A first prototype of a MWPC with CsI photo-cathode (active surface:
20 
20 cm 
)
has been built in Trieste. The design of the chamber follows
the RD26 experience. The CsI film deposit was made at CERN, where the chamber
has been brought last April and is presently being tested.
The chamber performances are under study: with UV lamp (May 96) and in a test beam with a liquid radiator (August and September 96), in a proximity focusing geometry. Figures 3.3 and 3.4 show the very recent results of the tests with the UV lamp, which were obtained during week 20 of 1996. Two sets of data are shown, the first obtained with a cathode plane without CsI, the second with a cathode plane on which a CsI film was deposited. In both cases the pulse height distributions of single electron signals, as well as the pad multiplicity distributions, look perfectly normal, and in agreement with the standard RD26 results.