D. Domenici

Status of the cylindrical-GEM project for the KLOE-2 Inner Tracker

We present the status of the RD characterization of the single-mask GEM technology for the realization of large area GEM foils; study of the 2-D, XV patterned, readout strips performed with small planar prototypes in a dedicated test at the H4-SPS beam facility, in presence of a magnetic field (up to 1.5T intensity). In addition, for the design of the final detector a finite element simulation of the mechanics together with specific load tests of the materials and the structure used for the construction of the prototype have been carried out.

The cylindrical GEM detector for the KLOE-2 Inner Tracker

Part of the upgrade of the KLOE detector at the DAΦNE Φ-factory consists of the insertion of a tracking device around the interaction region, composed of four tracking layers with radii from 130 mm to 205 mm and an active length of 700 mm. Each layer was realized as a cylindrical triple-GEM (CGEM) kapton-based detector, a solution that allows us to keep the total material budget below 2% of X0, of utmost importance to limit the multiple scattering of low-momentum tracks at KLOE-2, and to minimize dead spaces. The peculiar readout pattern with XV strips provides a spatial resolution of about 200xa0μm on both views, while a dedicated readout system has been developed by the KLOE-2 collaboration. It is composed of a digital readout front-end card based on the GASTONE ASIC and a General Interface Board with a configurable FPGA architecture and Gigabit Ethernet. The construction of the four CGEM layers has been completed and the detectors have been tested with a beta source and cosmic-ray muons. The insertion inside the KLOE apparatus was performed in July 2013. The construction procedure and the results of the validation tests will be reported.

Production and test of the first triple-GEM cylindrical layers of the KLOE-2 Inner Tracker

The construction of the KLOE-2 Inner Tracker, foreseen as upgrade of the tracking system of the experiment at the e+e- Φ-factory DA<;I>NE at the INFN Laboratori Nazionali di Frascati (LNF), has started in mid 2011. KLOE-2 is the first experiment using the GEM technology with a cylindrical geometry, developed at LNF by the Inner Tracker group and within the RD51 Collaboration as one of the key activities. Three layers of the Inner Tracker have been completed and the construction of the fourth and last layer has started. The productions procedure will be reported together with the first results obtained with 5.9 keY X-rays and cosmic-ray muons collected at LNF Inner Tracker test stand.

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.

The cylindrical GEM detector of the KLOE-2 experiment

The KLOE-2 experiment started its data taking campaign in November 2014 with an upgraded tracking system at the DAΦNE electron-positron collider at the Frascati National Laboratory of INFN. The new tracking device, the Inner Tracker, operated together with the KLOE-2 Drift Chamber, has been installed to improve track and vertex reconstruction capabilities of the experimental apparatus. The Inner Tracker is a cylindrical GEM detector composed of four cylindrical triple-GEM detectors, each provided with an X-V strips-pads stereo readout. Although GEM detectors are already used in high energy physics experiments, this device is considered a frontier detector due to its fully-cylindrical geometry: KLOE-2 is the first experiment benefiting of this novel detector technology. Alignment and calibration of this detector will be presented together with its operating performance and reconstruction capabilities.

The KLOE-2 cylindrical GEM inner tracker: Detector operation, calibration and performance

KLOE-2 at the e+e− DAφNE φ-factory is the main experiment of the INFN Frascati National Laboratories (LNF) and is the first high-energy experiment using the GEM technology with a cylindrical geometry, a novel idea that was developed at LNF exploiting the kapton properties to build a light and compact tracking system. Four concentric cylindrical triple-GEM detectors, for a total material budget below 2% of the radiation length X0, are inserted around the interaction region and before the inner wall of the pre-existing KLOE Drift Chamber, at distances from 130 mm to 205 mm. For this project, state-of-the-art solutions have been expressly developed or tuned: single-mask GEM etching, multi-layer XV patterned readout circuit, PEEK spacer grid, GASTONE front-end board, a custom 64-channel ASIC with digital output, and the Global Interface Board for data collection, with a configurable FPGA architecture and Gigabit Ethernet. The dedicated XV strips patterned readout allows space coordinates to be reconstructed. Alignment and calibration of a cylindrical GEM detector was never done before and represents one of the challenging activities of the experiment. During 2015 both KLOE-2 and DAPHNE successfully demonstrated the feasibility of a long term acquisition program with the first data taking campaign, started in November 2014 and ended in July 2015 with 1 fb−1 integrated luminosity. The second new data taking campaign started in September 2015 and KLOE-2 is presently taking data. The Inner Tracker detector operation, calibration and performance will be presented. Preliminary results obtained with cosmic-ray muons and Bhabha scattering events are within expectations for the Inner Tracker resolution.

Commissioning of the KLOE-2 Inner Tracker: The first cylindrical GEM detector

The KLOE-2 Inner Tracker, the first fully-cylindrical GEM detector ever built, is being commissioned at the Frascati Laboratory of INFN. KLOE-2 is the first experiment exploiting GEM technology with cylindrical geometry. Tracking performance of this novel detector are being studied using both cosmic-ray muon and Bhabha scattering events. Alignment and calibration procedures to reach design spatial resolutions are ongoing and will be reported.