1. Projects by User Groups in Spain: Application to g-ray Spectrometry
Begoña Quintana Arnés
Grupo de Física Nuclear
Universidad de Salamanca
GEANT4 Workshop, Geneva 2002

2. Introduction
Experiments with Ge detectors: a) nuclear structure (EUROBALL, AGATA, PRISMA); b) radionuclide analysis, background experiments
Groups in Spain devoted mainly to radionuclide analysis. Our group also to optimisation of large devices via MC simulation
GEANT4 Workshop, Geneva 2002

3. EUROBALL SIMULATION WITH GEANT3.21
GEANT4 Workshop, Geneva 2002

4. Code Validation
Simulated response of Ge detectors to quantitatively calculate efficiency, coincidence-summing and self-absorption corrections (I<3%) in [20,2500] keV
Very precise experimental results suitable for physics validation
GEANT4 Workshop, Geneva 2002

5. Physics Problem
Simple detector geometry
GEANT4 Workshop, Geneva 2002

6. Physics Problem
Physics processes into the crystal: fotoelectric, Compton (no polarized), pair production, e- energy losses, Ge X-rays (< 10 keV) production, Auger e-.
Outside the crystal, also X-ray production, radionuclide decay, bremsstrahlung, interaction of muons and neutrons, mainly, with heavy elements...
GEANT4 Workshop, Geneva 2002

7. Results with Geant3.21
“Effective” detector geometry: lack of precision in detector dimensions or in how physics is implemented?
Added routine to deal with Ge X-rays
Efficiency deviation < 3% in the [46,1800] keV energy range (also corrections)
Geant4 simulations of Seville Group also by fitting parameters: same order of magnitude in efficiency deviations
GEANT4 Workshop, Geneva 2002

8. Challenge No detector parameter fitting P-type detector response
GEANT4 Workshop, Geneva 2002

9. Next Steps Comparison GEANT3.21 and GEANT4 results
New simulation with GEANT4 without detector parameter fitting
Determination of performance
Building of user routines prepared to easily implement geometries and materials in run
Validation via lab intercomparison
GEANT4 Workshop, Geneva 2002