medical/fanoCavity2/README.md

0001 \page ExamplefanoCavity2 Example fanoCavity2
0002
0003
0004  This program computes the dose deposited in an ionization chamber by an
0005  extended (one dimensional) monoenergetic electron source.
0006  The geometry of the chamber satisfies the conditions of charged particle
0007  equilibrium. Hence, under idealized conditions, the ratio of the dose
0008  deposited over the beam energy fluence must be equal to 1.
0009  This variante of the Fano cavity test make use of an reciprocity theorem.
0010
0011  J.Sempau and P.Andreo, Phys. Med. Biol. 51 (2006) 3533
0012
0013 ## GEOMETRY
0014
0015  The chamber is modelized as a cylinder with a cavity in it.
0016
0017  5 parameters define the geometry :
0018    - the radius of the chamber (must be big)
0019    - the material of the wall
0020    - the thickness of the wall
0021    - the material of the cavity
0022    - the thickness of the cavity
0023
0024  Wall and cavity must be made of the same material, but with different
0025  density.
0026  Radius must be bigger than range of electrons in cavity.
0027
0028  All above parameters can be redifined via the UI commands built in
0029  DetectorMessenger class.
0030
0031 <pre>
0032                         _________________
0033      radius (infinite)  |     |   |     |
0034                         |     |   |     |
0035                         |     |   |     |
0036                         |     |   |     |
0037                         |     | <-+-----+--- cavity
0038                         |     |   |     |
0039                         |     |   |     |
0040                  ---------------------------- cylinder axis = e- source
0041                         |     |   |     |
0042                         |     |   |     |
0043                         |     |   |     |
0044                         |wall |   |wall |
0045                         |     |   |     |
0046                         |     |   |     |
0047                         |     |   |     |
0048                         -----------------
0049 </pre>
0050
0051 ## BEAM
0052
0053  Monoenergetic (E0) incident electron source is uniformly distribued along
0054  cylinder axis, within wall and cavity, with constant lineic density
0055  per mass: I.
0056  An effective wall thickness is defined from the range of e- at energy E0.
0057
0058  Beam_energy_fluence is `E0*I`
0059
0060 ## PURPOSE OF THE PROGRAM
0061
0062  The program computes the dose deposited in the cavity and the ratio
0063  Dose/Beam_energy_fluence. This ratio must be 1.
0064
0065  The program needs high statistic to reach precision on the computed dose.
0066  The UI command /run/printProgress allows to survey the convergence of
0067  the dose calculation.
0068
0069  The simplest way to study the effect of e- tracking parameters on dose
0070  deposition is to use the command /testem/stepMax.
0071
0072 ## PHYSICS
0073
0074  The physics list contains the standard electromagnetic processes, with few
0075  modifications listed here.
0076
0077  - Bremsstrahlung : Fano conditions imply no energy transfer via
0078  bremsstrahlung radiation. Therefore this process is not registered in the
0079  physics list. However, it is always possible to include it.
0080  See PhysListEm classes.
0081
0082  - Ionization : In order to have same stopping power in wall and cavity, one
0083  must cancel the density correction term in the dedx formula. This is done in
0084  a specific MollerBhabha model (MyMollerBhabhaModel) which inherites from
0085  G4MollerBhabhaModel.
0086  \n\n
0087  To prevent explicit generation of delta-rays, the default production
0088  threshold (i.e. cut) is set to 10 km (CSDA condition).
0089  \n\n
0090  The finalRange of the step function is set to 10 um, which more on less
0091  correspond to a tracking cut in water of about 20 keV. See emOptions.
0092  Once again, the above parameters can be controled via UI commands.
0093
0094  - Multiple scattering : is switched in single Coulomb scattering mode near
0095  boundaries. This is selected via EM options in PhysicsList, and can be
0096  controled with UI commands.
0097
0098  - All PhysicsTables are built with 100 bins per decade.
0099
0100 ## HISTOGRAMS
0101
0102    fanoCavity2 has several predefined 1D histograms :
0103    - 1 : emission point of e+-
0104    - 2 : energy spectrum of e+-
0105    - 3 : theta distribution of e+-
0106    - 4 : emission point of e+- hitting cavity
0107    - 5 : energy spectrum of e+- when entering in cavity
0108    - 6 : theta distribution of e+- before enter in cavity
0109    - 7 : theta distribution of e+- at first step in cavity
0110    - 8 : track segment of e+- in cavity
0111    - 9 : step size of e+- in wall
0112    - 10 : step size of e+- in cavity
0113    - 11 : energy deposit in cavity per track
0114
0115    The histograms are managed by G4AnalysisManager class and its Messenger.
0116    The histos can be individually activated with the command :
0117 ```
0118 /analysis/h1/set id nbBins  valMin valMax unit
0119 ```
0120    where unit is the desired unit for the histo (MeV or keV, deg or mrad, etc..)
0121
0122    One can control the name of the histograms file with the command:
0123 ```
0124 /analysis/setFileName  name  (default fanocavity2)
0125 ```
0126
0127    It is possible to choose the format of the histogram file : root (default),
0128    hdf5, xml, csv, by changing the default file type in HistoManager.cc
0129
0130    It is also possible to print selected histograms on an ascii file:
0131 ```
0132 /analysis/h1/setAscii id
0133 ```
0134    All selected histos will be written on a file name.ascii
0135    (default fanocavity2)
0136
0137 ## HOW TO START ?
0138
0139  - Execute fanoCavity2 in 'batch' mode from macro files
0140 ```
0141 % ./fanoCavity2  run01.mac
0142 ```
0143
0144  - Alternative macro files:
0145    - basic.mac - disabled  multiple scattering and fluctuations of energy loss
0146    - essai.mac - run WVI EM physics configuration
0147    - stepfunction.mac - the step function optimisation using histogram
0148
0149  - Execute fanoCavity2 in 'interactive mode' with visualization
0150 ```
0151 % ./fanoCavity2
0152 ....
0153 Idle> type your commands
0154 ....
0155 Idle> exit
0156 ```