Gabriele Cosmo
125 lines
4.1 KiB
Markdown
125 lines
4.1 KiB
Markdown
\page ExampleFissionFragment Example FissionFragment
|
|
|
|
This example demonstrates an application of the fission fragment model in the
|
|
NeutronHP model. This example is capable of using both models, but is designed
|
|
around the Wendt Fission Model. A warning will be shown if the environment
|
|
variable that enables the Wendt fission model is not set.
|
|
|
|
\tableofcontents
|
|
|
|
<HR>
|
|
|
|
## EXECUTION
|
|
|
|
### ENVIRONMENT
|
|
- `G4NEUTRONHP_PRODUCE_FISSION_FRAGMENTS`
|
|
- Required
|
|
- The example requires this enviroment variable to be set. An error will be
|
|
displayed and the example will terminate if this environment variable is
|
|
not set.
|
|
|
|
- `G4NEUTRON_HP_USE_WENDT_FISSION_MODEL`
|
|
- Optional
|
|
- This environment variable enables the Wendt fission model contained within
|
|
the NeutronHP model for simulating fission events. The default model will
|
|
be used otherwise. A warning will be displayed if this environment
|
|
variable is not set.
|
|
|
|
### COMMAND LINE ARGUMENTS
|
|
The example can be run without any input arguments. However, a few options
|
|
are available:
|
|
```
|
|
-i ARG : run in batch mode from script file ARG
|
|
-o ARG : write output to file ARG
|
|
(defaults to FF_Neutron_HP.out)
|
|
-n ARG : multithreading with ARG number of threads
|
|
(only works if Geant4 was compiled with multithreading enabled)
|
|
```
|
|
No output is currently generated, although the argument is provided. It is
|
|
anticipated that future versions will provide some form of output
|
|
summarizing the results of the simulation.
|
|
|
|
### INTERACTIVE
|
|
No specialized UI commands are currently provided.
|
|
|
|
To run the simulation, use the standard UI command:
|
|
```
|
|
/run/beamOn
|
|
```
|
|
|
|
### BATCH
|
|
Use the macro batch.in :
|
|
```
|
|
./FissionFragment batch.in
|
|
```
|
|
|
|
## GEOMETRY
|
|
|
|
The geometry is constructed in the FFDetectorConstruction class. The setup is
|
|
based on a subcritical assembly design.
|
|
|
|
### MATERIALS
|
|
This example requires a number of materials. They are loaded or constructed
|
|
in the "DefineMaterials" function. A few of the materials are obtained from
|
|
the NIST database. These materials are:
|
|
- Air
|
|
- Aluminum
|
|
- Graphite
|
|
- Polyethylene
|
|
- Stainless steel
|
|
- Water
|
|
|
|
For more information, visit: <A HREF="http://bit.ly/1rEHjhW"> Geant4 User's
|
|
Guide for Application Developers, Appendix: Geant4 Materials Database </A>
|
|
|
|
Not all of the necessary materials were available from the NIST database,
|
|
and were constructed manually from the estimated isotopics. These materials
|
|
are:
|
|
- 20% U235 enriched uranium
|
|
- 93% B10 enriched BF3
|
|
|
|
### VOLUMES
|
|
The world is composed of air instead of a vacuum to provide room return.
|
|
|
|
The subcritical assembly is a water-filled aluminum tank.
|
|
|
|
The fuel plates are composed of aluminum-clad uranium meat, and are
|
|
completely submersed in the water of the subcritical assembly.
|
|
|
|
An AmBe neutron source is placed in the exact center of the fuel plate
|
|
loading configuration. The material is currently modeled as steel until
|
|
more exact specifics of the AmBe isotopics can be obtained.
|
|
|
|
The subcritical assembly rests on top of a graphite pile for moderation and
|
|
shielding.
|
|
|
|
|
|
## PHYSICS LIST
|
|
|
|
The particle's type and the physic processes which will be available
|
|
in this example are set in the QGSP_BIC_HP physics list.
|
|
|
|
|
|
## PRIMARY GENERATOR
|
|
|
|
The primary generator is defined in the FFPrimaryGeneratorAction class.
|
|
The default particle is a 4.5 MeV neutron originating from the
|
|
"NeutronSource" volume. The particles initial direction is isotropically
|
|
sampled.
|
|
|
|
|
|
## DETECTOR RESPONSE
|
|
|
|
The scoring method is yet to be implemented, although the BF3 detector is
|
|
already included in the detector construction.
|
|
|
|
|
|
## VISUALISATION
|
|
An example "vis.mac" will be included in a future release. For now, please
|
|
refer to other examples for a few suggestions.
|
|
|
|
<HR>
|
|
|
|
\author B. Wendt (brycen.linn.wendt@cern.ch)
|
|
\date June 26, 2014
|
|
|