Background modelling in AHEAD A Joint Research Activity for background study, with application to current and future Space Missions Lorenzo Natalucci on behalf of a large collaboration (INAF, INFN, SRON, CESR, MPE, Soton University, CEA, …) 1Roma, February 9-10, 2009

Motivation 2 supporting the evaluation of space mission proposals against capability of satisfying the science requirements support instrument design / science definition support the definition of data analysis improve exchange of information among the groups, identify and prioritize issues Training young people, helping their approach to experimental studies

Main goals Estimation of sensitivity for future missions 3 Support dedicated studies, requiring detailed knowledge of the background components Improve physics within simulation tools (GEANT-4), according to the level of accuracy needed within applications Propose new requirements/standard models and practices Aim at a European Database of models/products? Roma, February 9-10, 2009

Applications 4 ApplicationDetector typesMissions (current & future) X-ray/CCD detector design CCDsXMM X-ray/ new detector types Microcalorimeters, APS, SDD etc IXO, EDGE/Xenia Hard X-rays/ Wide Field Telescopes Solid state (High-Z)INTEGRAL, SVOM, EDGE/Xenia, EXIST Hard X-rays/ focal plane Solid state (High-Z, Si) Simbol-X, SVOM, EDGE/Xenia, GRI Compton telescopes for soft γ-rays Si arrays (trackers), scintillators MEGA/GRIPS, DUAL

Topics [1/2] 5 Roma, February 9-10, 2009 LEO, HEO, L2 (Atmospheric?) Choosing input from radiation environment models Building instrument model: Input from detector performance Requirements on ground calibrations? Support instrument design Effects of induced radioactivity and delayed activation (especially LEO) Simulation of low angle scattering of protons and electrons in X-ray mirror shells Shielding optimization

Topics [2/2] 6 Roma, February 9-10, 2009 GEANT-4/ Physics modelling requirements: radioactive decay, fluorescence, Compton scattering, tracking etc. Other tools needed for the analysis, end results, quality parameters, interface to data analysis software Assess accuracy of standard models for: radiation environment, GEANT-4 physics, detector performance parameters Address the level of accuracy of a result

Input from Radiation Environment models Input from Radiation Environment models 7Roma, February 9-10, 2009 de facto standards Trapped particles: AP8 MIN/MAX (protons), AE-8MIN/MAX (electrons). Developed at NASA/GSFC, based on data from early satellites ( ). Models available in SPENVIS, CREME96. Many known limitations (from Lauenstein & Barth, IEEE 2005) Galactic CRs, including solar modulation: CREME86, also being updated New models development: sponsored by NASA, ESA & other Institutional & Corp.s Organizations

Issues for LEO 8 High impact on sensitivity for hard X-ray missions in LEO Difficulty of characterizing local radiation environment: steep variations of fluxes vs. altitude, inclination Significant Earth albedo flux, γ-rays and neutrons (geomagnetically modulated) Roma, February 9-10, 2009 (Ajello et al., ApJ 2008)

Considerations on the role/use of GEANT-4 9 Roma, February 9-10, 2009 Possibility to establish collaboration with GEANT-4 development team: (a) identify the need for development of specific tools as additional extensions (b) training experimental teams, especially young people in the use (and development?) of this tool GEANT-4 is the standard tool for the physical modelling of the interactions: its range extends down to low energy X-rays

Methods 10 Roma, February 9-10, 2009 Establish a co-operative research program and organizational structure with WGs working on topics Compare available models and data from currently flying observatories Discuss the different methods and assumptions for future space-borne instruments Identify the products of the simulations and the I/F to the data analysis S/W Discuss the requirements of a model/products database

Topics: prioritization 11 Roma, February 9-10, 2009 Define input from radiation environment models (clearly establish needs, might be different than for engineering applications?) Interactions and joint activities with instrumental teams to get reliable performance parameters Interface to data analysis tools (standardizing simulation/modelling data products) Encourage sinergy with GEANT-4 development Define background models standard (data, methods, tools, etc.) Others TBD…

Computing resources: a low cost benchmark? 12 Roma, February 9-10, 2009 Simulations are complex and time consuming: need much computing power Is it feasible to perform massive simulation runs on a “low cost” system? At IASF-Roma, a H/W cluster is being tested for INTEGRAL archive & analysis support. We plan to test it also as a benchmark for running GEANT-4

Details of the computing 13 INTEGRAL computing centre, to be used mainly for archive and analysis of IBIS calibration and survey data Current installation: 4 modules, to be soon improved to 7 (max. capacity) Basic Module N. of Units10 PCs Total N. of CPUs40 Memory40 GB RAM Disk Storage3.3 TB Computing power~ 70 Gflops Current cost6200 € Roma, February 9-10, 2009

Financial requests 14 Roma, February 9-10, 2009 To be discussed and agreed Proposal submitted to AHEAD

Links to other activities 15 Roma, February 9-10, 2009 JRA-1, Detectors JRA-2, Optics for High Energy Astrophysics JRA-4, Data software and Analysis Support to NA-2, Identification of science goals and associated requirements NA-7, Outreach Management (support to co-ordinator, access to research grants, others TBD)