GAMOS tutorial Plug-in’s Exercises

1. GAMOS tutorialPlug-in’sExercises Pedro Arce Dubois CIEMAT http://fismed.ciemat.es/GAMOS Introducción a GEANT4

2. Introducción a GEANT4 Introduction • This set of exercises are meant for a primer user to practice with each of the most common components used in the simulation of detectors • Geometry • Visualisation • Primary generator • Electromagnetic/hadronic physics • Production cuts and user limits • Scoring • Sensitive detectors • They represent examples on • How to do simulation using GAMOS commands • How to extend GAMOS adding new C++ code • They are sequential • Use the commands of the previous exercise (only change what indicated) • Some examples use code that is compiled in the previous examples

3. Introducción a GEANT4 RT simulation Exercises • Ex. 1: Basic example • Ex. 2: More difficult geometry • Generator • Ex. 3: Physics/cuts • Ex. 4: User actions • Ex. 5: Scoring • Ex. 6: Sensitive detectors

4. Introducción a GEANT4 Exercise 1: simple geometry • Geometry: • Tube radius 100cm length 200cm of Water • inside Box 30cm X 30cm X 40cm of Aluminun • Standard electromagnetic physics • Primary particle: gamma 10 MeV at (0,0,0) in random direction

5. Introducción a GEANT4 Exercise 1b: visualisation • Visualize geometry and tracks • OGLIX • VRML2FILE • DAWNFILE

6. Introducción a GEANT4 Exercise 1c: use different e.m. physics • Use low energy electromagnetic • Use Penelope • (Make statistics on processes/particles)

7. Introducción a GEANT4 Exercise 2: more difficult geometry • “Calorimeter” • 1cm X 1cm X 5cm LSO crystals, placed along X axis • LSO: Lu 76.4016%, Si 6.1328%, O 17.4656% • Block of 4X4 crystals • Place three crystal blocks at (5,-5,0), (5,0,0), (5,5,0) cm • “Tracker” • Box 40cm X 20cm X 20cm of CO2 (50%) Al (50%) • Place at (50,0,0) cm

8. Introducción a GEANT4 Exercise 2b: change generator position and direction • Position of primary gammas at (-200,0,0) mm • Direction along X axis

9. Introducción a GEANT4 Exercise 2c: create C++ generator position distribution • Create position distribution: • Along a semicircumpherence of radius 1 cm in YZ plane, centered in (0,0,0) • Change radius at the input script • Make it a plug-in and select it at the input script

10. Introducción a GEANT4 Exercise 3: Cuts by region • Production cut 0.1 mm in crystals, 0.01 mm in tracker • Limit step to 1 mm in crystals

11. Introducción a GEANT4 Exercise 3b: Change physics list • Primary particle: gamma 10 MeV • Use new physics list: eScatteringPhysicsList • Make it a plug-in

12. Introducción a GEANT4 Exercise 4a: User actions • Kill event if primary particle does not leave all its energy in crystal • If it exits the crystals • (it might exit and enter back and leave some energy in the meantime…)

13. Introducción a GEANT4 Exercise 4b: User actions • For each event count the energy deposited in the crystal when the process that defined the step is ionisation • Make an histogram of it

14. Introducción a GEANT4 Exercise 5: Scoring • Count number of secondaries with energy > 100 keV produced in the crystals per event • Count energy deposited in the tracker per event

15. Introducción a GEANT4 Exercise 6: Sensitive detector / hits • Make the crystals and the tracker sensitive detectors • Plot hits variables with GmHitsHistosUA • Save hits in a file

16. Introducción a GEANT4 Exercise 6b: Study detector effects • Use as primary particle F18 at position (50,0,0)mm with 1 miliCurie • Make energy resolution of crystals 20% and tracker 2% • Make measuring time 1 milisecond for both SD • Make dead time 1 milisecond for both SD • (look for number of hits and good hits in hits.root/hits.csv) • Make dead time 10 nanoseconds for both SD • Make energy resolution of crystals 0% and tracker 0% (look at hits output file)

17. Introducción a GEANT4 Exercise 6c: Create SD with C++ • Assign Sensitive Detector to crystals • Create hits with: • Track ID • Deposited energy • Position • Print number of hits in each event • Print Track ID, deposited energy and position of each hit