Results on 0.7% X0 thick pixel modules for the ATLAS detector

Abstract Modules are the basic building blocks of the ATLAS pixel detector system, they are made of a silicon sensor tile containing ∼46 000 pixel cells of 50 μm×400 μm, 16 front-end chips connected to the sensor through bump bonding, a kapton flex circuit and the module controller chip. The Pixel detector is the first to encounter particles emerging from LHC interactions, minimization of radiation length of pixel modules is therefore very important. We report here on the construction techniques and on the operation of the first ATLAS pixel modules of 0.7% radiation length thickness. We have operated these modules with threshold of 3700×10±300×10, mean noise value of 225×10 and 0.3% dead channels.