arXiv subjects

Jory Sonneveld

Publications and source records attributed to Jory Sonneveld.

At least 19 recordsLinked to original sources

arXiv2026

TPA-TCT analysis of the RD50-MPW4 monolithic pixel particle detector

The RD50-MPW4, a Depleted Monolithic Active Pixel Sensor (DMAPS) was analyzed using a Two Photon Absorption Transient Current Technique (TPA-TCT). This technique provides sensitivity maps with micrometer-scale spatial resolution, enabling the resolution of the boundaries of the detector's sensitive volume, even for small-area pixels (62 x 62 $μ$m$^2$ in this study). With a 3D resolution, the depletion depth, the boundaries of the detector electric field, the 3D hit detection efficiency and the charge sharing between neighboring pixels were measured. The RD50-MPW4, a multi-project wafer chip developed by the HV-CMOS working group within the CERN RD50 collaboration, features a 64 x 64 DMAPS pixel matrix. Illuminating the chip from the backside, the TPA-TCT technique can characterize any pixel element in the matrix because silicon is transparent for near infrared laser light (1550 nm). Electron-hole pairs are generated only around the light focal point, deep in the silicon, so that any charge collected is precisely only from the focal point. With the TPA-TCT technique, the RD50-MPW4 was found to be have a 100% hit detection efficiency under specified conditions and an effective depletion depth of 226 $μ$m. It was also found that part of the charge in the periphery of the pixel was collected in the neighboring pixel. A 3D map of the sensor clearly shows the in-pixel electronics and the limits of the depletion region.

physics.ins-det↗

arXiv2026

The RD50-MPW4: A Radiation Hard HV CMOS Sensor for Future Colliders

The former CERN RD50 collaboration develops monolithic active pixel high voltage (HV) CMOS sensors for future colliders with the aim of high radiation tolerance, good time resolution, and high granularity pixel detectors. The most recent prototype, the RD50-MPW4, was produced by LFoundry in December 2023 using a 150 nm CMOS process. It features a matrix of 64x64 pixels with a 62 $μ$m pitch and employs a column-drain readout architecture. Compared to its predecessor, it now has separate analog and digital power domains and a new biasing scheme with a guard ring structure that supports bias voltages over 600 V. This contribution will discuss the design and latest results of the MPW4, where tests with unirradiated samples showed more than 99.9% efficiency, 16 $μ$m spatial resolution and 10 ns timing resolution. Efficiencies of over 99% were achieved for samples irradiated to fluences of $1 \times 10^{15}$ 1 MeV n$_{\mathrm{eq}}/\mathrm{cm}^2$. A 3D map of the charge collection efficiency from a measurement with two-photon absorption laser is presented that nicely outlines the depletion depth of this radiation hard, high granularity monolithic active pixel sensor.

physics.ins-det↗

arXiv2026

Influence of Radiation and AC Coupling on Time Performance of Analog Pixels Test Structures in 65 nm CMOS technology

Monolithic Active Pixel Sensors (MAPS) in advanced CMOS imaging technologies are key to next-generation tracking systems for high-energy physics, where radiation hardness and precise vertex reconstruction are essential. As part of the ALICE ITS3 R&D program in synergy with the CERN R&D, we evaluated the performance of the Analog Pixel Test Structures (APTS) fabricated in the TPSCo 65 nm CMOS imaging process. The prototypes employ 10 um pitch pixels with a fast operational amplifier-based buffering stage at the output, enabling direct characterization of intrinsic sensor response. Beam tests with minimum ionizing particles assessed the timing and charge collection of DC- and AC-coupled designs, including devices exposed to 10^14 NIEL and 10^15 NIEL non ioninsing energy loss. DC-coupled sensors demonstrated stable performance, maintaining time resolution lower than 70 ps and >99% detection efficiency up to 10^15 NIEL. AC-coupled sensors demonstrated a wide operational margin, with efficiencies above 99% for clusterization thresholds below 150 electrons. Even though the AC coupling allows higher reverse bias than DC-coupled sensors, the reduced signal amplitude lowers the signal-to-noise ratio, increasing the jitter contribution. At high reverse bias, the AC-coupled sensors achieve time resolutions comparable to the DC-coupled version, demonstrating the viability of both approaches. These results also suggest that combining the low capacitance of DC-coupled designs with the high-bias capability of AC coupling could further enhance time resolution. These results confirm the suitability of 65 nm MAPS for future collider detectors requiring high radiation tolerance, efficiency, and timing precision.

physics.ins-det↗

arXiv2026

The design and expected performance of the ALICE ITS3 upgrade

During the LHC Long Shutdown 3 (2026-29) ALICE will replace its three innermost tracking layers by a new detector, the "ITS3". It will be based on newly developed, wafer-scale monolithic active pixel sensors, which are bent into truly cylindrical layers and held in place by light mechanics made from carbon foam. Unprecedented low values of material budget (0.09\% $X_0$ per layer) and proximity to the interaction point (19 mm) lead to a factor two improvement in pointing resolutions for particles from very low $p_{\mathrm{T}}$ (O(100 MeV/$c$)), achieving, for example, 20 $μ$m and 15 $μ$m in the transversal and longitudinal directions, respectively, for 1 GeV/$c$ particles. After a successful R&D phase (2019-2023), which demonstrated the feasibility of this innovative detector and led to the Technical Design Report (https://cds.cern.ch/record/2890181/), the final sensor and mechanics are being developed right now. This contribution will review the conceptual design and the main R&D achievements, as well as the current activities and road to completion and installation. It includes a projection of the improved physics performance, in particular for heavy-flavor mesons and baryons, as well as for thermal dielectrons that will come into reach with this new detector installed.

physics.ins-det↗

arXiv2025

Further Characterisation of Digital Pixel Test Structures Implemented in a 65 nm CMOS Process

The next generation of MAPS for future tracking detectors will have to meet stringent requirements placed on them. One such detector is the ALICE ITS3 that aims to be very light at 0.07% X/X$_{0}$ per layer and have a low power consumption in the active area of 40 mW/cm$^{2}$ by implementing wafer-scale MAPS bent into cylindrical half layers. To address these challenging requirements, the ALICE ITS3 project, in conjunction with the CERN EP R&D on monolithic pixel sensors, proposed the Tower Partners Semiconductor Co. 65 nm CMOS process as the starting point for the sensor. After the initial results confirmed the detection efficiency and radiation hardness, the choice of the technology was solidified by demonstrating the feasibility of operating MAPS in low-power consumption regimes, < 50 mW/cm$^{2}$, while maintaining high-quality performance. This was shown through a detailed characterisation of the Digital Pixel Test Structure (DPTS) prototype exposed to X-rays and ionising beams, and the results are presented in this article. Additionally, the sensor was further investigated through studies of the fake-hit rate, the linearity of the front-end in the range 1.7-28 keV, the performance after ionising irradiation, and the detection efficiency of inclined tracks in the range 0-45$^\circ$.

physics.ins-det↗

arXiv2025

SUSY Highlights: Current Results and Future Prospects

At the Large Hadron Collider (LHC) at CERN in Geneva, Switzerland, one of the goals of colliding protons together is to search for new physics. Supersymmetry (SUSY), a popular theory of physics beyond the well-established standard model of particle physics, is a large part of the search program of the ATLAS and CMS multi-purpose detectors located on opposite sides of the 27-kilometer LHC ring. So far no sign of supersymmetry has been found in the most obvious search channels such as all-hadronic searches with jets and missing energy. This led to the development of many new search strategies. A selection of current results, including several observations of deviations from the standard model and novel search techniques, as well as future prospects are discussed in this talk.

hep-ex↗

arXiv2025

Yield, noise and timing studies of ALICE ITS3 stitched sensor test structures: the MOST

In the LHC long shutdown 3, the ALICE experiment upgrades the inner layers of its Inner Tracker System with three layers of wafer-scale stitched sensors bent around the beam pipe. Two stitched sensor evaluation structures, the MOnolithic Stitched Sensor (MOSS) and MOnolithic Stitched Sensor with Timing (MOST) allow the study of yield dependence on circuit density, power supply segmentation, stitching demonstration for power and data transmission, performance dependence on reverse bias, charge collection performance, parameter uniformity across the chip, and performance of wafer-scale data transmission. The MOST measures 25.9 cm x 0.25 cm, has more than 900,000 pixels of 18x18 $μ$m$^2$ and emphasizes the validation of pixel circuitry with maximum density, together with a high number of power domains separated by switches allowing to disconnect faulty circuits. It employs 1 Gb/s 26 cm long data transmission using asynchronous, data-driven readout. This readout preserves information on pixel address, time of arrival and time over threshold. In the MOSS, by contrast, regions with different in-pixel densities are implemented to study yield dependence and are read synchronously. MOST test results validated the concept of power domain switching and the data transmission over 26 cm stitched lines which are to be employed on the full-size, full-functionality ITS3 prototype sensor, MOSAIX. Jitter of this transmission is still under study. This proceeding summarizes the performance of the stitched sensor test structures with emphasis on the MOST.

physics.ins-det↗

arXiv2025

Detection efficiency and spatial resolution of Monolithic Active Pixel Sensors bent to different radii

Bent monolithic active pixel sensors are the basis for the planned fully cylindrical ultra low material budget tracking detector ITS3 of the ALICE experiment. This paper presents results from testbeam campaigns using high-energy particles to verify the performance of 50 um thick bent ALPIDE chips in terms of efficiency and spatial resolution. The sensors were bent to radii of 18, 24 and 30 mm, slightly smaller than the foreseen bending radii of the future ALICE ITS3 layers. An efficiency larger than $99.9\%$ and a spatial resolution of approximately 5 um, in line with the nominal operation of flat ALPIDE sensors, is obtained at nominal operating conditions. These values are found to be independent of the bending radius and thus constitute an additional milestone in the demonstration of the feasibility of the planned ITS3 detector. In addition, a special geometry in which the beam particles graze the chip and traverse it laterally over distances of up to 3 mm is investigated.

physics.ins-det↗

arXiv2024

Time performance of Analog Pixel Test Structures with in-chip operational amplifier implemented in 65 nm CMOS imaging process

In the context of the CERN EP R&D on monolithic sensors and the ALICE ITS3 upgrade, the Tower Partners Semiconductor Co (TPSCo) 65 nm process has been qualified for use in high energy physics, and adopted for the ALICE ITS3 upgrade. An Analog Pixel Test Structure (APTS) featuring fast per pixel operational-amplifier-based buffering for a small matrix of four by four pixels, with a sensor with a small collection electrode and a very non-uniform electric field, was designed to allow detailed characterization of the pixel performance in this technology. Several variants of this chip with different pixel designs have been characterized with a (120 GeV/$c$) positive hadron beam. This result indicates that the APTS-OA prototype variants with the best performance achieve a time resolution of 63 ps with a detection efficiency exceeding 99% and a spatial resolution of 2 $μ$m, highlighting the potential of TPSCo 65nm CMOS imaging technology for high-energy physics and other fields requiring precise time measurement, high detection efficiency, and excellent spatial resolution.

physics.ins-det↗

arXiv2023

ITS3: A truly cylindrical inner tracker for ALICE

After the successful installation and first operation of the new Inner Tracking System (ITS2), which consists of about 10 m$^2$ of monolithic silicon pixel sensors, ALICE is pioneering the usage of bent, wafer-scale pixel sensors for the ITS3 for Run 4 at the LHC in 2029. Sensors larger than typical reticle sizes can be produced using the technique of stitching. At thicknesses of about 30 $μ$m, the silicon is flexible enough to be bent to radii of the order of 1 cm. By cooling such sensors with a forced air flow, it becomes possible to construct a detector with minimal material budget. The reduction of the material budget and the improved pointing resolution will allow new measurements, in particular of heavy-flavor decays and electromagnetic probes. Mechanical studies have shown the sensors to be unaffected by bending, and bent sensors have been shown to be fully efficient in test beams. New sensor developments for the ITS3 have shown promising results for fluences even beyond those expected for ITS3.

physics.ins-det↗

arXiv2023

Design and Performance of HV CMOS Sensors for Future Colliders by the RD50 Collaboration

The CERN RD50 collaboration develops depleted monolithic active pixel CMOS sensors for future colliders with the aim of high radiation tolerance, good time resolution, and high granularity pixel detectors. The most recent prototype, the RD50-MPW3, is a 150 nm High Voltage CMOS LFoundry chip that features pixels with a 62 $μ$m pitch that integrate both digital and analog readout electronics inside the sensing diodes. The 64 x 64 pixels on this chip are arranged in 32 double columns and have an optimized periphery for efficient configuration and fast serial data transmission. Post-layout simulations of a single pixel show a power consumption of 22 $μ$W per pixel and 9 ns time walk. The predecessor of this version, the RD50-MPW2, was shown to match simulation results in tests at beam facilities and to have a time resolution of 300 ps both before and after irradiation to a fluence of $Φ_{\mathrm{eq}} = 5\cdot 10^{14}/\mathrm{cm}^2$. This proceeding discusses the design of the latest advanced prototype, the RD50-MPW3, the first results for the RD50-MPW3, and the performance of the RD50-MPW2.

physics.ins-det↗

arXiv2023

Digital Pixel Test Structures implemented in a 65 nm CMOS process

The ALICE ITS3 (Inner Tracking System 3) upgrade project and the CERN EP R&D on monolithic pixel sensors are investigating the feasibility of the Tower Partners Semiconductor Co. 65 nm process for use in the next generation of vertex detectors. The ITS3 aims to employ wafer-scale Monolithic Active Pixel Sensors thinned down to 20 to 40 um and bent to form truly cylindrical half barrels. Among the first critical steps towards the realisation of this detector is to validate the sensor technology through extensive characterisation both in the laboratory and with in-beam measurements. The Digital Pixel Test Structure (DPTS) is one of the prototypes produced in the first sensor submission in this technology and has undergone a systematic measurement campaign whose details are presented in this article. The results confirm the goals of detection efficiency and non-ionising and ionising radiation hardness up to the expected levels for ALICE ITS3 and also demonstrate operation at +20 C and a detection efficiency of 99% for a DPTS irradiated with a dose of $10^{15}$ 1 MeV n$_{\mathrm{eq}}/$cm$^2$. Furthermore, spatial, timing and energy resolutions were measured at various settings and irradiation levels.

physics.ins-det↗

arXiv2021

Proceedings of the second MadAnalysis 5 workshop on LHC recasting in Korea

We document the activities performed during the second MadAnalysis 5 workshop on LHC recasting, that was organised in KIAS (Seoul, Korea) on February 12-20, 2020. We detail the implementation of 12 new ATLAS and CMS searches in the MadAnalysis 5 Public Analysis Database, and the associated validation procedures. Those searches probe the production of extra gauge and scalar/pseudoscalar bosons, supersymmetry, seesaw models and deviations from the Standard Model in four-top production.

hep-ph↗

arXiv2019

Searches for physics beyond the standard model at the LHC

At the Large Hadron Collider (LHC) at the European Organization for Nuclear Research (CERN), protons and heavy ions are accelerated to velocities close to the speed of light and collided in order to study particle interactions and give us an insight to the fundamental laws of nature. The energy and intensity of the particle beams at the LHC are unprecedented, and a tremendous amount of data is collected by three experiments on the circular ring of the LHC that are specialized in proton-proton collisions. The data confirm the most successful theory of particle physics to date known as the standard model of particle physics to very good precision, including the long expected and recently discovered Higgs boson. The standard model cannot, however, accommodate experimentally observed phenomena like gravity, neutrino masses, and dark matter. The theory can also be theoretically unsatisfying as a result of parameters that go unexplained, such as the relatively low value of the Higgs mass despite its large quantum corrections, implying a lack of understanding. For this reason, in addition to precision measurements of standard model observables, experiments search for new physics beyond the standard model that could explain some of the shortcomings of the standard model. A selection of results for searches for new physics beyond the standard model using data recorded by three experiments on the LHC are presented in this talk.

hep-ex↗

arXiv2018

Commissioning and first results from the CMS phase 1 upgrade pixel detector

The phase 1 upgrade of the CMS pixel detector has been designed to maintain the tracking performance at instantaneous luminosities of $2 \times 10^{34} \mathrm{~cm}^{-2} \mathrm{~s}^{-1}$. Both barrel and endcap disk systems now feature one extra layer (4 barrel layers and 3 endcap disks), and a digital readout that provides a large enough bandwidth to read out its 124M pixel channels (87.7 percent more pixels compared to the previous system). The backend control and readout systems have been upgraded accordingly from VME-based to micro-TCA-based ones. The detector is now also equipped with a bi-phase CO$_2$ cooling system that reduces the material budget in the tracking region. The detector has been installed inside CMS at the start of 2017 and is now taking data. These proceedings discuss experiences in the commissioning and operation of the CMS phase 1 pixel detector. The first results from the CMS phase 1 pixel detector with this year's LHC proton-proton collision data are presented. The new pixel detector outperforms the previous one in terms of hit resolution, tracking, and vertex resolution.

physics.ins-det↗

arXiv2018

Proceedings of the first MadAnalysis 5 workshop on LHC recasting in Korea

We present the activities performed during the first MadAnalysis 5 workshop on LHC recasting that has been organized at High 1 (Gangwon privince, Korea) on August 20-27, 2017. This report includes details on the implementation in the MadAnalysis 5 framework of eight ATLAS and CMS analyses, as well as a description of the corresponding validation and the various issues that have been observed.

hep-ph↗

arXiv2018

SModelS v1.1 user manual

SModelS is an automatised tool for the interpretation of simplified model results from the LHC. It allows to decompose models of new physics obeying a Z2 symmetry into simplified model components, and to compare these against a large database of experimental results. The first release of SModelS, v1.0, used only cross section upper limit maps provided by the experimental collaborations. In this new release, v1.1, we extend the functionality of SModelS to efficiency maps. This increases the constraining power of the software, as efficiency maps allow to combine contributions to the same signal region from different simplified models. Other new features of version 1.1 include likelihood and chi-square calculations, extended information on the topology coverage, an extended database of experimental results as well as major speed upgrades for both the code and the database. We describe in detail the concepts and procedures used in SModelS, explaining in particular how upper limits and efficiency map results are dealt with in parallel. Detailed instructions for code usage are also provided.

hep-ph↗

arXiv2015

Limits and Fits from Simplified Models

An important tool for interpreting LHC searches for new physics are simplified models. They are characterized by a small number of parameters and thus often rely on a simplified description of particle production and decay dynamics. We compare the interpretation of current LHC searches for hadronic jets plus missing energy signatures within simplified models with the interpretation within complete supersymmetric and same-spin models of quark partners. We found that the differences between the mass limits derived from a simplified model and from the complete models are moderate given the current LHC sensitivity. We conclude that simplified models provide a reliable tool to interpret the current hadronic jets plus missing energy searches at the LHC in a more model-independent way.

hep-ph↗