Gabriele Cosmo
143 lines
5.0 KiB
Plaintext
143 lines
5.0 KiB
Plaintext
$Id: README,v 1.28 2010-02-22 15:41:29 maire Exp $
|
|
-------------------------------------------------------------------
|
|
|
|
=========================================================
|
|
Geant4 - an Object-Oriented Toolkit for Simulation in HEP
|
|
=========================================================
|
|
|
|
TestEm2
|
|
-------
|
|
|
|
How to do shower profiles in an homogenous medium, with virtual
|
|
voxelisation.
|
|
|
|
1- GEOMETRY DEFINITION
|
|
|
|
The geometry consists of a cylinder of homegenous material.
|
|
|
|
The default geometry is constructed in DetectorConstruction class,
|
|
but all of the above parameters can be modified interactively via
|
|
the commands defined in the DetectorMessenger class.
|
|
|
|
Material can be choosen: Air Water lAr Al Fe BGO PbWO4 Pb.
|
|
eg: /testem/det/setMat PbWO4
|
|
|
|
The cylinder is virtually sliced longitudinaly (slice) and radialy (ring).
|
|
The size of the slices and rings are expressed in radiation length units
|
|
and can be changed.
|
|
eg: /testem/det/setLbin 20 1. ---> 20 slices of 1. radl
|
|
/testem/det/setRbin 5 0.25 ---> 5 rings of 0.25 radl
|
|
/testem/det/update ---> rebuild the geometry
|
|
|
|
(MaxBin = 500 in both directions)
|
|
|
|
An uniform magnetic field along the cylinder axis can be set.
|
|
eg: /testem/det/setField 5 tesla
|
|
|
|
2- PHYSICS LISTS
|
|
|
|
Physics lists can be local (eg. in this example) or from G4 kernel
|
|
physics_lists subdirectory.
|
|
|
|
Local physics lists:
|
|
- "local" standard EM physics with current 'best' options setting.
|
|
these options are explicited in PhysListEmStandard
|
|
|
|
From geant4/source/physics_lists/builders:
|
|
- "emstandard_opt0" recommended standard EM physics for LHC
|
|
- "emstandard_opt1" best CPU performance standard physics for LHC
|
|
- "emstandard_opt2"
|
|
- "emstandard_opt3" best current advanced EM options.
|
|
analog to "local" above
|
|
|
|
Physics lists and options can be (re)set with UI commands
|
|
|
|
Please, notice that options set through G4EmProcessOPtions are global, eg
|
|
for all particle types. In G4 builders, it is shown how to set options per
|
|
particle type.
|
|
|
|
3- AN EVENT : THE PRIMARY GENERATOR
|
|
|
|
The primary kinematic consists of a single particle which hits the
|
|
cylinder perpendicular to the input face. The type of the particle
|
|
and its energy are set in the PrimaryGeneratorAction class, and can
|
|
changed via the G4 build-in commands of ParticleGun class (see
|
|
the macros provided with this example).
|
|
|
|
A RUN is a set of events.
|
|
|
|
4- VISUALIZATION
|
|
|
|
The Visualization Manager is set in the main().
|
|
The initialisation of the drawing is done via the commands
|
|
/vis/.. in the macro vis.mac. In interactive session:
|
|
PreInit or Idle > /control/execute vis.mac
|
|
|
|
The detector has a default view which is a longitudinal view of the
|
|
cylinder.
|
|
|
|
The tracks are drawn at the end of event, and erased at the end of run.
|
|
Optionaly one can choose to draw all particles, only the charged one,
|
|
or none. This command is defined in EventActionMessenger class.
|
|
|
|
5- PHYSICS DEMO
|
|
|
|
The particle's type and the physic processes which will be available
|
|
in this example are set in PhysicsList class.
|
|
|
|
In addition a build-in interactive command (/process/inactivate proname)
|
|
allows to activate/inactivate the processes one by one.
|
|
|
|
The threshold for producing secondaries can be changed.
|
|
eg: /testem/phys/setCuts 100 microm
|
|
/run/initialize
|
|
|
|
The shower profiles are histogramed, if histograming is activated.
|
|
They can be also printed with the command /testem/run/verbose 1
|
|
|
|
6- HOW TO START ?
|
|
|
|
- Execute TestEm2 in 'batch' mode from macro files
|
|
% TestEm2 run01.mac
|
|
|
|
- Execute TestEm2 in 'interactive mode' with visualization
|
|
% TestEm2
|
|
....
|
|
Idle> type your commands
|
|
....
|
|
Idle> exit
|
|
|
|
7- HISTOGRAMS
|
|
|
|
TestEm2 produces several histograms:
|
|
|
|
Content of these histo:
|
|
|
|
1 : energy deposit per event
|
|
2 : charged track length per event
|
|
3 : neutral track length per event
|
|
|
|
4 : longitudinal energy profile
|
|
5 : rms of longitudinal energy profile
|
|
6 : cumulated longitudinal energy profile
|
|
7 : rms of cumulated longitudinal energy profile
|
|
|
|
8 : radial energy profile
|
|
9 : rms of radial energy profile
|
|
10 : cumulated radial energy profile
|
|
11 : rms of cumulated radial energy profile
|
|
|
|
To define the output file name with histograms, use the UI command :
|
|
|
|
"/testem/histo/setFileName name"
|
|
|
|
The format of the histogram file can be : root (default),
|
|
hbook, xml, csv, by selecting g4nnn.hh in RunAction.hh
|
|
|
|
Using hbook format
|
|
------------------
|
|
|
|
Need a special treatement : the Cern Library must be installed and the
|
|
environment variable CERNLIB correctly set. Then, *before* compiling,
|
|
activate G4_USE_HBOOK in GNUmakefile and g4hbook.hh in RunAction.hh
|