G.Casini$^1$, G.Ademard$^{2}$, S.Barlini$^1$, M.Bini$^{1}$, A.Boiano$^{3}$, E.Bonnet$^{4}$, B.Borderie$^{2}$, R.Bougault$^{5}$, G.Brulin$^2$, M.Bruno$^6$, A.Chbihi$^{4}$, M.Cinausero$^7$, M.Degerlier$^8$, D.Fabris$^9$, J.D.Frankland$^{4}$, E.Galichet$^{2}$, F.Gramegna$^7$, D.Gruyer$^{1}$, A.Kordyasz$^{10}$, T.Kozik$^{11}$, N.Le Neindre$^{5}$, O.Lopez$^{5}$, T.Marchi$^{7}$, L.Morelli$^6$, A.Olmi$^{1}$, A.Ordine$^{3}$, M.Parlog$^{5}$, G.Pasquali$^{1}$, G.Pastore$^{1}$, S.Piantelli$^{1}$, G.Poggi$^{1}$, M.F.Rivet$^{2}$, E.Rosato$^{3,\ast}$, F.Salomon$^{2}$, G.Spadaccini$^{3}$, A.A.Stefanini$^{1}$, G.Tortone$^{3}$, S.Valdré$^{1}$, G.Verde$^{2}$, E.Vient$^{5}$, and M.Vigilante$^{3}$ for FAZIA Collaboration.

$^{1}$INFN, Sezione di Firenze and Dipartimento di Fisica, Università di Firenze, Sesto F.no (FI), Italy
$^{2}$Institut de Physique Nucléeaire, IN2P3-CNRS, 91406 Orsay-Cedex, France
$^{3}$Dipartimento di Fisica, Università Federico II and INFN, Sezione di Napoli, Italy
$^{4}$GANIL, Caen, France
$^{5}$LPC, IN2P3-CNRS, ENSICAEN and Université de Caen, F-14050 Caen-Cedex, France
$^{6}$Dipartimento di Fisica, Università di Bologna and INFN, Sezione di Bologna, Italy
$^{7}$Laboratori Nazionali di Legnaro, Legnaro (PD), Italy
$^{8}$Nevsheir University, Turkey
$^{9}$Dipartimento di Fisica, Università di Padova, Padova, Italy
$^{10}$Heavy Ion Laboratory, Warsaw University, Warsaw, Poland
$^{11}$Jagiellonian University, Cracow, Poland
$^{*}$deceased

Abstract
After some years of R&D on detectors and electronics, the international FAZIA collaboration is entering the experimental phase using a Demonstrator array made of 192 Si-Si-CsI(Tl) telescopes. We will summarize the main achievements in terms of ion identification and energy thresholds obtained during the prototyping activity and from the recent commissioning test, performed with 25 MeV/u Ar beam at the LNS (Catania). The excellent perfomances of our detectors have been reached thanks to an integrated project including: a) specific investigation and expedients on detectors; b) high-quality electronics, carefully designed from the preamplifier stage to the fast sampling ADC's and c) strong efforts towards software/firmware solutions capable to extract the relevant parameters from the digitized waveforms.

Finally, we'll present the heavy-ion physics programme with the Demonstrator, centered on several themes typical of the Fermi energy domain, with a particular focus on the isospin dynamics as already undertaken by FAZIA using some of the first well-perfoming test telescopes.