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Summary of first wire chamber working group meeting of 31/03/2000
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(compiled by Burkhard)


1. April/May Testbeam Activities:
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a) Prototypes:
Two new small prototypes have been build in PNPI.
The main focus of the measurements with the CPC prototype is on
cross-talk. We also wnat to re-measure the plateau length together with
a determination of the streamer- and dark count rate.
For the WPC prototype the main focus is on a measurement of the
time resolution and efficiency within a time window of 20ns, as
function of the detector capacitance.
b) Electronics:
The measurements will be done using PNPI electronics. Further
measurements with the SONY chip are pending on the outcome of the
ongoing ageing studies in GIF.
In May measurements with the ASDQ chip are planned on one of the
prototypes.
c) Gas mixtures:
The baseline gas mixture is Ar/CO2/CF4.
Further mesurements with the Ar/CO2/C2H2F4 mixture are pending on the
analysis of the recent ageing tests(*).
Tests with C4F10 instead of CF4 are under consideration. According to
informations from GWG, it is feared that C4F10 has more impurities
than CF4.

(*) Samples of Anode-wires and Cathode-pads of the irradiated chamber will
be analyzed at CERN, Potenza and Rome I.


2. Wire Chamber Construction:
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a) Panels:
As reported in the General Meeting, Giulio is in contact with DITRON,
one possible supplier for panels. Together with his group (Potenza) he
takes the responsibility (for time being) for this part of the chamber
construction.
Two material types are under consideration, both based on a foam core.
The most important point is the flatness of the panel after the copper
cladded FR4 laminate has been glued to it. We will get first samples
from DITRON early May (4 weeks after the required files have been given
to them.)
b) Assembling:
So far all WPC/CPC prototypes have been assembled in Gatchina.
In order to make the participation of other collaborating institutes
in the assembling easier, the working group agreed to the proposal to
assemble the next prototypes here at CERN, as it is a central place
where people can meet easily. Moreover, the required infrastructure for
assembling wire chamber prototypes (lab space, clean room, tools etc.)
is available at CERN. Of course, this doesn't exclude prototype
assembling in other places whenever the infrastruscture is available.
c) Chamber Design:
The chamber design should be finalized by summer/autumn this year
(our next milestone). In order to avoid to have many different designs,
the prototype design should be discussed in the working group. There
should be a strong interplay between the design team and the experience
coming out from the chamber assembling.
The main engineer from PNPI who has done the CMS chamber design will be
free from June onwards and could participate in the design team.
Potenza expressed interest to participate with an engineer. There is
also potential interest from Florence to participate in the chamber
design.