Letter to the Editor

Monte Carlo simulations and generation of the SPI response^*

¹ Code 661, NASA/Goddard Space Flight Center, Greenbelt, MD 20771, USA
² Universities Space Research Association, 7501 Forbes Blvd. #206, Seabrook, MD 20706, USA
³ Centre d'Étude Spatiale des Rayonnements, BP 4346, 31028 Toulouse Cedex 4, France
⁴ DSM/DAPNIA/Service d'Astrophysique, CEA Saclay, 91191 Gif-sur-Yvette, France
⁵ Max-Planck-Institut für extraterrestrische Physik, Giessenbachstr. 1, 85748 Garching, Germany
⁶ Dept. of Physics and Astronomy, University of Southampton, Southampton, S017 1BJ, UK
⁷ CSIC-UV, Edificio Institutos de Paterna, Instituto de Física Corpuscular, PO Box 22085, 46071, Valencia, Spain

Corresponding author: S. J. Sturner, sturner@swati.gsfc.nasa.gov

Received: 10 July 2003
Accepted: 31 July 2003

Abstract

In this paper we discuss the methods developed for the production of the INTEGRAL/SPI instrument response. The response files were produced using a suite of Monte Carlo simulation software developed at NASA/GSFC based on the GEANT-3 package available from CERN. The production of the INTEGRAL/SPI instrument response also required the development of a detailed computer mass model for SPI. We discuss our extensive investigations into methods to reduce both the computation time and storage requirements for the SPI response. We also discuss corrections to the simulated response based on our comparison of ground and inflight calibration data with MGEANT simulations.