G. Martellotti CERN 22/04/20021 Tooling / Test Stations for MWPC (Meeting LNF, Roma1/Pz ) Production rate : 408 chambers (Fe + LNF) :192 R4 M1 144 R3 M1,M2,M3 48 R2 M4,M5 24 R1 M4,M5 Production rate/lab : 2–3 chambers / week

G. Martellotti CERN 22/04/20022 OPERATIONS INSIDE CLEAN ROOM (Responsibility of production centers) 1- Wiring ~ 2 hours / 2 gap 2- Glueing / soldering. - Control wire pitch 3 - cut in two mono-gap layers 4 - Wire tension test< 1 hours / gap (< 1 min / wire, wires in parallel) 5 - HV test in air on single gap with open chamber 6 - assembling 4 gap chamber

G. Martellotti CERN 22/04/ gas leakage test. < 1 hour / chamber Give over-pressure, close gas pipe, measure pressure decrease with time. Record pressure and temperature. 2 - chamber conditioning (Gas mixture and HV) ~ 24 hours (parallel operation for several chambers is needed) 3 - Gain uniformity measurement < 1 hour / chamber with radioactive source Record source position, total current 4 - cosmic rays test days/chamber measure efficiency plateau, time resolution (parallel operation for ≥ 4 chambers) OPERATIONS OUTSIDE CLEAN ROOM ( Tools developed by Roma1)

G. Martellotti CERN 22/04/ ) - gas leakage test 2) - chamber conditioning 1) can be done in air/argon in a short time 2) require a long time and the right gas mixture Tests outside the clean room need several working areas (problems of space, number of gas subsystems).  Try to reduce working areas - perform 1) and 2) on the same station (with final gas mixture?) Digital manometers and readout cards are being ordered. Three flow-meters are available…

G. Martellotti CERN 22/04/20025 Tentative layout for test stations

G. Martellotti CERN 22/04/ Gain measurement with radioactive source - We assume that a spot ~ 5cm diameter on the farthest gap is ok to monitor gain uniformity - a minimum current of >20-30 nA should be measured (assumimg a maximum acceptable dark current of order of 10 nA) - the most suitable source seems Ce137, mCurie intensity. According to Cern safety rules, 4-5 cm Pb screening is needed. - Best solution: screen with a layer of 4 cm Pb below the chamber. This implies about 500Kg Pb and a quite heavy table structure. (second option: eliminate the lead plate and protect operators from irradiation by closing the access to the table all around). To be recorded : source position, total current Current readout : digital nA 16 channels home made (G. Corradi)

G. Martellotti CERN 22/04/20027

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cosmic rays test Measure efficiency plateau, time resolution - Trigger : two layers of scintillator counters - Muon tracking with an hodoscope of 6 same-size chambers (top and bottom chamber used as reference) - Readout through DIALOG. Measure the efficiency of all front-end channels running with two DIALOG configurations. ( 2 runs of > 24 hours) (test single gap switching off HV ?) - A maximum of 96x6 channels must be readout. - Multiplexing by a factor 6 with a delay of ~ 200ns/chamber (home made V. Bocci) allows to use only one TDC (128 ch). # Estimated cost of ReadOut : - with multiplexing E / ch - with more TDC modules 55 E / ch

G. Martellotti CERN 22/04/ movable chambers