The Mini-Calorimeter on-board AGILE: 18 months in orbit

Abstract

AGILE, the Italian space mission dedicated to gamma-ray and hard-X astrophysics, was succesfully launched on 23 April 2007 and is currently fully operative. AGILE is placed in an equatorial Low-Earth Orbit, at 550 Ian altitude with 2.46 degrees inclination. The Mini-Calorimeter (MCAL) on-board AGILE is a scintillation detector made of 30 CsI(TI) bars with photodiode readout at both ends, arranged in two orthogonal layers, for a total amount of 20 kg of active material, an on-axis geometrical area of 1400 cm 2 and a thickness of 1.5 radiation lengths. MCAL can work both as a slave of the AGILE Silicon tracker and as an independent detector for gamma-ray burst (GRB) detection in the 300 keV -200 MeV energy range. H a trigger is issued by a dedicated onboard logic, data are dowloaded in photon-by-photon mode with a time resolution of 2J-Ls allowing complete spectral and timing analysis of the event, limited by counting statistics only. Moreover, 11 band energy spectra with 1 second time resolution (scientific ratemeters) are continuously integrated on-board and sent to telemetry for background monitoring. MCAL is currently one of the three detectors in space with microsecond timing accuracy in the MeV range, with a detection rate of 1 GRB/week. The performance of the instrument after 18 months of in orbit operations will be discussed, as weD as the scientific results achieved.

AGILE WebMon: Monitoring the AGILE payload through the WEB

“…The procedure produces plots of the instrument ratemeters and critical housekeepings. A discussion of the in-flight performance and on the burst detection of MCAL is reported in reference [16] and [17], respectively. If the 39.08 data package is present (Le.…”