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

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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

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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

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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)