I have added into myRun.mac the lines

/geometry/test/recursive_test

which is used to check for overlaps.

=> it seems that the MasterContainerVolumes of the MiniTorus and MainMagnet interfere with the Collimator volumes.
   See pic for details.

=> O.K. : MasterContainerVolumes of MainMagnet is ~3cm too large in Z
        : MasterContainerVolumes of MiniTorus  is twice as large

###> taking a closer look: Juliette is using a different z position for collimator 3 than
     I had extracted last November (region2 was stucking in the MainMagnet structure), where I pushed
     colli #3 as close to the MainMagnet as Stan would allow me (5cm gap requested). 

.

#
# Macro file for the initialization phase of "exampleN02.cc"
# when runing in interactive mode
#
# Sets some default verbose
#

#/control/verbose 1
#/control/saveHistory
#
#/run/verbose 1
#/event/verbose 1

# running geantinos thru geometry, check for correct tracking
#/tracking/verbose 4
#/hits/verbose 1

#overlap checkout
#/geometry/test/recursive_test

#
# Store particle trajactories for visualisation
#
/tracking/storeTrajectory 1
#/tracking/storeTrajectory 0

# Create a scene handler for a specific graphics system
# (Edit the next line(s) to choose another graphic system)
#
# Invoke the OpenGL Basic 3D-Viewer: interactive display
#/vis/open OGLIX

# Invoke the Coin3D (public OpenInventor) driver: interactive
# Note: close Coin3D with  File->Escape and again File->Escape,
# otherwise the root file is corrupted 
/vis/open OIX


# Invoke the WIRED driver: offline display
#/vis/open HepRepFile

# Invoke the VRML driver: offline display (freewrl)
#/vis/open VRML2FILE

# Invoke the DAWN  driver: offline display
#/vis/open DAWNFILE

#
# Create a new empty scene
#
/vis/scene/create

#
# Declare that the world volume should be added to the scene
#
/vis/scene/add/volume

#
# Attach scene to scenehandler
#
/vis/sceneHandler/attach

#
# Draw a picture that has just the detector (no trajectories or hits).
#
#/vis/viewer/flush

#
# Declare that trajectories and hits should be added to the scene
#
/vis/scene/add/trajectories
/vis/scene/add/hits

# Set camera
/vis/viewer/reset
#/vis/viewer/set/viewpointThetaPhi 90 180 deg
#/vis/viewer/set/viewpointThetaPhi 90 90 deg
#/vis/viewer/set/viewpointThetaPhi 90 0 deg
/vis/viewer/set/viewpointThetaPhi 60 20 deg
/vis/viewer/zoom 2.0
/vis/viewer/set/style surface
#/vis/viewer/set/style surface2
#/vis/viewer/flush

# meaning unclear
/vis/scene/notifyHandlers

#
# for drawing the tracks
# (if too many tracks cause core dump => storeTrajectory 0)
#
# If multiple events in one run, accumulate all events into a single
# graphical image.  If this line is commented out, each event will instead
# appear in a separate image.
/vis/scene/endOfEventAction accumulate

# refresh image
/vis/scene/endOfRunAction refresh


#==========================
# Physical Process related
#==========================
#/Physics/CerenkovMaxPhotonsPerStep 300

#==========================
# Main Magnet related (QTOR)
#==========================
#/MainMagnet/SetStepperType         4        # G4ClassicalRK4 
#/MainMagnet/SetStepperType         8       # G4CashKarpRKF45
#/MainMagnet/SetStepperType         9       # G4RKG3_Stepper
#/MainMagnet/SetMinStep             0.05 mm

#/MainMagnet/SetBFieldScalingFactor    1.040
#/MainMagnet/SetBFieldScalingFactor    0.001
#/MainMagnet/SetBFieldScalingFactor  10.040
#/MainMagnet/SetCenterPositionInZ      0.0 cm

#================================
# Mini Magnet related (MiniTorus)
#================================
#/MiniMagnet/SetStepperType         4        # G4ClassicalRK4 
#/MiniMagnet/SetMinStep             0.05 mm

#/MiniMagnet/SetBFieldScalingFactor                   -0.078175
#/MiniMagnet/SetBFieldScalingFactor                   -100.0
#/MiniMagnet/SetCenterPositionInZ                   -505.0 cm

#/MiniMagnet/SingleCoil/SetMinDiameter               175.0mm
#/MiniMagnet/SingleCoil/SetMaxDiameter               525.0 mm
#/MiniMagnet/SingleCoil/SetDistanceCenterToBeamLine  762.5.mm


#==========================
# Target related
#==========================
/Target/SetCenterPositionInZ  -650.0 cm
/Target/SetTargetMaterial    Vacuum
#/Target/SetTargetMaterial   H2Liquid
#/Target/SetTargetMaterial   Lead
#/Target/SetTargetMaterial   Air
#/Target/SetTargetMaterial   Scintillator
#/Target/SetTargetMaterial   Aluminium


#==========================
# Shielding Wall related
#==========================
#/ShieldingWall/SetCenterPositionInZ          365.00 cm
#/ShieldingWall/SetShieldingWallMaterial      Air
#/ShieldingWall/SetShieldingWallMaterial      Lead

#/ShieldingWall/OctantCutOut/SetRadialDistance   247.26 cm
#/ShieldingWall/OctantCutOut/SetFullLengthFront  44.00 cm
#/ShieldingWall/OctantCutOut/SetFullLengthBack   76.00 cm
#/ShieldingWall/OctantCutOut/SetFullHeightFront   17.00 cm	
#/ShieldingWall/OctantCutOut/SetFullHeightBack    13.00 cm
#/ShieldingWall/OctantCutOut/SetPolarAngle        20.82 degree

#==========================
# VDC related
#==========================
# angle in respect to SHORT Frame side
/VDC/DriftCell/SetWireAngleFront     60.0 degree
/VDC/DriftCell/SetWireAngleBack     -60.0 degree
#/VDC/DriftCell/SetWireAngleFront     45.0 degree
#/VDC/DriftCell/SetWireAngleBack     -45.0 degree

#/VDC/DriftCell/SetFullThickness      26.0 mm



#==============================================
# Thickness = 64/64 inch
#/VDC/DriftCell/SetFullThickness      25.4 mm 

# Thickness = 68/64 inch
/VDC/DriftCell/SetFullThickness      26.9875 mm
#==============================================


/VDC/DriftCell/SetFullHeight         80.0 cm
#/VDC/DriftCell/SetFullWidthOnFrame   10.3188 mm
/VDC/DriftCell/SetDCNumberPerPlane    401

#==========================
# Cerenkov Detector related
#==========================
#  Air    : without Cerenkov light production 
#  Quartz  :with    Cerenkov light production
# 
# angle is definedagaing vertical (y) axis
# - a tilt angle of 0.0*deg means vertical 
# - positive angle will tilt detector against target
#
/Cerenkov/SetCerenkovMaterial HeGas
#/Cerenkov/SetCerenkovMaterial Quartz

# positions to be extracted from SolidWorks
# or by Juliette Mammei's hit distribution
# on the vertical detector plane
 
/Cerenkov/SetCenterPositionInX    0.0 cm
/Cerenkov/SetCenterPositionInY  330.5 cm 
/Cerenkov/SetCenterPositionInZ  570.0 cm
/Cerenkov/SetTiltingAngle           0.0 degree
#/QweakSim/GeometryUpdate

#/gun/particle geantino
#/gun/particle e-
#/gun/energy 1065 MeV

# FullWidthOnFrame = 25/64 inch
/VDC/DriftCell/SetFullWidthOnFrame   9.9219 mm
/run/beamOn 1
#/Qweak/PrimaryGenerator/ResetNtupleEventCounter

# FullWidthOnFrame = 26/64 inch
#/VDC/DriftCell/SetFullWidthOnFrame   10.3188 mm
#/run/beamOn 10000
#/Qweak/PrimaryGenerator/ResetNtupleEventCounter

# FullWidthOnFrame = 27/64 inch
#/VDC/DriftCell/SetFullWidthOnFrame   10.7156 mm
#/run/beamOn 10000
#/Qweak/PrimaryGenerator/ResetNtupleEventCounter

# FullWidthOnFrame =  28/64 inch
#/VDC/DriftCell/SetFullWidthOnFrame   11.1125 mm
#/run/beamOn 10000
#/Qweak/PrimaryGenerator/ResetNtupleEventCounter

# FullWidthOnFrame = 29/64 inch
#/VDC/DriftCell/SetFullWidthOnFrame   11.5094 mm
#/run/beamOn 10000
#/Qweak/PrimaryGenerator/ResetNtupleEventCounter

# FullWidthOnFrame = 30/64 inch
#/VDC/DriftCell/SetFullWidthOnFrame   11.9063 mm
#/run/beamOn 10000
#/Qweak/PrimaryGenerator/ResetNtupleEventCounter

# FullWidthOnFrame = 31/64 inch
#/VDC/DriftCell/SetFullWidthOnFrame   12.3031 mm
#/run/beamOn 10000
#/Qweak/PrimaryGenerator/ResetNtupleEventCounter

# FullWidthOnFrame = 32/64 = 1/2 inch
#/VDC/DriftCell/SetFullWidthOnFrame   12.7 mm
#/run/beamOn 10000
#/Qweak/PrimaryGenerator/ResetNtupleEventCounter