ATLAS LUCID detector upgrade for LHC Run 2

During the 2009-2013 data taking period (Run I) LUCID was successfully providing information about the luminosity delivered to ATLAS by the LHC. Starting from 2015 (Run II) the LHC machine is expected to provide about twice larger peak instantaneous luminosity and the bunch spacing in the machine is decreased by factor of two (from 50 ns to 25 ns). The original LU-CID design could not cope with the new running conditions, which would lead to saturation of photomultipliers and the luminosity algorithms, as well as problems with the lifetime of the photomultipliers. To address these problems a new LUCID detector was built and the readout electronic was redesigned. This article describes the design, the performance, new calibration system and the first results of 13 TeV proton-proton collisions recorded by the new LUCID detector.