Radiation analysis for space GRAS презентация

Geant4 Radiation Analysis for Space GRAS G.Santin1, V.Ivanchenko2, R.Lindberg1, H.Evans1, P. Nieminen1, E.Daly1 1 Space Environments and Effects Analysis Section, ESA/ESTEC 2 PH SFT, CERN Geant4 Space Users Workshop Leuven, 5 Oct 2005

Outline Motivation Description of the tool structure and functionalities GRAS as framework for Monte Carlo analyses Monte Carlo engine for external packages (e.g. SPENVIS) Present status, expectations, conclusions

Simulations of the Space Radiation Environment

Commonly used Ready to Use Simulation Tools

The example of MULASSIS Geant4-based tool Geant4 is a “Toolkit” Flexible, powerful, extendable,… But intentionally “not a tool” ready for use MULASSIS Features 1D Layered geometry via scripting Geant4-based Predefined physics lists Materials by chemical formula Interfaced to the Space Environment spectra inside the Web-based SPENVIS framework User success Raised the level of radiation shielding analysis in the space community Limitations 1D geometry Extensibility

GRAS Geant4 Radiation Analysis for Space Analysis types 3D Dose, Fluence, NIEL, activation… for support to engineering and scientific design Dose Equivalent, Equivalent Dose,… for ESA exploration initiative SEE: PHS, LET, SEU models Analysis independent from geometry input format GDML, CAD, or existing C++ class, … Pluggable physics lists Different analyses without re-compilation Modular / extendable design Publicly accessible

GRAS components

GRAS components G4 General Particle Source

GRAS components

GRAS components

GRAS Analysis modules: Component degradation, Background Total Ionizing Dose Also per incoming particle type, with user choice of interface Gives event Pulse Height Spectrum For analysis of induced signal Units: MeV, rad, Gy

GRAS Analysis modules: Human Exploration Initiatives Dose equivalent ICRP-60 and ICRP-92 LET-based coefficients Units: MeV, Sv, mSv, Gy, rad

GRAS Analysis modules: SEE in microelectronics Path length analysis Event distribution of particle path length in a given set of volumes If used with “geantinos”, it provides the geometrical contribution to the energy deposition pattern change In a 3D model W.r.t. a 1D planar irradiation model

GRAS Analysis modules: Flexibility Volume To identify a volume in the geometry tree At present implemented as the couple (name, copy No) Volume Interface To identify the boundary between two volumes Couple of Volumes

GRAS Building blocks 1. Geometry 2. Primary generation 3. Physics 4. Modular analysis set via macros

MC analysis with no C++ coding Geometry via GDML Physics, Source, Analysis via scripts Upgrades of models / interfaces

GRAS Analysis Modular, extendable design

Analysis Module Easy to implement: Self contained analysis element Initialization, event processing, normalization, printout  all inside Only one class to create/derive in case a new type of analysis is needed No need to modify Run+Event+Tracking+Stepping actions AIDA histogramming “per module” G4 UI commands “per module” Automatic module UI tree a la GATE /gras/analysis/dose/addModule doseCrystal /gras/analysis/dose/doseCrystal/setUnit MeV

For present Geant4 users GRAS and previous work 2 ways of obtaining GRAS output without discarding hours/days/months of work Inserting C++ Geometry, Physics and/or Primary Generator classes inside GRAS In the main gras.cc Inserting GRAS into your existing applications Which way is the fastest depends on existing work

Engineering tools: GRAS as flexible Monte Carlo engine Geometry exchange format - GDML - CAD / STEP - …

User Requirements Complete tool (Geometry, Physics, Source, Analysis) Available as standalone executable No need to download and compile Geant4 Easy to integrate in existing applications Analysis types 3D Dose, Fluence, NIEL, activation… for support to engineering and scientific design Dose Equivalent, Equivalent Dose,… for ESA exploration initiative Transients: PHS, LET, SEU models Analysis independent from geometry input mode GDML, or existing C++ class, … Different analyses set without re-compilation Modular / extendable design Source and Physics description adequate to space applications Solar events Cosmic rays

GRAS is being used for Herschel Test beam detector study Radiation effects to photoconductors and bolometers JWST Dose Background ConeXpress See talk by Ronnie Lindberg Electronic components Rad-hardness, local shielding, etc.

GRAS for HERSCHEL Herschel PACS Photoconductor instrument Study and test of the detector to assess glitch rate Impact on science objectives Simulation of the proton irradiation at Leuven, Belgium Comparison with glitch data on-going Need precise description of energy degraders and beam parameters Extrapolation to detector behavior in space

GRAS for JWST NIRSpec Degradation Instrument design phase Radiation shielding, material choice

GRAS for JWST NIRSpec Background Secondary particle production Shielding effect on the particle flux on the detector Cosmic Ray background CRÈME’96 Solar Minimum Proton simulations

Status Perspectives CVS repository online http://geant4.esa.int Code Latest stable tag works with Geant4 7.1 GDML 2.3 Documentation Introduction README file Installation INSTALL file Detailed User Manual In preparation

Conclusions Modular, script driven analysis package Space users oriented, but trying to be generic Already used in the support of a number of space missions and ground beam tests GRAS as Ready-to-use Geant4 tool for common analysis types Framework for Monte Carlo analyses Monte Carlo engine for external packages GRAS used as framework for on-going ESA contracts REAT_MS (QinetiQ), Geant4 usability for space applications (CAD interface, SEE analysis, Physics lists for space applications) Open to comments / contributions for collaborative development http://geant4.esa.int We believe GRAS is significantly improving the Geant4 usability Some features could be used directly by the Geant4 kernel Related talk Ronnie Lindberg (ESA) with extensive validation and dosimetry / physics investigations