1. Simulation of X-ray Fluorescence and Application to Planetary Astrophysics A. Mantero, M. Bavdaz, A. Owens, A. Peacock, M. G. Pia IEEE NSS -- Portland, Thursday, Oct 23, 2003

2. Alfonso.Mantero@cern.ch The BepiColombo Mission to Mercury Composed of 3 spacecrafts: 2 orbiters and a lander carrying 25 scientific experiments. ● Magnetic Field Study ● Planet Surface Mapping ● Planet Surface Composition study ● 4 spectrometer (IR, X, , n) ● 1 laser altimeter ● 1 lander (X-Ray Spectrometer, Imaging Camera, Seismometer) HERMES Is an X-Ray spectrometer to measure the composition of the upper layers of planetary surface Basalt fluorescence spectrum Beam Energy 9.5 KeV Counts Energy (KeV)

3. IEEE NSS -- Portland, Thursday, Oct 23, 2003 Alfonso.Mantero@cern.ch Basalt fluorescence spectrum Beam Energy 9.5 KeV Counts Energy (KeV)

4. IEEE NSS -- Portland, Thursday, Oct 23, 2003 Alfonso.Mantero@cern.ch Fluorescence Simulation ● Space missions are risky, so solid strategies for risk mitigation are to be undertaken ● Preparing a correct and detailed simulation is a crucial part of these strategies ● HERMES is an X-Ray spectrometer studying Mercury's surface composition ● Space missions are risky, so solid strategies for risk mitigation are to be undertaken ● Preparing a correct and detailed simulation is a crucial part of these strategies ● HERMES is an X-Ray spectrometer studying Mercury's surface composition We need to simulate X-Ray fluorescence (1-10 KeV) from Mercury surface produced by solar radiation

5. IEEE NSS -- Portland, Thursday, Oct 23, 2003 Alfonso.Mantero@cern.ch Geant4 ● “A toolkit for the simulation of the passage of particles through matter” ● Object-Oriented technology ● Developed following ISO 15504 software process implementing iterative- incremental model ● Low energy electromagnetic processes extensions until 100 eV ● Advanced instruments for the description of geometry and materials Geant3 10 KeV EGS4 1 KeV

6. IEEE NSS -- Portland, Thursday, Oct 23, 2003 Alfonso.Mantero@cern.ch The Atomic Deexcitation Package Unique interface to be used by any process Modularity permits a better management and easiness of expansion (Auger) Fluorescence and Auger emissions are simulated using data present on the EADL (Evaluated Atomic Deexcitation Library) from Livermore The package has undergone both software and physical validation

7. IEEE NSS -- Portland, Thursday, Oct 23, 2003 Alfonso.Mantero@cern.ch Validation ● Software Validation ● System Tests ● Integration Tests ● Unit Tests ● Physical Validation ● Auger ● Fluorescence

8. IEEE NSS -- Portland, Thursday, Oct 23, 2003 Alfonso.Mantero@cern.ch Physical Validation - Auger Simulation of Auger emission from pure materials irradiated by an electron beam with continuous ramp spectrum. Comparison between energy of simulated outflowing electrons and data found in literature Percent Error: 0.74 % ± 0.07

9. Full comparison with experimental data from rocks X-Ray irradiation (Bessy) Iceland Basalt Fluorescence Spectrum Counts Energy (keV) IEEE NSS -- Portland, Thursday, Oct 23, 2003 Alfonso.Mantero@cern.ch Physical Validation - Fluorescence Parametric analysis of data Pure Elements Complex Materials Many Peaks Physical Background Many Peaks Physical Background Anderson-Darling ● Goodness of Fit test ● Doesn't depend upon data grouping ● No symmetry needed ● No cut on data number Look B. Mascialino Data Analysis in HEP: A Statistical Toolkit 2003 NNS, Portland, Oregon, USA

10. IEEE NSS -- Portland, Thursday, Oct 23, 2003 Alfonso.Mantero@cern.ch Physical Validation - Fluorescence Preliminar analysis Pearson correlation: r>0.93 p<0.0001 High Statistical correlation Ac (95%) =0.752 Anderson Darling results Beam Energy 4.9 6.5 8.2 9.5 Experimental and simulated X-Ray Spectra are statistically compatible at a 95% C.L. A2 0.04 0.01 0.21 0.41 Simulated Experimental

11. IEEE NSS -- Portland, Thursday, Oct 23, 2003 Alfonso.Mantero@cern.ch Application – DIANE Data for comparison have been taken during a test beam at BESSY laboratories. A GEANT4 application has been created reproducing: ● Experimental set-up ● Materials ● Detectors A GEANT4 application has been created reproducing: ● Experimental set-up ● Materials ● Detectors The application is CPU consuming, so it has been interfaced to the GRID thanks to the DIANE framework Execution Times are reduced of an order of magnitude (750 Mevents -> 24 Hours) Execution Times are reduced of an order of magnitude (750 Mevents -> 24 Hours) talk: DIANE -- Distributed Analysis Environment for GRID-enabled Simulation and Analysis of Physics Data (Friday 24 th October) The experimental set-up at the PTB laboratory at BESSY-II. The XRF chamber can be seen to be attached to the end of the Four Crystal Monochromator (FCM) beamline. Si GaAs FCM beamline Si reference XRF chamber

12. IEEE NSS -- Portland, Thursday, Oct 23, 2003 Alfonso.Mantero@cern.ch Work In Progress Optimization phase... Bepicolombo application: ● New Geometries ● Runtime Analysis Features (AIDA/ANAPHE)

13. IEEE NSS -- Portland, Thursday, Oct 23, 2003 Alfonso.Mantero@cern.ch Conclusions Full atomic deexcitation validation Predictive capability of deexcitation processes Use of Geant4 applications for Physic Reach studies and experimental set-up optimization Physic validation Geological material Detector Geometry