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Catalysing Impact - Superconductivity for Global Challenges
No full textSuperconductivity has underpinned major scientific achievements, including CERN’s discovery of the Higgs boson. Looking ahead, CERN aims to further the development of superconducting technologies, both for future research infrastructure and for wider applications aligned with global development goals
Catalysing Impact - Superconductivity for Global Challenges
No full textSuperconductivity Global Alliance: objectives, challenges, relevance to SDGs, strategic roadmap
Catalysing Impact - Superconductivity for Global Challenges
No full textAn overview of how superconductivity has advanced discovery science, from particle physics, through life and material sciences, to the quantum frontier. Needs and breakthroughs
Analysis of unstable leakage current in ATLAS18 Strip Sensors after long-term tests
No full textWith the upgrade of the LHC to the High-Luminosity LHC (HL-LHC), the Inner Detector will be replaced with the new all-silicon ATLAS Inner Tracker (ITk) to maintain tracking performance in a high-occupancy environment and to cope with the increase in the integrated radiation dose. Comprising an active area of 165m, the outer four layers in the barrel and six disks in the endcap region will host strip modules, built with single-sided micro-strip sensors and glued-on hybrids carrying the front-end electronics necessary for readout. Before being shipped out for module building, a total of 24010 ATLAS18 n-in-p strip sensors, of which 17888 sensors are to be installed in the experiment, were tested at different institutes in the collaboration for mechanical and electrical compliance with technical specifications, the quality control (QC), while technological parameters were verified on test structures from the same wafers before and after irradiation, the quality assurance (QA). Reverse bias leakage current characteristics of every single sensor and leakage current stability measurements on a sample basis are an important part of QC procedure. During these measurements, a recurring pattern of performance degradation and recovery in leakage current and sensor breakdown after long-term testing has been observed for a subset of sensors. A comprehensive analysis of those changes observed during Sensor QC will be shown. Mitigation and recovery procedures, such as ionizing guns, exposure to UV light and sensor baking, developed by the sensor community and applied at different QC sites will also be highlighted, including their impact on sensor performance
New results on performance studies of the 3D modules in tests beam for the ATLAS ITk detector
No full textFor the High Luminosity upgrade of the Large Hadron Collider, the current ATLAS Inner Detector will be replaced by an all-silicon Inner Tracker (ITk). The installation is foreseen during the next LHC Long Shut Down 3 (2026-2030). The new tracker has been designed to face the challenging environment associated with the high number of collisions per bunch crossing and the expected large integrated luminosity. Therefore, ITk design has been optimized to maintain the current tracking performance but in such much more hostile environment. The ITk consists of a Pixel detector in the innermost part and a Strip detector in the outermost part. Both detectors are arranged in a central barrel section and two endcaps, to guarantee tracking hermeticity up to the very forward region of pseudorapidity 4. Regarding the Pixel Detector, two different technologies have been chosen for the sensors: 3D and planar. Due to their intrinsic radiation hardness, 3D pixel sensor have been chosen to instrument the innermost layer of the Pixel detector while the other layers will use planar sensors. Two pixel cells have been chosen according to the detector location: a 25x100 um2 rectangular cell for the barrel, and a 50x50 um2 squared cell for the end-cap, to optimize the ATLAS detector performance. The 3D sensors are produced by two vendors: Fondazione Bruno Kessler (FBK, Italy) and Stiftelsen for industriell og teknisk forskning (SINTEF, Norway). Each 3D sensor is hybridized to a readout chip to form the so-called single bare module, and three bare modules are then assembled by a flex circuit in a triplet module. This arrangement makes the 3D modules very different from the planar ones, in which a single large sensor tile is hybridized to four readout chips to form a quad module. The 3D performance up to End of Lifetime (~1.7 10e16 neq/cm2) have been studied in R&D using preproduction parts on Single Chip Cards. Despite showing the excellent radiation hardness of the sensors, the main limitations of this approach have been the use of the readout chip ITkPixV1.1 that does not have the ability to read the ToT and the fact to test a single chip assembly only, rather than a final module. In this talk, we are showing for the first time results that overcome these limitations. We have built and tested in the laboratories triplet modules, thus formed by three single bare modules joint by a PCB, both with the preproduction readout ITkPixV1.1 and the production one, ITkPxV2. We have then irradiated few of them, at CERN IRRAD facility and at RARiS in Japan, and tested on a pion beam extracted by the CERN SPS. We are therefore presenting for the first time the performance of these 3D triplet modules, in the final hardware configuration as they will be installed in the detector. We will present their efficiency as a function of the fluence and the charge collection as ITkPxV2 allows for the ToT measurement
Proton Irradiation for Quality Assurance of ATLAS18 Strip Sensors with Birmingham MC40 Cyclotron
No full textThe Birmingham MC40 Cyclotron is used to perform proton irradiations of silicon detector devices as part of the ongoing ATLAS ITk Strip Quality Assurance program. It provides a dedicated beamline delivering 27 MeV protons at currents up to a few μA, collimated to a square beam profile of 10 mm x 10 mm of roughly uniform intensity. Samples are placed within a thermally controlled box, held below -20C, which is scanned across the beam allowing a uniform fluence to be delivered without uncontrolled annealing occurring during the irradiation. Recently, upgrades have been performed to the sample scanning system, including new motor stages and improved control software. These upgrades have increased the maximum scanning speed of the system, allowing the beam current to be increased from 200nA to 500nA, with the scanning speed increased proportionately from 4mm/s to 10mm/s. This increase in turn leads to faster irradiation times; for 6 10mm x 10mm mini sensors the ITk Strip QA fluence of neq/cm is now achievable in under 1.5 hours, twice as fast as before. A brief history of the facility will be presented, discussing the facility's early issues of unexpectedly low collected charge for irradiated mini sensors, and how these were resolved through changes to the beam collimators and scanning patterns. Following this the current status of the facility post-upgrade will be outlined in detail, and measurements of irradiated ITk strip test structures, showing consistency with both the pre-upgrade system and other irradiation facilities, will be presented. In summary, this talk will highlight the Birmingham MC40 Cyclotron's role in the successful continuation of the ATLAS ITk Strip QA program, along with it's potential use for high fluence irradiations for future detector R&D
