scholarly journals Readout Software for the Alice Integrated Online-Offline (O2) System

2019 ◽  
Vol 214 ◽  
pp. 01041 ◽  
Author(s):  
Sylvain Chapeland ◽  
Filippo Costa
Keyword(s):  
System Performance ◽  
Modular Design ◽  
Hadron Collider ◽  
Computing System ◽  
Heavy Ion ◽  
Data Sampling ◽  
Online Data ◽  
Processing Pipeline ◽  
Large Ion Collider ◽  
Collider Experiment

ALICE (A Large Ion Collider Experiment) is a heavy -ion detector studying the physics of strongly interacting matter and the quarkgluon plasma at CERN’s LHC (Large Hadron Collider). During the second long shutdown of the LHC, the ALICE detector will be upgraded to cope with an interaction rate of 50 kHz in Pb–Pb collisions, producing in the online computing system (O2) a sustained input throughput of 3 TB/s. The readout software is in charge of the first step of data-acquisition, handling the data transferred from over 8000 detector links to PC memory by dedicated PCI boards, formatting and buffering incoming traffic until sent to the next components in the processing pipeline. On the 250 readout nodes where it runs, the software has to sustain a throughput which can locally exceed 100 Gb/s. We present the modular design used to cope with various data sources (hardware devices and software emulators), integrated with the central O2 components (logging, configuration, monitoring, data sampling, transport) and initiating the online data flow using the standard O2 messaging system. Performance considerations and measurements are also discussed.

scholarly journals Multiplicity Dependence of Heavy-Flavour Hadron Decay Electron Production in Collisions at √sNN = 8.16 Measured with ALICE at the LHC

Proceedings ◽  
2019 ◽  
Vol 10 (1) ◽  
pp. 28
Author(s):  
Preeti Dhankher on behalf of ALICE collaboration
Keyword(s):  
Hadron Collider ◽  
Heavy Ion ◽  
Gluon Plasma ◽  
Extreme Condition ◽  
Nuclear Modification Factor ◽  
Electron Production ◽  
Hadron Decay ◽  
Modification Factor ◽  
Hadronic Collisions ◽  
Large Ion Collider

A Large Ion Collider Experiment (ALICE) at the Large Hadron collider (LHC) is a heavy-ion dedicated experiment designed to study nuclear matter at extreme condition of high temperature and high density at which quarks are deconfined and give rise to a new state of matter known as Quark Gluon Plasma (QGP). Heavy flavours (charm and beauty), are produced in the initial stages of hadronic collisions in hard scattering processes and therefore are effective probes to study the QGP. In this contribution, recent measurements of the production of electrons from heavy-flavour hadron decays, their nuclear modification factor and the self-normalised yield measured up to 14 in collisions at √sNN = 8.16 TeV collected in LHC Run2 in 2016 are presented.

scholarly journals QUARKONIA MEASUREMENTS WITH THE CENTRAL DETECTORS OF ALICE

2007 ◽  
Vol 16 (07n08) ◽  
pp. 2484-2490 ◽  
Author(s):  
◽  
WOLFGANG SOMMER ◽  
CHRISTOPH BLUME ◽  
FREDERICK KRAMER ◽  
JAN FIETE GROSSE-OETRINGHAUS
Keyword(s):  
Large Hadron Collider ◽  
Hadron Collider ◽  
Forward Region ◽  
Proton Proton ◽  
Physics Program ◽  
Expected Performance ◽  
Central Lead ◽  
Electron Measurement ◽  
Large Ion Collider ◽  
Collider Experiment

A Large Ion Collider Experiment – ALICE will become operational with the startup of the Large Hadron Collider – LHC at the end of 2007. One focus of the physics program is the measurement of quarkonia in proton-proton and lead-lead collisions. Quarkonia states will be measured in two kinematic regions and channels: di-muonic decays will be measured in the forward region by the muon arm, the central part of the detector will measure di-electronic decays. The presented studies show the expected performance of the di-electron measurement in proton-proton and central lead-lead collisions.

scholarly journals GEM Foil Quality Assurance For The ALICE TPC Upgrade

2018 ◽  
Vol 174 ◽  
pp. 03004 ◽  
Author(s):  
Erik Brücken ◽  
Timo Hildén
Keyword(s):  
Quality Assurance ◽  
Hadron Collider ◽  
Heavy Ion ◽  
Particle Identification ◽  
Electron Multiplier ◽  
Heavy Ion Physics ◽  
Proportional Chamber ◽  
Tracking Detector ◽  
Time Projection ◽  
Large Ion Collider

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 Proportional Chamber (MWPC) –based readout chambers. The MWPC are operated with gating grid that limits the rate to O(kHz). The new ReadOut Chamber (ROC) design is based on Gas Electron Multiplier (GEM) technology operating in continuous mode. The current GEM productions scheme foresees the production of more than 800 GEM foils of different types. To fulfill the requirements on the performance of the GEM TPC readout, necessitates thorough Quality Assurance (QA) measures. The QA scheme, developed by the ALICE collaboration, will be presented in detail.

scholarly journals The ALICE O2 data quality control system

2020 ◽  
Vol 245 ◽  
pp. 01027
Author(s):  
Piotr Konopka ◽  
Barthélémy von Haller
Keyword(s):  
Quality Control ◽  
Data Quality ◽  
Hadron Collider ◽  
Computing System ◽  
Quality Monitoring ◽  
Software Components ◽  
Data Quality Control ◽  
Alice Experiment ◽  
Online Data ◽  
Architecture And Design

The ALICE Experiment at CERN LHC (Large Hadron Collider) is undertaking a major upgrade during LHC Long Shutdown 2 in 2019–2021. The raw data input from the ALICE detectors will then increase a hundredfold, up to 3.5 TB/s. In order to cope with such a large amount of data, a new online-offline computing system, called O2, will be deployed. One of the key software components of the O2 system will be the data Quality Control (QC) that replaces the existing online Data Quality Monitoring and offline Quality Assurance. It involves the gathering, the analysis by user-defined algorithms and the visualization of monitored data, in both the synchronous and asynchronous parts of the O2 system. This paper presents the architecture and design, as well as the latest and upcoming features, of the ALICE O2 QC. The results of the extensive benchmarks which have been carried out for each component of the system are later summarized. Finally, the adoption of this tool amongst the ALICE Collaboration and the measures taken to develop, in synergy with their respective teams, efficient monitoring modules for the detectors, are discussed.

scholarly journals Study of multicharged heavy ion generation from CO2 laser-produced plasma

1996 ◽  
Vol 14 (3) ◽  
pp. 347-368 ◽  
Author(s):  
V.Yu. Baranov ◽  
K.N. Makarov ◽  
V.C. Roerich ◽  
Yu.A. Satov ◽  
A.N. Starostin ◽  
...  
Keyword(s):  
Hadron Collider ◽  
Laser System ◽  
Heavy Ion ◽  
Ion Source ◽  
Lead Ion ◽  
Ion Generation ◽  
Wavelength Radiation ◽  
Laser Heated ◽  
Work Done ◽  
Power Densities

The results of lead ion generation with charge state from Pb10+ to Pb35+ from laser-heated plasma are presented. CO2 lasers producing 10.6-μm wavelength radiation at power densities in the range 4.1011-6.1014 W/cm2 in TBKI and CERN were used. Results of detailed numerical simulations presented in the paper are in good agreement with the experimental data. Work done in collaboration with CERN, ITEP, and TBKI was aimed at the specification of requirements for a laser system that will be able to drive an ion source for the hadron collider (LHC) at CERN.

scholarly journals ηQ Meson Photoproduction in Ultrarelativistic Heavy Ion Collisions

2017 ◽  
Vol 2017 ◽  
pp. 1-7 ◽  
Author(s):  
Gong-Ming Yu ◽  
Gao-Gao Zhao ◽  
Zhen Bai ◽  
Yan-Bing Cai ◽  
Hai-Tao Yang ◽  
...  
Keyword(s):  
Heavy Ion Collisions ◽  
Hadron Collider ◽  
Heavy Ion ◽  
Relativistic Heavy Ion Collisions ◽  
Heavy Quarkonium ◽  
Color Singlet ◽  
Initial State ◽  
Color Octet ◽  
Ion Collisions ◽  
The Matrix

The transverse momentum distributions for inclusive ηc,b meson described by gluon-gluon interactions from photoproduction processes in relativistic heavy ion collisions are calculated. We considered the color-singlet (CS) and color-octet (CO) components within the framework of Nonrelativistic Quantum Chromodynamics (NRQCD) in the production of heavy quarkonium. The phenomenological values of the matrix elements for the color-singlet and color-octet components give the main contribution to the production of heavy quarkonium from the gluon-gluon interaction caused by the emission of additional gluon in the initial state. The numerical results indicate that the contribution of photoproduction processes cannot be negligible for midrapidity in p-p and Pb-Pb collisions at the Large Hadron Collider (LHC) energies.

scholarly journals Small System Collectivity in Relativistic Hadronic and Nuclear Collisions

2018 ◽  
Vol 68 (1) ◽  
pp. 211-235 ◽  
Author(s):  
James L. Nagle ◽  
William A. Zajc
Keyword(s):  
Large Hadron Collider ◽  
Nuclear Matter ◽  
Hadron Collider ◽  
Heavy Ion ◽  
Relativistic Heavy Ion Collider ◽  
Small System ◽  
Nuclear Collisions ◽  
Ion Collisions ◽  
Bulk Motion ◽  
Inviscid Hydrodynamics

The bulk motion of nuclear matter at the ultrahigh temperatures created in heavy ion collisions at the Relativistic Heavy Ion Collider and the Large Hadron Collider is well described in terms of nearly inviscid hydrodynamics, thereby establishing this system of quarks and gluons as the most perfect fluid in nature. A revolution in the field is under way, spearheaded by the discovery of similar collective, fluid-like phenomena in much smaller systems including p+ p, p+ A, d+Au, and3He+Au collisions. We review these exciting new observations and their profound implications for hydrodynamic descriptions of small and/or out-of-equilibrium systems.

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