feat!(sim): Use g4Config.yaml instead of deprecated .C

CHANGELOG.md

@@ -19,6 +19,7 @@ it in future.
 * Bump minimum ROOT version to 6.36
 * Bump minimum CMake version to 3.20 (same as ROOT)
 * Change naming convention for simulation files to `{sim,geo,params}_{uuid4}.root`, with optional `--tag` parameter to specify custom identifier
+* Use g4Config.yaml instead of deprecated .C macro for Geant4 VMC configuration
 
 ### Fixed
 
@@ -82,6 +83,10 @@ it in future.
   - The geometry configuration and detector setup (`geometry/geometry_config.py`, `python/shipDet_conf.py`) have been updated to instantiate all requested SND detectors.
   - This enables running with multiple SND subdetectors simultaneously and is future-proof for additional SND designs.
 * Added the hole for SND in the Muon Shield, that is created automatically if SND key is enabled (works so far for SND_design == 2)
+* Added YAML configuration files for Geant4 VMC setup (`g4Config.yaml`, `g4Config_basic.yaml`) to replace deprecated C macros
+  - Includes physics lists, Monte Carlo processes/cuts, and Geant4 macro commands
+  - Maintains full compatibility with original C configuration functionality
+* Add SHiP::VMCConfig class to setup VMC from the YAML configuration
 
 #### Geometry and Target Station
 
@@ -393,7 +398,9 @@ it in future.
 * Remove reloading of the `geometry_config.py` in `shipDet_conf.py`
 * Removed unused run_simPgun.py
 * Remove TTCluster.py
+* Removed deprecated Geant4 VMC configuration files (`g4Config.C`, `g4Config_basic.C`, `g4config.in`, `g4config_basic.in`)
 * Remove pid class
+* Remove GCUTS (replaced by CUTGAM in Geant4)
 
 #### Build System
 

CMakeLists.txt

@@ -118,7 +118,9 @@ include(ShipMacros)
 find_package2(PUBLIC Pythia8 REQUIRED)
 find_package2(PUBLIC EvtGen REQUIRED)
 # (GENERATORS REQUIRED)
-find_package2(PUBLIC GEANT4)
+# FairRoot::MCConfigurator has transitive dependencies on Geant4 CMake targets
+# (via FairRoot::FastSim -> Geant4::G4processes), so Geant4 must be found first.
+find_package2(PUBLIC GEANT4 REQUIRED)
 find_package2(PUBLIC GEANT4DATA)
 find_package2(PUBLIC GEANT4VMC)
 find_package2(PUBLIC HEPMC)

gconfig/g4Config.yaml

@@ -0,0 +1,45 @@
+Geant4_UserGeometry:     "geomRoot"
+Geant4_PhysicsList:      "FTFP_BERT_HP_EMZ"
+Geant4_SpecialProcess:   "stepLimiter+specialCuts+specialControls"
+Geant4_SpecialStacking:  false
+Geant4_Multithreaded:    false
+
+#Geant4_MaxNStep:         10000    #default is 30000
+Geant4_Commands:
+ - /mcVerbose/all 0
+ - /mcTracking/loopVerbose 0
+ - /mcPhysics/g4HadronicProcessStoreVerbose 0
+ - /physics_lists/em/PositronToMuons true
+ - /physics_lists/em/GammaToMuons true
+ - /process/em/UseGeneralProcess false
+ - /process/em/verbose 0
+ - /process/eLoss/verbose 0
+ - /mcDet/setIsLocalMagField true
+ - /mcPhysics/setExtDecayerSelection J/psi
+
+MonteCarlo_Process:
+    PAIR:         1        #pair production
+    COMP:         1        #Compton scattering
+    PHOT:         1        #photo electric effect
+    PFIS:         0        #photofission
+    DRAY:         1        #delta-ray
+    ANNI:         1        #annihilation
+    BREM:         1        #bremsstrahlung
+    HADR:         1        #hadronic process
+    MUNU:         1        #muon nuclear interaction
+    DCAY:         1        #decay
+    LOSS:         1        #energy loss
+    MULS:         1        #multiple scattering
+
+MonteCarlo_Cut:
+    CUTGAM:       1.0E-3   #gammas (GeV)
+    CUTELE:       1.0E-3   #electrons (GeV)
+    CUTNEU:       1.0E-3   #neutral hadrons (GeV)
+    CUTHAD:       1.0E-3   #charged hadrons (GeV)
+    CUTMUO:       1.0E-3   #muons (GeV)
+    BCUTE:        1.0E-3   #electron bremsstrahlung (GeV)
+    BCUTM:        1.0E-3   #muon and hadron bremsstrahlung (GeV)
+    DCUTE:        1.0E-3   #electron delta-rays (GeV)
+    DCUTM:        1.0E-3   #muon and hadron delta-rays (GeV)
+    PPCUTM:       1.0E-3   #direct pair production by muons (GeV)
+    TOFMAX:       1.E10    #time of flight cut (s)

gconfig/g4Config_basic.yaml

@@ -0,0 +1,41 @@
+Geant4_UserGeometry:     "geomRoot"
+Geant4_PhysicsList:      "emStandard"
+Geant4_SpecialProcess:   ""
+Geant4_SpecialStacking:  false
+Geant4_Multithreaded:    false
+
+#Geant4_MaxNStep:         10000    #default is 30000
+Geant4_Commands:
+ - /mcVerbose/all 0
+ - /mcTracking/loopVerbose 0
+ - /mcPhysics/g4HadronicProcessStoreVerbose 0
+ - /process/em/verbose 0
+ - /process/eLoss/verbose 0
+ - /mcDet/setIsLocalMagField true
+
+MonteCarlo_Process:
+    PAIR:         1        #pair production
+    COMP:         1        #Compton scattering
+    PHOT:         1        #photo electric effect
+    PFIS:         0        #photofission
+    DRAY:         1        #delta-ray
+    ANNI:         1        #annihilation
+    BREM:         1        #bremsstrahlung
+    HADR:         1        #hadronic process
+    MUNU:         1        #muon nuclear interaction
+    DCAY:         1        #decay
+    LOSS:         1        #energy loss
+    MULS:         1        #multiple scattering
+
+MonteCarlo_Cut:
+    CUTGAM:       1.0E-3   #gammas (GeV)
+    CUTELE:       1.0E-3   #electrons (GeV)
+    CUTNEU:       1.0E-3   #neutral hadrons (GeV)
+    CUTHAD:       1.0E-3   #charged hadrons (GeV)
+    CUTMUO:       1.0E-3   #muons (GeV)
+    BCUTE:        1.0E-3   #electron bremsstrahlung (GeV)
+    BCUTM:        1.0E-3   #muon and hadron bremsstrahlung (GeV)
+    DCUTE:        1.0E-3   #electron delta-rays (GeV)
+    DCUTM:        1.0E-3   #muon and hadron delta-rays (GeV)
+    PPCUTM:       1.0E-3   #direct pair production by muons (GeV)
+    TOFMAX:       1.E10    #time of flight cut (s)

macro/ShipAna.py

@@ -73,7 +73,10 @@
 run = ROOT.FairRunSim()
 run.SetName("TGeant4")  # Transport engine
 run.SetSink(ROOT.FairRootFileSink(ROOT.TMemFile("output", "recreate")))  # Dummy output file
-run.SetUserConfig("g4Config_basic.C")  # geant4 transport not used, only needed for the mag field
+# geant4 transport not used, only needed for the mag field
+ROOT.gInterpreter.ProcessLine(
+    'FairRunSim::Instance()->SetSimulationConfig(std::make_unique<SHiP::VMCConfig>("g4Config", "g4Config_basic.yaml"));'
+)
 rtdb = run.GetRuntimeDb()
 # -----Create geometry----------------------------------------------
 modules = shipDet_conf.configure(run, ShipGeo)

macro/ShipReco.py

@@ -136,7 +136,9 @@ def mem_monitor():
 run = ROOT.FairRunSim()
 run.SetName("TGeant4")  # Transport engine
 run.SetSink(ROOT.FairRootFileSink(ROOT.TMemFile("output", "recreate")))  # Dummy output file
-run.SetUserConfig("g4Config_basic.C")  # geant4 transport not used, only needed for creating VMC field
+ROOT.gInterpreter.ProcessLine(
+    'FairRunSim::Instance()->SetSimulationConfig(std::make_unique<SHiP::VMCConfig>("g4Config", "g4Config_basic.yaml"));'
+)  # geant4 transport not used, only needed for creating VMC field
 rtdb = run.GetRuntimeDb()
 # -----Create geometry----------------------------------------------
 modules = shipDet_conf.configure(run, ShipGeo)

macro/create_field_perturbation.py

@@ -25,14 +25,17 @@ def create_csv_field_map(options):
     run = r.FairRunSim()
     run.SetName("TGeant4")  # Transport engine
     run.SetSink(r.FairRootFileSink("tmp_file"))  # Output file
-    # user configuration file default g4Config.C
-    run.SetUserConfig("g4Config.C")
+    # Use SHiP::VMCConfig for YAML configuration
+    r.gInterpreter.ProcessLine(
+        'FairRunSim::Instance()->SetSimulationConfig(std::make_unique<SHiP::VMCConfig>("g4Config", "g4Config.yaml"));'
+    )
     shipDet_conf.configure(run, ship_geo)
     primGen = r.FairPrimaryGenerator()
     primGen.SetTarget(ship_geo.target.z0 + 70.845 * u.m, 0.0)
     #
     run.SetGenerator(primGen)
     run.SetStoreTraj(r.kFALSE)
+    # ShipStack is now automatically created by SHiP::VMCConfig
     run.Init()
     fieldMaker = geomGeant4.addVMCFields(ship_geo, "", True)
 

macro/inspectGeant4Geo.py

@@ -20,9 +20,13 @@
 run = ROOT.FairRunSim()
 ShipGeo = load_from_root_file(fgeo, "ShipGeo")
 modules = shipDet_conf.configure(run, ShipGeo)
-run.SetUserConfig("g4Config.C")
+# Use SHiP::VMCConfig for YAML configuration
+ROOT.gInterpreter.ProcessLine(
+    'FairRunSim::Instance()->SetSimulationConfig(std::make_unique<SHiP::VMCConfig>("g4Config", "g4Config.yaml"));'
+)
 run.SetName("TGeant4")
 run.SetSink(ROOT.FairRootFileSink(ROOT.TMemFile("output", "recreate")))
+# ShipStack is now automatically created by SHiP::VMCConfig
 run.Init()
 run.Run(0)
 import geomGeant4

macro/run_fixedTarget.py

@@ -248,7 +248,8 @@ def get_work_dir(run_number, tag=None):
 run = ROOT.FairRunSim()
 run.SetName(mcEngine)  # Transport engine
 run.SetSink(ROOT.FairRootFileSink(outFile))  # Output file
-run.SetUserConfig("g4Config.C")  # user configuration file default g4Config.C
+# Use SHiP::VMCConfig for YAML configuration
+run.SetSimulationConfig(ROOT.std.make_unique[ROOT.SHiP.VMCConfig]("g4Config", "g4Config.yaml"))
 rtdb = run.GetRuntimeDb()
 
 # -----Materials----------------------------------------------
@@ -385,6 +386,7 @@ def get_work_dir(run_number, tag=None):
 run.SetGenerator(primGen)
 
 # -----Initialize simulation run------------------------------------
+# ShipStack is now automatically created by SHiP::VMCConfig
 run.Init()
 
 gMC = ROOT.TVirtualMC.GetMC()