1. Muon Meeting Rome 27.07.2004 1 Some Results from M3R1 chamber tests at GIF with CARDIAC V.1 Boards Jean-Sebastien Graulich, Anatoli Kachtshuk, Dominik Neise, Burkhard Schmidt, Hermes Leon Vargas Goals:  Get acquainted with CARIDIAC- and SB-boards  Study high rate behaviour of CARIOCA  Compare old (40/40/20) and new (40/55/5) Gas mixtures (Ar/CO2/CF4)

2. Muon Meeting Rome 27.07.2004 2 Quad gap MWPC M3R1 Cathode readout CARDIAC v.1 gap1 gap4… 1.5m Weak beam of muons (X5) Cs-source of 20Ci 137 Intense flux of photons (660keV) Filters (absorbers) Hodoscope S2 (20x20cm) S1 (15x15cm) 5m 0.5m S3-finger (3x6cm horizontal) TRIGGER=S1S2S3 Beam tests setup on GIF in July 2004

3. Muon Meeting Rome 27.07.2004 3 Op.HV TH=50mV Count rate on cathodes raises slowly with HV until 2.6kV (more hits above threshold), than more rapidly due to crosstalk) Current raises with exp(ΔV/106V)

4. Muon Meeting Rome 27.07.2004 4 GIF off/on: Very minor effect statistical errors ~2% The 2 gas mixtures behave very similar Op.HV 95% Note: Gaps 1+2 are connected to the same FE-chip while Gaps 1+3 are connected to different chips

5. Muon Meeting Rome 27.07.2004 5 Op.HV

6. Muon Meeting Rome 27.07.2004 6 Op.HV GIF off/on: Very minor effect Op.HV 99%

7. Muon Meeting Rome 27.07.2004 7 GIF off/on: Very minor effect Op.HV 99%