Design and construction of a cylindrical GEM detector as Inner Tracker in KLOE-2

We report on the design and the construction of a triple-GEM detector as the new Inner Tracker (IT) for the KLOE-2 experiment at the Frascati Φ-factory. The IT is composed of four tracking layers, each providing an independent two-dimensional space point. Each layer is a fully cylindrical triple-GEM detector. The front-end electronics is based on the GASTONE ASIC, specifically developed for this detector, a charge amplifier with digital output integrating 64 channels in one single chip. After three years of R&D the construction of the first layer has started, with the aim of completing the detector by middle of 2012. We report on the R&D achievements, including the construction process, the results of two beam-tests with prototype detectors, and the present realization status of the final detector.