diff --git a/.README.txt b/.README.txt
deleted file mode 100644
index 0777aa1038142de74020046bdcc2a2943459bde2..0000000000000000000000000000000000000000
--- a/.README.txt
+++ /dev/null
@@ -1,124 +0,0 @@
-
-///\file "zdclg/.README.txt"
-///\brief LightGuide README page
-
-This simulation is based on OpNovice and OpNovice2
-
-Build requirements
-  Geant4 compiled with GDML and additional datasets
-  ROOT
-  -CADMesh is required to read CAD models (i.e. stl, step), but is optional for compiling
-
-\section lightGuide_s1 main()
-
-define Random Number Engine, initial seed, CAD input and GDML output
-
-\section lightGuide_s2 G4VUserPhysicsList
-
- - Define particles; including - *** G4OpticalPhoton     ***
- - Define processes; including
-   - *** G4Cerenkov          ***
-   - *** G4Scintillation     ***
-   - *** G4OpAbsorption      ***
-   - *** G4OpRayleigh        ***
-   - *** G4OpBoundaryProcess ***
-
-\section lightGuide_s3 Materials
-
-defines many materials for potential use
-    For our purposes the G4OpticalSurface AlSurface and the G4Material Al and Air
-    will be given optical properties and used for construction.
-
-\section lightGuide_s4 G4VUserDetectorConstruction
-
-A light guide is made either by simple G4trd or by importing a model
-    via CADMesh.
-    define G4LogicalBorderSurface between the light guide and world volume
-    defines a PMT window sensitive detector at the top of the light guide
-    AlSurface properties can be modified via DetectorMessenger via the following commands
-    /lightGuide/surfaceModel
-    /lightGuide/surfaceType
-    /lightGuide/surfaceFinish
-    /lightGuide/surfaceSigmaAlpha
-    /lightGuide/surfaceProperty
-
-    examples can be found in run1.mac
-
-\section lightGuide_s5 G4VUserPrimaryGeneratorAction
-
-Use G4GeneralParticleSource to shoot an optical photon into the light guide
-Particle type and distribution is set in run1.mac
-
-\section lightGuide_s6 G4UserRunAction
-
-define G4Timer (start/stop)
-define G4AnalysisManager (output .root file)
-set verbose levels
-
-\section lightGuide_s7 PMTHit
-
-stores G4int         trackID,
-       G4ThreeVector pos;      // Origin position of the photon
-       G4ThreeVector hit;      // Location where the photon hit the PMT window
-       G4double      energy;   // Energy of the photon
-       G4ThreeVector momentum; // Momentum of the photon (direction)
-       G4double      time;     // Time of arrival of the photon
-for each hit on the PMT sensitive detector
-
-\section lightGuide_s8 PMTSD
-
-Records a PMTHit if the photon strikes the PMT window
-
-\section lightGuide_s9 G4UserEventAction
-
- Show how to count the number of secondary particles in an event
-
-\section lightGuide_s10 Visualisation
-
- The Visualization Manager is set in the main().
- The initialisation of the drawing is done via a set of /vis/ commands
- in the macro vis.mac. This macro is automatically read from
- the main in case of interactive running mode.
-
-\section lightGuide_s11 How to start
-
- - compile and link to generate an executable
-\verbatim
-  % mkdir zdclg-build zdclg-install
-  % cd zdclg-build
-  % cmake -DCMAKE_INSTALL_PREFIX=../zdclg-install /path/to/zdclg
-\endverbatim
-
-   This example handles the program arguments in a new way.
-   It can be run with the following optional arguments:
-\verbatim
-  % ./lightGuide [-m macro ]
-                 [-u UIsession]
-                 [-t nThreads]
-                 [-r seed]
-                 [-o outputFileName]
-                 [-c CADmodelName filetype]
-                 [-co GDMLoutFileName]
-\endverbatim
-
-   The -t option is available only in multi-threading mode
-   and it allows the user to override the Geant4 default number of
-   threads. The number of threads can be also set via G4FORCENUMBEROFTHREADS
-   environment variable which has the top priority.
-
- - execute lightGuide in 'batch' mode from macro files
-\verbatim
-   % ./lightGuide -m run1.mac
-\endverbatim
-
- - execute lightGuide in 'interactive mode' with visualization
-\verbatim
-% lightGuide
-....
-Idle> type your commands. For instance:
-Idle> /control/execute run1.mac
-....
-Idle> exit
-\endverbatim
-
-*/
diff --git a/include/DetectorConstruction.hh b/include/DetectorConstruction.hh
index 79c4193a9d94c15239f1e1319ce89e08f2f06b20..17d50b72b8f9252664ad57dc4901d0f871dd45d0 100644
--- a/include/DetectorConstruction.hh
+++ b/include/DetectorConstruction.hh
@@ -52,7 +52,7 @@ class DetectorConstruction : public G4VUserDetectorConstruction
   public:
     virtual G4VPhysicalVolume* Construct();
     void SetCADFilename     (std::string name);
-    void SetCADFiletype     (std::string type){filetype   = type;}
+    void SetCADFiletype     (std::string type){m_filetype   = type;}
     void SetGDMLoutName     (std::string name){GDMLoutput = name;}
 
     void SetSurfaceSigmaAlpha (G4double v);
@@ -74,24 +74,30 @@ class DetectorConstruction : public G4VUserDetectorConstruction
     G4LogicalVolume*     m_logicWorld;
     G4VPhysicalVolume*   m_physWorld;
 
-    G4LogicalVolume*     cad_logical;
-    G4VPhysicalVolume*   cad_physical;
+    G4LogicalVolume*     m_logicLightGuide;
+    G4VPhysicalVolume*   m_physLightGuide;
+
+    G4Box*               m_solidFillGas;
+    G4LogicalVolume*     m_logicFillGas;
+    G4VPhysicalVolume*   m_physFillGas;
+
 
     G4int m_rotX;
     G4int m_rotY;
     G4int m_rotZ;
+
     G4double m_offsetX;
     G4double m_offsetY;
     G4double m_offsetZ;
 
     Materials* materials;
 
-    std::string filename = "";
-    std::string filetype = "";
+    std::string m_filename;
+    std::string m_filetype;
     std::string GDMLoutput;
 
-    G4GDMLParser fParser;
-    DetectorMessenger* fDetectorMessenger;
+    G4GDMLParser m_Parser;
+    DetectorMessenger* m_DetectorMessenger;
 };
 
 #endif /*DetectorConstruction_h*/
diff --git a/src/DetectorConstruction.cc b/src/DetectorConstruction.cc
index b0cfca98465edb8722f5d436ccbeaf3737f2decb..75434922819c7fe76077d75816de10e9fe6b121a 100644
--- a/src/DetectorConstruction.cc
+++ b/src/DetectorConstruction.cc
@@ -66,9 +66,11 @@
  *
  */
 DetectorConstruction::DetectorConstruction()
- : G4VUserDetectorConstruction(),fDetectorMessenger(nullptr){
+ : G4VUserDetectorConstruction(),m_DetectorMessenger(nullptr){
    materials = Materials::getInstance();
-   fDetectorMessenger = new DetectorMessenger(this);
+   m_DetectorMessenger = new DetectorMessenger(this);
+   m_filename = m_filetype = "";
+
 }
 
 
@@ -126,7 +128,7 @@ G4VPhysicalVolume* DetectorConstruction::Construct(){
 
   //----------------- Make the light guide -----------------//
   //If we have defined a CAD file, use it
-  if(filename != ""){
+  if(m_filename != ""){
 
     // CAD model rotation.
     G4RotationMatrix * rot = new G4RotationMatrix();
@@ -136,32 +138,32 @@ G4VPhysicalVolume* DetectorConstruction::Construct(){
 
 
     #ifdef CADMESH
-    if(filetype == "stl"){
-      CADMesh* mesh = new CADMesh((char*) filename.c_str());
+    if(m_filetype == "stl"){
+      CADMesh* mesh = new CADMesh((char*) m_filename.c_str());
       mesh->SetScale(mm);
       mesh->SetOffset( G4ThreeVector(-20*cm, 0, 0) );
       mesh->SetReverse(false);
 
-      cad_logical =
+      m_logicLightGuide =
         new G4LogicalVolume(mesh->TessellatedMesh(), //solid
                             Al,                      //material
                             "LightGuide");           //name
     }
     #endif
 
-    if(filetype == "gdml"){
-      fParser.Read(filename);
+    if(m_filetype == "gdml"){
+      m_Parser.Read(m_filename);
     }
-    if(filetype == "step"){
-      cad_logical = fParser.ParseST(filename,Air,Al);
+    if(m_filetype == "step"){
+      m_logicLightGuide = m_Parser.ParseST(m_filename,Air,Al);
     }
 
-    if(cad_logical !=0 ){
-      cad_physical =
+    if(m_logicLightGuide !=0 ){
+      m_physLightGuide =
         new G4PVPlacement(rot,
                           G4ThreeVector(0,0,lgHeight-(3*cm)),
-                          cad_logical,
-                          "cad_physical",
+                          m_logicLightGuide,
+                          "physLightGuide",
                           m_logicWorld,
                           false,
                           0);
@@ -169,26 +171,9 @@ G4VPhysicalVolume* DetectorConstruction::Construct(){
 
       if(GDMLoutput != ""){
         G4GDMLParser* gdml = new G4GDMLParser();
-        gdml->Write("GDMLoutput",cad_physical);
+        gdml->Write("GDMLoutput",m_physLightGuide);
       }
 
-
-    //Make the surface optically reflective
-    /*G4LogicalSkinSurface* alumLSS =
-      new G4LogicalSkinSurface("AlSkinSurface",
-                               cad_logical,
-                               materials->AlSurface );*/
-    G4LogicalBorderSurface* alumLSS =
-      new G4LogicalBorderSurface("AlSurface",
-                                 m_physWorld,
-                                 cad_physical,
-                                 materials->AlSurface );
-   G4LogicalBorderSurface* alumLSS1 =
-     new G4LogicalBorderSurface("AlSurface",
-                                cad_physical,
-                                m_physWorld,
-                                materials->AlSurface );
-
   }else{
     //Create a trapezoidal air light guide made of aluminum sheet
     G4double thickness = 1.0*mm;
@@ -220,38 +205,35 @@ G4VPhysicalVolume* DetectorConstruction::Construct(){
                              outter,
                              inner);
 
-    G4LogicalVolume* logicLightGuide =
+    G4LogicalVolume* m_logicLightGuide =
       new G4LogicalVolume(LightGuide,
                           Al,
                           "BasicLightGuide");
 
-    G4VPhysicalVolume*  physLightGuide =
+    G4VPhysicalVolume*  m_physLightGuide =
       new G4PVPlacement(0,
                         G4ThreeVector(0, 0, HeightZ),
-                        logicLightGuide,
+                        m_logicLightGuide,
                         "BasicLightGuide",
                         m_logicWorld,
                         false,
                         0);
-    (void)physLightGuide;
-
-    /*G4LogicalSkinSurface* alumLSS =
-      new G4LogicalSkinSurface("AlSkinSurface",
-                               logicLightGuide,
-                               materials->AlSurface );*/
-   G4LogicalBorderSurface* alumLSS1 =
-     new G4LogicalBorderSurface("AlSurface",
-                                physLightGuide,
-                                m_physWorld,
-                                materials->AlSurface );
-   G4LogicalBorderSurface* alumLSS2 =
-     new G4LogicalBorderSurface("AlSurface",
-                                m_physWorld,
-                                physLightGuide,
-                                materials->AlSurface );
 
   }//end else
 
+  //----------------- Define Optical Borders -----------------//
+
+  G4LogicalBorderSurface* alumLSS1 =
+    new G4LogicalBorderSurface("AlSurface",
+                               m_physLightGuide,
+                               m_physWorld,
+                               materials->AlSurface );
+  G4LogicalBorderSurface* alumLSS2 =
+    new G4LogicalBorderSurface("AlSurface",
+                               m_physWorld,
+                               m_physLightGuide,
+                               materials->AlSurface );
+
 
   //----------------- Define PMT window -----------------//
   double PMTradius = 65.0/2*mm;
@@ -336,8 +318,8 @@ void DetectorConstruction::SetSurfaceModel(const G4OpticalSurfaceModel model){
 }
 
 void DetectorConstruction::SetCADFilename(std::string name){
-  filename = name;
-  G4cout << "Using " << filename << G4endl;
+  m_filename = name;
+  G4cout << "Using " << m_filename << G4endl;
   delete G4SDManager::GetSDMpointer()->FindSensitiveDetector("MyPMT");
   G4RunManager::GetRunManager()->GeometryHasBeenModified();
   //G4RunManager::GetRunManager()->ResetNavigator();