1. Dose Mapping for the SIXS Module and X-ray detector BepiColombo Mission 7 th GEANT4 Space Users’ Workshop August 18 – 20, 2010 Seattle - USA F. García, H. Andersson, M. Roos, K. Banzuzi, A. Lehtolainen, L. Alha and J. Huovelin F. García 1, H. Andersson 2, M. Roos 2, K. Banzuzi 2, A. Lehtolainen 3, L. Alha 3 and J. Huovelin 3 1 Helsinki Institute of Physics and University of Helsinki, Helsinki, Finland 2 Oxford Instrument Analytical Oy, Espoo, Finland 3 Observatory, University of Helsinki, Helsinki, Finland

2. SIXS Sensor Unit Dose Mapping and X-ray detector – BepiColombo Mission OUTLINE  INTRODUCTION and MOTIVATION  SOLAR INTENSITY X-RAY and PARTICLE SPECTROMETER  GEOMETRY DESCRIPTION and MATERIALS  SSAT - SIMULATIONS and DOSE MAPPING  X-RAY DETECTOR  CONCLUSIONS  ACKNOWLEDGEMENTS 18-Aug-10 7th GEANT4 Space Users’ Workshop – Plenary Session II Apparatus Simulation F. García 2

3. SIXS Sensor Unit Dose Mapping and X-ray detector – BepiColombo Mission INTRODUCTION BepiColombo is a joint mission between ESA and JAXA. It has been named after the Italian mathematician and engineer Giuseppe(Bepi) Colombo (1920-1984). He was a scientist who studied Mercury's orbital motion in detail as well as orbits and interplanetary travel in general. This is one of ESA’s Cornerstone missions, for the studying and understanding of the composition, atmosphere, magnetosphere and history of Mercury. Launch is expected for 2014 with a journey of about six years 18-Aug-10 7th GEANT4 Space Users’ Workshop – Plenary Session II Apparatus Simulation F. García 3

4. SIXS Sensor Unit Dose Mapping and X-ray detector – BepiColombo Mission MOTIVATION SIXS Module Mercury Planetary Orbiter (MPO) 18-Aug-10 7th GEANT4 Space Users’ Workshop – Plenary Session II Apparatus Simulation F. García 4 STM (Structural and Thermal model)

5. SIXS Sensor Unit Dose Mapping and X-ray detector – BepiColombo Mission SIXS Module The Solar Intensity X-ray and Particle spectrometer 18-Aug-10 7th GEANT4 Space Users’ Workshop – Plenary Session II Apparatus Simulation F. García 5

6. SIXS Sensor Unit Dose Mapping and X-ray detector – BepiColombo Mission SIXS Sensor Unit The Solar Intensity X-ray and Particle spectrometer Particle Spectrometer 18-Aug-10 7th GEANT4 Space Users’ Workshop – Plenary Session II Apparatus Simulation F. García 6 Three Silicon X-ray detectors and one CsI Particle Spectrometer

7. SIXS Sensor Unit Dose Mapping and X-ray detector – BepiColombo Mission Geometry Description and Materials 18-Aug-10 7th GEANT4 Space Users’ Workshop – Plenary Session II Apparatus Simulation F. García 7 CAD model was implemented in SolidWorks. Then the GDML file format was generated using Fastrad and ST-Viewer

8. SIXS Sensor Unit Dose Mapping and X-ray detector – BepiColombo Mission SSAT Simulations and Dose Mapping SSAT: The Sector Shielding Analysis Tool performs ray-tracing from a user-defined point within the a geometry to determine shielding levels 18-Aug-10 7th GEANT4 Space Users’ Workshop – Plenary Session II Apparatus Simulation F. García 8

9. SIXS Sensor Unit Dose Mapping and X-ray detector – BepiColombo Mission SSAT Simulations and Dose Mapping, cont. Tests of the SSAT simulations with an Aluminium Sphere Total Dose: 22473 rad  224.73 Thickness: 1.3437 g/cm2  0.01 Radius: 0.4976 cm 18-Aug-10 7th GEANT4 Space Users’ Workshop – Plenary Session II Apparatus Simulation F. García 9

10. SIXS Sensor Unit Dose Mapping and X-ray detector – BepiColombo Mission SSAT Simulations and Dose Mapping, cont. Engineering Model Top View Bottom View 18-Aug-10 7th GEANT4 Space Users’ Workshop – Plenary Session II Apparatus Simulation F. García 10 2

11. SIXS Sensor Unit Dose Mapping and X-ray detector – BepiColombo Mission SSAT Simulations and Dose Mapping, cont. Qualification Model of Particle Detector Main PCB 18-Aug-10 7th GEANT4 Space Users’ Workshop – Plenary Session II Apparatus Simulation F. García 11 Top ViewBottom View

12. SIXS Sensor Unit Dose Mapping and X-ray detector – BepiColombo Mission X-ray detector The are three of such detectors. One in the front of the SIXS has large aperture of 0.6 mm and two located on the sides with 0.3 mm. The components of such detector are: Be-window Ti-foil Collimator Si–detector Peltier cooler X-ray energy: 1 – 20 keV 18-Aug-10 7th GEANT4 Space Users’ Workshop – Plenary Session II Apparatus Simulation F. García 12

13. SIXS Sensor Unit Dose Mapping and X-ray detector – BepiColombo Mission X-ray detector, cont X-ray tomography images Boxes are of 2  m 3 Aperture of the X-ray detector 18-Aug-10 7th GEANT4 Space Users’ Workshop – Plenary Session II Apparatus Simulation F. García 13

14. SIXS Sensor Unit Dose Mapping and X-ray detector – BepiColombo Mission X-ray detector, cont This work has been done by the unconditional effort of Ben Masefield 18-Aug-10 7th GEANT4 Space Users’ Workshop – Plenary Session II Apparatus Simulation F. García 14 From the DICOM images the isosurfaces were extracted and then exported to STL format. STL file was processed with the STL2GDML program and parsed into GEANT4. Here we observe the incident electron in red and the secondary photons in green http://www.solveering.com/products/products_stl2gdml.html

15. SIXS Sensor Unit Dose Mapping and X-ray detector – BepiColombo Mission CONCLUSIONS The Sector Shielding Analysis Tool (SSAT) has been tested with a rather complex CAD Geometry The SSAT results for an Aluminium sphere were as expected The dose mapping for the SIXS module has been obtained. The X-ray tomography can be use to obtain the exact dimension of the aperture A new package has been develop to generate GDML files from STL The SSAT was a suitable tool for SIXS module R&D, because it gave us a good estimate for the radiation hardness requirements of the electronic components. 18-Aug-10 7th GEANT4 Space Users’ Workshop – Plenary Session II Apparatus Simulation F. García 15

16. SIXS Sensor Unit Dose Mapping and X-ray detector – BepiColombo Mission ACKNOWLEDGEMENT This Research is conducted with TEKES (Finnish Founding Agency for Technology and Innovation) decision # 40355/06 for the University of Helsinki 18-Aug-10 7th GEANT4 Space Users’ Workshop – Plenary Session II Apparatus Simulation F. García 16