Changed .README.txt .README.mdy

.README.md

+
+### ZDC Light Guide Monte Carlo
+
+
+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
+
+#### main()
+
+define Random Number Engine, initial seed, CAD input and GDML output
+
+#### G4VUserPhysicsList
+
+ - Define particles; including - *** G4OpticalPhoton     ***
+ - Define processes; including
+   - *** G4Cerenkov          ***
+   - *** G4Scintillation     ***
+   - *** G4OpAbsorption      ***
+   - *** G4OpRayleigh        ***
+   - *** G4OpBoundaryProcess ***
+
+#### 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.
+
+#### 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
+
+#### G4VUserPrimaryGeneratorAction
+
+Use G4GeneralParticleSource to shoot an optical photon into the light guide
+Particle type and distribution is set in run1.mac
+
+#### G4UserRunAction
+
+define G4Timer (start/stop)
+define G4AnalysisManager (output .root file)
+set verbose levels
+
+#### 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
+
+#### PMTSD
+
+Records a PMTHit if the photon strikes the PMT window
+
+#### G4UserEventAction
+
+ Show how to count the number of secondary particles in an event
+
+#### 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.
+
+#### How to start
+
+ - compile and link to generate an executable
+```
+  $ mkdir zdclg-build zdclg-install
+  $ cd zdclg-build
+  $ cmake -DCMAKE_INSTALL_PREFIX=../zdclg-install /path/to/zdclg
+```
+
+   This example handles the program arguments in a new way.
+   It can be run with the following optional arguments:
+```
+  $ ./lightGuide [-m macro ]
+                  [-u UIsession]
+                  [-t nThreads]
+                  [-r seed]
+                  [-o outputFileName]
+                  [-c CADmodelName filetype]
+                  [-co GDMLoutFileName]
+```
+
+   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
+```
+   $ ./lightGuide -m run1.mac
+```
+
+ - execute lightGuide in 'interactive mode' with visualization
+```
+$ lightGuide
+....
+Idle> type your commands. For instance:
+Idle> /control/execute run1.mac
+....
+Idle> exit
+```