Gabriele Cosmo
82 lines
2.9 KiB
Markdown
82 lines
2.9 KiB
Markdown
\page ExampleRE04 Example RE04
|
|
|
|
|
|
Contact : M.Asai (SLAC)
|
|
|
|
## Introduction
|
|
|
|
This example demonstrates how to define a layered mass
|
|
geometry in parallel world. In the mass (tracking) world,
|
|
there are two boxes only. One is the world volume and the
|
|
other is a box in the world. They both are made of air.
|
|
Thus, if tracks do not see materials (water and lead)
|
|
defined in the parallel world, they rarely interact.
|
|
In the parallel world, there are boxes made of water and
|
|
lead.
|
|
|
|
### Geometry
|
|
|
|
RE04DetectorConstruction defines the mass (tracking)
|
|
geometry. It firstly defines all materials which apear
|
|
either in mass world or parallel world. Then in SetupGeometry()
|
|
method, it defines the world volume and a box named "phantom".
|
|
Both boxes are made of air.
|
|
|
|
RE04ParallelWorldConstruction defines the parallel world.
|
|
For a parallel world, solid, logical and physical volumes
|
|
which represent parallel world must not be created here but
|
|
should be taken through G4VUserParallelWorld::GetWorld()
|
|
method which creates clones of solid, logical and physical
|
|
volumes of the world volume of the mass world. Please note
|
|
that this cloned logical volume of the parallel world volume
|
|
does not have a valid pointer to aa material but null.
|
|
|
|
In the parallel world, if a logical volume has a valid
|
|
material pointer, a track in this volume (precisely saying
|
|
a physical volume which is made of this logical volume)
|
|
will see the material defined in this logical volume,
|
|
regardless of the material in the mass geometry. If a
|
|
logical volume has a null material pointer, a track will
|
|
see the ordinary material defined in the mass world.
|
|
|
|
RE04ParallelWorldConstruction defines one placement
|
|
volume of box-shape, which is made of water, and a mother
|
|
box (placement volume with null material pointer), which
|
|
contains parameterized volumes. RE04ParallelWorldParam
|
|
class defines a parameterization of the parameterized
|
|
volume "paraPara", which represents two boxes at different
|
|
locations and made of water and lead respectively.
|
|
|
|
### Physics
|
|
|
|
The physics list is taken from referenced physics-list FTFP_BERT
|
|
in Geant4.
|
|
|
|
## Macro files
|
|
|
|
The macro file score.mac defines a scoring mesh which covers
|
|
the "Phantom" and scores energy deposition. It shoots 1000
|
|
primary particles (by default 10 GeV muon-). Though the mass
|
|
world has only air, given tracks, both primary muons and
|
|
secondary particles see water and lead defined in the parallel
|
|
world, you will see the energy deposition is not evenly
|
|
distributed.
|
|
|
|
The macro file batch.mac defines the same setup as score.mac,
|
|
but visualization is disabled and the score dump is activated.
|
|
|
|
## User action classes
|
|
|
|
In the RE04ActionInitialization class, three user action classes are commented out,
|
|
i.e.
|
|
- RE04EventAction
|
|
- RE04TrackingAction
|
|
- RE04SteppingAction
|
|
|
|
By using RE04SteppingAction, you will
|
|
see a material name which a track sees for each step.
|
|
By using RE04EventAction and RE04TrackingAction, you will
|
|
see the similar information for all trajectories of one
|
|
event.
|
|
|