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

Hybrid assemblies of LHC1 read-out chips and 300μm thick silicon pixel detectors have been tested with a 120GeV/c pion beam at the CERN SPS. The equivalent noise charge at the input of the preamplifier is ∼200e−. The particle detection efficiency is higher than 99.9%. A 30ns wide efficiency plateau is reached for a 60ns wide trigger pulse applied after a ∼2μs delay. The 50μm×50μm pixels yield a spatial precision of σ=129.4±0.2μm in the large pitch direction. In the other direction the precision is σ=12.2±0.2μm for single-pixel clusters and σ=8.2±0.2μm for double-pixel clusters, yielding an average of σ=11.4±0.2μm. Three different detector layouts on the same pitch were characterized.