SPENVIS Integration of Mulassis

Space Environments and EffectsSpace Environments and EffectsAnalysis SectionAnalysis Sectionee

SPENVIS Integration of MulassisSPENVIS Integration of Mulassis

H.D.R. EvansH.D.R. Evans

Space Environments and Effects Section

TEC-EES

5th October 2005 SPENVIS Integration of Mulassis - SPENVIS Workshop

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What is Mulassis? What is Mulassis? What can it Do?What can it Do?

What is Mulassis:• A 1-D geometrical Monte-Carlo application• Based on the Geant4 toolkit• Simple, easy to use.What can it Do?• Simulates energetic particle interactions in 1-D geometries

(slab/sphere)• Includes physical models and material properties of Geant4.• Calculates total dose, NIEL, shielded fluences, PHS, Dose-

Equivalent• Can be used determine dose, c.f. SHIELDOSE, but for shields

other than Aluminium.


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Spenvis/Local VersionSpenvis/Local Version

• Can run via SPENVIS interface– Easy to use, simplified inputs

– Can directly include radiation environment spectra

• Can download from REAT server, install and run as a standalone application– Can run simulations with more events

– Greater flexibility in specifying input parameters.

– No network connection required

– Useful for parametric analyses


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Spenvis/Mulassis:Spenvis/Mulassis:http://http://www.spenvis.oma.be/spenviswww.spenvis.oma.be/spenvis//

• Accessed via the SPENVIS Server.• Provides a series of Web pages to set up a simulation

– Geometry definition– Particle source definition– Physics to include in simulation

• Novice user has simpler options• Advanced user can set production cuts (by region), selection of physics models

– Output analysis specification (one type per run, which simplifies the interface)– Plotting of outputs

• Provides the G4MAC file that can be used directly in a local Mulassis run.• Caveat: The space environment spectra vary by several orders of magnitude

over their energy range -> leads to oversampling of non-effectual low-energy particles to the detriment of high energy ones; energy biasing of spectra would be very useful, but is still to be implemented.


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Standalone MulassisStandalone Mulassis

• Download it from http://reat.space.qinetiq.com/mulassis/mulassis.htm

• Linux and Win32 binary versions available. (Win32 split into two install wizards: G4data and Mulassis)

• Statically linked Linux version is available – saves installing Geant4 and rebuilding Mulassis – should run on most Linux boxes – does not include OpenGL.

• Provides more functionality and flexibility than available with SPENVIS, e.g. energy/angular biasing of GPS particle source.


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Geometry SpecificationsGeometry Specifications

• Default – SHIELDOSE Slab with layers commensurate with SD shielding thicknesses

• Planar Slab• Spherical Shell


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Geometry SpecificationGeometry Specification

• 1-D geometries used: Slab/Sphere:/geometry/layer/shape [slab|sphere]

• Layers specified by:/geometry/layer/add <layerNo> <Material> <colour> <thick> <thick_units>

/geometry/layer/add 0 Aluminium 1 4.0 mm/geometry/layer/add 1 Silicon 2 50 mum

• Other commands include:– /geometry/layer/delete <layerNo>– /geometry/layer/list


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SPENVIS Geometry InterfaceSPENVIS Geometry Interface


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Material SpecificationMaterial Specification/geometry/material/geometry/material

• Predefined Materials:– Vacuum

– Air

– Aluminium

– Silicon

• Adding new materials:– /geometry/material/add <Name> <Chem. Formula> <density g/cm3>– /geometry/material/add fused_quartz Si-O2 2.200E+00


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SPENVIS Materials InterfaceSPENVIS Materials Interface


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Incident Particle SpecificationIncident Particle Specification

• Easiest: Use SPENVIS to set up the General Particle Source (GPS) macros.• Establish particle type:

/gps/particle [ion|proton|neutron|e-|…]• Establish particle source shape (point source)• Establish angular distribution (isotropic -> cosine law)

/gps/ang/type cos• Establish particle spectrum (mono, data, eEnergy, …), Emin, Emax

• Optional:– Energy Biasing– Angular Biasing– Etc.

• See the GPS documentation


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Normalisation FactorNormalisation Factor

• What is it? – It’s a factor to scale the Mulassis outputs to the

environment -> to provide the real dose/fluence.– Total number of environmental particles in

simulation energy range that would impact per cm2.– E.g. NF = ¼ [Flux(>10 MeV) – Flux(>100 MeV)]

• New version of SPENVIS calculates this automatically from environment spectra.


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Spenvis Source ParticlesSpenvis Source Particles


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Spenvis Source ParticlesSpenvis Source Particles


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Physics to includePhysics to include/phys/scenario <scenario>/phys/scenario <scenario>

• Electro-Magnetic /“Lepton-gamma transport” (em)• Low Energy Electro-Magnetic (leem)• Hadrons (hadron)• Low Energy Neutrons (+/- ln)• Binary Cascades (binary)• For Example, for hadron AND electro-Magnetic but

NO low energy neutrons:/phys/scenario hadron+em-ln

See Mulassis User Manual for more documentation


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SPENVIS Physical ModelsSPENVIS Physical Models


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Analysis TypesAnalysis Types

• Fluence – shielded particle spectra• Dose – Total dose in layer/shell• Dose Equivalent: ICRP-60 Q(L) definition• Non-Ionising Energy Loss (NIEL) Dose in layer

interface• Pulse Height Spectrum (PHS)


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Fluence AnalysisFluence Analysis

• Calculation of the shielded flux spectrum for a particle.

• This is the number of particles crossing a layer boundary.

• Data is the number of particles counted per energy bin -> divide by the bin width to get the differential spectrum.


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SPENVIS Fluence AnalysisSPENVIS Fluence Analysis


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Dose AnalysisDose Analysis

• Calculates the total energy deposited in a layer.

• Numerous units available: MeV, Rads, Gy, etc.

• Can be compared to SHIELDOSE outputs : (60 day GTO Trapped proton spectrum, 2 mm Al. shield, Si target) – Mulassis: 1711 ± 427 Rads– SD-2: 1880 Rads


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SPENVIS Dose AnalysisSPENVIS Dose Analysis


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SPENVIS Dose AnalysisSPENVIS Dose Analysis


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NIEL AnalysisNIEL Analysis

• Uses various NIEL curves to calculate the NIEL in an interface between two layers from the Fluence analysis.– Limited to NIEL analyses for specific curves:

• SPENVIS/JPL proton curve• CERN/ROSE curves for protons, electrons, neutrons, pions• SAVANT/NRL curves for protons, electrons & neutrons in Silicon, GaAs,

and InP (c.f. S. Messenger presentation yesterday).

– Can now set NIEL curve by layer.

• This is unlike the DOSE analysis, which calculates the total energy deposited in the layer.

• For thin targets, this should be adequate.


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SPENVIS NIEL AnalysisSPENVIS NIEL Analysis


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PHS AnalysisPHS Analysis

• A “cross” between the dose and fluence analysis: it provides the number of particles that deposit a specific energy in an energy bin.

• Used to predict the energy deposited spectra in, for example a silicon detector.


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SPENVIS PHS AnalysisSPENVIS PHS Analysis


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SPENVIS PHS AnalysisSPENVIS PHS Analysis


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Dose Equivalent AnalysisDose Equivalent Analysis

• Not yet implemented in SPENVIS

• Uses ICRP-60 Q(L) function to calculate Dose Equivalent

• Deviates from standard for H*(d) due to geometry simplifications: H(d) in Mulassis is calculated for the whole spherical shell, not just the solid angle along a particular direction.

Proton; H(10)

1.0.E-10

1.0.E-09

1.0.E-08

0.01 0.1 1 10 100 1000 10000

Energy (GeV)p+

to H

*(10

) co

nver

sion

Fluka (adepr)

Version G4.7, ML1.7a (SPHERE)

Version G4.7, ML1.7a (SLAB)

Pelliccioni, M. “Overview of Fluence-to-Effective Dose and Fluence-to-Ambient Dose Equivalent Conversion Coefficients for High Energy Radiation Calculated Using the FLUKA Code”, Radiat. Prot. Dosim. 88(4), 279-297 (2000)


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VisualisationVisualisation

• Most useful are:– OpenGL: X windows visualisation

on the screen as simulation runs.– VRML2FILE: visualisation within

VRML viewer (Cortona plugin, vrmlview for Linux)*

– DAWN: with the dawn application, can produce postscript files.

– WIRED

• Static binary version does not support OpenGL.

• Only the first 100 events will be displayed.

*my preferences


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Output FilesOutput Files

• Mulassis G4 Macro File• Report file

– Contains information about run– Dose and NIEL results

• Comma Separated Value (CSV) file– In SPENVIS CSV format– Contains outputs from all analysis modules (dose, PHS,

Fluence and NIEL)

• Program output/log file


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Spenvis Output PageSpenvis Output Page


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SPENVIS Mulassis MacroSPENVIS Mulassis Macro# SPENVIS generated macrofile for MULASSIS/geometry/layer/delete 0/geometry/material/add ICRU_Tissue H5398-C498-N100-O2566 1.000E+00/geometry/layer/shape slab/geometry/layer/add 0 Aluminium 1 2.000E+00 mm/geometry/layer/add 1 Silicon 2 1.000E+01 mum/geometry/layer/add 2 Silicon 1 1.000E+01 mum/geometry/layer/add 3 Silicon 1 1.000E+01 mum/geometry/layer/add 4 Silicon 1 1.000E+01 mum/analysis/file spenvis/analysis/normalise 8.188E+13 cm2/analysis/phs/add 2/analysis/phs/add 3/analysis/phs/add 4/analysis/phs/energy/default/geometry/update/phys/scenario em/gps/particle proton/gps/ene/type Arb/gps/hist/type arb/gps/ene/min 1.000E-01 MeV/gps/ene/max 4.000E+02 MeV/gps/hist/point 1.000E-01 3.056E+08/gps/hist/point 1.500E-01 2.336E+08/gps/hist/point 2.000E-01 1.724E+08/gps/hist/point 3.000E-01 1.012E+08/gps/hist/point 4.000E-01 6.619E+07/gps/hist/point 5.000E-01 4.443E+07/gps/hist/point 6.000E-01 3.149E+07/gps/hist/point 7.000E-01 2.327E+07/gps/hist/point 1.000E+00 1.153E+07/gps/hist/point 1.500E+00 3.808E+06/gps/hist/point 2.000E+00 1.474E+06/gps/hist/point 3.000E+00 3.337E+05/gps/hist/point 4.000E+00 1.176E+05

/gps/hist/point 5.000E+00 5.061E+04/gps/hist/point 6.000E+00 2.858E+04/gps/hist/point 7.000E+00 1.771E+04/gps/hist/point 1.000E+01 6.902E+03/gps/hist/point 1.500E+01 1.603E+03/gps/hist/point 2.000E+01 4.551E+02/gps/hist/point 3.000E+01 9.342E+01/gps/hist/point 4.000E+01 3.074E+01/gps/hist/point 5.000E+01 1.888E+01/gps/hist/point 6.000E+01 1.085E+01/gps/hist/point 7.000E+01 8.428E+00/gps/hist/point 1.000E+02 5.459E+00/gps/hist/point 1.500E+02 2.826E+00/gps/hist/point 2.000E+02 1.595E+00/gps/hist/point 3.000E+02 5.442E-01/gps/hist/point 4.000E+02 3.608E-02/gps/hist/inter Lin/gps/ang/type cos/gps/ang/mintheta 0.000E+00 deg/gps/ang/maxtheta 9.000E+01 deg/vis/open VRML2FILE/vis/scene/create/vis/viewer/set/style wireframe/vis/viewer/set/viewpointThetaPhi 90. 180./vis/drawVolume/vis/scene/endOfEventAction accumulate/tracking/storeTrajectory 1/event/printModulo 1000/run/cputime 6.000E+02/run/beamOn 10000


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CSV File FormatCSV File Format

• SPENVIS Comma Separated Value (CSV) format:http://spenvis.oma.be/spenvis/help/models/outputs.html#UNIFMT

• Can be directly imported into Excel• Header lines/Meta Data

– “navigation info”: # variable, header lines, data lines, …

– Plotting annotation

– Data variable descriptions: name, units, dimensions, description

• Data in columns


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Misc.Misc.

• SPENVIS – download output files directly into Excel• Use SPENVIS to set up simulation and then tailor the

macro file to your own ends.• Material “calculator” Excel Spreadsheet (G. Santin)• CREME-86 Excel implementation of M1 environment

to provide GCR Spectra• “help” command in command line version.


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Future Activities/Desires:Future Activities/Desires:

• Provide GCR spectra via SPENVIS/MULASSIS “Source Particles” page.

• Include physics to handle high energy ions (E>10 GeV/n).

• Provide energy biasing of spectra.• Include Köln NIEL developments to

calculate NIEL directly during simulation.• Solar Cells:

– Include SAVANT Solar Cell degradation calculation as an analysis output- not just the NIEL damage output.

– Implement a simplified interface for solar cell engineer in SPENVIS

• Include Nuclear Decay Model.• Implement Dose Equivalent Analysis in

SPENVIS.

Elemental Integral Flux for GCRs

1E-05

1E-04

1E-03

1E-02

1E-01

1E+00

1E+01

1 10 100 1000 10000 1E+05

Energy (MeV/nucl)

Flu

x (#

/m2/

s/sr

)

HHeFeCON10 GeV/n


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Questions?Questions?


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DemonstrationDemonstration

• Spenvis simulation

• Command line (local) simulation

• Excel spreadsheets:– Normalisation factor– Material properties– CREME M1 spectra

Documents

SPENVIS Integration of Mulassis