Search results for "ATLAS"

Simulations of convectively-driven density currents in the Atlas region using a regional model: Impacts on dust emission and sensitivity to horizonta…

2009

[1] During the SAMUM field campaign in southern Morocco in May and June 2006 density currents generated by evaporative cooling after convective precipitation were frequently observed at the Sahara side of the Atlas Mountain chain. The associated strong surface cold-air outflow during such events has been observed to lead to dust mobilization in the foothills. Here a regional model system is used to simulate a density current case on 3 June 2006 and the subsequent dust emission. The model studies are performed with different parameterization schemes for convection, and with different horizontal model grid resolutions to examine to which extent the model system can be used for reproducing dus…

Construction, assembly and tests of the ATLAS electromagnetic barrel calorimeter

2006

The construction and assembly of the two half barrels of the ATLAS central electromagnetic calorimeter and their insertion into the barrel cryostat are described. The results of the qualification tests of the calorimeter before installation in the LHC ATLAS pit are given.

Surgery Illustrated - Surgical Atlas

2010

Measurement of dijet production with a veto on additional central jet activity in pp collisions at sqrt(s)=7 TeV using the ATLAS detector

2011

A measurement of jet activity in the rapidity interval bounded by a dijet system is presented. Events are vetoed if a jet with transverse momentum greater than 20 GeV is found between the two boundary jets. The fraction of dijet events that survive the jet veto is presented for boundary jets that are separated by up to six units of rapidity and with mean transverse momentum 50 < p¯T < 500 GeV. The mean multiplicity of jets above the veto scale in the rapidity interval bounded by the dijet system is also presented as an alternative method for quantifying perturbative QCD emission. The data are compared to a next-to-leading order plus parton shower prediction from the powheg-box, an all-order…

Deployment of the ATLAS high level trigger

2005

The ATLAS combined test beam in the second half of 2004 saw the first deployment of the ATLAS high-level triggers (HLT). The next steps are deployment on the pre-series farms in the experimental area during 2005, commissioning and cosmics tests in 2006 and collisions in 2007. This paper reviews the experience gained in the test beam, describes the current status and discusses the further enhancements to be made. We address issues related to the dataflow, selection algorithms, testing, software distribution, installation and improvements

Fault rate controls on carbonate gravity-flow deposits of the Liassic of Central High Atlas (Morocco).

2013

21 pages; International audience; The aim of this work is to describe and to explore linkages between fault activity and gravity-related sedimentary deposits during the early rifting of a carbonate depositional system. The study area, located at the southern edge of Central High Atlas (Morocco), hosts 900 m thick Liassic gravity-related sedimentary deposits, preserved at the hanging wall of one of the possibly inherited, reactivated Hercynian faults (Tizi n'Firest fault). This study documents gravity-flow deposits constrained by a highresolution biostratigraphic framework (ca. 100 ka). These gravity-flow deposits evolve over time. Unstratified conglomerate beds are limited to the Sinemurian…

Measurement of the inelastic proton-proton cross-section at √s = 7 TeV with the ATLAS detector

2011

The dependence of the rate of proton–proton interactions on the centre-of-mass collision energy, √s, is of fundamental importance for both hadron collider physics and particle astrophysics. The dependence cannot yet be calculated from first principles; therefore, experimental measurements are needed. Here we present the first measurement of the inelastic proton–proton interaction cross-section at a centre-of-mass energy, √s, of 7 TeV using the ATLAS detector at the Large Hadron Collider. Events are selected by requiring hits on scintillation counters mounted in the forward region of the detector. An inelastic cross-section of 60.3±2.1 mb is measured for ξ>5×10[superscript −6], where ξ is ca…

The ATLAS Level-1 Calorimeter Trigger

2008

The ATLAS Level-1 Calorimeter Trigger uses reduced-granularity information from all the ATLAS calorimeters to search for high transverse-energy electrons, photons, tau leptons and jets, as well as high missing and total transverse energy. The calorimeter trigger electronics has a fixed latency of about 1 microsecond, using programmable custom-built digital electronics. This paper describes the Calorimeter Trigger hardware, as installed in the ATLAS electronics cavern.

Muon identification with the ATLAS Tile Calorimeter Read-Out Driver for Level-2 trigger purposes

2008

The Hadronic Tile Calorimeter (TileCal) at the ATLAS experiment is a detector made out of iron as passive medium and plastic scintillating tiles as active medium. The light produced by the particles is converted to electrical signals which are digitized in the front-end electronics and sent to the back-end system. The main element of the back-end electronics are the VME 9U Read-Out Driver (ROD) boards, responsible of data management, processing and transmission. A total of 32 ROD boards, placed in the data acquisition chain between Level-1 and Level-2 trigger, are needed to read out the whole calorimeter. They are equipped with fixed-point Digital Signal Processors (DSPs) that apply online …

Skolotāju piesaiste Latvijas vispārizglītojošajās skolās un tās pilnveides iespējas

2019

Skolotāju trūkums Latvijas skolās ir bijis īpaši aktuāls kopš ekonomiskās krīzes 2007-2010.gadā. Krīzes laikā daudzi skolotāji pensijas vecumā izlēma beigt skolotāju karjeru un kopš tā brīža Latvijas skolas ir izjutušas skolotāju trūkumu, it īpaši dabaszinību priekšmetos un angļu valodā. Skolotājiem pārtraucot darbu skolā, viņu vietā nav nācis pietiekami daudz jauno skolotāju. Lai arī Latvijas universitātes izglīto pietiekamu skaitu jauno skolotāju, bieži vien jaunie skolotāji neaiziet strādāt uz skolu un izvēlas citu karjeras attīstību. Kritiski ir tas, ka Latvijas skolu direktoriem nemitīgi aktuāls ir jautājums, kur atrast vajadzīgos skolotājus. Šī maģistra darba mērķis ir teorētiski izpē…