outline of recent esa-related developments giovanni santin , petteri nieminen esa / estec rhea...

Outline of recent ESA-related

developments

Giovanni Santin*, Petteri Nieminen

ESA / ESTEC*RHEA System SA

GEANT4 – SPENVIS Space Users’ Workshop ‘06Pasadena, 9-10 November 2006

Giovanni Santin - Recent ESA-related developments - Pasadena, Nov 2006 2

Geant4 for space environment analyses Environments – Physics - Geometry - Analysis

ESA involvement in the Geant4 collaboration (since 1997) contributed to

new capabilities in the Geant4 kernel of relevance for space applications and tools in the space radiation environments and effects domain.

Applications:

Science mission analyses

Radiation engineering and shielding applications

Planetary environment modelling

Human effects

Physics

UsabilityGeometry modelling


Physics

New requirements from– Science missions– Human space flight– Effects to micro-electronics– Environment modelling


Space environment and Physics models

100 eV 1 keV 10 MeV 100 MeV 100 GeV 100 TeV 100 PeV

Tr. Protons

Tr. Electrons

Solar protons

Cosmic rays: p,,ions

Extreme Energy Cosmic Rays

Plasma

Spa

ce e

nviro

nmen

tG

eant

4 m

odel

s

HAD protons

HAD ions

EM Standard

EM Low Energy

Optical


Physics developments

Ion physics– P. Truscott, REAT_MS 1, MARSREM

Very low energy extensions– MG Pia, Geant4-DNA

Physics lists for space applications– V. Ivantchenko, REAT_MS 1

Inverse Monte Carlo– Laurent Desorgher, REAT_MS 1 & 2

See

relat

ed ta

lks

at th

is wor

ksho

p


Geant4 Reverse MC

“Adjoint” technique [Kalos 1968] New transport equation, “adjoint” to the conventional

“forward” transport equation Transport analogous to the forward one, but backward

– successive points are higher in energy, earlier in time

Suitable for Monte Carlo calculations Computations start at the detector and score at the source Possibility of computing doses at a point!

Feasibility study (REAT_MS 1)

G4 RMC Prototype for fast e- dose computation Only continuous energy loss and simple multiple scattering Completed

Full implementation (REAT_MS 2)

RMC in G4 for fast e- dose computation Backward simulation of :

– e- ionisation with delta production, continuous energy loss and multiple scattering

– Bremstrahlung, compton scattering, photo-electric effect

In development - Release mid 2007

Laurent Desorgher

Space IT and Uni. Bern

Proposed to be included in Geant4 release


Geometry

GDML– Upgrades– Developments for CAD I/F

CAD– Prototype interface through ST-Viewer– GDML Interface in Space Engineering CAD tools

ESABASE1– Through ES9 meshing– Under investigation


GDML Geometry Description Markup Language

Initial frame: XML based geometry description for Geant4 (CERN, ~2000)

Motivation– move away from hard-coded geometry (C++)– enable geometry interchange between applications

Presently part of the CERN Simulation Framework (Simulation Project) as

Geometry interchange format– Actively used at CERN for

Physics comparisons (Geant4 - FLUKA)

Geometry model exchange (Geant4 - ROOT)


GDML schema and I/O

GDML is defined through XML Schema (XSD) • defines document structure and the list of legal

elements (position, rotation, material, solid,…)

• XSD are in XML -> they are extensible

GDML I/O

– C++ implementation of GDML processor• Input

Xerces-C SAX parser 'in-memory' representation of the geometry description

• Output

Writing-out GDML data

– Alternative Python-based processor• uses xml.sax Python module

• allows very light binding to applications

GDMLSchema

GDML file

user application (1)

GDML writer

GDML reader

user application (2)


GDML example

Similar to HTML, explicit tags for elements, …

ASCII file: easy to create, read, debug, modify,…

<?xml version="1.0" encoding="UTF-8"?><gdml xsi:noNamespaceSchemaLocation="GDMLSchema/gdml.xsd">

<define><position name="TrackerinWorldpos" unit="mm" x="0" y="0"

z="100" /> </define>

<materials> <material formula=" " name="Air" > <D value="1.290" unit="mg/cm3"/> <fraction n="0.7" ref="Nitrogen" /> <fraction n="0.3" ref="Oxygen" /> </material> </materials>

<solids> <box lunit="mm" name="Tracker" x="50" y="50" z="50" /> </solids>

<structure> <volume name="World" > <materialref ref="Air" /> <solidref ref="world" /> <physvol>

<volumeref ref="Tracker" /> <positionref ref="TrackerinWorldpos" />

<rotationref ref="TrackerinWorldrot" />

</physvol> </volume> </structure>

<setup name="Default" version="1.0" > <world ref="World" /> </setup></gdml>

positions, rotations

materials

solids

geometry tree

'world' volume


GDML 2.8 - Status Solids supported:

– box, sphere (G4Sphere and G4Orb), tube, cone, polycone, parallepiped, trapezoid (G4Trap and G4Trd), torus, polyhedron, hype (tube with hyperbolic profile), elliptical tube

– Tetrahedron, tessellated, ellipsoid, twisted solids NEW Boolean solids:

– Union, subtraction, intersection Assembly of volumes Replicas and divisions Parameterized volumes

– Position, rotation and size Loops, modular models NEW

– E.g. space electronic components,…

Open source, collaborative development

– http://cern.ch/gdml

Stable, mature Main G4 geometry format at ESA

Antropomorphic Phantom, INFN, Giorgio Guerrieri, Maria Grazia Pia, Susanna Guatelli

ConeXpress, ESA, Ronnie Lindberg

LHCB, CERN, R.Maunder

http://cern.ch/gdml

http://cern.ch/gdml

http://cern.ch/gdml

http://cern.ch/gdml

http://cern.ch/gdml

http://cern.ch/gdml


Geant4 CAD interface

Prototype by ESA REAT_MS contract (QinetiQ+sub.)

– Uses G4TessellatedSolid (P.Truscott)– Requires auxiliary files created with ST-

Viewer commercial S/W– Based on GDML (v 2.8)

CAD-GDML interfaces in engineering toolsESABASE2 (eta_max)

FASTRAD (TRAD)

Future contract to integrate GEANT4 in CAD GUI framework

CAD model

STEP

model

GDML

ST-Viewer

StepTools

Geant4

External CAD tool

CAD tool

OpenCascade library

10 GeV proton in wood

LHEP_BIC_HP ES

AB

AS

E 2

FA

ST

RA

D


ConeXpress model: R.Lindberg, ESA

Sector Shielding Analysis Tool SSAT DOSE

Estimate of the dose at a point – Based on external Dose-Depth curve

• E.g. SHIELDOSE-2 curve [rad VS g/cm2]

– Ray-by-ray dose calculation

Results:– Total dose– Dose-Depth profile– Dose directionality

Ray tracing: from a user-defined point within a Geant4 geometry

NORM, SLANT and MIXED tracing

SHIELDING

shielding levelsfraction of solid angle for which the shielding is within a defined interval

global and from single materials

shielding distributionthe mean shielding level as a function of look direction

It utilizes geantinos


MULASSIS and GEMAT

Layer Geometry Physics list choice Analysis options

– Dose– Pulse Height Spectrum– Ion. dose– NIEL– Dose Equivalent

Primary particle spectrum and fluences from SPENVIS

– Trapped protons– Solar protons– Trapped electrons– …

Web interface

Geant4-based Microdosimetry Tool

Microdosimetry in geometries representing features of a semiconductor device (transistor/junction geometries)

Analysis includes– single event effects (SEE)– simultaneous energy deposition in several

sensitive regions (MBU)

Trajectory average spectra

1.00E-02

1.00E-01

1.00E+00

1.00E+01

1.00E+02

1.00E+03

1.00E+04

1.00E+05

0.01 0.1 1 10 100 1000

Energy (MeV)

Dif

fere

nti

al f

lux

(/c

m2/

s/M

eV

)

electronsprotons


GRAS Geant4 Radiation Analysis for Space

Detector / Component effects– Dose, Fluence, NIEL, LET… for support to engineering and scientific design

Human dosimetry– Dose Equivalent, Equivalent Dose,… for ESA exploration initiative

3D geometry– GDML format, or existing C++ class, …

Ready-To-Use tool– Different analyses set without re-compilation

Modular / extendable design Is being integrated into SPENVIS

Santin et al, IEEE Trans. Nucl. Sci. 52, 2005


GRAS componentsRADIATION ENVIRONMENT /gps/pos/type Surface

/gps/pos/shape Sphere.../gps/ang/type cos/gps/particle e-

...

2Source

- GDML- Used also for STEP CAD models

Also provided:- MULASSIS – like- Interface to ESABASE (in progress)- C++ model

/gras/geometry/type gdml/gdml/file geometry/conexpress.gdml

Geometry

1

/gras/phys/addPhysics em_standard/gras/phys/addPhysics binary/gras/phys/addPhysics binary_ion/gras/phys/addPhysics lowe_neutron

/gras/physics/setCuts 0.1 mm/gras/physics/stepMax 0.01 mm

Geant4 physics models through script commands

Physics

3GEAN

T4

Analysis Manager

DoseAnalysis Modules





FluenceAnalysis Modules



NIELAnalysis Modules



…Analysis Modules

/gras/analysis/dose/addModule doseB12/gras/analysis/dose/doseB12/addVolume b1/gras/analysis/dose/doseB12/addVolume b2/gras/analysis/dose/doseB12/setUnit rad

4Analysis

In progress:Activationmore SEE

- NIEL- Fluence- Charging- LET- Path-length

- Dose (TID)- Dose equivalent- Equivalent dose- Source monitoring- Detector analysis

Santin et al, RADECS, 2005


GRASShielding assessmentComparison to ray-tracing

Comparison of transmission (p, e-) Parametric study: stability of Geant4

dose estimates after transmission VS tracking parameters

Dose comparison in simple and realistic satellite geometries

Lindberg et al, accepted, IEEE Trans. Nucl. Sci.

1.E-10

1.E-09

1.E-08

1.E-07

1.E-06

0 10 20 30 40 50 60 70 80 90 100Incident Proton Energy (MeV)

Do

se

/un

it flu

en

ce

(R

ad

s.c

m2

)

1mm SH2 1mm GRAS

2mm SH2 2mm GRAS

8mm SH2 8mm GRAS

16mm SH2 16mm GRAS

Geant4 v7.1 Dose for Particle Energy of 1.75 MeV

0.004

0.008

0.012

0.016

0.02

0.01 0.1 1 10 100StepMax (mm)

Av

r. D

os

e p

er

Ev

en

t (M

eV

)

G4 v7.1, Cuts= 0.01 mm G4 v7.1,Cuts=0.10 mmG4 v7.1,Cuts=1.00 mm G4 v7.1,Cuts=100.00 mmG4 v8.0, cuts. 0.01 mm G4 v8.0, cuts 0.1 mmG4 v8.0, cuts 1 mm G4 v8.0, cuts 100 mm


GRASStatus and plans

Current release V1.3– Using Geant4 8.0.p01, GDML 2.5

Ongoing studies using GRAS– SREM radiation monitor (calibration)– HERSCHEL (glitch studies)– ConeXpress (dosimetry)– GAIA (dosimetry, transients)– RF filters (surface effects)

Upgrades– New analysis modules– Review of uncertainties to Geant4 release– Interface to PHITS (T. Koi)– Upgrade of physics list

Coming release V1.4– Using Geant4 8.1.p01, GDML 2.8– Next weeks– Software Installation & User Manual NEW

JWST NIRSpec

Neutron production TOF

HERSCHEL

Glitch study


Planetary exploration

Robotic and human missions Long interplanetary journey Long permanence with scarce natural shielding

New user requirements include: planetary models

e.g. scaling of SPE fluence to other planets, magnetic field description, crustal maps

ion physics electromagnetics / hadronics for HZE

biological effectsmacroscopic / microscopic models

very low energy physics


Geant4 DNA

Damage mechanisms

Interactions of Radiation with Biological Systems at the Cellular and DNA Level

Geant4 extension to simulate electromagnetic interactions in liquid water down to ~7.5 eV

– e-, p, H, He

Processes for cell survival

Human phantom library Applications in radiation

protection, therapy protocol studies

Analytical modelINFN Genova


GEANT4 GEOMETRY

ISS configuration 14A, 400 volumes Columbus, 800 volumes

Model available for collaborations from Tore Ersmark (KTH)

CALCULATED DOSE RATES INSIDE COLUMBUS

Trapped protons: 2.0 Gy/hSPENVIS, AP8-min

GCR protons: 3.3 Gy/hCREME96, solar minimum

Example spectra of penetrating trapped protons and secondary particles.

Courtesy: T. Ersmark, KTH Stockholm

The DESIRE project is funded by ESA (15613/NL/LvH) and the Swedish National Space Board.

DESIRE

DESIRE (cont)DESIREDose Estimation by Simulation of the ISS Radiation Environment


REMSIM

Simulation and Analysis of Vehicle Concepts and Surface Habitat Designs

Quantitative dosimetry Evaluation of interplanetary transfer vehicle concepts and habitat Interplanetary space radiation environment

See

S.G

uate

lli’s t

alk

at th

is wor

ksho

p


IEEE Trans Nucl Sci 52, No. 6, Dec 2005


PLANETOCOSMICS

Interactions of cosmic rays with planets – Mars, Mercury, Earth

Propagation in magnetosphere Interactions with atmosphere and soil

Flux of shower particles in atmosphere and soil (new) Energy deposited in atmosphere and soil (new)

In development– Jupiter case

Available at

http://cosray.unibe.ch/~laurent/planetocosmics

Laurent Desorgher













Active Shielding

MarsREM project

Literature review on active magnetic shielding

Development of a G4 magnetic shielding tool for computing shielding of space radiation by artificial magnetic fields

Comparative study of active and passive shielding by using this tool

In progress – release end 2007

Laurent Desorgher



Tools for the Space Users’ community

http://geant4.esa.int

Geant4 Space Users’ web page

– Users– ~100 publications– News

Feedback appreciated

http://geant4.esa.int/





To do

outline of recent esa-related developments giovanni santin , petteri nieminen esa / estec rhea...

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outline of recent esa-related developments giovanni santin *, petteri nieminen esa / estec *rhea...

outline of recent esa-related developments giovanni santin , petteri nieminen esa / estec rhea...