ALICE (A Large Ion Collider Experiment) at the LHC is designed for studies of nuclear matter at extreme temperatures and energy densities, so called Quark-Gluon Plasma (QGP). Two detectors for measurements of electromagnetic signals, high-granularity photon spectrometer PHOS and large acceptance electromagnetic calorimeter EMCal/DCal, are incorporated into the ALICE apparatus. In order to enhance the data sample of the high-energy part of the spectra, a dedicated triggers on high energetic photons or jets are used. High precision measurements of neutral mesons require fine energy and timing calibrations. Photon signal purity is improved using dedicated photon PID criteria based on cluster shape and anti-track matching with the ALICE central tracking system, as well as a special detector located in front of PHOS called CPV. PHOS and EMCal participated in LHC Run 1 (2009-2013) and Run 2 (2015-2018) during data taking periods of pp, p-Pb and Pb-Pb collisions. We give an overview of their performance in Runs 1 and 2 in low and high multiplicity environments as well as the upgrade plans for future LHC runs.
The high flux of charged particles interacting with the CMS Forward Hadron Calorimeter PMT windows introduced a significant background for the trigger and offline data analysis. During Long Shutdown 1, all of the original PMTs were replaced with multi-anode, thin window photomultiplier tubes. At the same time, the back-end electronic readout system was upgraded to μTCA readout. The experience with commissioning and calibration of the Forward Hadron Calorimeter is described as well as the μTCA system. The upgrade was successful and provided quality data for Run 2 data-analysis at 13 TeV.
The ALICE experiment at LHC studies the strong interaction sector of the Standard Model with pp, pA and AA collisions. Within the scope of the physics program, measurements of photons, neutral mesons and jets in ALICE are performed by two electromagnetic calorimeters. Precise and high-granularity photon spectrometer (PHOS) composed of lead-tungstate crystals, along with a wide-aperture lead-scintillator sampling calorimeter (EMCal) provide complementary measurements of photon observables in a wide kinematic range. The calorimeter trigger system allows the experiment to utilize efficiently the …
A radiation-hard quad-channel 12-bit 40 MSPS pipeline analog-to-digital converter (ADC) has been designed for the trigger readout electronics Phase-I upgrade of the ATLAS Liquid Argon calorimeter, at the CERN Large Hadron Collider. The final version of the custom design, fabricated in a commercial 130 nm CMOS process, is presented and found to meet the system requirements for analog performance and radiation tolerance. The procedure for quality control of 17200 ADCs is described and the results are presented.
The PreProcessor of the ATLAS Level-1 Calorimeter Trigger prepares the analogue trigger signals sent from the ATLAS calorimeters by digitising, synchronising, and calibrating them to reconstruct transverse energy deposits, which are then used in further processing to identify event features. During the first long shutdown of the LHC from 2013 to 2014, the central components of the PreProcessor, the Multichip Modules, were replaced by upgraded versions that feature modern ADC and FPGA technology to ensure optimal performance in the high pile-up environment of LHC Run 2. This paper describes the…
The ATLAS detector is set to undergo a substantial upgrade termed the "Phase-II" upgrade during the Long-Shutdown in preparation for the start of operation of the High Luminosity Large Hadron Collider (HL-LHC). This paper describes the development and implementation of the Phase-II upgrade low voltage power supply transformer-coupled buck converter (Brick) test bench. A large scale production of approximately 2048 finger low voltage power supplies, with an identical output voltage, is set to be undertaken in the year 2022. This production will culminate in the complete replacement of the LVPS …
An optical link system is being developed for the ATLAS Liquid Argon Calorimeter Phase-II upgrade. The optical link system is responsible for transmit the data of over 182 thousand detector channels from 1524 Front-End Boards (FEBs) through 26 optical fibers per FEB over 150 meters to the counting room and brings clocks, bunch crossing reset signals and slow control/monitoring signals back to the FEBs. The optical link system is based on the Low-Power GigaBit Transceivers (lpGBTs) and the Versatile optical Transceiver (VTRx+) modules, which both are being developed for the High-Luminosity LHC …
The Tile Calorimeter (TileCal) is the central hadronic calorimeter of the ATLAS experiment at the Large Hadron Collider (LHC). The LHC is scheduled to undergo a major upgrade, in 2022, for the High Luminosity LHC (HL-LHC). The ATLAS upgrade program for high luminosity is split into three phases: Phase-0 occurred during $2013-2014$ and prepared the LHC for Run 2; Phase-I, foreseen for 2019, will prepare the LHC for Run 3, whereafter the peak luminosity reaches $2-3 \times 10^{34}$ cm$^{2}s^{-1}$; finally, Phase-II, which is foreseen for 2024, will prepare the collider for the HL-LHC operation (…
The ATLAS hadronic Tile Calorimeter will undergo major upgrades to the on- and off-detector electronics in preparation for the High Luminosity program of the Large Hadron Collider (HL-LHC) in 2026, so that the system can cope with the HL-LHC increased radiation levels and out-of-time pileup. The on-detector electronics of the upgraded system will continuously digitize and transmit all photo-multiplier signals to the off-detector systems at a 40 MHz rate. The off-detector electronics will store the data in pipeline buffers, produce digital hadronic tower sums for the ATLAS Level-0 trigger syste…
CMS-HF Calorimeters have been undergoing a major upgrade for the last couple of years to alleviate the problems encountered during Run I, especially in the PMT and the readout systems. In this poster, the problems caused by the old PMTs installed in the detectors and their solutions will be explained. Initially, regular PMTs with thicker windows, causing large Cherenkov radiation, were used. Instead of the light coming through the fibers from the detector, stray muons passing through the PMT itself produce Cherenkov radiation in the PMT window, resulting in erroneously large signals. Usually, …
HybridMC: a fast detailed simulation framework for optical calorimeter technologies at the LHCb ECAL Upgrade II
Università degli Studi di Milano-Bicocca（米兰比可卡大学）；CERN（欧洲核子研究中心）；Peking University（北京大学）；INFN Sezione di Bologna（意大利国家核物理研究所博洛尼部分所）；Karlsruhe Institute of Technology（卡尔斯鲁厄理工学院）
A Radiation-Hard Dual Channel 4-bit Pipeline for a 12-bit 40 MS/s ADC Prototype with extended Dynamic Range for the ATLAS Liquid Argon Calorimeter Readout Electronics Upgrade at the CERN LHC
The Tile Calorimeter (TileCal) is the hadronic calorimeter covering the central region of the ATLAS detector at the LHC. It is a sampling calorimeter consisting of alternating thin steel plates and scintillating tiles. Wavelength shifting fibers coupled to the tiles collect the produced light and are read out by photomultiplier tubes. Currently, an analog sum of the processed signal of several photomultipliers serves as input to the first level of trigger. Photomultiplier signals are then digitized and stored on detector and are only transferred off detector once the first trigger acceptance h…
The High Luminosity Large Hadron Collider (HL-LHC) will have a peak luminosity of $5\times10^{34} $cm$^{-2} $\,s$^{-1}$, five times higher than the design luminosity of the LHC. The hadronic ATLAS Tile Calorimeter TileCal) is a sampling calorimeter with steel as absorber and plastic scintillators as active medium. The light produced in the scintillating tiles is guided to photomultiplier tubes (PMTs), where analogue signals are produced to be shaped and conditioned before being digitized every 25\,ns. TileCal Phase-II Upgrade for the HL-LHC will allow the system can cope with the increased rad…
For Run 4, ALICE is pioneering the construction of truly cylindrical tracking layers, which will improve the measurements of heavy-flavour hadrons and dielectrons. In addition, a Forward Calorimeter (FoCal) for the measurement of direct photons is being developed to access the gluon distributions of nucleons and nuclei at low $x$. For Run 5 and beyond, ALICE 3 is proposed. It combines a unique high-resolution vertex detector with a silicon pixel tracker and modern particle identification solutions over a large acceptance. This will permit heavy-flavour and dielectron measurements with unpreced…
ALICE (A Large Ion Collider Experiment) is the CERN LHC experiment optimized for the study of the strongly interacting matter produced in heavy-ion collisions and devoted to the characterization of the Quark-Gluon Plasma. To achieve the physics program for LHC Run 3 and 4, ALICE is undergoing a major upgrade of the experimental apparatus during the ongoing second long LHC shutdown. A key element of the ALICE 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 which coul…
The CMS Collaboration is preparing to build replacement endcap calorimeters for the HL-LHC era. The new high-granularity calorimeter (HGCAL) is, as the name implies, a highly-granular sampling calorimeter with approximately six million silicon sensor channels (approx. 1.1cm2 or 0.5cm2 cells) and about 250 thousand channels of scintillator tiles readout with on-tile silicon photomultipliers. The calorimeter is designed to operate in the harsh radiation environment at the HL-LHC, where the average number of interactions per bunch crossing is expected to exceed 140. Besides measuring energy and p…
A Large Ion Collider Experiment (ALICE) is built to study the properties of the strongly interacting matter created in heavy-ion collisions at the LHC. With the upgrade of its Inner Tracking System (ITS), the ALICE experiment is going to increase the rate of data taking by almost two orders of magnitude. At the same time, the precision of secondary vertex reconstruction will become by at least a factor 3 better than it currently is. In this talk, we briefly show some selected physics results motivating the upgrade of the ITS, describe the design goals and the layout of the new detector, and hi…
National Research University Higher School of Economics（国家研究型高等经济大学）；The Yandex School of Data Analysis（Yandex数据分析学院）
In this paper, we discuss the way advanced machine learning techniques allow physicists to perform in-depth studies of the realistic operating modes of the detectors during the stage of their design. Proposed approach can be applied to both design concept (CDR) and technical design (TDR) phases of future detectors and existing detectors if upgraded. The machine learning approaches may speed up the verification of the possible detector configurations and will automate the entire detector R\&D, which is often accompanied by a large number of scattered studies. We present the approach of using ma…
The increased particle flux at the high luminosity phase of the Large Hadron Collider (HL-LHC), with instantaneous luminosities of up to 7.5 times the original design value, will have an impact on many sub-systems of the ATLAS detector. This contribution highlights the particular impacts on the ATLAS liquid argon calorimeter system, together with an overview of the various upgrade plans leading up to the HL-LHC. The higher luminosities are of particular importance for the forward calorimeters (FCal), where the expected increase in the ionization load poses a number of problems that can degrade…
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 adoptio…
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 (ITS 2) 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 …
The electromagnetic ealorimeter (ECAL) of the CMS detector has played an important role in the physics program of the experiment, delivering outstanding performance throughout data taking. The High-Luminosity LHC will pose new challenges. The four to five-fold increase of the number of interactions per bunch crossing will require superior time resolution and noise rejection capabilities. For these reasons the electronics readout has been completely redesigned. A dual gain trans-impedance amplifier and an ASIC providing two 160 MHz ADC channels, gain selection, and data compression will be used…
The CMS Level-1 calorimeter trigger is being upgraded in two stages to maintain performance as the LHC increases pile-up and instantaneous luminosity in its second run. In the first stage, improved algorithms including event-by-event pile-up corrections are used. New algorithms for heavy ion running have also been developed. In the second stage, higher granularity inputs and a time-multiplexed approach allow for improved position and energy resolution. Data processing in both stages of the upgrade is performed with new, Xilinx Virtex-7 based AMC cards.
ALICE (A Large Ion Collider Experiment) experiment at CERN LHC is designed to study the properties of the Quark-Gluon Plasma (QGP) in heavy-ion collisions. In 2019-2020 the upgrade of CERN LHC will increase the luminosity and the collision rate beyond the design parameters of the current ALICE setup. To be able to benefit from the improved performance of the LHC, ALICE will upgrade several of its key detector systems including the Fast Interaction Trigger (FIT) [2]. FIT is designed to provide the functionality of the old forward detectors while retaining or even improving their performance. It…
Between 2025 and 2027, some essential components of the CMS (Compact Muon Solenoid) detector - most notably the tracker and the calorimeter endcap - will be upgraded to prepare for HL-LHC (High Luminosity Large Hadron Collider) conditions. The upgraded CMS Outer Tracker and parts of the new CMS High Granularity Calorimeter (HGCAL) will encompass over $50{,}000$ new silicon sensors covering a total area of about $800\,\text{m}^{2}$. The sensor series production requires a dedicated strategy to monitor the quality and stability of the production process. The strategy is based on a test structure…
The Tile PreProcessor (TilePPr) is the core element of the Tile Calorimeter (TileCal) off-detector electronics for High-luminosity Large Hadron Collider (HL-LHC). The TilePPr comprises FPGA-based boards to operate and read out the TileCal on-detector electronics. The Tile Computer on Module (TileCoM) mezzanine is embedded within TilePPr to carry out three main functionalities. These include remote configuration of on-detector electronics and TilePPr FPGAs, interface the TilePPr with the ATLAS Trigger and Data Acquisition (TDAQ) system, and interfacing the TilePPr with the ATLAS Detector Contro…
The ALICE (A Large Ion Collider Experiment) experiment at the Large Hadron Collider (LHC) at CERN is dedicated to heavy ion physics to explore the structure of strongly interacting matter. The Time Projection Chamber (TPC) of ALICE is a tracking detector located in the central region of the experiment. It offers excellent tracking capabilities as well as particle identification. After the second long shutdown (LS2) the LHC will run at substantially higher luminosities. To be able to increase the data acquisition rate by a factor of 100, the ALICE TPC experiment has to replace the Multi-Wire Pr…
A large Time Projection Chamber (TPC) is the main device for tracking and charged-particle identification in the ALICE experiment at the CERN LHC. After the second long shutdown in 2019-2020, the LHC will deliver Pb beams colliding at an interaction rate up to 50 kHz, which is about a factor of 100 above the present read-out rate of the TPC. To fully exploit the LHC potential the TPC will be upgraded based on the Gas Electron Multiplier (GEM) technology. A prototype of an ALICE TPC Outer Read-Out Chamber (OROC) was equipped with twelve large-size GEM foils as amplification stage to demonstrate…
The Inner Tracking System (ITS) of the ALICE experiment will be upgraded during the second long LHC shutdown in $\mathrm{2019}-\mathrm{2020}$. The main goal of the ALICE ITS Upgrade is to enable high precision measurements of low - momentum particles (< 1 GeV/c) by acquiring a large sample of events, benefiting from the increase of the LHC instantaneous luminosity of $\mathrm{Pb}-\mathrm{Pb}$ collisions to $\mathcal{L} = 6 \cdot 10^{27} cm^{-2} s^{-1} $ during Run 3. Working in this direction the ITS upgrade project is focusing on the increase of the readout rate, on the improvement of the imp…
ATLAS LAr calorimeter will perform its Phase-I upgrade during the long shut down (LS2) in 2018, a new LAr Trigger Digitizer Board (LTDB) will be designed and installed. Several commercial-off-the-shelf (COTS) multichannel high-speed ADCs have been selected as possible backups of the radiation tolerant ADC ASICs for LTDB. In order to evaluate the radiation tolerance of these back up commercial ADCs, we developed an ADC radiation tolerance characterization system, which includes the ADC boards, data acquisition (DAQ) board, signal generator, external power supplies and a host computer. The ADC b…
The ALICE experiment at CERN is undergoing a major upgrade during the Long Shutdown 2 (LS2) of the LHC during 2019-2020. The key elements regarding the central barrel are the installation of a new Inner Tracking System (ITS) and the upgrade of the large Time Projection Chamber (TPC). The TPC is currently being upgraded with a new readout system, including new GEM-based Readout Chambers and new front-end electronics enabling us to operate it in continuous mode. The new ITS based on CMOS Monolithic Active Pixel Sensors will significantly improve the impact parameter resolution and the tracking e…
We present a first proof of concept to directly use neural network based pattern recognition to trigger on distinct calorimeter signatures from displaced particles, such as those that arise from the decays of exotic long-lived particles. The study is performed for a high granularity forward calorimeter similar to the planned high granularity calorimeter for the high luminosity upgrade of the CMS detector at the CERN Large Hadron Collider. Without assuming a particular model that predicts long-lived particles, we show that a simple convolutional neural network, that could in principle be deploy…
The Inner Tracking System (ITS) Upgrade for the ALICE experiment at LHC is the first large-area ($\sim$10~m$^2$) silicon vertex detector based on the CMOS Monolithic Active Pixel Sensor (MAPS) technology, which combines sensitive volume and front-end readout logic in the same piece of silicon. This technology allows a reduced material budget (target value of 0.3\% on the innermost layers) thanks to the thin sensors (50-100~$μ$m) and limited need of cooling, in combination with light-material interconnection circuits and support structures. The small pixel pitch ($\sim$30~$μ$m), the location of…
