Warning, /geant4/examples/extended/exoticphysics/channeling/ch2/README is written in an unsupported language. File is not indexed.
0001 -------------------------------------------------------------------
0002
0003 =========================================================
0004 Geant4 - an Object-Oriented Toolkit for Simulation in HEP
0005 =========================================================
0006
0007 Example ch2
0008 -----------
0009 A. Sytov, G. Paternò
0010 INFN Ferrara Division, sytov@fe.infn.it, paterno@fe.infn.it
0011
0012 INTRODUCTION
0013 Example ch2 is an enhanced version of ch1, providing the user with the full functionality of
0014 both the G4ChannelingFastSimModel and G4BaierKatkov, with parameters set up via a macro,
0015 in order to simulate the physics of channeling and channeling radiation/coherent bremsstrahlung.
0016
0017 The example can be exploited for a wide range of cases to study coherent effects in
0018 a straight, bent or periodically bent crystal (crystalline undulator). Channeling
0019 physics in ch2 is active for protons, ions, muons, pions, electrons and their antiparticles.
0020 Any other charged particle can also be activated.
0021
0022 DESCRIPTION
0023
0024 The setup of the example ch2 is identical to ch1. As ch1, this example includes a bent crystal
0025 and a detector positioned behind it. Like ch1, it is based on the experiments on
0026 channeling [1] and channeling radiation [2] in a bent crystal, carried out at
0027 Mainz Mikrotron MAMI with 855 MeV electrons. The experimental validation of
0028 G4ChannelingFastSimModel is described in [3].
0029
0030 However, since ch2 parameters are fully set up in the macro run.mac, this example
0031 is quite flexible and can be easily adapted for entirely different cases.
0032
0033 A description of all the available options is provided in run.mac.
0034 It includes crystal and detector geometry, activation flags for
0035 G4ChannelingFastSimModel and G4BaierKatkov and various options.
0036
0037 The example also provides detailed descriptions of various options for
0038 G4ChannelingFastSimModel and G4BaierKatkov, which can adjust model parameters
0039 depending on the specific case (see ConstructSDandField in DetectorConstruction).
0040
0041 The front surface of the crystal is placed at z=0 (with z as the beam direction),
0042 while the front position of the detector can be set up via run.mac.
0043
0044 The output is recorded into the file results.root as a set of root ntuples.
0045 These ntuples include:
0046 - crystal: particles recorded at the crystal entrance,
0047 - detector: all particles (except photons) recorded at the detector entrance,
0048 - detector_photons: photons recorded at the detector entrance.
0049
0050 The format of every ntuple includes the following 10 variables (columns):
0051
0052 "eventID", "volume", "x", "y", "angle_x", "angle_y", "Ekin", "particle", "particleID", "parentID"
0053
0054 The variables represent:
0055 - the event number within the run (column 0),
0056 - the volume, either the crystal or the detector (column 1),
0057 - the coordinate (x,y) and the angles (x'=dx/dz, y'=dy/dz) of the impinging particles (columns 2-6),
0058 - the kinetic energy of the particle (column 7),
0059 - the particle name (column 8),
0060 - the particle ID (column 9),
0061 - the parent ID of the particle (column 10).
0062
0063 To visualize these data, one should either open results.root using root TBrowser or use the python script analysis_ch2.py.
0064
0065 REFERENCES
0066 [1] A. Mazzolari et al. Phys. Rev. Lett. 112, 135503 (2014).
0067 [2] L. Bandiera et al. Phys. Rev. Lett. 115, 025504 (2015).
0068 [3] A. Sytov et al. Journal of the Korean Physical Society 83, 132–139 (2023).
