Session 2 : Enoncé

Code for download: session2_start.tar.gz

Update login script:

To get the environment setup called automatically when a new terminal is open, you can add the commands for this setting in your login script, which is in our case in $HOME/.zshrc file. Open this file in your editor and add the following lines:

# Geant4 environment
cd /usr/local/bin
. geant4.sh
cd

Exercise:

The picture shows geometry which will be implemented in this session.

  • Inspect implemented geometry and modify materials to correspond to the geometry description. The code already present describes the geometry of the first arm detector.
    • Identify the code used for printing all materials.
  • Implement geometry of a second arm described below
    • Get inspired by the code already present
    • Proceed step by step. After adding each piece of geometry, recompile and test your application with visualization.
    • Note that the Second Arm detector has a similar components as the First Arm detector.
  • Add visualization attributes for added volumes in vis.mac macro
  • Check your geometry with geometry tree browser, visualization and with tracking geantinos with tracking verbose level=1
  • Add axes on your scene to check your geometry

Geometry already implemented:

  • Material galactic(vacuum) defined using NIST manager
  • World volume
    • represented as a box of hx=10.*m, hy=3.*m, hz=10.*m
    • of Air material
  • Tube volume
    • of a tube shape with rmin = 0.*m, rmax=1.*m, hz=1.*m
    • of galactic (vacuum) material
  • First arm detector:
    • represented as a box of hx=1.5*m, hy=1.0*m, hz=3.0*m
    • of Air material
    • placed in -5.*m in z-direction (in front of Tube (in blue colour).)
    • including:
      1. 5 Drift chambers (in green colour)
        • of a box shape with hx=1.*m, hy=30.*cm, hz=1.*cm
        • of Argon gas material
        • placed along z-axis with a distance of 0.5*m from each other with the middle one in the center of the parent volume
      2. Wire plane
        • of a box shape with hx=1.*m, hy=30.*cm, hz=0.1*mm
        • of Copper material
        • placed inside each drift chamber in its center.

Geometry to be implemented:

  • Add following materials (using NIST manager):Argon gas (G4_AR), CsI (G4_CESIUM_IODIDE) and Copper (G4_Cu) and update materials in First Arm detector
  • Second arm detector
    • represented as a box of hx=1.5*m, hy=1.*m, hz=3.*m
    • of Air material
    • placed in 5.*m in z-direction (behind Tube (in blue colour)).
    • Including:
      1. 5 Drift chambers (in green colour)
        • of a box shape with hx=1.5*m, hy=30.*cm, hz=1.*cm
        • of Argon gas material
        • placed along z-axis with a distance of 0.5*m from each other with the middle one in the center of the parent volume.
      2. Wire plane
        • of a box shape with hx=1.5*m, hy=30.*cm, hz=0.1*mm
        • of Copper material
        • placed inside each drift chamber in its center
      3. EM calorimeter (in yellow colour)
        • of a box shape with hx=1.5*m, hy=30.*cm, hz=15.*cm
        • of CsI material
        • placed at 2*m in z-direction from  the center of its parent volume (Second Arm Detector).
      4. Fill the EM calorimeter with 15*cm layers along x-direction of the same material (CsI)

    Solution: session2_solution.tar.gz

    Exercise ++:

    The exercises marked as ++ are optional; they are recommended for participants who have already some experience with Geant4 and get some time left for practicing more than the basic exercise proposed above.

    Extend geometry described above (see also the new picture)

    • Add Scintillator material (G4_PLASTIC_SC_VINYLTOLUENE)
    •  15 hodoscopes (in red colour) in First Arm Detector
      • of a box shape with hx=5.*cm, hy=20.*cm, hz=0.5*cm
      • of Scintillator material
      • placed along x-axis one next to another one at -1.5*m in z-direction from the center of the parent volume
    •  25 hodoscopes (in red colour) in Second Arm Detector
      • of the same shape and dimensions as in First Arm Detector
      • of Scintillator material
      • placed along x-axis one next to another one at +1.5*m in z-direction from the center of the parent volume.