diff --git a/Generators/FaserCosmicGenerator/CMakeLists.txt b/Generators/FaserCosmicGenerator/CMakeLists.txt
new file mode 100644
index 0000000000000000000000000000000000000000..5bea0687466c0e7a4d51398e3fc9ed718215a6c6
--- /dev/null
+++ b/Generators/FaserCosmicGenerator/CMakeLists.txt
@@ -0,0 +1,10 @@
+################################################################################
+# Package: FaserCosmicGenerator
+################################################################################
+
+# Declare the package name:
+atlas_subdir( FaserCosmicGenerator )
+
+# Install files from the package:
+atlas_install_python_modules( python/*.py POST_BUILD_CMD ${ATLAS_FLAKE8} )
+
diff --git a/Generators/FaserCosmicGenerator/README.md b/Generators/FaserCosmicGenerator/README.md
new file mode 100644
index 0000000000000000000000000000000000000000..4a1e19c73dbd391e77de2b05907fa5778b006165
--- /dev/null
+++ b/Generators/FaserCosmicGenerator/README.md
@@ -0,0 +1,3 @@
+Faser cosmic-ray generator
+
+Documentation goes here...
\ No newline at end of file
diff --git a/Generators/FaserCosmicGenerator/python/__init__.py b/Generators/FaserCosmicGenerator/python/__init__.py
new file mode 100644
index 0000000000000000000000000000000000000000..42ea59fd7bebf56ad3497e2c7352f475aaba0950
--- /dev/null
+++ b/Generators/FaserCosmicGenerator/python/__init__.py
@@ -0,0 +1,4 @@
+# Copyright (C) 2021 CERN for the benefit of the FASER collaboration
+
+from FaserCosmicGenerator.cosmicSampler import CosmicSampler
+
diff --git a/Generators/FaserCosmicGenerator/python/cosmicSampler.py b/Generators/FaserCosmicGenerator/python/cosmicSampler.py
new file mode 100644
index 0000000000000000000000000000000000000000..4dca1fed08bdd7321d9bba772677af9af7b5bfa2
--- /dev/null
+++ b/Generators/FaserCosmicGenerator/python/cosmicSampler.py
@@ -0,0 +1,47 @@
+# Copyright (C) 2021 CERN for the benefit of the FASER collaboration
+
+import ROOT,math,random
+
+PI = math.pi
+TWOPI = 2*math.pi
+
+from ParticleGun.samplers import Sampler, SampledParticle
+
+class CosmicSampler(Sampler):
+ "Cosmic ray sampler"
+
+ def __init__(self, maxMuonEnergyGeV = 10000, targetDepthMeters = 85, targetRadiusMm = 3000, thetaMinDegree = 0, thetaMaxDegree = 80):
+ if thetaMinDegree > thetaMaxDegree :
+ return RuntimeError("thetaMin must be less than or equal to thetaMax")
+
+ self.maxEnergy = maxMuonEnergyGeV
+ self.depth = targetDepthMeters
+ self.radiusMm = targetRadiusMm # used for generating start position
+ self.radiusCm = self.radiusMm/10 # used for calculating rates
+ self.cosThMax = math.cos(thetaMinDegree*PI/180)
+ self.cosThMin = math.cos(thetaMaxDegree*PI/180)
+ # read range data
+ # compute rate
+
+ def shoot(self):
+ # generate one event here
+ self.genPosition = ROOT.TLorentzVector()
+ self.genMomentum = ROOT.TLorentzVector()
+
+ # placeholders to test class structure - should create a vertically down 1 TeV mu- starting above the detector
+ self.genPosition.SetY(self.radiusMm)
+ self.genMomentum.SetPxPyPzE(0,-math.sqrt((1.0e6)**2-(105.71)**2),0,1.0e6)
+ self.pdgCode = 13
+ # end placeholders
+
+ particles = []
+ p = SampledParticle(self.pdgCode)
+ p.mom = self.genMomentum
+ p.pos = self.genPosition
+ particles.append(p)
+ return particles
+
+ def __call__(self):
+ return self.shoot()
+
+
diff --git a/Simulation/G4Faser/G4FaserAlg/test/runG4Cosmics.py b/Simulation/G4Faser/G4FaserAlg/test/runG4Cosmics.py
new file mode 100644
index 0000000000000000000000000000000000000000..ad04571192f49a3500e5de4eca60b3a2e12019f5
--- /dev/null
+++ b/Simulation/G4Faser/G4FaserAlg/test/runG4Cosmics.py
@@ -0,0 +1,137 @@
+#!/usr/bin/env python
+if __name__ == "__main__":
+ import os
+ import sys
+ import GaudiPython
+ import ParticleGun as PG
+ from FaserCosmicGenerator import CosmicSampler
+ from AthenaConfiguration.ComponentAccumulator import ComponentAccumulator
+ from AthenaConfiguration.ComponentFactory import CompFactory
+ from AthenaCommon.AppMgr import *
+ from AthenaCommon.Logging import log, logging
+ from AthenaCommon.SystemOfUnits import TeV
+ from AthenaCommon.PhysicalConstants import pi
+ from AthenaCommon.Constants import VERBOSE, INFO
+ from AthenaCommon.Configurable import Configurable
+ from CalypsoConfiguration.AllConfigFlags import ConfigFlags
+ from CalypsoConfiguration.MainServicesConfig import MainServicesCfg
+ from AthenaPoolCnvSvc.PoolReadConfig import PoolReadCfg
+ from McEventSelector.McEventSelectorConfig import McEventSelectorCfg
+ from OutputStreamAthenaPool.OutputStreamConfig import OutputStreamCfg
+ from FaserGeoModel.FaserGeoModelConfig import FaserGeometryCfg
+ from G4FaserAlg.G4FaserAlgConfigNew import G4FaserAlgCfg
+ from G4FaserServices.G4FaserServicesConfigNew import G4GeometryNotifierSvcCfg
+#
+# Set up logging and new style config
+#
+ log.setLevel(VERBOSE)
+ Configurable.configurableRun3Behavior = True
+#
+# Input settings (Generator file)
+#
+# from AthenaConfiguration.TestDefaults import defaultTestFiles
+# ConfigFlags.Input.Files = defaultTestFiles.EVNT
+#
+# Alternatively, these must ALL be explicitly set to run without an input file
+# (if missing, it will try to read metadata from a non-existent file and crash)
+#
+ ConfigFlags.Input.Files = [""]
+ ConfigFlags.Input.isMC = True
+ ConfigFlags.Input.RunNumber = 12345
+ ConfigFlags.Input.Collections = [""]
+ ConfigFlags.Input.ProjectName = "mc19"
+ ConfigFlags.Common.isOnline = False
+ ConfigFlags.Beam.Type = "collisions"
+ ConfigFlags.Beam.Energy = 7*TeV # Informational, does not affect simulation
+ ConfigFlags.GeoModel.FaserVersion = "FASER-01" # Always needed
+ ConfigFlags.IOVDb.GlobalTag = "OFLCOND-XXXX-XXX-XX" # Always needed; only the OFLCOND part matters
+# Workaround for bug/missing flag; unimportant otherwise
+ ConfigFlags.addFlag("Input.InitialTimeStamp", 0)
+# Workaround to avoid problematic ISF code
+ ConfigFlags.GeoModel.Layout = "Development"
+#
+# Output settings
+#
+ ConfigFlags.Output.HITSFileName = "cosmics.HITS.pool.root"
+ ConfigFlags.GeoModel.GeoExportFile = "faserGeo.db" # Optional dump of geometry for browsing in vp1light
+#
+# Geometry-related settings
+# Do not change!
+#
+ ConfigFlags.Detector.SimulateVeto = True
+ ConfigFlags.Detector.GeometryVeto = True
+ ConfigFlags.Detector.SimulateTrigger= True
+ ConfigFlags.Detector.GeometryTrigger= True
+ ConfigFlags.Detector.SimulatePreshower = True
+ ConfigFlags.Detector.GeometryPreshower = True
+ ConfigFlags.Detector.SimulateFaserSCT = True
+ ConfigFlags.Detector.GeometryFaserSCT = True
+ ConfigFlags.Detector.SimulateUpstreamDipole = True
+ ConfigFlags.Detector.SimulateCentralDipole = True
+ ConfigFlags.Detector.SimulateDownstreamDipole = True
+ ConfigFlags.Detector.GeometryUpstreamDipole = True
+ ConfigFlags.Detector.GeometryCentralDipole = True
+ ConfigFlags.Detector.GeometryDownstreamDipole = True
+ ConfigFlags.GeoModel.Align.Dynamic = False
+ ConfigFlags.Sim.ReleaseGeoModel = False
+#
+# All flags should be set before calling lock
+#
+ ConfigFlags.lock()
+#
+# Construct ComponentAccumulator
+#
+ acc = MainServicesCfg(ConfigFlags)
+#
+# Particle Gun generator (comment out to read generator file)
+# Raw energies (without units given) are interpreted as MeV
+#
+ pg = PG.ParticleGun()
+ pg.McEventKey = "GEN_EVENT"
+ pg.randomSeed = 123456
+
+ pg.sampler = CosmicSampler()
+ acc.addEventAlgo(pg, "AthBeginSeq") # to run *before* G4
+#
+# Only one of these two should be used in a given job
+# (MCEventSelectorCfg for generating events with no input file,
+# PoolReadCfg when reading generator data from an input file)
+#
+ acc.merge(McEventSelectorCfg(ConfigFlags))
+ # acc.merge(PoolReadCfg(ConfigFlags))
+#
+# Output stream configuration
+#
+ acc.merge(OutputStreamCfg(ConfigFlags,
+ "HITS",
+ ["EventInfo#*",
+ "McEventCollection#TruthEvent",
+ "McEventCollection#GEN_EVENT",
+ "ScintHitCollection#*",
+ "FaserSiHitCollection#*"
+ ], disableEventTag=True))
+ acc.getEventAlgo("OutputStreamHITS").AcceptAlgs = ["G4FaserAlg"] # optional
+ acc.getEventAlgo("OutputStreamHITS").WritingTool.ProcessingTag = "StreamHITS" # required
+#
+# Here is the configuration of the Geant4 pieces
+#
+ acc.merge(FaserGeometryCfg(ConfigFlags))
+ acc.merge(G4FaserAlgCfg(ConfigFlags))
+ acc.addService(G4GeometryNotifierSvcCfg(ConfigFlags, ActivateLVNotifier=True))
+#
+# Verbosity
+#
+# ConfigFlags.dump()
+# logging.getLogger('forcomps').setLevel(VERBOSE)
+# acc.foreach_component("*").OutputLevel = VERBOSE
+# acc.foreach_component("*ClassID*").OutputLevel = INFO
+# acc.getService("StoreGateSvc").Dump=True
+# acc.getService("ConditionStore").Dump=True
+# acc.printConfig()
+ f=open('FaserG4AppCfg_EVNT.pkl','wb')
+ acc.store(f)
+ f.close()
+#
+# Execute and finish
+#
+ sys.exit(int(acc.run(maxEvents=500).isFailure()))