On-ground calibration of AGILE-GRID with a photon beam results and lessons for the future
Author(s)
Cattaneo, P. W.
Rappoldi, A.
Argan, A.
Buonomo, B.; Bulgarelli, A.; Chen, A. W.; D'Ammando, F. ; Foggetta, L.; Fuschino, F.; Galli, M.; Gianotti, F.; Giuliani, A.; Longo, F.; Marisaldi, M.; Mazzitelli, G.; Pellizzoni, A.; Prest, M.; Pucella, G.; Quintieri, L.; Tavani, M.; Trifoglio, M.; Trois, A.; Valente, P.; Vallazza, E.; Vercellone, S.; Barbiellini, G.; Caraveo, P.; Costa, E.; De Paris, G.; Del Monte, E.; Di Cocco, G.; Donnarumma, I.; Evangelista, Y.; Ferrari, A.; Feroci, M.; Fiorini, M.; Giusti, M.; Labanti, C.; Lapshov, I.; Lazzarotto, F.; Lipari, P.
Date Issued
2012-09-01
Mission(s)
Abstract
At the core of the AGILE scientific instrument, designed to operate on a satellite, there is the Gamma Ray Imaging Detector (GRID) consisting of a Silicon Tracker (ST), a Cesium Iodide Mini-Calorimeter and an Anti-Coincidence system of plastic scintillator bars. The ST needs an on-ground calibration with a γ-ray beam to validate the simulation used to calculate the energy response function and the effective area versus the energy and the direction of the γ rays. A tagged γ-ray beam line was designed at the Beam Test Facility (BTF) of the INFN Laboratori Nazionali of Frascati (LNF), based on an electron beam generating γ rays through bremsstrahlung in a position-sensitive target. The γ-ray energy is deduced by the difference with the post-bremsstrahlung electron energy^(1-.2) The electron energy is measured by a spectrometer consisting of a dipole magnet and an array of position sensitive silicon strip detectors, the Photon Tagging System (PTS). The use of the combined BTF-PTS system as tagged photon beam requires understanding the efficiency of γ-ray tagging, the probability of fake tagging, the energy resolution and the relation of the PTS hit position versus the γ-ray energy. This paper describes this study comparing data taken during the AGILE calibration occurred in 2005 with simulation.