diff -u -r1.10 -r1.11
--- MultiLayerTrackerConverter.java	28 Aug 2007 22:26:34 -0000	1.10
+++ MultiLayerTrackerConverter.java	7 Nov 2007 21:57:29 -0000	1.11
@@ -8,6 +8,7 @@

 import org.lcsim.detector.identifier.ExpandedIdentifier;
 import org.lcsim.detector.identifier.IIdentifier;
 import org.lcsim.detector.identifier.IIdentifierDictionary;

+import org.lcsim.detector.identifier.IdentifierContext;

 import org.lcsim.detector.identifier.IdentifierDictionaryManager;
 import org.lcsim.detector.identifier.IdentifierUtil;
 import org.lcsim.detector.identifier.IIdentifierDictionary.InvalidIndexException;

@@ -31,11 +32,18 @@

 {
     public void convert( Subdetector subdet, Detector detector)
     {

-        MultiLayerTracker tracker = (MultiLayerTracker)subdet;
-                
-        ILogicalVolume trackingVolume = 
-            detector.getTrackingVolume().getLogicalVolume();

+        ILogicalVolume mother = null;
+        if (subdet.isInsideTrackingVolume())
+        {
+            mother = detector.getTrackingVolume().getLogicalVolume();
+        }
+        else
+        {
+            mother = detector.getWorldVolume().getLogicalVolume();
+        }

+        MultiLayerTracker tracker = (MultiLayerTracker)subdet;
+                        

         tracker.setDetectorElement( new DeSubdetector( detector, subdet ) );
         
         Layering layering = tracker.getLayering();

@@ -69,7 +77,7 @@

                     null,
                     name + "_layer" +i,
                     layerLV,

-                    trackingVolume,

+                    mother,

                     i);
             
             double sliceInnerR=layerInnerR;          

@@ -155,6 +163,23 @@

         }
         return id;
     }

+
+    public void makeIdentifierContext(Subdetector subdet) throws Exception
+    {
+        IIdentifierDictionary iddict = subdet.getDetectorElement().getIdentifierHelper().getIdentifierDictionary();
+        
+        int systemIndex = iddict.getFieldIndex("system");
+        int barrelIndex = iddict.getFieldIndex("barrel");
+        int layerIndex = iddict.getFieldIndex("layer");
+        
+        IdentifierContext systemContext = new IdentifierContext(new int[] {systemIndex});
+        IdentifierContext subdetContext = new IdentifierContext(new int[] {systemIndex,barrelIndex});
+        IdentifierContext layerContext = new IdentifierContext(new int[] {systemIndex,barrelIndex,layerIndex});
+        
+        iddict.addIdentifierContext("system", systemContext);
+        iddict.addIdentifierContext("subdetector", subdetContext);
+        iddict.addIdentifierContext("layer", layerContext);
+    }    

     
     public Class getSubdetectorType()
     {

diff -u -r1.14 -r1.15
--- DiskTrackerConverter.java	11 Sep 2007 20:18:13 -0000	1.14
+++ DiskTrackerConverter.java	7 Nov 2007 21:57:30 -0000	1.15
@@ -12,8 +12,10 @@

 import org.lcsim.detector.identifier.ExpandedIdentifier;
 import org.lcsim.detector.identifier.IIdentifier;
 import org.lcsim.detector.identifier.IIdentifierDictionary;

+import org.lcsim.detector.identifier.IdentifierContext;

 import org.lcsim.detector.identifier.IdentifierDictionaryManager;
 import org.lcsim.detector.identifier.IdentifierUtil;

+import org.lcsim.detector.identifier.IIdentifierDictionary.FieldNotFoundException;

 import org.lcsim.detector.identifier.IIdentifierDictionary.InvalidIndexException;
 import org.lcsim.detector.material.IMaterial;
 import org.lcsim.detector.material.MaterialStore;

@@ -36,9 +38,17 @@

 implements ISubdetectorConverter
 {
 	public void convert( Subdetector subdet, Detector detector)

-	{        
-		ILogicalVolume trackingVolume = detector.getTrackingVolume().getLogicalVolume();
-

+	{       
+        ILogicalVolume mother = null;
+        if (subdet.isInsideTrackingVolume())
+        {
+            mother = detector.getTrackingVolume().getLogicalVolume();
+        }
+        else
+        {
+            mother = detector.getWorldVolume().getLogicalVolume();
+        }
+        

 		DiskTracker tracker = (DiskTracker)subdet;
 
 		// Some DiskTracker subdetectors are used for support material

@@ -108,7 +118,7 @@

 									layerInnerZ + layer.getThickness()/2 )),
 									name + "_positive_layer" + i,
 									layerLV,

-									trackingVolume,

+									mother,

 									i);           
 
 			// Reflected layer in negative z.

@@ -125,7 +135,7 @@

 						),
 						name + "_negative_layer" + i,
 						layerLV,

-						trackingVolume,

+						mother,

 						i);                                       
 			}                 
 

@@ -238,6 +248,30 @@

 		}
 		return id;
 	}

+    
+    public void makeIdentifierContext(Subdetector subdet)
+    {
+        IIdentifierDictionary iddict = subdet.getDetectorElement().getIdentifierHelper().getIdentifierDictionary();
+        
+        int systemIndex, barrelIndex, layerIndex;
+        try {
+            systemIndex = iddict.getFieldIndex("system");
+            barrelIndex = iddict.getFieldIndex("barrel");
+            layerIndex = iddict.getFieldIndex("layer");
+        }
+        catch (FieldNotFoundException x)
+        {
+            throw new RuntimeException(x);
+        }
+        
+        IdentifierContext systemContext = new IdentifierContext(new int[] {systemIndex});
+        IdentifierContext subdetContext = new IdentifierContext(new int[] {systemIndex,barrelIndex});
+        IdentifierContext layerContext = new IdentifierContext(new int[] {systemIndex,barrelIndex,layerIndex});
+        
+        iddict.addIdentifierContext("system", systemContext);
+        iddict.addIdentifierContext("subdetector", subdetContext);
+        iddict.addIdentifierContext("layer", layerContext);
+    }        

 
 	public Class getSubdetectorType()
 	{