Day 1 - Exercises on Hadronic shower development

OBJECTIVE

Simulate a shower for a 10 GeV negative pion in the same lead - scintillator sandwich calorimeter as for the electrons (Lecture1).

For comparison make a plot which contains both an electron and a pion shower. Make different species visible, distinguish neutrons from others.

Simulate showers of 30 GeV negative pions in an iron - scintillator sandwich calorimeter with diron = 10 mm and dsci = 3 mm and 400 layers each; shower axis perpendicular to sandwich plates.

HOW

Run the prepared application

        % calorimeter.py

PRACTICE

Exercise L2.1

What is the radiation length of such a sandwich? (calculate with the formula given in the lecture)

Exercise L2.2

Simulate a single 30 GeV electron, and compare the longitudinal profile with a single 30 GeV pion.

Exercise L2.3

Deterimine the resolution both for electrons and for pions (30 GeV).

Exercise L2.4

Download a modified version of TestEm3

  wget http://www.ifh.de/geant4/g4course2011/TestEm3a.tgz
  tar xzf TestEm3a.tgz
  cd TestEm3a
  gmake clean
  gmake -j2
  
  TestEm3

And specify the calorimeter geometry using macro commands.

	/testem/det/setNbOfLayers 400
	/testem/det/setNbOfAbsor  2
	/testem/det/setAbsor 1 Iron 10 mm
	/testem/det/setAbsor 2 Scintillator 3 mm
	/testem/det/setSizeYZ 100 cm
    

Exercise L2.5

Compare events for a single 30 GeV electron and single 30 GeV pion visually.

• Deactivate drawing of photons:

       /vis/filtering/trajectories/create/particleFilter noGamma
       /vis/filtering/trajectories/noGamma/add gamma
       /vis/filtering/trajectories/noGamma/invert true
    

• Change the coloring scheme:

       /vis/modeling/trajectories/create/drawByParticleID colorID
       /vis/modeling/trajectories/colorID/set e+ blue
       /vis/modeling/trajectories/colorID/set e- red
       /vis/modeling/trajectories/colorID/set neutron green
       /vis/modeling/trajectories/colorID/set proton yellow
     

• Simulate an event with both an electron and an pion

         /vis/scene/endOfEventAction accumulate 10
         /vis/scene/endOfRunAction accumulate

         /gun/particle e-
	 /gun/position -400.0 -100.0 -100.0 mm
         /run/beamOn 1

	 /gun/particle pi+
	 /gun/position -400.0 100.0 100.0 mm
         /run/beamOn 1
     

• You can turn back to the standard refresh method using

        /vis/scene/endOfEventAction refresh
        /vis/scene/endOfRunAction refresh
     

Exercise L2.6 (optional)

• How would you visualize only neutron?