Search results for "Large"

MuPix and ATLASPix -- Architectures and Results

2020

High Voltage Monolithic Active Pixel Sensors (HV-MAPS) are based on a commercial High Voltage CMOS process and collect charge by drift inside a reversely biased diode. HV-MAPS represent a promising technology for future pixel tracking detectors. Two recent developments are presented. The MuPix has a continuous readout and is being developed for the Mu3e experiment whereas the ATLASPix is being developed for LHC applications with a triggered readout. Both variants have a fully monolithic design including state machines, clock circuitries and serial drivers. Several prototypes and design variants were characterised in the lab and in testbeam campaigns to measure efficiencies, noise, time reso…

Upgrade of ALICE forward detectors

2019

ALICE will upgrade its subsystems in 2019−2020 to fully benefit from the increased collision rate and luminosity of the LHC at CERN. Two new forward detectors will be installed at the core of ALICE: the Fast Interaction Trigger (FIT) and the Muon Forward Tracker (MFT). Additionally, during the shutdown between Run 3 and Run 4, there will be an opportunity to install the Forward Calorimeter (FoCal). This paper describes these new forward detectors, their physics justification and goals, selected design features along with performance of detector prototypes and simulated performance figures. peerReviewed

Ultrascale+ for the new ATLAS calorimeter trigger board dedicated to jet identification

2018

To cope with the expected increase in luminosity at the Large Hadron Collider in 2021, the ATLAS collaboration is planning a major detector upgrade to be installed during Long Shutdown 2. As a part of this, the Level 1 trigger, based on calorimeter data, will be upgraded to exploit the fine granularity readout using a new system of Feature EXtractors (FEXs), which each reconstruct different physics objects for the trigger selection. The Jet FEX (jFEX) is one of three FEXs and has been conceived to identify small/large area jets, large area tau leptons, missing transverse energy and the total sum of the transverse energy. The use of the latest generation Xilinx Field Programmable Gate Array …

Analysis of the ATLAS Rome Production Experience on the LHC Computing Grid

2006

The Large Hadron Collider at CERN will start data acquisition in 2007. The ATLAS (A Toroidal LHC Apparatus) experiment is preparing for the data handling and analysis via a series of Data Challenges and production exercises to validate its computing model and to provide useful samples of data for detector and physics studies. The last Data Challenge, begun in June 2004 and ended in early 2005, was the first performed completely in a Grid environment. Immediately afterwards, a new production activity was necessary in order to provide the event samples for the ATLAS physics workshop, taking place in June 2005 in Rome. This exercise offered a unique opportunity to estimate the reached improvem…

The Inchworm as a precision translator in a high magnetic field and UHV environment

1989

Abstract A new set-up has been designed and tested for on-line, high-precision mass measurements of short-lived radioactive isotopes via a determination of the ion cyclotron resonance. Ions delivered by the on-line isotope separator ISOLDE at CERN/Geneva are stored in a Penning trap installed in a superconducting solenoid. Due to severe space limitations in the bore of the solenoid, it is impossible to use conventional mechanical feedthroughs for the necessary manipulations inside the uhv chamber. Instead, a number of Inchworms, a high-precision positioning device based on the piezo-electric effect are employed. This publication reports on the first application of this device in a uhv envir…

Upgrade of the ATLAS Central Trigger for LHC Run-2

2015

The increased energy and luminosity of the LHC in the run-2 data taking period requires a more selective trigger menu in order to satisfy the physics goals of ATLAS. Therefore the electronics of the central trigger system is upgraded to allow for a larger variety and more sophisticated trigger criteria. In addition, the software controlling the central trigger processor (CTP) has been redesigned to allow the CTP to accommodate three freely configurable and separately operating sets of sub detectors, each independently using the almost full functionality of the trigger hardware. This new approach and its operational advantages are discussed as well as the hardware upgrades.

Analysis of the XENON100 dark matter search data

2014

The XENON100 experiment, situated in the Laboratori Nazionali del Gran Sasso, aims at the direct detection of dark matter in the form of weakly interacting massive particles (WIMPs), based on their interactions with xenon nuclei in an ultra low background dual-phase time projection chamber. This paper describes the general methods developed for the analysis of the XENON100 data. These methods have been used in the 100.9 and 224.6 live days science runs from which results on spin-independent elastic, spin-dependent elastic and inelastic WIMP-nucleon cross-sections have already been reported.

Photoelectrochemical Synthesis of Conducting Polymers Layers on Large Band Gap Nb2O5 and Ta2O5 Anodic Oxides Films

2008

Weak convergence to the coalescent in neutral population models

1999

For a large class of neutral population models the asymptotics of the ancestral structure of a sample of n individuals (or genes) is studied, if the total population size becomes large. Under certain conditions and under a well-known time-scaling, which can be expressed in terms of the coalescence probabilities, weak convergence in D E ([0,∞)) to the coalescent holds. Further the convergence behaviour of the jump chain of the ancestral process is studied. The results are used to approximate probabilities which are of certain interest in applications, for example hitting probabilities.

The doodle of a finitely determined map germ from R2 to R3

2009

Let f:U⊂R2→R3 be a representative of a finitely determined map germ f:(R2,0)→(R3,0). Consider the curve obtained as the intersection of the image of the mapping f with a sufficiently small sphere Sϵ2 centered at the origin in R3, call this curve the associated doodle of the map germ f. For a large class of map germs the associated doodle has many transversal self-intersections. The topological classification of such map germs is considered from the point of view of the associated doodles.