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 2003-2005. 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 2001

AGILE has entered the C/D phase (which is the prototyping and construction phase) at the beginning of 2001. The architectural design of each subsystem has been completed and prototypes (with the same features of the flight ones) are being built. Two test beams have been performed in July and October at the CERN PS. The final set-up for the photon beam has been studied. We have built and tested 4 x-y silicon beam chambers to measure the directions of the incoming electron and of the deflected one. The features of the photon beam have been measured using a NaI(Tl) calorimeter. We are developing offline analysis programs in order to study the reconstruction of the photon energy from the multiple scattering angles through the converter of the tracker planes. We have used a micro-tracker structure with 4 single sided planes with one detector each. A data-taking period has been performed at the INFN National Laboratories of Legnaro at the TANDEM accelerator in order to irradiate the front-end ASICs to understand the latch-up and SEU behaviour. The data analysis is in progress.

The following achievements have been obtained:

Test at CERN of a prototype of the FEB (Front-End Board) and of the trigger board | 31-05-2001 | 50%
Assembly of a tray | 31-05-2001 | 100%
Test at CERN of some grade B trays with the final electronics both for the tracker front-end and data handling | 31-08-2001 | 40%
Tracker assembly line ready | 31-10-2001 | 50%
Engineering model of the trigger and data acquisition system | 31-12-2001 | 40%

1. The FEB design is finished; the test at CERN has been delayed due to the delay of one of the industrial partners.

2. We are preparing the thermo-vacuum and the vibration tests

3. We are assembling the first INFN prototype trays in order to test them with particles. The engineering model prototypes of the trays made by one of the industrial partners will not be ready before April 2002. The electronics prototype boards will be ready at the same time.

4. The ladder assembly line is ready but the tray one is still waiting for inputs from the industrial partners.

The circuit design has been completed. The boards will be ready by April 2002.

Milestones 2002:

Thermal and vibration tests on the tracker tray | 28-02-2002
Tests on the simplified engineering model - SEM | 28-02-2002
Test systems for the front-end boards (FTB) and the complete trays | 30-03-2002
Start of assembly of the flight model of the tracker | 30-03-2002
Tools for the assembly of the tracker in the main frame | 30-06-2002
Satellite calibration facility: mechanical structures and data acquisition | 30-11-2002

3. INFN contribution to the experiment in terms of manpower and financial support

Manpower:13 researchers (9 FTE)

Budget for the Year 2002: 111.5 kEuro

4. Publications in referred journals (in 2001): 3

5. Conference talks (in 2001): 7

6. Number of undergraduate and doctoral thesis on the experiment

- 4 Laurea Thesis in Physics completed
- 1 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)

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)