11 research outputs found
Effect of prealuminizing diffusion treatment on microstructural evolution of high-activity pt-aluminide coatings
New vegetation type map of India prepared using satellite remote sensing: comparison with global vegetation maps and utilities
A seamless vegetation type map of India (scale 1: 50,000) prepared using medium-resolution IRS LISS-III images is presented. The map was created using an on-screen visual interpretation technique and has an accuracy of 90%, as assessed using 15,565 ground control points. India has hitherto been using potential vegetation/forest type map prepared by Champion and Seth in 1968. We characterized and mapped further the vegetation type distribution in the country in terms of occurrence and distribution, area occupancy, percentage of protected area (PA) covered by each vegetation type, range of elevation, mean annual temperature and precipitation over the past 100 years. A remote sensing-amenable hierarchical classification scheme that accommodates natural and semi-natural systems was conceptualized, and the natural vegetation was classified into forests, scrub/shrub lands and grasslands on the basis of extent of vegetation cover. We discuss the distribution and potential utility of the vegetation type map in a broad range of ecological, climatic and conservation applications from global, national and local perspectives. Weused 15,565 ground control points to assess the accuracy of products available globally (i.e., GlobCover, Holdridge’s life zone map and potential natural vegetation (PNV) maps). Hence we recommend that the map prepared herein be used widely. This vegetation type map is the most comprehensive one developed for India so far. It was prepared using 23.5m seasonal satellite remote sensing data, field samples and information relating to the biogeography, climate and soil. The digital map is now available through a web portal (http://bis.iirs.gov.in)
New vegetation type map of India prepared using satellite remote sensing: Comparison with global vegetation maps and utilities
International audienceA seamless vegetation type map of India (scale 1: 50,000) prepared using medium-resolution IRS LISS-III images is presented. The map was created using an on-screen visual interpretation technique and has an accuracy of 90%, as assessed using 15,565 ground control points. India has hitherto been using potential vegetation/forest type map prepared by Champion and Seth in 1968. We characterized and mapped further the vegetation type distribution in the country in terms of occurrence and distribution, area occupancy, percentage of protected area (PA) covered by each vegetation type, range of elevation, mean annual temperature and precipitation over the past 100 years. A remote sensing-amenable hierarchical classification scheme that accommodates natural and semi-natural systems was conceptualized, and the natural vegetation was classified into forests, scrub/shrub lands and grasslands on the basis of extent of vegetation cover. We discuss the distribution and potential utility of the vegetation type map in a broad range of ecological, climatic and conservation applications from global, national and local perspectives. We used 15,565 ground control points to assess the accuracy of products available globally (i.e., GlobCover, Holdridge’s life zone map and potential natural vegetation (PNV) maps). Hence we recommend that the map prepared herein be used widely. This vegetation type map is the most comprehensive one developed for India so far. It was prepared using 23.5 m seasonal satellite remote sensing data, field samples and information relating to the biogeography, climate and soil. The digital map is now available through a web portal (http://bis.iirs.gov.in)
New vegetation type map of India prepared using satellite remote sensing: Comparison with global vegetation maps and utilities
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
Beam Test Performance Studies of CMS Phase-2 Outer Tracker Module Prototypes
International audienceA 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 . The information is generated at a frequency of 40 MHz 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 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
Beam test performance of a prototype module with Short Strip ASICs for the CMS HL-LHC tracker upgrade
International audienceThe Short Strip ASIC (SSA) is one of the four front-endchips designed for the upgrade of the CMS Outer Tracker for the HighLuminosity LHC. Together with the Macro-Pixel ASIC (MPA) it willinstrument modules containing a strip and a macro-pixel sensorstacked on top of each other. The SSA provides both full readout ofthe strip hit information when triggered, and, together with theMPA, correlated clusters called stubs from the two sensors for useby the CMS Level-1 (L1) trigger system. Results from the firstprototype module consisting of a sensor and two SSA chips arepresented. The prototype module has been characterized at theFermilab Test Beam Facility using a 120 GeV proton beam
Evaluation of HPK - planar pixel sensors for the CMS Phase-2 upgrade
International audienceTo cope with the challenging environment of the planned high luminosity upgrade of the Large Hadron Collider (HL-LHC), sched-uled to start operation in 2029, CMS will replace its entire tracking system. The requirements for the tracker are largely determinedby the long operation time of 10 years with an instantaneous peak luminosity of up to 7.5 × 1034 cm−2 s−1 in the ultimate perfor-mance scenario. Depending on the radial distance from the interaction point, the silicon sensors will receive a particle fluencecorresponding to a non-ionizing energy loss of up to Φeq = 3.5 × 1016 cm−2. This paper focuses on planar pixel sensor design andqualification up to a fluence of Φeq = 1.4 × 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 μm with pixel sizes of 100 × 25 μm2 and 50 × 50 μm2 manufactured by Hamamatsu.Single chip modules with ROC4Sens and RD53A readout chips were made. Irradiation with protons and neutrons, as well was anextensive test beam campaign at DESY were carried out. This paper presents the investigation of various assemblies mainly withROC4Sens readout chips. It demonstrates that multiple designs fulfill the requirements in terms of breakdown voltage, leakagecurrent and efficiency. The single point resolution for 50 × 50 μm2 pixels is measured as 4.0 μm for non-irradiated samples, and6.3 μm after irradiation to Φeq = 7.2 × 1015 cm−2