exoticphysics/monopole/README.md

0001 \page Examplemonopole Example monopole
0002
0003  \author V.Ivanchenko, M.Vladymyrov \n
0004  CERN,  Geneva, Switzerland \n
0005  Lebedev Physical Institute, Moscow, Russia \n
0006
0007
0008 This example is devoted to the energy deposited by classical magnetic
0009 monopole.
0010
0011 ## GEOMETRY DEFINITION
0012
0013  The geometry consists of a single block of a homogenous material,
0014  placed in a world.
0015
0016  Four parameters define the geometry :
0017     - the material of the box
0018     - the thickness of the box
0019     - the tranverse dimension of the box
0020     - the maximal step size in target
0021
0022  The default is 10 cm of alumunium, step is limited by 5mm.
0023  Equivalent UI commands are following:
0024 ```
0025 /testex/det/setMat G4_Al
0026 /testex/det/sizeX  10 cm
0027 /testex/det/sizeYZ 5 cm
0028 /testex/det/setStepSize 5 mm
0029 ```
0030
0031  The default geometry is constructed in DetectorConstruction class,
0032  but all of the above parameters can be changed interactively via
0033  the commands defined in the DetectorMessenger class.
0034
0035  In addition, a global, uniform, and transverse magnetic field can be applied
0036  via G4MonopoleFieldSetup class, with the default z-value 0.2 tesla.
0037  This value can be changed via UI command:
0038 ```
0039 /testex/fld/setField 0.2 tesla
0040 ```
0041
0042 ## PHYSICS LIST
0043
0044  The physics list includes standard FTFP_BERT physics and the additional builder
0045  for monopole physics.
0046  To define monopole parameters an extra string should be provided via
0047  the program arguments:
0048 ```
0049 ./monopole -s '2 0 200 GeV'              # in the interactive mode
0050 ./monopole -m file.mac -s '2 0 200 GeV'  # in the batch mode
0051 ```
0052
0053 ## AN EVENT : THE PRIMARY GENERATOR
0054
0055  The primary kinematic consists of a single particle which hits the
0056  block perpendicular to the input face. The type of the particle
0057  and its energy are set in the PrimaryGeneratorAction class, and can
0058  changed via the G4 build-in commands of G4ParticleGun class (see
0059  the macros provided with this example).
0060  The default is monopole 100 GeV
0061
0062 ## VISUALIZATION
0063
0064  The Visualization Manager is set in the main() for interactive session,
0065  the initial parameters of the program are defined in the init_vis.mac macro
0066  which then executes the visualisation macro, vis.mac.
0067
0068  The detector has a default view which is a longitudinal view of the box.
0069
0070  The tracks are drawn at the end of event, and erased at the end of run.
0071
0072 ## HOW TO RUN ?
0073
0074  This example handles the program arguments in a similar way as the basic
0075  B4 example.
0076  It can be run with the following optional arguments:
0077 ```
0078  % ./monopole [-m macro ] [-s setupMonopole] [-t nThreads]
0079 ```
0080
0081  The -s option was already explained in the Physics list section.
0082  The -t option is available only in multi-threading mode
0083  and it allows the user to override the Geant4 default number of
0084  threads. The number of threads can be also set via G4FORCENUMBEROFTHREADS
0085  environment variable which has the top priority.
0086
0087  - Execute program  in the 'batch' mode from macro files
0088 ```
0089 % ./monopole  -m monopole.in [-s setupMonopole]
0090 ```
0091
0092  - Execute program  in the 'interactive mode' with visualization
0093 ```
0094 % ./monopole [-s setupMonopole]
0095   ....
0096 Idle> type your commands
0097   ....
0098 Idle> exit
0099 ```
0100
0101 ## HISTOGRAMS
0102
0103  The result is five histograms:
0104     - Monopole eneregy deposition in current material
0105     - dedx for proton
0106     - dedx for monopole
0107     - range for proton in current material
0108     - range for monopole in current material
0109
0110  The histogram is saved in Root file.
0111  Limit of bin size can be set with testex/run/binSize (default 5mm). Real size
0112  is chosen as a minimal between this and step limit (see Geometry section)