usage.md

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+# Usage
+
+Run a simulation:  `./VKRun run.mac`
+
+## run.mac
+
+The file `run.mac` contains commands which can be used to modify the simulation. The commands currently available are:
+
+### Verbosity
+* /run/verbose  0
+* /event/verbose  0
+* /tracking/verbose 0
+* /process/em/verbose 0
+
+### Physics
+* /VK/physics/opticalPhysics false
+
+### Setup
+* /VK/detector/volumes/betaDetector true
+* /VK/detector/volumes/magnet true
+* /VK/detector/volumes/catcherFoil true
+* /VK/detector/volumes/shield true
+* /VK/storeTrajectoryData false
+
+### Magnetic Field
+* /VK/field/enable true
+* /VK/field/maxbfield 0.48 tesla
+                
+### Initialization
+* /run/initialize
+
+### Particle source
+* /gps/direction 0 0 1
+* /gps/position 0 0 30.5 cm
+* /gps/particle e-
+* /gps/energy 1 MeV
+* /gps/ang/type iso
+* /gps/ang/mintheta  90 deg
+* /gps/ang/maxtheta 180 deg
+* /gps/particle e-
+* /VK/source/betaSpectrum true
+* /VK/source/betaEndPoint 7.00 MeV
+* /VK/source/betaMinEnergy 5.00 MeV
+* /VK/source/betaMaxEnergy 7.00 MeV
+* /gps/energy 1 GeV
+* /VK/source/cosmicRayAngDist true
+* /VK/source/cosmicRayMinZenithAngle  0 deg
+* /VK/source/cosmicRayMaxZenithAngle 90 deg
+* /VK/source/diskShapedSource true
+* /VK/source/innerDiameter 0 cm
+* /VK/source/outerDiameter 60 cm
+* /VK/source/surfaceNormal 0 1 0
+
+### Output 
+/VK/output/zeroSuppression true
+/VK/output/openFile output/allowed_Emin4.8MeV.root                
+
+### Run simulation
+* /run/beamOn 100000
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