Yazar "Beaumont, W." seçeneğine göre listele

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    Beam test performance studies of CMS Phase-2 Outer Tracker module prototypes
    (Iop Publishing Ltd, 2024) Adam, W.; Bergauer, T.; Damanakis, K.; Dragicevic, M.; Fruehwirth, R.; Steininger, H.; Beaumont, W.
    A new tracking detector will be installed as part of the Phase-2 upgrade of the CMS detector for the high-luminosity LHC era. This tracking detector includes the Inner Tracker, equipped with silicon pixel sensor modules, and the Outer Tracker, consisting of modules with two parallel stacked silicon sensors. The Outer Tracker front-end ASICs will be able to correlate hits from charged particles in these two sensors to perform on-module discrimination of transverse momenta (p(T)). The p(T) information is generated at a frequency of 40MHz and will be used in the Level-1 trigger decision of CMS. Prototypes of the so-called 2S modules were tested at the Test Beam Facility at DESY Hamburg between 2019 and 2020. These modules use the final front-end ASIC, the CMS Binary Chip (CBC), and for the first time the Concentrator Integrated Circuit (CIC), optical readout and on-module power conversion. In total, seven modules were tested, one of which was assembled with sensors irradiated with protons. An important aspect was to show that it is possible to read out modules synchronously. A cluster hit efficiency of about 99.75% was achieved for all modules. The CBC p(T) discrimination mechanism has been verified to work together with the CIC and optical readout. The measured module performance meets the requirements for operation in the upgraded CMS tracking detector.
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    Evaluation of planar silicon pixel sensors with the RD53A readout chip for the Phase-2 upgrade of the CMS ınner tracker
    (Iop Publishing Ltd, 2023) Adam, W.; Bergauer, T.; Damanakis, K.; Dragicevic, M.; Fruehwirth, R.; Beaumont, W.; Sağır, Sinan
    The Large Hadron Collider at CERN will undergo an upgrade in order to increase its luminosity to 7.5 x 1034 cm-2s-1. The increased luminosity during this High-Luminosity running phase, starting around 2029, means a higher rate of proton-proton interactions, hence a larger ionizing dose and particle fluence for the detectors. The current tracking system of the CMS experiment will be fully replaced in order to cope with the new operating conditions. Prototype planar pixel sensors for the CMS Inner Tracker with square 50 gm x 50 gm and rectangular 100 gm x 25 gm pixels read out by the RD53A chip were characterized in the lab and at the DESY-II testbeam facility in order to identify designs that meet the requirements of CMS during the High-Luminosity running phase. A spatial resolution of approximately 3.4 gm (2 gm) is obtained using the modules with 50 gm x 50 gm (100 gm x 25 gm) pixels at the optimal angle of incidence before irradiation. After irradiation to a 1 MeV neutron equivalent fluence of (Deq = 5.3 x 1015 cm-2, a resolution of 9.4 gm is achieved at a bias voltage of 800 V using a module with 50 gm x 50 gm pixel size. All modules retain a hit efficiency in excess of 99% after irradiation to fluences up to 2.1 x 1016 cm-2. Further studies of the electrical properties of the modules, especially crosstalk, are also presented in this paper.
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    Measurement of the fractional radiation length of a pixel module for the CMS Phase-2 upgrade via the multiple scattering of positrons
    (Iop Publishing Ltd, 2024) Adam, W.; Bergauer, T.; Damanakis, K.; Dragicevic, M.; Fruehwirth, R.; Steininger, H.; Beaumont, W.
    High-luminosity particle collider experiments such as the ones planned at the High-Luminosity Large Hadron Collider require ever-greater vertexing precision of the tracking detectors, necessitating reductions in the material budget of the detectors. Traditionally, the fractional radiation length (x/X-0) of detectors is either estimated using known properties of the constituent materials, or measured in dedicated runs of the final detector. In this paper, we present a method of direct measurement of the material budget of a CMS prototype module designed for the Phase-2 upgrade of the CMS detector using a 40-65 MeV positron beam. A total of 630 million events were collected at the Paul Scherrer Institut PiE1 experimental area using a three-plane telescope consisting of the prototype module as the central plane, surrounded by two MALTA monolithic pixel detectors. Fractional radiation lengths were extracted from scattering angle distributions using the Highland approximation for multiple scattering. A statistical technique recovered runs suffering from trigger desynchronisation, and several corrections were introduced to compensate for local inefficiencies related to geometric and beam shape constraints. Two regions of the module were surveyed and yielded average x/X-0 values of (0.72 +/- 0.05)% and (0.95 +/- 0.09)%, which are compatible with empirical estimates for these regions computed from known material properties of 0.753% and 0.892%, respectively. Two types of higher-granularity maps of the fractional radiation length were produced, subdivided either into rectangular regions of uniform size, or polygonal-shaped regions of uniform material composition. The results bode well for the CMS Phase-2 upgrade modules, which will play a key role in the minimisation of the material of the upgraded detector.