Jornadas LIP 2003, Lisboa, 20-21 de DezembroJornadas LIP 2003, Lisboa, 20-21 de Dezembro

Aplicações de Geant4 Aplicações de Geant4 em experiências de Astropartículasem experiências de Astropartículas

M.C. Espírito-Santo, P. Gonçalves, M. Pimenta, P. Rodrigues, M.C. Espírito-Santo, P. Gonçalves, M. Pimenta, P. Rodrigues, B. ToméB. Tomé, A. Trindade, A. Trindade

The main objectives of the LIP-ESA contract “Radiation Interaction Simulations for High-Energy Astrophysics Experiments EUSO and AMS”1 are:

to allow/promote the participation of Portuguese groups in the Geant4 activities related to space applications.

to develop a software framework for application of Geant4 in the first instance to astroparticle experiments (EUSO and AMS) on the ISS.

to perform detailed inter-comparison with results from Monte Carlo and analytical codes and experimental data.

Introduction

The team joins collaborators from AMS, EUSO and Medical Physics LIP groups

1 ESA/ESTEC Contract No. 17097/03/NL/LvH/bjESA/ESTEC Contract No. 17097/03/NL/LvH/bj

Contract deliverables

• Monthly progress reports

• 2 Technical Notes (KO+3 months, KO+12 months)

• Mid-term review meeting at LIP premises (held on October 15th)

• Final presentation (to be held at ESTEC)

• Article for publication in ESA´s bulletin

• WWW site for the project IEEE Nuclear Science Symposium/Medical Imaging Conference, 19-25 October, 2003, Portland, Oregon, USA"

Simulation Requirements

Simulation of AMS/RICH and EUSO/ULTRA sub-detector geometries

Interface with different primary event generators

• Cosmic-ray flux in high-altitude orbit • Atmospheric cosmic-ray flux at ground-level• Accelerator beam phase-space data

Simulation of readout electronics, signal digitisation and event reconstruction

OO technology for event data persistency and data analysis

Simulation Organization

Analysis: ROOT

Radiation Transport: GEANT4

Signal Digitization: DIGITsim

Event Storage: ROOT I/O

Code Management System:

CVS System

GEANT4GEANT4 DIGITsimDIGITsim

ROOT AnalysisROOT Analysis

ROOT I/OROOT I/O

CVS Code ManagementCVS Code Management

Framework Highlights

Ability to accommodate different geometry organizations

General Particle Source (GPS) developed by ESA for primary particle sampling (ISS orbit or Earth surface)

Physics Lists: Electromagnetic Standard Physics (for leptons and hadrons) Low Energy Electromagnetic Physics for sensitive detectors Optical transport of scintillation and Cherenkov light, Rayleigh dispersion, bulk

attenuation (plus WLS process for GEANT4.6.0 release) UNIFIED optical boundary model No hadronic modes for now (physics lists for air showers are under test by beta-

testers)

AMS/RICH and EUSO/ULTRA

related applications

Simulation of an ULTRA station

Internal walls are coated with white diffusing paint

Plastic scintillator is NE102A

PMTs are Phillips XP3462B

AMP ADC

PMT

1. Energy deposition in the scintillator,

photon generation

2. Light propagatio

n and collection

3. Photoelectron production and

signal generation

4. Signal shaping and amplification

5. Time sampling, analog to digital

conversion

GEANT4Space

DataFrame

The LIP-PAD

Simulation scheme

… a 80MeV electron

Simulation of the ULTRA UV telescope (I)

Photomultiplier

Fresnel lens: 457 mm diameter

457 mm focal length

5.6 grooves/mm

UV transmitting acrylicAluminum housing

Simulation of the ULTRA UV telescope (II) (Fresnel lens implementation in the simulation framework)

(work in progress...)

AMS/RICH radiator simulation

AMS/RICH aerogel studies

Improve description/understanding of light scattering in aerogel

Introduce realistic modelling of aerogel surface

Mapping of aerogel surface using Atomic Force Microscope (ongoing measurements)

Upgrade related classes of Geant4.

Sumário

As actividades realizadas no âmbito do contracto LIP-ESA permitiram alargar competências já existentes no LIP no grupo de Física Médica aos grupos envolvidos em experiências de Astropartículas.

Foram identificadas áreas de intervenção para o desenvolvimento do código de Geant4.

A colaboração Geant4 manifestou já interesse em aplicações desenvolvidas utilizando o “framework” descrito.