Session 2 : Exercise

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/.bash_profile file. Open this file in your editor and add the following lines:

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

Exercise 2a:

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

  • Inspect the code of the geometry already implemented and modify materials to correspond to the geometry description below. The code already present describes the geometry of the first arm detector.
    • Identify the code used for printing all materials.
  • Add following materials (using the NIST manager):
    • Argon gas (G4_Ar), CsI (G4_CESIUM_IODIDE) and Copper (G4_Cu)
    • and update the materials in the First Arm detector according to the geometry description below
  • Implement geometry of the second arm described below.
    • Get inspired by the code already present
    • Proceed step by step. After adding each piece of geometry(solid, logical volume and its placement(s)), recompile and test your application with visualization.
    • Note that the Second Arm detector has similar components as the First Arm detector but not same.

Exercise 2b:

Explore implemented geometry:

  • Add visualization attributes for added volumes in vis.mac macro.
    Tips : First change the color with the scene tree browser and look in the output for the command name
  • Add axes on your scene to check your geometry (use Qt User Interface Help widget)
  • Check your geometry with geometry scene tree browser and with tracking geantinos with tracking verbose level=1
    • Remember the command /tracking/verbose 1 from the previous session

Geometry already implemented, to be completed:

  • Material Air defined using NIST manager  (the remaining materials have to be added and assigned to the volumes )
  • 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 Air 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 Air material to be changed to Argon gas
        • 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 Air material to be changed to Copper
        • placed inside each drift chamber in its center.

Geometry to be implemented:

  • 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