4 research outputs found
Evaluation of planar silicon pixel sensors with the RD53A readout chip for the Phase-2 Upgrade of the CMS Inner Tracker
The Large Hadron Collider (LHC) at CERN will undergo an upgrade in order to increase its luminosity to cms. The increased luminosity during this High-Luminosity running phase\\
(HL-LHC), 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 m m and rectangular m m 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 at the HL-LHC. A spatial resolution of approximately 3.4m (2m) is obtained using the modules with m m (m m) pixels at the optimal angle of incidence before irradiation. After irradiation to a 1 MeV neutron equivalent fluence of cm, a resolution of 9.4m is achieved at a bias voltage of 800 V using a module with m m pixel size. All modules retain a hit efficiency in excess of 99\% after irradiation to fluences up to cm.
Further studies of the electrical properties of the modules, especially crosstalk, are also presented in this paper.The Large Hadron Collider at CERN will undergo an upgrade inorder to increase its luminosity to7.5 × 10 cms. The increased luminosityduring this High-Luminosity running phase, starting around 2029,means a higher rate of proton-proton interactions, hence a largerionizing dose and particle fluence for the detectors. The currenttracking system of the CMS experiment will be fully replaced inorder to cope with the new operating conditions. Prototype planarpixel sensors for the CMS Inner Tracker with square50 μm × 50 μm and rectangular100 μm × 25 μm pixels read out by theRD53A chip were characterized in the lab and at the DESY-II testbeamfacility in order to identify designs that meet the requirements ofCMS during the High-Luminosity running phase. A spatial resolutionof approximately 3.4 μm (2 μm) is obtained using themodules with 50 μm × 50 μm(100 μm × 25 μm) pixels at the optimalangle of incidence before irradiation. After irradiation to a 1 MeVneutron equivalent fluence ofΦ = 5.3 × 10 cm, a resolution of9.4 μm is achieved at a bias voltage of 800 V using a modulewith 50 μm × 50 μm pixel size. All modulesretain a hit efficiency in excess of 99% after irradiation tofluences up to 2.1 × 10 cm. Further studies ofthe electrical properties of the modules, especially crosstalk, arealso presented in this paper.The Large Hadron Collider (LHC) at CERN will undergo an upgrade in order to increase its luminosity to cms. The increased luminosity during this High-Luminosity running phase (HL-LHC), 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 m m and rectangular m m 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 at the HL-LHC. A spatial resolution of approximately 3.4m (2m) is obtained using the modules with m m (m m) pixels at the optimal angle of incidence before irradiation. After irradiation to a 1 MeV neutron equivalent fluence of cm, a resolution of 9.4m is achieved at a bias voltage of 800 V using a module with m m pixel size. All modules retain a hit efficiency in excess of 99% after irradiation to fluences up to cm. Further studies of the electrical properties of the modules, especially crosstalk, are also presented in this paper
Evaluation of HPK n plus -p planar pixel sensors for the CMS Phase-2 upgrade
To cope with the challenging environment of the planned high luminosity upgrade of the Large Hadron Collider (HL-LHC), scheduled to start operation in 2029, CMS will replace its entire tracking system. The requirements for the tracker are largely determined by the long operation time of 10 years with an instantaneous peak luminosity of up to 7.5 x 1034 cm-2 s-1 in the ultimate performance scenario. Depending on the radial distance from the interaction point, the silicon sensors will receive a particle fluence corresponding to a non-ionising energy loss of up to ?eq = 3.5 x 1016 cm-2. This paper focuses on planar pixel sensor design and qualification up to a fluence of ?eq = 1.4 x 1016 cm-2. For the development of appropriate planar pixel sensors an R&D program was initiated, which includes n+-p sensors on 150 mm (6") wafers with an active thickness of 150 mu m with pixel sizes of 100 x 25 mu m2 and 50 x 50 mu m2 manufactured by Hamamatsu Photonics K.K. (HPK). Single chip modules with ROC4Sens and RD53A readout chips were made. Irradiation with protons and neutrons, as well was an extensive test beam campaign at DESY were carried out. This paper presents the investigation of various assemblies mainly with ROC4Sens readout chips. It demonstrates that multiple designs fulfil the requirements in terms of breakdown voltage, leakage current and efficiency. The single point resolution for 50 x 50 mu m2 pixels is measured as 4.0 mu m for non-irradiated samples, and 6.3 mu m after irradiation to ?eq = 7.2 x 1015 cm-2