1. © Copyright QinetiQ 2007 Geant4 based tools for space applications Fan Lei QinetiQ 12 th Geant4 Workshop, Hebden Bridge, UK 15 September 2007

2. © Copyright QinetiQ 2007 2 Outline Background/History A survey of G4 space tools Direction for future developments Summary

3. © Copyright QinetiQ 2007 3 Background Space radiation environment: –Broad range of particle species: x, γ to heavy ions –Energy band: ~10s ev to TeVs Radiation effects: –Secondary radiation –Background/signal in sensors –Degradation in components (TID, NIEL) –Single event effect (SEE) –Radiobiological effects (dose, effective dose) Radiation analysis tools are required for –Environment Modelling –Mission, payload designs –Data analysis

4. © Copyright QinetiQ 2007 4 A little bit of history First real G4 space application/tool: XMM-Newton simulation 1999. Some of the issues faced at that time: –Geometry construction –Incident particle definition –Physics list Some of the early G4 developments ESA supported –G4/CAD interface –G4GeneralParticleSource –G4 Physics Developments Low-energy EM Firsov scattering

5. © Copyright QinetiQ 2007 5 A survey of G4 space tools Not an exhausted list and not including the more specific applications Main features surveyed –User I/F –Geometry construction –Incident particle definition –Physics List –Analysis/Histogram –Post processing

6. © Copyright QinetiQ 2007 6 NameFunctionsUsr I/FGeometryInc. ParticlePhysics ListAnalysis/HistoPost Proc. MULASSIS Shielding analysis UI WWW UI GPS/SPENVI S Own/ GRAS CSVSPENVIS PLANETOCOSMI CS Planetary Radiation UI GPS Mod G4 Packaged CSV/AIDA/RO OT n MAGNETOCOSMI CS C.P. tracking in M.F. UI OwnTransportationCSVn MRED/RADSAFEmicrodosimetryPythonTCAD I/FOwn Mathmatica Mathmatica/P ython GEMATmicrodosimetry UI WWW UI GPS/SPENVI S GRAS CSV/AIDA/RO OT SPENVIS SSAT Shielding analysis UI WWW GDML/C+ + Own CSV/AIDA/RO OT SPENVIS GRAS General Tool/Framework UI (WWW) UI / GDML C++ GPS Mod G4 Packaged CSV/AIDA/RO OT n FASTRAD CAD/User Front end GUI Open Frontier CAD /user Front end GUI

7. © Copyright QinetiQ 2007 7 MULASSIS-MUti-Layered Shielding SImulation Software 1D simulation of shielding effects (planar or spherical). » Multiple layers of predefined or user defined materials. –General source particle distribution: »Standard spectral distribution or point-wise fit. »Unidirectional/isotropic/cosine-law angular distributions. »Spectra output by other SPENVIS utilities. – Choice of physical processes and defined cut-offs » Standard and low-energy Geant4 EM physics. » Geant4 Hadronic processes. –Facilities to determine: » Fluence (layer, particle type, energy, angle). »NIEL based on coefficients. »Energy deposition or dose calculation for layer. »Energy deposition spectra as a function of layer. –Results are histogrammed and outputted in Comma Separated Values (CSV) format – Available under SPENVIS (WWW)

8. © Copyright QinetiQ 2007 8

9. PLANETOCOSMICS PLANETOCOSMICS Permises Interdites Interaction of energetic particles with Earth, Mars, Mercury Fluxes of secondary particles at user defined altitudes atmospheric depths, and soil depths Energy deposited vs atmospheric depth and vs soil depth Propagation in magnetic field Different coordinate system relative to planets Visualisation of particle trajectories and field lines Analysis based on Root or AIDA (Slide from L. Desorgher)

10. Dose in Europa soil (ice) Gurtner et al, 2006 (Slide from L. Desorgher)

11. © Copyright QinetiQ 2007 11 MRED 8 Unique Features Python control shell TCAD structure file parsing General voxel array input mechanism Constructive solid tetrahedron Now G4Tet! Screened Coulomb scattering and recoil tracking Hadronic cross section biasing Custom particle gun derived from G4ParticleGun Interpolating function or C2Function tool Detector class with multiple sensitive volumes Histogram class with Python and Mathematica ® analogs Mathematica ® output files with a compatible Python processing tool (Slide from R. Weller, VU)

12. © Copyright QinetiQ 2007 12 (Slide from R. Reed, VU)

13. © Copyright QinetiQ 2007 13 GEMAT- GEant4 Macrodosimetry Analysis Tool Miscrodosimetry tool primarily aimed for SEE analysis: » Define multiple layered geometry with contact and depletion volumes via UI. » GPS for incident particle definition. » Physics list based on the G4 packaged lists, similar to GRAS. » Analysis type: Dose, Fluence, Path length, Charge collection, Coincidence Detector (MBU) » Results are outputted in Comma Separated Values (CSV) format » Available under SPENVIS (WWW)

14. © Copyright QinetiQ 2007 14 MBU rates Neutron Data

15. © Copyright QinetiQ 2007 15

16. © Copyright QinetiQ 2007 16 SSAT-Sector Shielding Analysis Tool G4 based sector shielding analysis tools: – Geometry in GDML or C++ – Build-in particle gun to fire geantinos specified angle window cells – Physics: G4Transport and new G4NormalTransport for Geantino – Path length analysis: » 1D/2D distributions » in terms of material – Dose analysis » with user supplied dose depth curve – Results are outputted in Comma Separated Values (CSV) format – Available under SPENVIS (WWW)

17. © Copyright QinetiQ 2007 17

18. © Copyright QinetiQ 2007 18

19. Giovanni Santin - GRAS - Geant4 tutorial, Paris 200719 GRAS tool description Analysis types –3D –Dose, Fluence, NIEL, charge deposit… for support to engineering and scientific design –Dose Equivalent, Equivalent Dose,… for ESA exploration initiative –SEE: PHS, LET, SEU models –Open to new analysis models Analysis independent from geometry input format –GDML, CAD, or existing C++ class, … Pluggable physics lists All text UI (macro) driven! Different analyses without re-compilation Modular / extendable design Publicly accessible Radiation environment SPENVIS, CREME96,… Physics EM, Hadronics, Ions Geometry GDML, C++, CAD (GDML) Histogramming AIDA, ROOT, CSV

20. Giovanni Santin - GRAS - Geant4 tutorial, Paris 200720 GRAS for James Webb Space Telescope G. Santin et al., IEEE TNS Dec 2005 JWST background and TID JWST TOF neutron production experiment Total Ionizing Dose Tool, Model Dose [krad] (11 mm eq. Al) Dose [krad] (18 mm eq. Al) SHIELDOSE-2, Spherical Shell, 3.91.9 GRAS, Spherical shell 3.5 +/- 0.22.3 +/- 0.2 GRAS, Realistic model 2.2 +/- 0.11.1 +/- 0.1

21. Ecole Geant4 Presentation June 8 th, 2007 21 Radiation CAD (Computer-Aided Design) Tool –3D Geometry (simple shapes), materials, sensitive detectors –Design assistance tools. –Import 3D models : STEP, IGES Sector Analysis Tools –Ray-tracing on complex shapes –Post processing CAD Interface for others softwares –NOVICE import/export (EMPC) –GEANT4 export (CERN) FASTRAD – G4 See FASTRAD Talk/Demonstration This Afternoon Main Functionalities

22. Slide provided by K.D. Bunte Open Frontier Overview Open Frontier is the engineering framework of ESABASE2. –ESABASE2 provides tools for space related engineering tasks. –Currently implemented: space debris and meteoroid flux and damage analysis. Open Frontier provides –a user friendly and well proven window- and event- handling through the use of Eclipse (graphical user interface). –a very flexible and extendible concept for both data handling and user interface. –a CAD-like 3D editor for geometrical models (based on OpenCASCADE). –STEP import and export facilities (AP 203, AP 214; based on OpenCASCADE). –a GDML export facility. –specific editors for input data handling depending on the type of analysis. –specific editors for results (output) data handling depending on the type of analysis. –the flexibility needed for the potential integration of additional modules/libraries (e.g. radiation analysis input editors and tools for post-processing).

23. Slide provided by K.D. Bunte 23 Open Frontier Look and Feel Property Explorer Outline Project Explorer Geometry Editor(s)

24. © Copyright QinetiQ 2007 24 Direction for future developments Geometry definition Incident particle definition Physics list Analysis, Scoring User interface A very personal view

25. © Copyright QinetiQ 2007 25 Geometry definition UI based simple geometry construction (e.g. MULASSIS, GEMAT) In the engineering world, complex geometry design is done with a CAD tool –STEP is the exchange format A G4 CAD I/F is the most desire solution –G4 had a STEP I/F, but –Issues with material definition –Requires further developments in G4 geometry classes Tessellated geometry solution –G4Tet (used in RADSAFE) –G4TessellatedSolid (ESA) Current solution: GDML –CAD -> GDML (FASTRAD, Open Frontier) –CAD -> STEP -> Tessellation ->GDML Future: G4 STEP I/F?

26. © Copyright QinetiQ 2007 26 Incident Particle Definition Link G4GeneralParticleSource to space radiation environment models –SPENVIS (ESA/BIRA) –OMERA (TRAD) –SPACERAD (USA) Solutions: –Update GPS to accept model outputs –Convert model output to GPS format (as done in SPENVIS)

27. © Copyright QinetiQ 2007 27 Physics Lists: Currents tools use a range of lists, but they are –Not properly validated –Not easy to maintain, some are in fact outdated/not working now A dedicated set of physics lists for space applications should be created –Some work done in the ESA REAT-MS project GRAS physics list

28. © Copyright QinetiQ 2007 28 Analysis, Scoring (I) Common analysis types: –Dose/Energy Depositions (MULASSIS,GEMAT,MRED,FASTRAD,GRAS) –Biological Dose (GRAS) –Fluence (MULASSIS,GEMAT,GRAS) –NIEL (MULASSIS, GRAS) –Deposited charge (GRAS) –Detector (GRAS,GEMAT) –Path length (SSAT,GRAS,FASTRAD) –LET (GRAS) –Pulse Height Spectrum (MULASSIS,GEMAT,GRAS) –Charge Collection (GEMAT,(GRAS),MRED)

29. © Copyright QinetiQ 2007 29 Analysis, Scoring (II) Histogramming –CVS, AIDA, ROOT, Mathmatica! A common analysis package is desirable/possible –GRAS has the most complete implementations –Make use of the G4 native scorer?

30. © Copyright QinetiQ 2007 30 User Interface Existing ones: –Command line script –Python (MRED) –GUI (FASTRAD, Open Frontier) –WWW (SPENVIS – MULASSIS/SSAT/GEMAT/(GRAS)) CL, GUI, WWW are required

31. © Copyright QinetiQ 2007 31 A General Purpose Engineering Tool for Space Radiation and Effect Analysis? GRAS is being developed into such a tool –MULASSIS,SSAT,GEMAT,PLANETOCOSMICS has been/is being/can be integrated into it –Flexible geometry construction with UI or GDML –Can be link to space environment models via GPS –Most recent and complete physics list –New analysis module can be added easily –Can be run under SPENVIS, FASTRAD or Open Frontier

32. © Copyright QinetiQ 2007 32 Summary A wide range of space engineering tools have been developed using the Geant4 Toolkit –Shielding analysis, Micodosimetry, Radiation environment analysis, TID, NIEL, SEE … etc. Common features of the tools: –Geometry construction –Incident particle definition: link to radiation models –Physics list –Analysis/scoring –GUI A G4 general purpose space radiation and effect analysis tool is desirable/possible.