Background modelling in Background modelling in AHEADAHEAD
A Joint Research Activity for background study, with application to current and future
Space Missions
Lorenzo Nataluccion behalf of a large collaboration
(INAF, INFN, SRON, CESR, MPE, Soton University, CEA, …)
1Roma, February 9-10, 2009
MotivationMotivation
2Roma, February 9-10, 2009
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 goalsMain 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
ApplicationsApplications
4Roma, February 9-10, 2009
Application Detector types Missions (current & future)
X-ray/CCD detector design
CCDs XMM
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]Topics [1/2]
5Roma, 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]Topics [2/2]
6Roma, 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 Input from Radiation Environment modelsEnvironment 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 (1958-1979) . 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 LEOIssues 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 Considerations on the role/use of GEANT-4 role/use of GEANT-4
9Roma, 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
MethodsMethods
10Roma, 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: prioritizationTopics: prioritization
11Roma, 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: Computing resources: a low cost benchmark?a low cost benchmark?
12Roma, 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 Details of the computing facility @IASF/Romefacility @IASF/Rome
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 Units 10 PCs
Total N. of CPUs 40
Memory 40 GB RAM
Disk Storage 3.3 TB
Computing power ~ 70 Gflops
Current cost 6200 €
Roma, February 9-10, 2009
Financial requestsFinancial requests
14Roma, February 9-10, 2009
To be discussed and agreed
Proposal submitted to AHEAD
Links to other activitiesLinks to other activities
15Roma, 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)