Sector Shielding analysis tool (SSAT)
Computation Automation Using UNIX Awk and
MSC/NASTRAN FEM model
EFACEC - October 3-7 2005
Adolfo Aguilar
Overview
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Objective:
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Optimized Mass for the Electronics unit
TID and Aluminium Shielding Map for PCBs
Internal radiative environment definition for the equipment
Selection of appropriate electronics for the unit
Engineering approach to reduce analysis costs
Approach
– Use of programming scripts to translate from FEM information
to GEANT4 analysis
– SPENVIS SHIELDOSE-2 - GEANT4 SSAT computation
Leuven - 3-7 October
SPENVIS & GEANT4 WORKSHOP
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HARDWARE UNDER STUDY
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Components Technology Test
Bed (CTTB)
Two Units
– Control Unit
– Experiment Board (EB) Pallet
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Limited Mass budget
EB Pallet located outside S/C
Mass optimization required
Leuven - 3-7 October
SPENVIS & GEANT4 WORKSHOP
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ORBIT DEFINITION
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Orbit Location
Mission 1 GSTB-IOV
Orbit type: Walker 27/3/1+3
Apogee: 23616.00 km
Perigee: 23616.00 km
Inclination: 56.00º
R.A. Ascending Node: 120.00º
Argument of Perigee: 0.00º
Period: 14.36 hrs
Duration: 0.60 days
Number of orbits: 1.0
Orbit start: 01/01/2006 00:00: 0.0
Orbit end: 01/01/2006 14:21:18.4
Mission end: 31/12/2010 00:00: 0.0
Mission length: 1825.00 days (5.00 years)
Leuven - 3-7 October
SPENVIS & GEANT4 WORKSHOP
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GALILEO-IOV S/C
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EB PALLET LOCATED OUSIDE S/C
Leuven - 3-7 October
SPENVIS & GEANT4 WORKSHOP
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RADIATION ENVIRONMENT
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SPENVIS SHIELDOSE-2 (Al-spheres) Analysis based
on GALILEO orbit too pessimistic
6 mm Al thickness for the desired TID on PCBs (50krad)
Leuven - 3-7 October
SPENVIS & GEANT4 WORKSHOP
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GEANT4 DRAWBACKS
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Physicist Oriented Tool
– Lack of physical models explanation
– Lack of definition of applicability limits
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Very time consuming tool
– Geometry definition demands a lot of workload
– Output Results not directly applicable for engineering use
• Too theoretical/ideal results
• Not directly applicable to front-end electronics simulation
• Lot of post-process required to be cost-effective
Leuven - 3-7 October
SPENVIS & GEANT4 WORKSHOP
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FEM Model A source of Analysis Points
A translation from FEM
to GEANT4 is possible
Each node in the FEM
mode is the location
of a target point for
the analysis
Leuven - 3-7 October
SPENVIS & GEANT4 WORKSHOP
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SECTORIAL ANALYSIS (GEANT4-SSAT)
GEANT4 model for
S/C and EB Pallet
Leuven - 3-7 October
SPENVIS & GEANT4 WORKSHOP
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UNIX tools to translate FEM into GEANT4
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FEM models are ASCII based files
Node and connectivity definition is defined
Material and geometrical definition already coded
AWK, Perl, Phyton process can automate the task
Output results can be plotted using FEM postprocessors
– PATRAN
– IDEAS
Leuven - 3-7 October
SPENVIS & GEANT4 WORKSHOP
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Sectorial Analysis for the PCBs
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FEM Grids used as point target for the analysis
Shielding and TID map for each PCB
Very Fast and Efficient Method
– From Geometry definition to post-process 3 days
Leuven - 3-7 October
SPENVIS & GEANT4 WORKSHOP
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Post-Processed Results using PATRAN
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TID Maps obtained for each location of the PCB
3.5 mm (30krad) Al thickness reduced the mass
Leuven - 3-7 October
SPENVIS & GEANT4 WORKSHOP
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Conclussions
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GEANT4 needs a more engineering approach to be a
cost effective tool for electronics/detectors design tool
Existing tools for FEM analysis can be used to optimize
the analysis time
UNIX tools like AWK, Perl or Phyton can be used to
translate FEM models information into GEANT4
analysis cases
Post-Process can be done using existing tools from the
market like PATRAN or IDEAS.
A better understanding of the GEANT4 physical models
is demanded with proper explanation of the applicability
limits for better engineering use.
Leuven - 3-7 October
SPENVIS & GEANT4 WORKSHOP
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