AGILE
Collaboration:
Location of the experiment: Satellite
National Responsible: G. Barbiellini (Ts)
1. Goal of the experiment
Gamma-rays of cosmic origin are a manifestation of the most energetic phenomena in our Universe. A large variety of sources emit gamma-rays including relativistic compact stars, massive black holes in active galactic nuclei, gamma-ray burst sources, and our Sun during intense flares. Many gamma-ray sources are transient, often on timescale of hours/days, showing a Universe in turmoil and subject to catastrophic events.
The mission AGILE (Astro-rivelatore Gamma a Immagini LEggero) will provide a powerful and cost-effective Observatory for gamma-ray (30 MeV-50 GeV) astrophysics during the years 2004-2006. No other gamma-ray mission sensitive to photons above 30 MeV is being planned during the first five years of the next Millennium.
2.
Activities during 2002
AGILE is completing the construction of the Simplified Engineering Model that will be used for mechanical, thermal and functional tests while starting the assembly of the protoflight model.
During 2002, the procedure for the assembly of the silicon tracker (main responsibility of INFN) has been defined and all the mechanical tools have been produced and tested.
Vibration and thermal tests have been performed on the prototype trays to validate the tray materials and the assembly procedures of the silicon tiles on the tray itself.
As far as vibration is concerned, both the Pegasus and Soyuz vibration masks have been used to study the response of the tracker mechanical structure.
The flight hybrid has been designed and tested (functional, thermal and vibration tests). To manufacture it, a new technology has been developed in order to insert the ASICs inside the hybrid itself so that once the ASICs are coated, the maximum height of the hybrid is given by the top layer.
Two testbeam periods have been performed in June and August at the CERN PS facility, to complete the setup of the calibration line. In June, we have also tested our silicon detector at the SPS (H4, North Area) in order to measure the charge distribution between the readout and floating strip.
For the PS testbeams, a minitracker structure has been developed which has the same features of the AGILE tracker: it is made of 6 trays with one tile per side of the tray, readout by the flight ASICs. The tray materials are the flight ones. The collected data will be used to develop the offline programs and to test the onboard software
The following achievements have been obtained:
(*) we are ready and waiting for the Critical Design Review
(**) the main frame is still under study by the provider
Milestones 2003:
End of the assembly and test phase of the AGILE silicon tracker | 30-09-2003 |
Definition of the AGILE calibration plan and organization of the calibration beamlines, of the data acquisition system and of the analysis programs | 30-06-2003 |
3. INFN contribution to the experiment in terms of manpower and financial support
· Manpower:15 researchers (10.2 FTE)
· Budget for the Year 2003: 0.6% of the CSNII budget
4. Publications in referred journals (in 2002): 6
5. Conference talks (in 2002): 10
6. Number of undergraduate and doctoral thesis on the experiment
7. Leadership roles and primary responsibilities in the experiment:
In the present organization:
· The Trieste group has the complete responsibility of the AGILE main instrument, which is the silicon tracker, as far as the design, the prototypes and the final instrument are concerned. The Trieste group is also responsible of the test-beam activity at CERN and of the setting up of the calibration facility.
· The Roma II group is the coordinator of the data handling subsystem, which consists of the trigger system, the data acquisition, the power supply and the telemetry management.
· The Roma I group is the coordinator of the preparation of the calibration plan of the scientific instrument.
· The 3 INFN groups are involved in the development of the simulation and analysis tools and of the Level 2 software to be implemented on board
8. Innovative instruments
AGILE is the first example of a large quantity of silicon detectors (4 m2) used on a satellite.
This requires the development of innovative technologies such as a compact space frame, a fast and low power electronics, a trigger processing able to reject a background 104 higher than the expected signal.
Moreover, construction procedures adequate to the use of silicon detectors in a spatial environment (large temperature range, vibration stresses up to 10 G) have to be developed.
The instrument is able to observe transient phenomena both in the X (10-40 keV) range and the gamma (30 MeV-50 GeV) one.
9. Competing experiments
As already said, during the operational period of AGILE, no other experiment able to study gamma rays above 30 MeV is foreseen.
In the year 2006, the launch of GLAST is scheduled. The technologies of the two satellites are very similar, but GLAST offers a much wider effective area and energy range.
10. International committee which has reviewed the experiment
AGILE is annually reviewed by the INFN National Committee II.