ATLAS EMC Policy

Electromagnetic compatibility of ATLAS electronic equipments must be insured to achieve the expected level of performance of the experiment. The ATLAS EMC Policy covers the electrical safety aspects of the front end and racked installations, and aims the proper operation of the experiment in the electromagnetic environment that it creates. For this, the policy defines a set of procedures to document and approve the installations from the safety, compatibility and maintenance points of view

Grounding of the ATLAS experiment

This document describes the implementation of the grounding in the ATLAS experiment and its associated services and control rooms

Implosion Symmetry of Laser-Irradiated Cylindrical Targets

We consider the symmetry of cylindrical implosions of laser targets with parameters corresponding to experiments proposed for the LIL laser facility at Bordeaux: eight laser beams in octahedrical configuration, delivering a total of 50 kJ of 0.35 (xm laser light in 5 ns, impinging on 1.26 mm diameter polystyrene cylindrical shells filled with deuterium at 30 bar and 5.35 mg cm"3; this configuration allows to place diagnostics along the symmetry axis to evaluate directly the uniformity of implosion. Numerical studies have been carried out by using the hydrodynamic computer codes MULTI and CHIC, including one-dimensional, and two-dimensional R-Z and R-6 simulations. Deuterium is compressed into a 1 mm long and 50 |xm diameter filament, with density ranging from 2 to 6 g cm-3 and temperatures above 1000 eV. In spite of the reduced numbers of beams, a good symmetry can be achieved with a careful choice of the irradiation pattern. The heat transport smoothing between laser absorption zone and ablation layer plays a fundamental role in the attenuation of residual non-uniformities. Also, it has been found that the radiation transport determines the radial structure of the compressed filament

‘Mind the gap’: Responding to the indeterminable in migration

Prompted by the paper by Miriam Tedeschi, this commentary attempts to unsettle the dominant understanding of a relation in migration research that prioritises linkages between people, places and organisations while treating boundaries as limits to overcome. Building on geographers’ earlier engagements with Adorno, Levinas and extending this conversation to include Blanchot, the analysis attempts to move beyond the hold of mastery on a relation with alterity. The paper argues for an interruptive non-relation that resists the appropriation and affirms the dispersion of the self by the alterity it cannot internalise. It offers an alternative response to difference in migration that avoids bringing it to unifying continuity. Instead of treating interruptions in migration as gaps to be resolved through language, the paper considers the possibility of a neutral writing that reflects the powerlessness to say the unspeakable. In a movement of inscription and effacement, neutral writing invokes the unspeakable pain and affliction that exceeds the concepts to which it gives rise. The neuter answers for the non-subject of loss and trauma, the nothing often haunting international migrants

System Integration Issues of DC to DC converters in the sLHC Trackers

The upgrade of the trackers at the sLHC experiments requires implementing new powering schemes that will provide an increased power density with reduced losses and material budget. A scheme based on buck and switched capacitors DC to DC converters has been proposed as an optimal solution. The buck converter is based on a power ASIC, connected to a custom made air core inductor. The arrangement of the parts and the board layout of the power module are designed to minimize the emissions of EMI in a compact volume, enabling its integration on the tracker modules and staves

Re: Silences--: The Sensing of Sound

There is always a pressing need to make sense of the inexplicable. Research as teaching, writing as inquiry, texts as performative—we embark on a series of encounters and engagements. We draw and write lines in, and around, our experiences. Straightforward is not a geometry that sense, time, identity, or language takes. Usually, texts are considered to be the domain of authors but we ask that you engage with us as we explore how matter and fact warp and where theory is practice rather than applied, expressed, or attached to practice

Electromagnetic Compatibility of a Low Voltage Power Supply for the ATLAS Tile Calorimeter Front-End Electronics

The front-end electronics of the ATLAS Tile Calorimeter is powered by DC/DC converters that sit close to it. The performance of the detector electronics is constrained by the conducted noise emissions of its power supply. A compatibility limit is defined for the system. The noise susceptibility of the front-end electronics is evaluated, and different solutions to reduce the front-end electronics noise are discussed and tested

Prototyping and qualification of 2S modules for the CMS Outer Tracker upgrade at the HL-LHC

In preparation for the High Luminosity LHC, the entire tracker detector of the CMS experiment will be exchanged as part of the Phase-2 Upgrade. The new Outer Tracker will comprise approximately 13,000 silicon sensor modules, of which 7608 are "2S modules" consisting of two parallel mounted silicon strip sensors, and 5592 are "PS modules" consisting of one pixel and one strip sensor in a single module. These modules provide tracking information to the Level 1 trigger by correlating the hit information of both sensor layers, allowing discrimination of particle tracks by their transverse momentum. To guarantee successful operation during data-taking, the production of the outer tracker modules has to fulfill strict requirements. This note will discuss the assembly procedures as well as some key results of the electronic, thermal and vibration tests performed at CERN for qualifying the 2S module design and for preparing the module assembly procedures