Gabriele Cosmo
125 lines
4.8 KiB
Plaintext
125 lines
4.8 KiB
Plaintext
$Id: README,v 1.4 2002/06/16 15:05:45 mantero Exp $
|
|
-------------------------------------------------------------------
|
|
|
|
=========================================================
|
|
Geant4 - an Object-Oriented Toolkit for Simulation in HEP
|
|
=========================================================
|
|
|
|
xray_fluorescence
|
|
-----------------
|
|
XrayFluo is an advanced Geant4 example based on a realistic simulation of
|
|
a test beam.
|
|
The aim of the test beam was to characterize the response function of an
|
|
HPGe detector used to measure fluorescence emissions from samples composed
|
|
of different materials irradiated with a monochromatic beam of photons.
|
|
In this example the geometry of the detector is simplified:
|
|
one single pixel is used instead of an array of pixels.
|
|
The response function is tabulated for ten different values of incident
|
|
energy and stored in the file response.dat.
|
|
The sample, a simple box whose material can be selected, can be irradiated
|
|
with different particles, with different spectra for the incident energy and
|
|
with different shapes of the primary generator.
|
|
Apart from the sample and the detector there are two diaphragm reproducing
|
|
those used to collimate the incident beam during the test beam.
|
|
|
|
The aim of this advanced example is to illustrate the use of particle
|
|
generation and analysis schemes available in Geant4:
|
|
|
|
- the generation of particles is done via the G4ParticleGun: the example
|
|
shows how to use it in order to obtain a beam of circular section or
|
|
a particle source isotropic in space
|
|
|
|
_ the example includes the possibility to shoot particles according to a
|
|
given energy spectrum: the files B_flare.dat, C_Flare.dat and M_flare.dat
|
|
store the spectra of photons during solar flares, the files
|
|
mercury2_flx_solmax.dat and mercury_flx_solmin.dat contain the spectra of
|
|
protons respectively during solar maximum and solar minimum conditions, and
|
|
merc2_flx_alp_max.dat merc_flx_alp_min.dat contain the spectra of alpha
|
|
particles again respectively during solar maximum and solar minimum
|
|
conditions.
|
|
|
|
- histograming facilities are presently provided for the Linux environment
|
|
either by using the AIDA interfaces, or through the Anaphe/Lizard system.
|
|
The AIDA compliant version has not been tested by the developers and is
|
|
here as a example of "forward compatibility" on how to use analysis.
|
|
|
|
In order to be able to use any of these packages, prior installation is
|
|
necessary and a number of environment variables will have to be set.
|
|
|
|
|
|
#set up VRMLview
|
|
setenv G4VRMLFILE_MAX_FILE_NUM 100
|
|
setenv G4VRMLFILE_VIEWER vrmlview #if installed
|
|
setenv PATH ${PATH}:"/afs/cern.ch/sw/contrib/VRML/bin/Linux"
|
|
|
|
#set up OpenGL or Mesa
|
|
setenv G4VIS_BUILD_OPENGLX_DRIVER 1
|
|
setenv G4VIS_USE_OPENGLX 1
|
|
setenv OGLHOME /afs/cern.ch/sw/geant4/dev/Mesa/Linux-g++
|
|
|
|
#set up DAWN
|
|
setenv G4VIS_BUILD_DAWN_DRIVER 1
|
|
setenv G4VIS_USE_DAWN 1
|
|
setenv PATH ${PATH}:"/afs/cern.ch/sw/geant4/dev/DAWN/Linux-g++"
|
|
|
|
# flag that we want to use analysis:
|
|
setenv G4ANALYSIS_USE 1
|
|
|
|
# select analysis system: any AIDA 2.2 compliant system or Anaphe 3.6.5
|
|
|
|
# set up for AIDA 2.2 compliancy:
|
|
# Compilation and link flags to hook and AIDA compliant system
|
|
# are passed to the Geant4 GNUmakefile system by using the "aida-config" tool
|
|
# that should come with any AIDA compliant system. Examples are:
|
|
# setenv G4ANALYSIS_AIDA_CONFIG_CFLAGS `aida-config --include`
|
|
# setenv G4ANALYSIS_AIDA_CONFIG_LIBS `aida-config --libs`
|
|
|
|
#set up Anaphe/Lizard for the gcc-2.95 compiler
|
|
setenv G4ANALYSIS_SYSTEM Lizard
|
|
setenv PATH ${PATH}:/afs/cern.ch/sw/lhcxx/specific/redhat61/gcc-2.95.2/3.6.5/bin
|
|
source /afs/cern.ch/sw/lhcxx/share/LHCXX/3.6.5/install/sharedstart.csh
|
|
|
|
#path to the lowEnergy data base
|
|
|
|
setenv G4LEDATA /afs/cern.ch/sw/geant4/stt/dev1/src/G4EMLOW1.1
|
|
|
|
1. Run
|
|
To execute a sample simulation with visualisation of tracks
|
|
reaching the detector run:
|
|
|
|
XrayFluo
|
|
|
|
execute command "/control/execute xxxxx.mac"
|
|
|
|
|
|
If the Lizard analysis options are set, histograming windows will
|
|
automatically stored in the corresponding files
|
|
|
|
2. Detector description
|
|
|
|
The telescope and detector geometry is defined in
|
|
XrayFluoDetectorConstruction.cc
|
|
|
|
3. Physics processes
|
|
|
|
The physics processes are in XrayFluoPhysicsList.cc
|
|
The main process in this example is fluorescence emission from the sample.
|
|
|
|
4. Event generation
|
|
|
|
This is done using the G4ParticleGun with some modifications. See
|
|
XrayFluoParticleGeneratorAction.cc
|
|
|
|
5. Analysis
|
|
|
|
At present the analisys is provided by any AIDA-2.2 compliant analysis system.
|
|
In the example the Anaphe toolkit is used.
|
|
|
|
To build and execute the example on platforms where there is no
|
|
implementation of the analysis system, the environment variables
|
|
must not be set.
|
|
|
|
The example provides also two Python files used to display and fit the
|
|
histograms with Lizard 1.3.x.
|
|
|