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Luciano Pandola, INFN Gran Sasso What is needed ? (my collection...) High energy muons interactions & showers : neutron and hadron production (critical for DM experiments) isotope production Low energy electromagnetic extensions : precise tracking of low-energy leptons and hadrons more precise energy and angular spectra atomic de-excitation (e.g. fluorescence x-rays) Other: very precise decay schemes for Radioactive decay (low-branching channels) EC decay (with fluorescence) Other decays (e.g. spont. fission) has ever been validated or cross-checked?
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Luciano Pandola, INFN Gran Sasso
Luciano PandolaINFN Gran Sasso
Genova, July 18th, 2005
Geant4 and the underground physics
community
Luciano Pandola, INFN Gran Sasso
User requirements & validationUser requirements & validation(My feeling) Geant4 is still not considered a fully established and trustworthy Monte Carlo in the underground physics community
The goal of the G4 Collaboration –> to improve this situation, consistently with the available manpower.
• small overlap between the Collaboration and the experiments ( = 2)
• no test-beams available, so validation much more complicated
• requires extensions to High Energy (e.g. muons) and to LowEnergy (e.g. fluorescence) typically “decoupled” in the modular development of Geant4
Effort for a more complete validation plan (what are the priorities?). Needs strong connection with experimental and
MC groups of the experiments, also for providing data!
Luciano Pandola, INFN Gran Sasso
What is needed ? (my collection...)What is needed ? (my collection...)High energy muons interactions & showers:
• neutron and hadron production (critical for DM experiments)
• isotope production
Low energy electromagnetic extensions:
• precise tracking of low-energy leptons and hadrons
• more precise energy and angular spectra
• atomic de-excitation (e.g. fluorescence x-rays)
Other: • very precise decay schemes for Radioactive decay (low-branching channels)
• EC decay (with fluorescence) Other decays (e.g. spont. fission)
has ever been validated or cross-checked?
Luciano Pandola, INFN Gran Sasso
A few examples of applications...A few examples of applications...Double beta decay 76Ge experiment (GERDA & Majorana):
common parts (e.g. generators, physics, other tools) not duplicated
OO toolkit based on Geant4 (MaGe)
Flexible enough to allow
experiment-specific parts (geometry, i/o)
Preliminary physics studies: background from outside and from
structures (ropes, contact) efficiency of segmentation/anticoincidence
background from cosmic ray muons
Luciano Pandola, INFN Gran Sasso
A few examples of A few examples of applications...applications...
Preliminary results:
76Ge 02 region
Cosmic ray muons
Achievable for and cosmic ray (with dedicated veto):
Fission, (,n) and cosmogenic neutrons are not an issue
(very different for DM expts)
mainly from EM showers physics reliable
physics reliable? (with the proper physics list) work in progress
from DM groups
Goal 10-3-10-4 counts/keV·kg·y @ Q
Isotope production not an issuereliability unknown we plan
to cross-check (!)
Luciano Pandola, INFN Gran Sasso
A few examples of applications...A few examples of applications...Small (simple) application derived from studies of environmental radioactivity from rocks and sands
Geant4 (LowE EM) can reproduce very well the results of a calibration with a 60Co source (in presence of the sample)
detectorsample
source
it works very well in this regime
simulation
datasimulation
data
Luciano Pandola, INFN Gran Sasso
A few examples of applications...A few examples of applications...Dark matter experiment (ZEPLIN 3):
Code from A. Howard and H. Araujo.
Released as an advanced example of Geant4
Luciano Pandola, INFN Gran Sasso
A few examples of applications...A few examples of applications...Dark matter experiment (WARP):
Goals: understand the background spectrum and its components
F. Di Pompeo, N. Ferrari, L. P.
energy (MeV) energy (MeV)
39Ar
85Kr
Data
Simulation(all components
included)
Data
Simulation(all components
included)
208Tl
Luciano Pandola, INFN Gran Sasso
Priorities for validationPriorities for validationSuggestions from ILIAS meeting in Prague
Validation is this field is a difficult task close collaboration required with MC and experimental groups
• Production of -induced neutrons in high-Z materials
• Propagation of Low Energy neutrons (up to a few MeV)
• Inelastic scattering of neutrons
• Interactions of high-energy muons
• Isotope production
comparison with FLUKA, experimental data
comparison with MCNP, experimental data
comparison with other codes t.b.d.
Luciano Pandola, INFN Gran Sasso
ConclusionsConclusions
Present ILIAS activity of cross-check and comparison between different Monte Carlo codes is very welcome
A lot of work!
Requires constant feedback and support from the experimental groups
Validation & cross-check should be done in synergy
Luciano Pandola, INFN Gran Sasso
Backup slides
Luciano Pandola, INFN Gran Sasso
A few examples of applications...A few examples of applications...Experiment backgroundsinternal detector radioactivityrock radioactivity-induced neutron productionshielding and veto systems
CalibrationNeutronsGammas
OpticsPhoton generationLight collection studies
Detector responseScintillationIonisation(thermal)
Simulated DataVisualisationRun-time analysisInput to data analysis software
G4 is uniquely suited for integrated simulations of Dark Matter detectors