The 29th International Workshop on Vertex Detectors

Asia/Tokyo
Vertex2020 will be held virtually
Description

The International Workshop on Vertex Detectors (VERTEX) is a major annual series of international workshops for physicists and engineers from the high energy and nuclear physics community. VERTEX provides an international forum to exchange the experiences and needs of the community, and to review recent, ongoing, and future activities on silicon based vertex detectors. The workshop covers a wide range of topics: existing and future detectors, new developments, radiation hardness, simulation, tracking and vertexing, electronics and triggering, applications to medical and other fields. 

The 29th edition of the series VERTEX2020 will be held on October 5th-8th 2020 virtually by video conferencing. The presentators are required to upload the presentation files in indico beforehand.

Participation to the workshop is open to all. The standard presentations are by invitation only. Short oral presentations (as "poster session") are for open contributinos. Abstracts should be submitted by August 20th.

Participants
  • Abdul Basith Kaliyar
  • Adriano Lai
  • Akimasa Ishikawa
  • Akira Sato
  • Alessandro La Rosa
  • Amanda Simone Krieger
  • Amr Habib
  • Andrey Starodumov
  • Angelo Loi
  • Anjan Giri
  • Anna Macchiolo
  • Anthony Bwembya
  • Aravind Thachayath Sugunan
  • Arturo Rodriguez Rodriguez
  • Bjoern Spruck
  • Carlos Marinas
  • Carsten Niebuhr
  • Chris Parkes
  • Christian Irmler
  • Christian Scharf
  • Christoph Schwanda
  • Clara Nellist
  • Claudia Gemme
  • Cyrille Praz
  • Daniela bortoletto
  • Davide Brundu
  • Dinko Ferencek
  • Domenico Colella
  • Dong Su
  • Duccio Abbaneo
  • Elena Dall'Occo
  • Elisabetta Pianori
  • Erik Brücken
  • Esteban Curras Rivera
  • Federico Siviero
  • Francesco Forti
  • Gagan Mohanty
  • Gian-Franco Dalla Betta
  • Giovanni Calderini
  • Giulia Casarosa
  • Giuliana Rizzo
  • Gourab Saha
  • Grzegorz Deptuch
  • Guillaume Batigne
  • Hans Krüger
  • Hans-Günther Moser
  • Heiko Christian Augustin
  • Heinz Pernegger
  • Hikaru Tanigawa
  • Hiroki Yamauchi
  • Hongtao Yang
  • Hua Ye
  • Huiling Li
  • Ian Shipsey
  • Ignacio Asensi Tortajada
  • Ikuo Kurachi
  • Ivan Vila Alvarez
  • Jan Cedric Honig
  • Jan Hammerich
  • Jens Kroeger
  • Jerome Baudot
  • Jordi Duarte Campderros
  • Katharina Dort
  • Katsuro Nakamura
  • Kazuhiko Hara
  • Kazuyoshi Carvalho Akiba
  • Kevin Heijhoff
  • Klaas Padeken
  • Koji Hara
  • Koji Hara
  • Koji Nakamura
  • Lars Eklund
  • Leena Diehl
  • Lingxin Meng
  • Lopamudra Nayak
  • Manfred Krammer
  • Manuel Franco Sevilla
  • Marco Bomben
  • Maria Golovleva
  • marina artuso
  • Marlon Barbero
  • Marta Tornago
  • Martin van Beuzekom
  • Matias Senger
  • Matteo Milanesio
  • Michael Campbell
  • Michael Moll
  • Michiko Sekimoto
  • Mihail Bogdan Blidaru
  • Miho Yamada
  • Miljenko Suljic
  • N Sushree Ipsita
  • Naim Bora Atlay
  • Nan Lu
  • Oscar Ariel Villarreal
  • Patrick Pangaud
  • Patrick Sieberer
  • Paula Collins
  • Peter Paulitsch
  • Philipp Leitl
  • Prafulla Behera
  • Qingyuan Liu
  • Rahmat Rahmat
  • Ricardo Marco Hernández
  • Richard Brenner
  • Robbert Geertsema
  • Roberta Arcidiacono
  • Sagar Hazra
  • Sagarika Rao Valluri
  • Sebastian Grinstein
  • Seema Bahinipati
  • Shubhangi Maurya
  • Shudhashil Bharthuar
  • Shuji Tanaka
  • Sinuo Zhang
  • Slavomira Stefkova
  • Stella Orfanelli
  • Taohan Li
  • Thomas Bergauer
  • Timon Heim
  • Toru TEST please delete this entry Tsuboyama
  • Toru Tsuboyama
  • Toshinobu Miyoshi
  • Tsutomu Mibe
  • Vagelis Gkougkousis
  • Valentina Sola
  • Venkata Narasimha Manyam
  • Victor Coco
  • Weimin Song
  • Xiaolin Wang
  • Yasuo Arai
  • Yoshiyuki Onuki
  • Yosuke Takubo
  • Yuji Goto
  • Yuma Uematsu
  • Yusuke Uchiyama
  • Yuta Takahashi
    • 20:00 20:15
      welcome
      • 20:00
        Welcome and some notice 15m
        Speaker: Kazuhiko Hara (University of Tsukuba (JP))
    • 20:15 21:45
      Current Detectors I
      Conveners: Paula Collins (CERN), Kazuhiko Hara (University of Tsukuba (JP))
      • 20:15
        [A01] Operational Experience and Performance with the ATLAS Inner Detector at the Large Hadron Collider at CERN 30m

        The Inner Detector in the ATLAS experiment consisting of Pixel, SCT and TRT has been operated successfully with high performance in LHC Run 1 (2010 - 2012) and Run 2 (2015 - 2018). The LHC instantaneous luminosity of pp collisions has been increased during the operation and reached a maximal value of 2.2×1034 cm−2s−1 in 2017, more than twice of LHC design value (1.0×1034 cm−2s−1). Even with such high luminosity, the Inner Detector took physics data with high efficiency, improving the data-taking system and optimizing the operation settings. The Inner Detector was exposed to a radiation dose higher than what has ever been experienced in any other detectors in high energy physics experiments. Effects of radiation damage on silicon sensors and front-end ASICs were intensively studied. In this talk, the operational experience of the Inner Detector in the ATLAS experiment as well as its performance after high radiation dose will be presented.

        Speaker: Yosuke Takubo (High Energy Accelerator Research Organization (JP))
      • 20:45
        [A02] Operational Experience and Performance of the Belle II Pixel Detector 30m

        The Belle II experiment at the super KEK B factory (SuperKEKB) started its physics operation with the full detector setup in March 2019, and it aims at collecting 50ab−1 of e+e− collision data. The vertex detector of Belle II contains a 4-layer silicon vertex detector (SVD) using double sided silicon strips and an inner 2-layer pixel detector (PXD) that is based on the depleted P-channel Field Effect Transistor (DEPFET) technology. The signal generation and amplification are combined in pixels with a minimum pitch of 50µm × 55µm. The sensors are thinned down to 75 µm, and each module has interconnects and ASICs integrated on the sensor with silicon frames for mechanical support. This approach led to a material budget of around 0.2% X0 per layer including the cooling structure in the acceptance region. The PXD has an integration time of around 20µs, a signal-to-noise ratio of around 50 and a detecting efficiency of better than 99%. Its two layers are arranged at the radii of 14mm and 22mm around the interaction point, and a d0 resolution of better than 15µm has been achieved. Due to its close proximity to the beam line and its sensitivity to few-keV photons, the PXD also plays an important role in background studies. In this talk, the operational experience and performance of the PXD measured with the data taken in the first year will be presented.

        Speaker: Qingyuan Liu (DESY)
      • 21:15
        [A03] The Belle II Silicon Vertex Detector: Performance and Operational Experience in the first year of data taking 30m

        In spring 2019 the Belle II experiment at the high luminosity SuperKEKB e+e− collider (KEK, Japan) has resumed operation after the installation of the new vertex detector. Two inner layers of DEPFET-based pixels (PXD) and four layers of double-sided silicon strip detectors (SVD) make up the vertex detector. In the first period of operation SuperKEKB has already reached the record luminosity of 2.4×1034cm−2s−1, which will be increased by about a factor 30 in the coming years.

        Speaker: Giuliana Rizzo (INFN & University - Pisa)
    • 21:45 21:55
      break 10m
    • 21:55 23:25
      Current Detector II
      Conveners: Richard Brenner (Uppsala University (SE)), Toru Tsuboyama (High Energy Accelerator Research Organization)
      • 21:55
        [A04] ALICE ITS upgrade for LHC Run 3: commissioning in the laboratory 30m

        ALICE is the CERN LHC experiment optimised for the study of the strongly interacting matter produced in heavy-ion collisions and devoted to the characterisation of the quark-gluon plasma. To achieve the physics program for LHC Run 3, a major upgrade of the experimental apparatus is ongoing. A key element of the upgrade is the substitution of the Inner Tracking System (ITS) with a completely new silicon-based detector whose features will allow the reconstruction of rare physics channels, not accessible with the previous layout. The enabling technology for such a performance boost is the adoption of custom-designed CMOS MAPS as detecting elements.

        Speaker: Domenico Colella (Wigner Research Centre for Physics (Wigner RCP) (HU))
      • 22:25
        [A05] New silicon trackers for a triggerless LHCb: the Vertex Locator (VELO) and the Upstream Tracker (UT) 30m

        Since 2010, the LHCb experiment at CERN has been accumulating 1--2 fb−1 of pp collision data every year. This b- and c-hadron rich data sample, together with the detector's excellent performance, has allowed LHCb to carry out world leading measurements in the field of flavor physics. However, many of these results will benefit from datasets significantly larger than what the current detector would be able to record in a reasonable amount of time. This challenge is being overcome via a major upgrade of the LHCb detector scheduled to be completed in 2021. With three completely new trackers as well as more powerful electronics, LHCb will be able to read out the collision data at the unprecedented rate of 30 MHz, with all trigger decisions performed at the software level. The data collection is expected to exceed 5 fb−1 a year. This contribution will describe the two new trackers that are based on silicon technology: the Vertex Locator(VELO) and the Upstream Tracker (UT). The new VELO is a hybrid pixel detector with 55×55μm2silicon pixels read out every pp bunch crossing by the VeloPix ASIC. This subdetector will be moved closer to the proton beams, only 3.5~mm apart, to further improve the vertexing precision. The modules are separated from the beam vacuum by a custom-made foil that can now be thinner thanks to a novel milling process and chemical etching. It will withstand a total ionization dose (TID) of about 400 MRad, leading to a bias voltage of 1000~V by the end of its 10-year lifetime. The sensors will be cooled by bi-phase CO2 flowing under the chips via microchannels etched on the silicon substrate. The UT is a new silicon microstrip detector placed between the VELO and the LHCb dipole magnet that will have finer granularity (down to 95 μm pitch close to the beam), improved coverage, and smaller material budget than those of the Tracker Turicens is that it replaces. The UT is composed of four planes of silicon sensors cooled by evaporative CO2 and read out by a dedicated front-end ASIC (SALT). This chip provides pulse shaping, digitization, and digital signal processing including pedestal and common-mode noise subtraction as well as zero-suppression, allowing too for the readout of the charge deposition on the silicon sensors after every pp bunch crossing. In this contribution we will describe these two detectors as well as their current installation and commissioning status.

        Speaker: Manuel Franco Sevilla (University of Maryland (US))
      • 22:55
        [A06] CMS Pixel: New Layer 1 and other Upgrades to the current Tracker during LS2 30m

        The CMS Phase-1 Pixel Detector was successfully operated in 2017 and 2018 of the LHC Run 2. To be ready for Run 3 many updates and improvements are done or will be done in the second long shutdown of the LHC.

        Speaker: Klaas Padeken (Vanderbilt University (US))
    • 23:30 23:55
      Poster I
      Convener: Kazuhiko Hara (University of Tsukuba (JP))
      • 23:30
        [P01] Investigation of nitrogen enriched silicon detectors 5m

        A promising approach to increase the radiation hardness of existing detector designs are defect engineering and the dedicated and controlled enrichment of the silicon bulk with foreign atoms. NitroStrip is a RD50 project with the goal of understanding the effect of nitrogen enrichment on the radiation hardness of high resistivity float zone silicon.
        Previous works suggest an increased radiation hardness for nitrogen enriched silicon, but only bare silicon wafers and simple pad detectors were investigated.
        In the framework of the NitroStrip project fully processed strip detectors with sample groups consisting of oxygen and nitrogen enriched as well as pure float zone silicon and magnetic Czochralski silicon were studied.
        This presentation will give an overview of the findings and challenges the NitroStrip project encountered. We conclude that the treatment of the wafers during the processing of the detectors makes gaining from the Nitrogen enrichment of the Silicon wafers difficult.

        Speaker: Jan Cedric Honig (Albert Ludwigs Universitaet Freiburg (DE))
      • 23:35
        [P02] A Study for Hit-time Reconstruction of Belle II Silicon Vertex Detector 5m

        The Belle II experiment, with a vertex detector installed, started operation in the spring of 2019. The experiment aims to probe new physics beyond the Standard Model by analyzing a large number of generated $\mathrm{B\overline{B}}$-pairs in high-luminosity $\mathrm{e^+e^-}$ collisions at SuperKEKB (KEK, Japan). The Silicon Vertex Detector (SVD) is a part of the vertex detector and is composed of four layers of Double-sided Silicon Strip Detectors (DSSDs), which provide two-dimensional hit position information for the track reconstruction. SVD is crucial for the precise measurement of $\mathrm{B\overline{B}}$ decay vertices and the track reconstruction of low-momentum charged particles.
        During the first year of data taking, SVD has demonstrated very stable and excellent performance. One of the next operational challenges will be the large amount of beam-related background caused by the future high-luminosity operation of SuperKEKB. High hit occupancy from this background decreases the track-finding efficiency and increases the fake-track rate. To reject such background hits, we can use a selection based on hit-time information. We study the hit-time estimation of SVD and achieve 2.4 ns hit-time resolution for $\mathrm{B\overline{B}}$-like events using the signal waveform information of the readout ASIC (APV25) configured to have a shaping-time constant of around 50 ns and a sampling period of 31 ns. This excellent hit-time resolution will be exploited in the future to improve tracking performance in the high-luminosity operation.
        In this presentation, we explain the algorithm to estimate the hit-time and summarize the results of the performance study.

        Speaker: Yuma Uematsu (The University of Tokyo)
      • 23:40
        [P03] Particle identification in Belle II silicon vertex detector 5m

        Particle identification plays an important role in the physics program of the Belle II experiment at the SuperKEKB asymmetric-energy e+e− collider. We have developed a particle identification (PID) framework based on energy loss information in the silicon-strip vertex detector (SVD) for charged pions, kaons, and protons using D∗0→D0[→K−π+]π+ and Λ→pπ− decay samples. The study is based on 6.1fb−1 data recorded near the Υ(4S) resonance by Belle II. The results are compared to those obtained from simulated data. We show that the introduction of additional PID information from the SVD improves the overall PID performance in the low-momentum region.

        Speaker: Sagar Hazra (TIFR Mumbai)
      • 23:45
        [P04] The CLICTD monolithic CMOS sensor 5m

        CLICTD is a monolithic pixel sensor fabricated in a modified 180 nm CMOS imaging process with a small collection electrode design and a high-resistivity epitaxial layer. It features an innovative sub-pixel segmentation scheme and is optimised for fast charge collection and high spatial resolution. The chip was developed to target the requirements for the tracking detector of the proposed future Compact Linear Collider CLIC. Most notably, a temporal resolution of a few nanoseconds and a spatial resolution below 7 microns are demanded. In this contribution, the chip performance measured in beam tests is presented with emphasis on recent studies using assemblies thinned down to 50 microns and inclined particle tracks.

        Speaker: Katharina Dort (Justus-Liebig-Universitaet Giessen (DE))
      • 23:50
        [P05] Development of the thin and fine-pitch silicon strip detector aiming for the Belle II upgrade 5m

        The Belle II experiment has started to consider a possible upgrade leading a higher luminosity than the current design value. Due to a larger beam background and a higher trigger rate expected at the upgraded luminosity, the Belle II silicon strip detector, which measures the vertex position together with the Belle II pixel detector, has to be upgraded as well. Aiming for this upgrade, we are developing a new double-sided silicon strip detector (DSSD) and a new front-end ASIC.
        The DSSD sensor is required to have a thinner thickness and finer strip pitches for better beam background tolerance and better physics-measurement performance. The target thickness of the DSSD sensor is 140um and the dimension is about 53mm x 59mm. The strip pitches are 50um for p-side and 75um for n-side. The mask design of the new DSSD sensor which satisfies those specifications has been completed.
        The front-end ASIC is required to have smaller noise performance and higher trigger capability. The ASIC reads out 128-channel binary hit information with the 127MHz clock frequency. Each readout channel has 2k-depth ring buffer memory to store the hit information until the ASIC receives a trigger signal to output the hit event. The design of the first prototype ASIC, SNAP128A, is almost finalized with 180nm CMOS technology. The size of SNAP128A is about 5.9mm x 6.1mm.
        In this presentation, we report the designs of the developed DSSD sensor and SNAP128A, and simulated performance of SNAP128A. We also present the prospect of the new silicon strip detector development.

        Speaker: Katsuro Nakamura (KEK)
    • 20:00 20:30
      Current Detector III
      Conveners: Prafulla Behera (Indian Institute of Technology Madras (IN)), Akimasa Ishikawa (KEK)
      • 20:00
        [A07] Tracking performance and interaction point properties at the Belle II experiment 30m

        The Belle II experiment is located in Tsukuba, Japan along the SuperKEKB e+e− collider, which achieved in 2020 the world's highest instantaneous luminosity and is aiming to reach in the years to come an instantaneous luminosity of 8×1035cm−2s−1, a value ∼40 times larger than the instantaneous luminosity delivered for the previous experiment (Belle). Compared to Belle, the Belle II experiment also has an improved vertex detector that can be used as a stand-alone tracking device and offers a better impact parameter resolution. This presentation gives a brief overview of the Belle II tracking system and shows a measurement of the impact parameter resolution and of several properties of the interaction point using a selection of e+e−→e+e− and e+e−→μ+μ− events collected in 2019 and 2020 at a centre-of-mass energy of 10.6 GeV.

        Speaker: Cyrille Praz (Deutsches Elektronen-Synchrotron DESY)
    • 20:30 21:30
      Upgrade I
      Conveners: Prafulla Behera (Indian Institute of Technology Madras (IN)), Akimasa Ishikawa (KEK)
      • 20:30
        [B01] Upgrade of the vertex detector of the Belle II experiment 30m

        Authors:
        Jerome Baudot, for the VXD Upgrade R&D Working Group of the Belle II collaboration
        The success of the Belle II experiment relies for a large part on the very high instantaneous luminosity, close to 8x10^35 cm^-2.s^-1, expected from the SuperKEKB collider. The beam conditions to reach such luminosity levels generate a large rate of background particles in the inner detection layers of Belle II, which exceeds by far the rate of particles stemming from elementary collisions. This beam-induced background creates stringent constraints on the vertex detector, in addition to the requirements coming from physics capability.
        After a commissioning phase in 2018, the SuperKEKB machine and Belle II experiment have started full operation in 2019, establishing in 2020 a world record with an instantaneous luminosity of 2.4x10^34 cm^-2.s^-1. The Belle II vertex detector (VXD), made of a combination of DEPFET pixel sensors and Double-Sided Silicon Strip Detectors (DSSD) installed between 1.4 cm and 14 cm in radius, has been operating very satisfactorily. While efforts are still ongoing to mitigate beam-induced backgrounds, current prospects for the related occupancy rates in the VXD layers at full luminosity range between 1 and 6%, and fall close to the acceptable limits of the employed technologies.
        To reach the nominal luminosity parts of SuperKEKB like the final focusing magnets will be modified with a time frame currently predicted to be around 2026. Thus, the Belle II collaboration is considering the possibility to install an upgraded VXD system on the same time scale. Such an upgrade should provide a sufficient safety factor with respect to the background rate expected at the nominal luminosity and possibly enhance performances for tracking and vertexing.

        Several technologies are under consideration for the upgrade. One approach consists in improving performances of the technologies present in Belle II: faster DEPFET sensors for innermost layers, thinner and more granular DSSDs for the remaining layers. New monolithic technologies for pixel sensors are also under discussion, namely SOI and CMOS. They offer a combination of granularity, speed, low material budget and radiation tolerance matching well Belle II requirements and could be exploited to design a fully pixelated VXD, also benefiting from significant developments made in recent years for other experiments.
        Following this last concept, both simplified and complete simulations have been conducted to evaluate tracking and vertexing performances with various geometries (e.g. number of layers, addition of disks) and technical specifications (e.g. granularity, speed).

        This talk will review the context of the proposed VXD upgrade in Belle II, providing some details of the existing technological proposals and discussing performance expectations from simulations.

        Speaker: Jerome Baudot (IPHC - Strasbourg)
      • 21:00
        [B02] Pixelated 3D sensors for tracking in radiation harsh environments 30m

        The High Luminosity upgrade of the CERN Large Hadron Collider (HL-LHC) will be able to reach a peak instantaneous luminosity of 5×1034 cm−2s−1. The innermost detectors of CMS and ATLAS experiments will have to cope with unprecedented requirements on radiation hardness. At the end of the operation period, radiation levels are expected to reach values above 2.6 × 1016 n_eq/cm2. Sensors based on 3D pixel technology, with intrinsic radiation tolerance, are being considered for the innermost layers of the vertex detectors of several HL-LHC experiments. This presentation gives an overview of the ongoing characterization of the pixelated 3D sensor technology, their performance and their current development status for tracking on radiation harsh environments.

        Speaker: Dr Jordi Duarte Campderros (Universidad de Cantabria and CSIC (ES))
    • 21:30 21:40
      break 10m
    • 21:40 23:10
      Upgrade II
      Conveners: Dong Su (SLAC National Accelerator Laboratory (US)), Koji Nakamura (High Energy Accelerator Research Organization (JP))
      • 21:40
        [B03] The upgrade of the CMS Tracker at HL-LHC 30m

        In the high luminosity scenario of the LHC (HL-LHC), which will bring the instantaneous luminosity up to 7.5 x 10^34 cm^−2 s^−1, ATLAS and CMS will need to operate at up to 200 interactions per 25 ns beam crossing time and with up to 4000 fb^-1 of integrated luminosity. To achieve their physics goals the experiments will need to improve the tracking resolution and the ability to selectively trigger on specific physics events at reasonable thresholds. The upgrade of the CMS Tracker requires designing new inner and outer tracking detectors to cope with the increased luminosity and to implement first trigger level functionality. This talk will describe the new layout and the technological choices together with some highlights of research and development activities

        Speaker: Alessandro La Rosa (CERN)
      • 22:10
        [B04] The ATLAS tracker system for HL-LHC 30m

        Claudia Gemme
        The ATLAS experiment is currently preparing for an upgrade of the Inner Tracking for High-Luminosity LHC operation, scheduled to start in 2027. The radiation damage at the maximum integrated luminosity of 4000/fb implies integrated hadron fluencies over 2x10^16 neq/cm2 and tracking in very dense environment call for a replacement of the existing Inner Detector. An all-silicon Inner Tracker (ITk) is proposed with a pixel detector surrounded by a strip detector.

        After the approval of the TDRs by the CERN Research Board, the pre-production readiness phase has started at the institutes involved and the community is now moving in production mode. In this contribution we present the design of the ITk Detector and its expected performance. An overview of the current status of the various detector components, both pixel, strip and the other common items, focusing on the preparation for production, with its more challenging aspects, will be summarized.

        Speaker: Claudia Gemme (INFN Genova (IT))
      • 22:40
        [B05] First test results from the ITkPixV1 pixel readout chip 30m

        The ITkPixV1 readout chip was designed by the RD53 collaboration as the pre-production chip for the ATLAS Inner Tracker (ITk) Pixel detector upgrade and is the successor of the RD53A demonstrator chip. It features a 400x384 pixel array with each pixel being 50um by 50um size. The chip was designed in 65nm CMOS technology and is optimised for the operation as the innermost pixel layer in the ATLAS and CMS detectors at the HL-LHC. ITkPixV1 was submitted in March of 2020 and this presentation will summarise the most recent results from testing to this date. The full verification of the chip needs to occur within a one year time frame, at which point the final ITk pixel production chip, ITkPixV2, will be submitted.

        Speaker: Timon Heim (Lawrence Berkeley National Lab. (US))
    • 23:10 23:40
      Poster II
      Convener: Toru Tsuboyama (High Energy Accelerator Research Organization)
      • 23:10
        [P06] Effect of thermal donors induced in bulk and variation in p-stop dose on the no-gain distance measurements of LGADs 5m

        The Phase-2 upgrade of LHC to HL-LHC by 2027, would increase the number of interactions per bunch crossings (pileup) up to a value of 140-200. To cope with high pileup rates, a precision minimum ionizing particles timing detector(MTD) with a time resolution of∼30-40 ps is proposed by the CMS experiment. An endcap part (1.6<|η|<3) of MIP timing detector (ETL) will be based on low-gain avalanche detector (LGAD) technology.
        The UFSD3.1 production LGADs from Fondazione Bruno Kessler (FBK) include 2x2 pad sensors from three wafers, with different p-stop dose, but identical gain layer with boron doping - equivalent to FBK scale factor of 1.02 (without any carbon co-doping). Two of the wafers with low p-stop dose have thermal donors induced in the bulk. The purpose behind the variation in p-stop doping was to solve the issue of ’pop-corn noise’ that was observed in the previous FBK UFSD3 production batch. Within the individual wafers, the sensors vary with their nominal interpad-gap values. The idea behind these variations within the no-gain region of the sensors is to estimate the optimum nominal interpad-gap value such that the sensors have a high fill-factor (defined as the ratio of the area within the gain region to the area of the total scanning region) and at the same time not undergo an early breakdown.
        The IV and CV measurement of the detectors help us in understanding how a variation in the p-stop dose and thermal donors induced in the bulk of the detector affects the properties of the sensor.
        We have also carried out a comparison study by using IR-laser in Scanning-Transient Current Technique (Scanning-TCT) for the sensors with different interpad designs from the wafers that differ in thermal donors induced within the bulk. Since, the gain is dependent on temperature, we will show how the fill-factor as well as the charge collected in voltage scans varies with temperature (from 25◦C to -25◦C). As a result of these studies, we can get a clear understanding on how the p-stop dose, thermal donor induced in the bulk and the structural design of the no-gain region cumulatively affect the fill-factor of the sensors with temperature.

        Speaker: Shudhashil Bharthuar (Helsinki Institute of Physics (FI))
      • 23:15
        [P07] LPNHE - FBK thin n-on-p pixels for HL-LHC upgrades and beyond 5m

        In view of the LHC upgrade phases towards the High Luminosity LHC (HL-LHC), the ATLAS experiment plans to upgrade the Inner Detector with an all-silicon system.
        The n-on-p silicon technology is a promising candidate to achieve a large area instrumented with
        pixel sensors, since it is radiation hard and cost effective.
        The paper reports on the performance of LPNHE thin n-on-p planar pixel sensors produced at FBK-CMM; the sensors were bump-bonded to the
        RD53A prototype chip, featuring a 50x50 um^2 pixel cell.
        After discussing the sensor technology an overview of 2019-2020 testbeam results of the produced
        devices will be given, before and after irradiation, including cluster
        properties, hit efficiency and space resolution.
        Results for new 50 um thick n-on-p pixel sensors, still produced by LPNHE at FBK-CMM and bump-bonded to the RD53A prototype chip, will be presented too.
        These very thin modules are attractive for detectors at future high luminosity and high energy machines where the lowest possible
        material budget is required to achieve the best tracking and vertexing resolution.

        Speaker: Giovanni Calderini (Centre National de la Recherche Scientifique (FR))
      • 23:20
        [P08] Performance of the 2S Modules of the CMS Phase 2 Tracker in a Test Beam environment 5m

        The present CMS tracker will be replaced by a new improved tracking detector for operation at the High Luminosity LHC (HL-LHC). The outer part of the new tracker will comprise modules with two closely spaced parallel silicon sensors with front-end ASICs capable of transmitting information about high pT tracks to the CMS Level-1 (L1) trigger system at the 40 MHz beam bunch crossing rate. The inclusion of tracking information in the L1 trigger decision will be crucial to select events of interest with high efficiency at the HL-LHC. The three outermost layers of the tracker will be made of strip-strip (2S) sensors and read out by the CMS Binary Chip (CBC) designed to correlate hits on the pair of sensors, forming the so-called track stubs. Three full-sized 2S modules, equipped with the final version of the CBC have been tested in a beam test setup at DESY, Germany. The performance of these prototype 2S modules will be discussed in detail.

        Speaker: Mr Gourab Saha (Saha Institute of Nuclear Physics (IN))
      • 23:25
        [P09] Production, calibration and performance of the layer 1 replacement modules for the CMS pixel detector 5m

        The layer 1 modules of the CMS pixel detector will be substituted with the new ones during long shutdown 2 in 2021. An improved readout chip is used to build these modules. Module production took place in 2019-2020.

        In this poster we describe the module assembly, quality assurance and calibration procedures. Performance of the modules obtained in electrical tests under controlled temperature and humidity as well as under high X-rays irradiation will be presented.

        Speaker: Dinko Ferencek (Rudjer Boskovic Institute (HR))
      • 23:30
        [P10] Efficient Analysis of Test-beam Data with the Corryvreckan software framework 4m

        Future high-energy particle physics experiments pose stringent requirements on the detector technologies. For the next generations of vertex and tracking detectors, a large variety of monolithic as well as hybrid pixel sensors targeting the specific needs of each use-case are developed and tested both in laboratory and test-beam measurement campaigns. Corryvreckan is a flexible, fast and lightweight test-beam data reconstruction and analysis framework based on a modular concept of the reconstruction chain. It is designed to fulfil the requirements for offline event building in complex data-taking environments combining detectors with different readout architectures, but is also capable of online monitoring during data taking. Initially created within the CLICdp collaboration, it is supported by a growing user and developer community from various experiments. Its modular structure allows for a separation between the framework core and the implementation of the algorithms in each module. This allows users to ‘plug-in’ the wanted modules and configure their parameters easily from one configuration file. With its extensive manual and available tutorials, it is user-friendly and allows to get started quickly with a new analysis. This contribution gives an overview of the Corryvreckan software project, focussing on available features. This is supplemented by example use cases based on recent data-taking campaigns at the DESY test-beam facility.

        Speaker: Jens Kroeger (Ruprecht Karls Universitaet Heidelberg (DE))
    • 20:00 22:00
      Monolithic I
      Conveners: Daniela Bortoletto (University of Oxford (GB)), Toshinobu Miyoshi (KEK)
      • 20:00
        [C01] R&D status of monolithic SOI pixel sensor for vertex detector 30m

        SOI wafer consists of high-resistive handle wafer and CMOS LSI circuit layer, and these two layers are isolated by Silicon oxide layer. The handle wafer corresponds to radiation sensor.
        Produced charges in the sensor are readout through a tungsten via to the circuit. Sensor thickness can be changed from 500 to 50 um according to application. It satisfy both of a complex circuit implementation in a small size pixel since there is no mechanical bonding like hybrid type silicon detector. Recent high-luminosity collider experiments propose to reconstruct vertices with a few micrometer resolution in high background environment. 3D stacking SOI pixel detector offers high spatial resolution and high functional signal processing circuit by extending circuit area three dimensionally. Prototype pixel sensor for the ILC vertex detector, SOFIST4, has 20x20 um pixel and it expect to perform 3 um of position resolution. We have already obtained 90Sr beta-ray tracks image and hits of 120 GeV proton beam by SOFIST4. Recent results of beam test with 120 GeV proton beam at Fermilab will be shown in this presentation. Conceptual design of pixel detector, DuTip (Dual Timer pixel), for the Belle II upgrade vertex detector will be also presented. Feature of DuTip is that has dual timers (two down counters) in a pixel to store hits and wait for trigger decision during trigger latency. Signal is readout as collision of current (next/previous) timing if the counter is consistent with trigger signal timing.

        Speaker: Miho Yamada (TMCIT)
      • 20:30
        [C02] Latest depleted CMOS sensor developments in the CERN RD50 collaboration 30m

        Depleted Monolithic Active Pixel Sensors (DMAPS) using commercial CMOS and High-Voltage CMOS (HV-CMOS) processes are one of the main candidate technologies for future tracking detectors in high luminosity colliders. Its capability of integrating the sensing diode into the CMOS wafer hosting the front-end electronics allows for reduced noise and higher signal sensitivity. They are suitable for high radiation environments due to the possibility of applying high depletion voltage and the availability of relatively high resistivity substrates. The use of a CMOS commercial fabrication process leads to their cost reduction and allows faster construction of large area detectors. Despite the advantages and good performance demonstrated by DMAPS, these sensors still require further research to improve their time resolution and radiation tolerance to cope with the challenging environment of future particle physics experiments. In this context, the study and development of DMAPS is one of the priorities of the CERN-RD50 collaboration.

        Speakers: Ricardo Marco Hernandez (Instituto de Fisica Corpuscular (ES)), Dr Ricardo Marco Hernandez (CERN)
      • 21:00
        [C03] Latest developments and results of radiation tolerance CMOS sensors with small collection electrodes 30m

        The development of radiation hard Depleted Monolithic Active Pixel Sensors (DMAPS) targets the replacement of hybrid pixel detectors to meet radiation hardness requirements of at least 1.5E16 1 MeV neq/cm2 for the HL-LHC and beyond.

        DMAPS were designed and tested in the TJ180nm TowerJazz CMOS imaging technology with small electrodes pixel designs. This technology reduces costs and provides granularity of 36.4x36.4μm2 with low power operation (1 uW / pixel), low noise of ENC<20e- , a small collection electrode (3 um) and fast signal response within 25 ns bunch crossing.

        This contribution will present the latest developments after the MALTA and Mini-MALTA sensors. It will illustrate the improvements and results of the Czochralski substrate with a bigger depletion zone to improve efficiency. It will also present the plans for MALTA 2, which will be produced in late 2020, with enlarged transistors to reduce noise and cascoded front-end corrected slow control to improve chip operation.

        Speaker: Ignacio Asensi Tortajada (Univ. of Valencia and CSIC (ES))
      • 21:30
        [C04] Depleted Monolithic Active Pixel Sensors in LFoundry 150 nm and TowerJazz 180 nm CMOS technologies: The Monopix developments 30m

        Depleted CMOS Active Pixel Sensors (DMAPS) provide interesting solutions in environments where timing precision and radiation tolerance are needed, by achieving a sizable fully depleted sensitive layer with strong drift field. They also have the advantage of using commercial processes and do not need hybridization, which eases production at relatively low cost. Developments have recently followed several lines and concepts, and the focus of this talk will be DMAPS Monopix developments in two technologies, LFoundry 150 nm CMOS and TowerJazz 180 nm CMOS processes.

        The development of DMAPS in LFoundry 150 nm relies on using a large collection electrode to achieve a depleted sensitive layer by combining high resistive substrate (> 2 kΩ.cm) as sensitive layer and high bias voltage (> 200 V). Its sensor structure mimics the standard planar sensor, and it incorporates a large-area implant as the collection node, thus is an intrinsically radiation-hard structure with uniform drifting field. The in-pixel electronics is integrated in the collection well thanks to the multiple nested wells offered by the foundry.

        The TowerJazz development line uses a small collection well, and the resulting sensor capacitance can be as small as ~ 5 fF, a value typically at least an order of magnitude smaller than in the case of the large electrode design. A major benefit of small sensor capacitance is the possibility to employ a very low power analog front-end design (~ 1 µW/pixel) yet keep a low electronic noise value. In order to achieve a fully depleted sensitive layer, together with enhanced lateral collection field, dedicated process modifications are needed in this process.

        This talk will focus on large scale demonstrators fabricated in the two processes, named LF-Monopix and TJ-Monopix, both using a synchronous architecture based on column drain as was utilized in the FE-I3 pixel chip currently used in the ATLAS pixel detector. Characterization results will be given, in particular for what concerns the behavior of the chips in both technologies after irradiation. A new design has recently been submitted (LF-Monopix2) / is about to be submitted (TJ-Monopix2) and a focus will be brought to the design of these new prototypes.

        Speaker: Marlon B. Barbero (CPPM, Aix-Marseille Université, CNRS/IN2P3 (FR))
    • 22:00 23:59
      Monolithic II
      Conveners: Lars Eklund (University of Glasgow (GB)), Koji Hara (KEK)
      • 22:00
        [C05] Muon Forward Tracker: a new ALICE upgrade at forward rapidities for LHC Run 3 30m

        During Runs 1 and 2, the ALICE Muon Spectrometer has produced many results at forward pseudorapidities (2.5<η<4) mainly on quarkonia and open heavy flavours. Nevertheless, the frontal absorber of the spectrometer prevents the separation of charm and beauty contributions to these observables. To remove this limitation, the Muon Forward Tracker (MFT), a new tracker with high spatial resolution, will be installed between the interaction point and the frontal absorber. The MFT is composed of 936 pixel sensors of high performances (ALPIDE), also used for the new ALICE inner tracking system. Covering almost the full acceptance of the muon spectrometer, the sensors are placed on both sides of 5 vertically positioned disks made of composite materials which are surrounding the beam pipe.
        This contribution will review the design of the MFT and its specific developments. While its commissioning is on-going at CERN, the status of the MFT before installation in the experiment will also be reported.

        Speaker: Guillaume Batigne (Centre National de la Recherche Scientifique (FR))
      • 22:30
        [C06] Smart Three-Dimensional (3D) Chip Stacking Process for Detectors using High Energy Physics Experiments 30m

        Authors:
        Ikuo Kurachi, Toru Tsuboyama, Makoto Motoyoshi, Miho Yamada, Kazuhiko Hara, Yasuo Arai
        Smart and unique three-dimensional (3D) chip stacking process is proposed for detectors using high energy physics experiments. In this process, chip-on-chip scheme with base chips fabricated by silicon-on-insulator (SOI) technology is considered instead of wafer-on-wafer or chip-on-wafer schemes because of process feasibility even for shuttle run die. Unique 3 um Au micro bump formation called as Au cylinder bump has developed and newly introduced to connect electrically between the chips with less planarization process of the chips. Low via resistance of around 0.35 Ω/via was obtained. Submicron through buried oxide via (TBV) which is fabricated in wafer processing of SOI chips are used as via between the upper chip and bonding pads to etch off handle wafer silicon of the upper chip instead of generally used through silicon via (TSV). The detector was fabricated by using this 3D process in pixel. The beta-lay tracking from 90Sr was successfully observed. More than 99% via yield was also confirmed.

        Speaker: Ikuo Kurachi (High Energy Accelerator Research Organization)
      • 23:00
        [C07] The novel ALICE Inner Tracking System based on truly cylindrical, wafer-scale Monolithic Active Pixel Sensors 30m

        ALICE is planning to replace its innermost tracking layers during the LHC Long Shutdown 3 with a novel detector that will be as close as 18 mm to the interaction point and will have a target thickness of below 0.05 %X0 per layer. To achieve these figures, a wafer-scale Monolithic Active Pixel Sensor in 65 nm technology is being developed. The sensors, fabricated on 300 mm wafers, will reach dimensions of up to 280 mm × 94 mm. They will subsequently be thinned down to values between 20-40 μm, where they become flexible and are bent into truly cylindrical half-barrels.

        This contribution will review the detector concept and will lay out the R&D path. Most importantly, first results from laboratory and beam tests with bent sensors will be presented.

        Speaker: Miljenko Suljic (CERN)
      • 23:30
        [C08] MuPix10: First Results from the Final Design 29m

        Many years of research and development of High Voltage Monolithic Active Pixel Sensors (HVMAPS) have culminated in the final design for the Mu3e pixel detector.
        MuPix10 is a fully monolithic sensor with an active pixel matrix size of 20×20mm2 produced in the 180nm HV-CMOS process at TSI Semiconductors. The pixel size is 80×80μm2. Hits are read out using a column drain architecture and sent over up to four serial links with up to 1.6Gbit/s each.
        By means of DC/DC converters and exclusive usage of on-chip biasing, MuPix10 is fully operable with a minimal set of electrical connections. This is an integral requirement by the Mu3e experiment since it enables the construction of ultra-thin pixel modules with 1 permil radiation length per
        layer. In this talk first results from lab characterisation and testbeam campaigns are presented.

        Speaker: Heiko Christian Augustin (Ruprecht Karls Universitaet Heidelberg (DE))
    • 20:00 22:00
      Timing Detector I
      Conveners: Hans-Gunther Moser (Max-Planck-Institut fur Physik (DE)), Yoshiyuki Onuki
      • 20:00
        [D01] Precision Timing with the CMS MTD Endcap Timing Layer for HL-LHC 30m

        The CMS MIP Timing Detector (MTD) is designed to provide precision timing information, with resolution of ~40 ps per layer for charged particles, with hermetic coverage up to a pseudo-rapidity of |η|=3. The endcap region of the MTD, called the Endcap Timing Layer (ETL), will be instrumented with silicon-based low gain avalanche detectors (LGADs), covering the high radiation pseudo-rapidity region between |η|=1.6 and 3.0. We will provide an overview of the ETL design and present recent results from the R&D and test beam studies of the LGAD and the readout ASIC performance.

        Speaker: Valentina Sola (Universita e INFN Torino (IT))
      • 20:30
        [D02] A High-Granularity Timing Detector for the Phase-II upgrade of the ATLAS Calorimeter system: detector concept, description and R&D and beam test results 30m

        The increase of the particle flux (pile-up) at the HL-LHC with luminosities of L ≃ 7.5 × 1034 cm−2s−1 will have a severe impact on the ATLAS detector reconstruction and trigger performance. The end-cap and forward region where the liquid Argon calorimeter has coarser granularity and the inner tracker has poorer longitudinal vertex position resolution will be particularly affected. A High Granularity Timing Detector (HGTD) is proposed in front of the LAr end-cap calorimeters for pile-up mitigation and for luminosity measurement.

        The HGTD will cover the pseudo-rapidity range from 2.4 to 4.0. Two Silicon sensors double sided layers will provide precision timing information for MIPs with a resolution better than 30 ps per track in order to assign each particle to the correct vertex. Readout cells have a size of 1.3 mm × 1.3 mm, leading to a highly granular detector with 3 millions of channels. Low Gain Avalanche Detectors (LGAD) technology has been chosen as it provides enough gain to reach the large signal over noise ratio needed. A dedicated ASIC is being developed and some prototypes have been already submitted and measured.

        The requirements and overall specifications of the HGTD will be discussed. LGAD R&D campaigns are carried out to study the sensors, the related ASICs, and the radiation hardness. Laboratory and test beam results will be presented.

        Speaker: Sebastian Grinstein (IFAE - Barcelona (ES))
      • 21:00
        [D03] 3D-trench Silicon Pixels with 20ps timing resolution 30m

        The increase in instantaneous luminosity at the HL-LHC experiments will have a severe impact on event reconstruction. Original tracking capabilities could however be restored by measuring tracks with picosecond precision. Within the INFN-TIMESPOT initiative we are developing innovative 3D pixels with the aim to build a demo mini-tracker using 55µm x 55µm silicon pixels with a required time resolution of better than 50ps per hit. The 3D technology allows a new approach to timing with respect to traditional planar approaches and can push time resolution performance without affecting the radiation resistance of the devices. The first production batch of sensors was produced in 2019 by FBK in Trento, Italy. Different structures, designed on the basis of different electrodes geometries, were tested in 2019 and 2020. A high-density trench-type pixel layout was found to be particularly interesting from the point of view of timing performances. In this seminar results on the sensor time resolution measured both in the laboratory with an infrared pulsed laser and a beta source and with charged hadrons at the PSI πM1 beamline in October 2019 will be presented. In all tests, time resolutions around 20 ps per hit have been measured, showing also that the performance obtained can be further improved, being still limited by the front-end electronics used.

        Speaker: Adriano Lai (Universita e INFN, Cagliari (IT))
      • 21:30
        [D04] Vertex detector for LHCb Upgrade II 30m

        LHCb has recently submitted a document describing the physics case for
        Upgrade II of the detector to begin operation in 2031.
        The Upgrade II of LHCb is planned to run at an
        instantaneous luminosity of 2×1034 cm−2s−1, an order of
        magnitude above that of Upgrade I, which will be commissioned in 2021.
        The goal of Upgrade II is to accumulate a sample of at least 300 fb−1 in about 5 years.
        At this luminosity the mean number of interactions per crossing will be 56,
        producing around 2500 charged particles within the LHCb acceptance every bunch crossing.
        To meet this challenge it is foreseen to modify the existing spectrometer, exploiting precision timing in the event reconstruction.

        The LHCb upgrade physics programme relies in particular on an efficient
        and precise vertex detector (VELO). The higher luminosity poses significant
        challenges and require the construction of a new VELO with enhanced
        capabilities. Compared to Upgrade I there will be an order of magnitude
        increase in data output rate and hence also an order of magnitude increases in
        radiation levels, giving a lifetime fluence of nearly 1×1017 1 MeV neqcm−2.

        Similarly to Upgrade I, the next detector generation will not have a trigger at
        the hardware level, and event selection will be done by complete event
        reconstruction in real time in a CPU farm. To cope with the large increase in
        pile-up, new techniques to efficiently assign each b-hadron to the primary
        vertex from which it originates are needed.
        Therefore a new hybrid pixel detector with enhanced rate and timing
        capabilities in the ASIC and sensor will be developed.

        The most promising technologies to be used for this future HL-LHCb upgrade will
        be presented, with emphasis on the timing precision as a tool for vertexing in
        the next generation detectors. The most recent results from beam tests,
        focussing on time measurements, will be shown together with possible R&D
        scenarios for the future upgrade.

        Speaker: Martin Van Beuzekom (Nikhef National institute for subatomic physics (NL))
    • 22:00 23:30
      Timing Detector II
      Conveners: Ivan Vila Alvarez (Instituto de Física de Cantabria (CSIC-UC)), Tsutomu Mibe (KEK)
      • 22:00
        [D05] The Timepix family of pixel detector readout chips 30m

        The Timepix family of pixel detector readout chips was started in 2005 following the request of colleagues from the EUDet Collaboration to provide timestamp information pixel-by-pixel on an adapted version of the Medipix2 photon counting readout chip. The family now includes Timepix2, Timepix3 and Timepix4. Timepix2 provides both arrival time and amplitude information using a frame-based readout with a sophisticated shutter functionality overcoming many of the limitations of the predecessor Timepix chip. In Timepix3 a data driven readout was implemented for the first time and the bin of the timestamp is reduced to 1.6ns. In Timepix4the timestamp bin is further reduced to 200ps, the chip area is increased and the chip is designed to be tiled on 4 sides permitting a large area to be covered for the first time. The presentation will review the features and performance of these chips and highlight some original applications.

        Speakers: Michael Campbell (NPL), Michael Campbell (CERN)
      • 22:30
        [D06] Low Gain Avalanche Detectors for 4-dimensional tracking applications in severe radiation environments 30m

        For the High Luminosity upgrade of the CERN Large Hadron Collider (HL-LHC), the collider will reach a peak instantaneous luminosity of 5x1034 cm-2s-1, with a total integrated luminosity of 3000 fb-1 after around 12 years of expected life time. The pile-up during the p+p+ collisions is expected to reach values of ~ 200 and the experiments are expected to be exposed to a radiation levels up to 1.6x1016 neq/cm2 at the innermost layers of the detectors.

        Speaker: Esteban Curras Rivera (CERN)
      • 23:00
        [D07] First prototype of finely segmented HPK AC-LGAD detectors 30m

        Abstract : The presentation describes the development of silicon detector for high energy particle physics experiment, focusing on the detectors that combine fast timing capabilities with fine spatial resolution. The Low Gain Avalanche Detector(LGAD) technology developed by HPK achieved 30 ps time resolution with larger (~ millimeter scale) pad type electrode detectors. To have spatial resolution with high fill factor, development of LGAD detectors with AC-coupled electrode (AC-LGAD) is carried out at KEK/Tsukuba and Hamamatsu Photonics (HPK). In this talk, first prototype performance of finely Stripped/Pixelated AC-LGAD detectors will be presented.

        Speaker: Koji Nakamura (High Energy Accelerator Research Organization (JP))
    • 23:30 23:59
      Workshop Closing
      Convener: Kazuhiko Hara (University of Tsukuba (JP))
      • 23:30
        Instrumentation the great enabler & ICFA Instrumentation Innovation and Development Panel Report 29m
        Speakers: Ian Shipsey (University of Oxford (GB)), Kazuhiko Hara (University of Tsukuba (JP))