Session 3

Primary Particles & Visualization

Objectives

• Explain how to shoot the initial / primary particles in the simulation
• Provide some information on the way to randomize such particle characteristics
• Explain how to initiate, save, restart the random engine status
• Introduce the visualization system.
  • Explain its philosophy and the concept of visualization drivers.

Presentations

• Primary Particles ( slides )
  • Primary particle generation, G4VUserPrimaryGeneratorAction and G4VPrimaryGenerator classes, Primary vertex and primary particle, Built-in primary particle generators, Particle gun, GPS, Interfaces to HEPEvt and HepMC

• Random number generators ( slides )
  • Introduction, HepRandom engine, /random commands
• Random number usage in Geant4 ( slides )
  • An informative presentation on how random numbers are used in Geant4 to “sample” distributions.
• Visualization 2 (slides, video1, video2)
  • Visualization commands

Hands-On

• Use of G4ParticleGun
• Randomizing particle direction, Storing/retrieving random generator status
• Explore vis commands