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

© Copyright QinetiQ 2007

Geant4 based tools for space applications

Fan LeiQinetiQ

12th Geant4 Workshop, Hebden Bridge, UK15 September 2007

2


Outline

• Background/History

• A survey of G4 space tools

• Direction for future developments

• Summary

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


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

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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

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Name Functions Usr I/F Geometry Inc. Particle Physics ListAnalysis/Histo

Post Proc.

MULASSISShielding analysis

UI

WWWUI

GPS/SPENVIS

Own/

GRASCSV SPENVIS

PLANETOCOSMICS

Planetary Radiation

UI UI GPSMod G4 Packaged

CSV/AIDA/ROOT

n

MAGNETOCOSMICS

C.P. tracking in M.F.

UI UI OwnTransportation

CSV n

MRED/RADSAFEmicrodosimetry

Python TCAD I/F Own Own MathmaticaMathmatica/Python

GEMATmicrodosimetry

UI

WWWUI

GPS/SPENVIS

GRASCSV/AIDA/ROOT

SPENVIS

SSATShielding analysis

UI

WWW

GDML/C++

Own OwnCSV/AIDA/ROOT

SPENVIS

GRASGeneral Tool/Framework

UI

(WWW)

UI / GDML

C++GPS

Mod G4 Packaged

CSV/AIDA/ROOT

n

FASTRADCAD/User Front end

GUI

Open FrontierCAD /user Front end

GUI

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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


PLANETOCOSMICSPLANETOCOSMICS

Permises

Interdites

Interaction of energetic particles with Earth, Mars, MercuryFluxes of secondary particles at user defined altitudes atmospheric depths, and soil depthsEnergy deposited vs atmospheric depth and vs soil depth Propagation in magnetic fieldDifferent coordinate system relative to planets Visualisation of particle trajectories and field lines Analysis based on Root or AIDA

(Slide from L. Desorgher)

Dose in Europa soil (ice) Dose in Europa soil (ice)

Gurtner et al, 2006

(Slide from L. Desorgher)

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MRED8 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 (Slide from R. Reed, VU)

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GEMAT- GEant4 Macrodosimetry Analysis ToolMiscrodosimetry 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)

Depleted regions non-depleted active orinactive regions

x

y

z

Contacts

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1.E-20

1.E-19

1.E-18

1.E-17

1.E-16

1.E-15

1.E-14

1.E-13

1.E-12

0 100 200 300 400 500 600

Proton Energy (MeV)

SE

U C

ross

-Sec

tion

(cm

2)

Single Double Triple

1.E-19

1.E-18

1.E-17

1.E-16

1.E-15

1.E-14

1.E-13

1.E-12

0 100 200 300 400 500 600

Neutron Energy (MeV)

SE

U C

ross

-Sec

tion

(cm

2)

Single Double Triple

MBU rates

1.E-16

1.E-15

1.E-14

1.E-13

1.E-12

0 100 200 300 400 500

Particle Energy (MeV)

SE

U-b

it X

-Se

ctio

n (

cm2)

G4 Neutron Simulation (Weibull 1)Neutron ExperimentalIRTS Neutron Simulation

Neutron Data

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SSAT-Sector Shielding Analysis ToolG4 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)

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Giovanni Santin - GRAS - Geant4 tutorial, Paris 2007 19

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,…

PhysicsEM,

Hadronics,Ions

GeometryGDML,C++,

CAD (GDML)

HistogrammingAIDA,ROOT,

CSV

Giovanni Santin - GRAS - Geant4 tutorial, Paris 2007 20

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,

3.9 1.9

GRAS,

Spherical shell

3.5 +/- 0.2 2.3 +/- 0.2

GRAS,

Realistic model

2.2 +/- 0.1 1.1 +/- 0.1

21Ecole Geant4 PresentationJune 8th, 2007

• 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)

See F

ASTRAD

See F

ASTRAD

Talk

/Dem

onst

ratio

n

Talk

/Dem

onst

ratio

n

This A

fter

noon

This A

fter

noon

Main FunctionalitiesMain Functionalities

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).

Slide provided by K.D. Bunte 23

Open Frontier Look and Feel

Property Explorer

Outline

Project Explorer

Geometry Editor(s)

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Direction for future developments

• Geometry definition

• Incident particle definition

• Physics list

• Analysis, Scoring

• User interface

• A very personal view

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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?

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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)

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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

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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)

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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?

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User Interface

• Existing ones:

– Command line script

– Python (MRED)

– GUI (FASTRAD, Open Frontier)

– WWW (SPENVIS – MULASSIS/SSAT/GEMAT/(GRAS))

• CL, GUI, WWW are required

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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


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.

Documents

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