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Antihydrogen annihilation detection: the ALPHA-g radial TPC
No full textThe recent measurement of the antihydrogen terrestrial gravitational acceleration with the ALPHA-g apparatus at CERN relies upon the detection of the annihilation of the anti-atoms that are released from their magnetic confinement and that move under the influence of gravity. The ALPHA-g magnetic trap is surrounded by a Time Projection Chamber designed to identify the annihilation products and to reconstruct the annihilation position. The TPC is called “radial”, or rTPC, because the drift field is perpendicular to the trap axis and, therefore, to the magnetic field of the external field. The design, construction and commissioning of this detector are described in the following
ITS3: the next upgrade of the ALICE Inner Tracking System
No full textThe ALICE experiment, optimized to study nuclei collisions at the ultra relativistic energies provided by the LHC, is approaching to a new upgrade phase, foreseen in 2026 during the third Long Shutdown of the accelerator. This upgrade includes the replacement of the 3 innermost layers of the Inner Tracking System, the detector closest to the interaction point, which is currently made of 7 layers of Monolithic Active Pixels Sensors (MAPS). The main features of this new vertex detector, named ITS3 are the extremely low material budget (only 0.07% per layer) and the reduced radial distance of 19 mm to the interaction point. To achieve this goal, the ITS3 will be made of wafer scale MAPS, thinned down to 50 m and curved in order to ensure a true cylindrical geometry, without any flexible printed circuits in the active area. The mechanical support and the cooling system will be optimized to reduce the total material budget: the layers will be kept in place thanks to ultra-light carbon-foam support elements, and they will be cooled through a speed air flow.The success of the project depends on many interconnected aspects and an intense R&D; activity is ongoing to investigate all technological aspects related to the development of the sensor, mechanics, cooling, and integration. This paper summarizes the status of the project and presents selected results from the characterisation of the first prototype chips
Environmental stress screening of the CMS ECAL barrel VFE and LVR cards
No full textIn preparation for the operation at HL-LHC the electronics of the electromagnetic calorimeter barrel must be replaced. The new 12240 very front end (VFE) cards will amplify and digitize signals of 62100 lead-tungstate crystals instrumented with avalanche photodiodes, while 2448 low voltage regulator (LVR) cards provide power for the VFE and digital interface cards. Reliable operation of these cards with failure rates as low as 0.5% at the end-of-life, after ∼20 years, is targeted, requiring environmental stress screening (ESS). Implementation of the hardware and software components of the custom developed ESS system is presented, highlighting its modularity, configurability, flexibility, and scalability
CAS, CERN Accelerator School,Intensity Limitations in Hadron Beams, Bulgaria, 2025
No full textPictures from Pushing the Limits: Intensity Limitations in Hadron Beams (15-25 June, 2025) In collaboration with the Faculty of Physics, Sofia University, the CERN Accelerator School organised a topical course on Intensity Limitations in Hadron Beams. An unprecedented intensity demand for hadron beams has become the norm today for a variety of particle accelerators from different fields. This CERN Accelerator School course explores the challenges of generating and maintaining high-intensity hadron beams, crucial for a variety of applications in fundamental research. Achieving peak performance in these machines requires a deep understanding of the factors that can limit beam intensity. During a two weeks course, we will delve into the limitations which these beams encounter in both linear accelerators (linacs) and circular accelerators. This course provides a comprehensive overview of these limitations, including: Beam interactions with the surroundings: We'll examine how the beam interacts with its environment, starting from vacuum chambers and other accelerator components up to beam intercepting devices. Wakefields and impedances: Learn about the electromagnetic fields generated by the beam itself and derive their impact on beam stability. High-intensity instabilities: Explore the various instabilities that can arise in high-intensity beams, and understand how to mitigate them. Space charge effects: Understand the impact of the beam's own electric charge on its dynamics. Collective effects: Discover how the combined behaviour of particles in the beam can lead to complex phenomena. The course also examines specific intensity limitations encountered in diverse applications, such as: Neutron sources Radioactive ion beams Neutrino factories and muon colliders Hadron colliders Accelerator Driven Systems for energy production Through a combination of lectures and case studies, you'll gain the knowledge and learn about the required tools to analyse, understand, and overcome intensity limitations in hadron beams
Alvaro Martinez Landete: "Production Test Suite Framework as testing platform"
No full textValidation, characterization, and testing of custom electronics are critical throughout their entire lifecycle, from early prototypes to final products for CERN. These tests allow us to plan maintenance, schedule interventions and ensure hardware will perform as expected. In the past, this has been addressed by developing specifically tailored, dedicated, test routines for each device under test. While solving short-term needs, this approach presents significant long-term challenges such as maintenance, inconsistent documentation, and a lack of standardization across projects and versions.
A new, unified Production Test Suite (PTS) Framework has been developed to address these shortcomings and formalize the test workflow. The framework is designed to separate the test logic from the sequencing infrastructure. It provides developers with a standardized, hardware-agnostic interface for test execution, a consistent graphical user interface for operators, and automated, easily parsable reporting. This approach significantly reduces development time and improves the long-term maintainability and comparability of test results across all development phases.
This talk will present the challenges that motivated the framework's creation and demonstrate how it helps the ATS community validate custom electronics. It will cover the status of the project, including its recent open-source release and initial adoption in active projects, and discuss the future roadmap for its development and community engagement.</p
Irradiation studies of ATLAS18 mini strip detectors with 23 GeV protons in IRRAD facility
No full textSeveral irradiation campaigns using 23 GeV protons were conducted at the IRRAD facility at CERN, employing test structures from ATLAS18 wafers for the ATLAS ITk strip sensors. These campaigns aimed to study charge collection efficiency after irradiation. When irradiating with a narrow beam of high energy protons, various effects must be considered to accurately estimate the actual fluence and interpret detector performance. Secondary particles generated in interactions of the primary protons with material of the support structure, as well as geometrical effects due to shallow incidence angle, can significantly increase the actual fluence to which samples are exposed. These effects were also studied using Geant4 simulation, which showed good agreement with measurements. Extensive studies of effects of annealing at 60C on CCE were also performed. For detectors irradiated with neutrons or low energy protons the collected charge exhibited a beneficial effect of short-term annealing which was followed by a decrease in charge collection efficiency at longer annealing times. After irradiation with 23 GeV protons to fluences above 1.2e15 n/cm2 the collected charge remained unchanged or even decreased significantly after the first few tens of minutes of annealing. Edge-TCT measurements indicated that this unusual annealing behaviour is related to the double-peak electric field profile in the detector. Mixed irradiation with 23 GeV protons and neutrons to fluences matching the expected in the upgraded ATLAS experiment confirmed that this unusual annealing effect will not impact the operation of the ITk strip detector. The results of these studies will be presented in this contribution
Vector-like quark summary plot
No full textThis note presents a plot summarising latest ATLAS confidence level exclusion lower limits on the vector-like quark mass for various assumptions on the decay modes. Results are current as of June 2025
RD53 Pixel Readout Integrated Circuits for ATLAS and CMS HL-LHC Upgrades
No full textThe RD53 collaboration has since 2013 developed new hybrid pixel detector chips with 50x50um pixels for the HL-LHC upgrades of the ATLAS and CMS experiments at CERN. A common architecture, design and verification framework has been developed to enable final pixel chips with different chip sizes to be designed, verified and tested to handle extreme hit rates of 3GHz/cm (12GHz per chip) together with significantly increased trigger rate of 1MHz and efficient readout of up to 5.12Gbits/s per pixel chip. Tolerance to an extremely hostile radiation environment with 1Grad over 10 years and SEU (Single Event Upset) rates of up to 100 upsets per second per chip have been major challenges to make reliable pixel chips for the two main CERN experiments. Three generations of pixel chips, and many specific mixed signal building block and radiation test chips, have been submitted and extensively tested to get to final production chips. The large complex and high rate pixel chips have been developed with a strong emphasis on low power consumption together with a concurrent development and qualification of novel serial powering at chip, module and system level, to minimize detector material budget
Additive manufacturing of a 3D-segmented plastic scintillator detector for tracking and calorimetry of elementary particles
No full textPlastic-scintillator detectors are devices used for the detection of elementary particles. They provide good particle identification with excellent time resolution, whilst being inexpensive due to the affordability of plastic materials. Particle tracking is achieved by segmenting the scintillator into smaller optically-isolated 3D granular sub-structures which require the integration of multiple types of plastic materials as well as several thousands of tiny holes through a compact volume of several cubic meters. Future particle detectors necessitate larger volumes, possibly with even finer segmentation. However, manufacturing such geometries with current production strategies is challenging, as they involve time-consuming and costly fabrication processes, followed by the assembly of millions of individual parts. The difficulty in scaling up such a workflow can be addressed by additive manufacturing, enabling the construction of complex, monolithic geometries in a single operation. This article presents the fabrication of the first additive manufactured plastic scintillator detector, capable of 3D tracking elementary particles and measuring their stopping power. Its performance is comparable to the state of the art of plastic scintillator detectors. This work paves the way towards a new feasible, time and cost-effective process for the production of future plastic-based scintillator detectors, regardless their size and difficulty in geometry