The LHC1 pixel detector studied in a 120 GeV/c pion test beam

Hybrid assemblies of LHC1 read-out chips and 300 mu m thick silicon pixel d etectors have been tested with a 120 GeV/c pion beam at the CERN SPS. The e quivalent noise charge at the input of the preamplifier is similar to 200 e (-). The particle detection efficiency is higher than 99.9%. A 30 ns wide e fficiency plateau is reached for a 60 ns wide trigger pulse applied after a similar to 2 mu s delay. The 50 mu m x 50 mu m pixels yield a spatial prec ision of sigma = 129.4 +/- 0.2 mu m in the large pitch direction. In the ot her direction the precision is sigma = 12.2 +/- 0.2 mu m for single-pixel c lusters and sigma = 8.2 +/- 0.2 mu m for double-pixel clusters, yielding an average of sigma = 11.4 +/- 0.2 mu m. Three different detector layouts on the same pitch were characterized. (C) 2000 Elsevier Science B.V. All right s reserved.