElements; i++)
+        {
+            radinv += _nAtomsPerVolume.get(i) * ( _elements.get(i).getTsaiFactor() );
+        }
+        _radiationLength = ( radinv <= 0.0 ? MAX_RADIATION_LENGTH : 1.0 / radinv);                
+    }
+    
+    /** compute nuclear interaction length in g/cm2 */
+    void computeNuclearInteractionLength()
+    {
+        double NILinv = 0.0;
+        for ( int i = 0; i < _nElements; i++)
+        {
+            NILinv += _nAtomsPerVolume.get(i) * pow(_elements.get(i).getN(), 0.6666667);
+        }
+        NILinv *= AMU/LAMBDA0;
+        
+        _nuclearInteractionLength = (NILinv <= 0.0 ? MAX_NUCLEAR_INTERACTION_LENGTH : 1.0/NILinv);
+    }
+    
+    public double getRadiationLength()
+    {
+        return _radiationLength;
+    }
+    
+    /* get radiation length for this material in mm */
+    public double getNuclearInteractionLengthForMaterial()
+    {
+        return ( _nuclearInteractionLength / _density) * 10;
+    }

-    // 1 mole
-    //public static double AvogN = 6.022136736e23;

+    public double getNuclearInteractionLength()
+    {
+        return _nuclearInteractionLength;
+    }
+    
+    public String toString()
+    {
+        return "name=" + getName() + "; nComponents=" + _nComponents + 
+                "; nElements=" + _nElements + "; temp=" + _temp + 
+                "; pressure=" + _pressure + "; density=" + _density + 
+                "; state=" + _state.toString() + "; elecPerVol=" + 
+                _totalElectronsPerVolume + "; NIL=" + _nuclearInteractionLength + 
+                "; NILmat=" + getNuclearInteractionLengthForMaterial() +
+                "; RL=" + _radiationLength;
+    }

 }

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