AGILE

Collaboration:

- Agenzia Spaziale Italiana
- IAS (CNR) - Roma ,Italy
- IFCTR (CNR) - Milano, Milano, Italy
- University and INFN Roma 1, Rome, Italy
- University and INFN Roma 2, Rome, Italy
- University and INFN Trieste, Trieste, Italy
- TESRE (CNR) - Bologna, Italy

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.

More on the experiment…

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:

- Thermal and vibration tests on the tracker tray (100%)
- Tests on the simplified engineering model - SEM (on-going)
- Test systems for the front-end boards (FTB) and the complete trays (70%)
- Start of assembly of the flight model of the tracker (*)
- Tools for the assembly of the tracker in the main frame (**)
- Satellite calibration facility: mechanical structures and data acquisition (100%)

(*) 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

- 1 Laurea Thesis in Physics completed
- 2 Laurea Thesis in Physics in progress
- 1 Diploma Thesis in Mechanical Engineering in progress
- 1 PhD in progress

7. Leadership roles and primary responsibilities in the experiment:

In the present organization:

- Co-Principal Investigator of AGILE: Guido Barbiellini (INFN Trieste)
- Instrument scientist: Aldo Morselli (INFN Roma II)
- Instrument Scientist and Program Manager of the AGILE tracker: Michela Prest (INFN Trieste)
- Coordinator of the Agile P/L calibration group: Michela Prest (INFN Trieste)

· 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.

- The AGILE Phase B has been reviewed and approved for the phase C/D by an international committee appointed by ASI:
- Prof. Marcello Giorgi (University and INFN of Pisa, Italy)
- Prof. Oscar Pace - ESA
- Prof. Jacques Paul (CE-Saclay, France)
- Dr. Luigi Piro (IAS-CNR Rome, Italy)
- Prof. Marco Salvati (Osservatorio Astrofisico di Arcetri, Italy)