The photon detectors for the COMPASS RICH's will consist of a set of 14
identical MWPC's. The active surface of each chamber will be
100 
60 cm 
.
(4 + 4) chambers will be used for RICH1 and (3 + 3) for RICH2. The mechanical
design will be based on that of the photon chambers which are being designed
for the ALICE experiment. The design of the photon chamber is
shown in fig. 3.5.
Figure: General view of the modular photon chamber (100 60 cm )
The first chamber that will be built, will be tested using "end 96
state of the art" CsI photo-cathodes. The final photo-cathodes for all the
chambers will be produced later to take advantage of further improvements
in MWPC CsI technology.
As soon as the RICH radiators will be built, tests
of one (or more) chambers will be performed; later, we plan to study
the overall RICH performances detecting photons produced in the final
radiators.
Figure 3.6: Schedule foreseen for the construction of the photon detectors
of the RICH's.
The foreseen schedule is the following:
This schedule is illustrated in figure 3.6.