Gabriele Cosmo
177 lines
6.1 KiB
Plaintext
177 lines
6.1 KiB
Plaintext
$Id: README,v 1.13 2006/05/15 14:40:24 maire Exp $
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-------------------------------------------------------------------
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=========================================================
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Geant4 - an Object-Oriented Toolkit for Simulation in HEP
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=========================================================
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TestEm7
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-------
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How to produce a Bragg curve in a water phantom.
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How to compute the dose in small 'test volumes' called tallies.
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How to define a maximum step size.
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1- GEOMETRY DEFINITION
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The geometry consists of a single block of a homogenous material,
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placed in a world.
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Three parameters define the geometry :
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- the material of the box,
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- the thickness of the box (sizeX),
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- the tranverse dimension of the box (sizeYZ).
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The default is 20 cm of water.
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In addition a transverse uniform magnetic field can be applied.
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The default geometry is constructed in DetectorConstruction class,
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but all of the above parameters can be changed interactively via
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the commands defined in the DetectorMessenger class.
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The size, matter, positions of several test-volumes (tallies) can be
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defined via UI commands : /testem/det/tally...
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2- PHYSICS LIST
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Physics Lists are subdivided on 4 following modules:
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1. "particles" - particle definitions
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2. "general" - decays and transportation
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3. "standard" (alternative) - standard EM physics
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4. "model" (alternative) - standard EM physics using model approach
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Notice that there is an example of definition of a static ion : IonC12
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(see PhysListParticle.cc) and an example of use : ionC12.mac
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3- AN EVENT : THE PRIMARY GENERATOR
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The primary kinematic consists of a single particle which hits the
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block perpendicular to the input face. The type of the particle
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and its energy are set in the PrimaryGeneratorAction class, and can
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changed via the G4 build-in commands of ParticleGun class (see
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the macros provided with this example).
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The default is proton 160 MeV
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In addition one can define randomly the impact point of the incident
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particle. The corresponding interactive command is built in
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PrimaryGeneratorMessenger class.
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A RUN is a set of events.
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4- VISUALIZATION
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The Visualization Manager is set in the main().
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The initialisation of the drawing is done via the command
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> /control/execute vis.mac
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The detector has a default view which is a longitudinal view of the box.
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The tracks are drawn at the end of event, and erased at the end of run.
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Optionaly one can choose to draw all particles, only the charged one,
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or none. This command is defined in EventActionMessenger class.
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5- HOW TO START ?
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- compile and link to generate an executable
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% cd geant4/examples/extended/electromagnetic/TestEm7
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% gmake
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- execute Test in 'batch' mode from macro files
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% TestEm7 proton.mac
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- execute Test in 'interactive mode' with visualization
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% TestEm7
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....
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Idle> type your commands
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....
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Idle> exit
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6- HISTOGRAM OF THE BRAGG PEAK
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Testem7 computes the total energy deposited along the trajectory of
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the incident particle : the so-called Bragg peak.
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In order to control the accuracy of the deposition, the user can limit
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the maximum allowed for the step size of charged particles.
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(command /testem/stepMax )
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The result is a 1D histogram which is the total energy deposited along
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the trajectory of the incident particle.
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The histogram is saved in hbook format (testem7.hbook)
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The bin size is egal to stepMax. The number of bins is determined by
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the thickness of the absorber (with a minimum of 100 bins).
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The total energy deposited is plotted in MeV/mm per incident particle.
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Note that, by default, histograms are disabled. To activate them, uncomment
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G4ANALYSIS_USE in GNUmakefile.
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7- DOSE IN 'TEST-VOLUMES'
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The energy deposited in the test-volumes (tallies) defined in
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DetectorConstruction are printed at EndOfRun, both in MeV and gray.
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8- USING HISTOGRAMS
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By default the histograms are not activated. To activate histograms
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the environment variable G4ANALYSIS_USE should be defined. For instance
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uncomment the flag G4ANALYSIS_USE in GNUmakefile.
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It is possible to choose the format of the histogram file (hbook, root, XML):
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comment/uncomment 1 line in RunAction::bookHisto().
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Before compilation of the example it is optimal to clean up old files:
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gmake histclean
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gmake
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To use histograms, at least one of the AIDA implementations should be
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available (see http://aida.freehep.org).
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8a - PI
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A package including AIDA and extended interfaces also using Python is PI,
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available from: http://cern.ch/pi
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Once installed PI or PI-Lite in a specified local area $MYPY, it is required
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to add the installation path to $PATH, i.e. for example, for release 1.2.1 of
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PI:
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setenv PATH ${PATH}:$MYPI/1.2.1/app/releases/PI/PI_1_2_1/rh73_gcc32/bin
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CERN users can use the PATH to the LCG area on AFS.
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Before running the example the command should be issued:
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eval `aida-config --runtime csh`
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8b - OpenScientist
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OpenScientist is available at http://OpenScientist.lal.in2p3.fr.
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You have to "setup" the OpenScientist AIDA implementation before compiling
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(then with G4ANALYSIS_USE set) and running your Geant4 application.
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On UNIX you setup, with a csh flavoured shell :
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csh> source <<OpenScientist install path>/aida-setup.csh
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or with a sh flavoured shell :
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sh> . <<OpenScientist install path>/aida-setup.sh
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On Windows :
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DOS> call <<OpenScientist install path>/aida-setup.bat
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You can use various file formats for writing (AIDA-XML, hbook, root).
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These formats are readable by the Lab onx interactive program
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or the OpenPAW application. See the web pages.
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With OpenPAW, on a run.hbook file, one can view the histograms
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with something like :
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OS> opaw
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opaw> h/file 1 run.hbook ( or opaw> h/file 1 run.aida or run.root)
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opaw> zone 2 2
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opaw> h/plot 1
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opaw> h/plot 2
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