Tutorial for restG4
Table of contents
- Exercise 1. Create a simple geometry using GDML
- Exercise 2. Create a simple RML file to launch simulations
This page follows day2/session2 of the rest-school where codes can be found to run the following code.
Exercise 1. Create a simple geometry using GDML
In this exercise you will learn how to create a simple geometry using GDLM. Remember that this file has different sections:
XML Declaration
<?xml version="1.0" encoding="utf-8" ?>
External files to be included (in this case we are including material file)
<!DOCTYPE gdml [
<!ENTITY materials SYSTEM "https://rest-for-physics.github.io/materials/rest.xml">
]>
XML Schema and GDML Schema location
<gdml xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="http://service-spi.web.cern.ch/service-spi/app/releases/GDML/schema/gdml.xsd">
Numerical definitions
<define>
<variable name="world_size" value="120" />
<!-- The gas target -->
<variable name="quencherDensity" value="2.51*0.01"/> <!-- mg/cm3 -->
<variable name="quencherFraction" value="0.01"/>
<variable name="targetGasDensity" value="1.66201e-3"/> <!-- in g/cm3 -->
<variable name="gasTemperature" value="300"/> <!-- K -->
<variable name="gasPressure" value="1"/> <!-- bar -->
<!-- The vessel definitions -->
<constant name="vesselThickness" value="10" /> <!--in mm's -->
<constant name="vesselXSize" value="100" />
<constant name="vesselYSize" value="100" />
<constant name="vesselZSize" value="100"/>
<position name="vesselPosition" unit="mm" x="0" y="0" z="0"/>
</define>
Material definitions As we have included a file with material definitions, just need to referenciate it.
&materials;
Geometry
Solid declarations
<solids>
<box name="WorldSolid" x="world_size" y="world_size" z="world_size" lunit="mm"/>
<box name="solidBox" x="vesselXSize" y="vesselYSize" z="vesselZSize" lunit="mm" />
<box name="gasSolid" x="vesselXSize-2*vesselThickness" y="vesselYSize-2*vesselThickness" z="vesselZSize-2*vesselThickness" lunit="mm" />
<subtraction name="vesselSolid">
<first ref="solidBox"/>
<second ref="gasSolid"/>
</subtraction>
</solids>
Structure
<structure>
<!-- Volumes definition (material and solid assignment) -->
<volume name="gasVolume">
<materialref ref="PureArgon"/>
<solidref ref="gasSolid"/>
</volume>
<volume name="vesselVolume">
<materialref ref="G4_Cu"/>
<solidref ref="vesselSolid"/>
</volume>
<!-- Physical volume definition (volume and position assignment) -->
<volume name="World">
<materialref ref="G4_AIR"/>
<solidref ref="WorldSolid"/>
<physvol name="gas">
<volumeref ref="gasVolume"/>
<position name="gasPosition" x="0" y="0" z="0"/>
</physvol>
<physvol name="vessel">
<volumeref ref="vesselVolume"/>
<positionref ref="vesselPosition"/>
</physvol>
</volume>
</structure>
Definition of top volume
<setup name="Default" version="1.0">
<world ref="World"/>
</setup>
Final mark of GDM file
</gdml>
Activity 1: Identify in the material repository the materials appearing in the GDML file. Activity 2: Create your own box.gdml file including all the sections and visualize the geometry using the REST macro REST_Geant4_ViewGeometry("box.gdml") after launching a restRoot session restRoot -m 1.
NOTE: The argument -m 1 is equivalent to use the command restRootMacros and it will load in your ROOT interactive shell environment the REST macros installed in the installation directory.
Exercise 2. Create a simple RML file to launch simulations
In this exercise you will learn how to create an RML file to launch a restG4 simulation.
XML Declaration
<?xml version="1.0" encoding="utf-8" ?>
Initial tag
<restG4>
Parameters for the Run section
<TRestRun name="TestRun" title="A basic test with 2 active volumes">
<parameter name="experimentName" value="Test"/>
<parameter name="readOnly" value="false"/>
<parameter name="runNumber" value="auto"/>
<parameter name="runDescription" value=""/>
<parameter name="user" value="${USER}"/>
<parameter name="verboseLevel" value="1"/>
<parameter name="overwrite" value="off"/>
<parameter name="outputFileName" value="Run[fRunNumber]_[fRunType]_[fRunTag]_[fRunUser].root"/>
</TRestRun>
TRestGeant4 Metadata
<TRestGeant4Metadata name="restG4 run" title="CosmicMuonTest">
<parameter name="gdmlFile" value="box.gdml"/>
<parameter name="subEventTimeDelay" value="100us"/>
<parameter name="nRequestedEntries" value="1000"/>
<parameter name="seed" value="137"/>
<parameter name="saveAllEvents" value="false"/>
<parameter name="printProgress" value="true"/>
<generator type="surface" shape="wall" position="(0,10,0)cm" size="(30,30,0)cm" rotationAngle="3.1416/2"
rotationAxis="(1,0,0)">
<source particle="mu-" fullChain="on">
<energy type="TH1D" file="Muons.root" name="cosmicmuon"/>
<angular type="formula" name="Cos2" direction="(0,-1,0)"/>
</source>
</generator>
<detector>
<parameter name="activateAllVolumes" value="false"/>
<volume name="gas" sensitive="true" maxStepSize="1mm"/>
<volume name="vessel" maxStepSize="1mm"/>
</detector>
</TRestGeant4Metadata>
Physics List
<TRestGeant4PhysicsLists name="default" title="First physics list implementation." verboseLevel="warning">
<parameter name="cutForGamma" value="1" units="um"/>
<parameter name="cutForElectron" value="1" units="um"/>
<parameter name="cutForPositron" value="1" units="um"/>
<parameter name="cutForMuon" value="1" units="mm"/>
<parameter name="cutForNeutron" value="1" units="mm"/>
<parameter name="minEnergyRangeProductionCuts" value="1" units="keV"/>
<parameter name="maxEnergyRangeProductionCuts" value="1" units="GeV"/>
<!-- EM Physics lists -->
<physicsList name="G4EmLivermorePhysics"/>
<!-- <physicsList name="G4EmPenelopePhysics"> </physicsList> -->
<!-- <physicsList name="G4EmStandardPhysics_option3"> </physicsList> -->
<!-- Decay physics lists -->
<physicsList name="G4DecayPhysics"/>
<physicsList name="G4RadioactiveDecayPhysics"/>
<physicsList name="G4RadioactiveDecay">
<option name="ICM" value="true"/>
<option name="ARM" value="true"/>
</physicsList>
<!-- Hadron physics lists -->
<physicsList name="G4HadronElasticPhysicsHP"/>
<physicsList name="G4IonBinaryCascadePhysics"/>
<physicsList name="G4HadronPhysicsQGSP_BIC_HP"/>
<physicsList name="G4EmExtraPhysics"/>
</TRestGeant4PhysicsLists>
Final Tag
</restG4>
Activity 1: Create your own basicSim.rml file and launch simulation restG4 basic.rml.
Activity 2: Once a root file has been created, open a root session restRoot -m 1 and use the macro REST_Geant4_ViewEvent("fileName.root") to visualise the geometry and the particle tracks; use the new TBrowser to explore the Tree inside the file.
Extra activity: Go to examples and to the documentation to choose any other generator or a different geometry.
### Exercise 3. Create an RML file to launch a g4Analysis In this exercise you will learn how to create a simple rml file for g4Analysis. XML Declaration
<?xml version="1.0" encoding="UTF-8" standalone="no"?>
Initial label for TRestManager
<TRestManager name="RESTManagerSim" title="Template manager to process a simulation generated by restG4.">
Global definitions
<globals><parameter name="mainDataPath" value="."/><parameter name="verboseLevel" value="warning"/> %options are : essential silent, warning, info, debug
</globals>
Parameters for the Run section
<TRestRun name="Process" title="Geant4 basic analysis">
<parameter name="experimentName" value="preserve"/>
<parameter name="readOnly" value="false"/>
<parameter name="runNumber" value="preserve"/>
<parameter name="runTag" value="preserve"/>
<parameter name="runType" value="G4Analysis"/>
<parameter name="runDescription" value=""/>
<parameter name="user" value="${USER}"/>
<parameter name="verboseLevel" value="1"/>
<parameter name="overwrite" value="off"/>
<parameter name="outputFileName" value="Run[fRunNumber]_[fRunType]_[fRunTag]_[fRunUser].root"/>
</TRestRun>
Initial label for the TRestProcessRunner and parameter’s declarations
<TRestProcessRunner name="TemplateEventProcess" verboseLevel="info"><parameter name="eventsToProcess" value="0"/>
<parameter name="inputEventStorage" value="OFF"/>
<parameter name="outputEventStorage" value="OFF"/>
Adding a G4Analysis Process and declaring observables
<addProcess type="TRestGeant4AnalysisProcess" name="g4Ana" observable="all">
<!-- Custom observables -->
<observable name="gasVolumeEDep" value="ON"
description="Energy deposited in the gas volume in keV" />
<observable name="vesselVolumeEDep" value="ON"
description="Energy deposited in the vessel volume 1 in keV" />
<observable name="gasMeanPosX" value="ON"
description="Mean position X of the energy deposited in the gas volume " />
<observable name="gasMeanPosY" value="ON"
description="Mean position Y of the energy deposited in the gas volume " />
<observable name="gasMeanPosZ" value="ON"
description="Mean position Z of the energy deposited in the gas volume " />
</addProcess>
Final mark for the TRestProcess Runner
</TRestProcessRunner>
Adding a task
<addTask type="processEvents" value="ON"/>
Final mark for TRestManager
</TRestManager>
Activity 1: Create your own g4analyis.rml file and launch analysis restManager --f fileName.root -c g4analysis.rml.
Activity 2: Once a root file has been created, open a root session restRoot -m 1 and use the new TBrowser to explore the Tree inside the Analysis file you have created.
Extra activity: Explore the TRestGeant4Analysis documentation to know more about G4Analysis observables.