995 research outputs found
The ALICE Inner Tracking System Upgrade
A central component of the ALICE Upgrade will be a completely new Inner
Tracking System (ITS). The performance of the new ITS will be a significant
improvement over that of the present ITS, in particular in the areas of
material budget, granularity, a reduced radial distance from the first layer to
the beam and rate capability. This will enable many key measurements of the
properties of the quark-gluon plasma to be performed, in particular with rare
probes such as low momentum charm and beauty mesons and baryons.Comment: 4 pages, 1 figure, Proceedings of Quark Matter 2012, The XXIII
International Conference on Ultrarelativistic Nucleus-Nucleus Collisions,
August 13-18, 2012, Washington D.C., US
Pixel Detectors
Pixel detectors for precise particle tracking in high energy physics have
been developed to a level of maturity during the past decade. Three of the LHC
detectors will use vertex detectors close to the interaction point based on the
hybrid pixel technology which can be considered the state of the art in this
field of instrumentation. A development period of almost 10 years has resulted
in pixel detector modules which can stand the extreme rate and timing
requirements as well as the very harsh radiation environment at the LHC without
severe compromises in performance. From these developments a number of
different applications have spun off, most notably for biomedical imaging.
Beyond hybrid pixels, a number of monolithic or semi-monolithic developments,
which do not require complicated hybridization but come as single sensor/IC
entities, have appeared and are currently developed to greater maturity. Most
advanced in terms of maturity are so called CMOS active pixels and DEPFET
pixels. The present state in the construction of the hybrid pixel detectors for
the LHC experiments together with some hybrid pixel detector spin-off is
reviewed. In addition, new developments in monolithic or semi-monolithic pixel
devices are summarized.Comment: 14 pages, 38 drawings/photographs in 21 figure
Upgrade of the ALICE Inner Tracking System
The Inner Tracking System (ITS) is the key ALICE detector for the study of
heavy flavour production at LHC. Heavy flavor can be studied via the
identification of short-lived hadrons containing heavy quarks which have a mean
proper decay length in the order of 100-300 m. To accomplish this task,
the ITS is composed of six cylindrical layers of silicon detectors (two pixel,
two drift and two strip) with a radial coverage from 3.9 to 43 cm and a
material budget of 1.1% X0 per layer. %In particular, the properties of the two
innermost layers define the ITS performance in measuring the displaced vertex
of such short-lived particles.
In order to enhance the ALICE physics capabilities, and, in particular, the
tracking performance for heavy-flavour detection, the possibility of an ITS
upgrade has been studied in great detail. It will make use of the spectacular
progress made in the field of imaging sensors over the last ten years as well
as the possibility to install a smaller radius beampipe. The upgraded detector
will have greatly improved features in terms of: the impact parameter
resolution, standalone tracking efficiency at low , momentum resolution
and readout capabilities.
The Conceptual Design Report, which covers the design and performance
requirements, the upgrade options, as well as the necessary R&D efforts, was
made public in September 2012. An intensive R&D program has been launched to
review the different technological options under consideration. The new
detector should be ready to be installed during the long LHC shutdown period
scheduled in 2017-2018.Comment: 6 pages, 9 figures PIXEL2012 - International Workshop on
Semiconductor Pixel Detectors for Particles and Imagin
A review of advances in pixel detectors for experiments with high rate and radiation
The Large Hadron Collider (LHC) experiments ATLAS and CMS have established
hybrid pixel detectors as the instrument of choice for particle tracking and
vertexing in high rate and radiation environments, as they operate close to the
LHC interaction points. With the High Luminosity-LHC upgrade now in sight, for
which the tracking detectors will be completely replaced, new generations of
pixel detectors are being devised. They have to address enormous challenges in
terms of data throughput and radiation levels, ionizing and non-ionizing, that
harm the sensing and readout parts of pixel detectors alike. Advances in
microelectronics and microprocessing technologies now enable large scale
detector designs with unprecedented performance in measurement precision (space
and time), radiation hard sensors and readout chips, hybridization techniques,
lightweight supports, and fully monolithic approaches to meet these challenges.
This paper reviews the world-wide effort on these developments.Comment: 84 pages with 46 figures. Review article.For submission to Rep. Prog.
Phy
The STAR MAPS-based PiXeL detector
The PiXeL detector (PXL) for the Heavy Flavor Tracker (HFT) of the STAR
experiment at RHIC is the first application of the state-of-the-art thin
Monolithic Active Pixel Sensors (MAPS) technology in a collider environment.
Custom built pixel sensors, their readout electronics and the detector
mechanical structure are described in detail. Selected detector design aspects
and production steps are presented. The detector operations during the three
years of data taking (2014-2016) and the overall performance exceeding the
design specifications are discussed in the conclusive sections of this paper
Silicon Sensors for Trackers at High-Luminosity Environment
The planned upgrade of the LHC accelerator at CERN, namely the high
luminosity (HL) phase of the LHC (HL-LHC foreseen for 2023), will result in a
more intense radiation environment than the present tracking system was
designed for. The required upgrade of the all-silicon central trackers at the
ALICE, ATLAS, CMS and LHCb experiments will include higher granularity and
radiation hard sensors. The radiation hardness of the new sensors must be
roughly an order of magnitude higher than the one of LHC detectors. To address
this, a massive R&D program is underway within the CERN RD50 collaboration
"Development of Radiation Hard Semiconductor Devices for Very High Luminosity
Colliders" to develop silicon sensors with sufficient radiation tolerance.
Research topics include the improvement of the intrinsic radiation tolerance of
the sensor material and novel detector designs with benefits like reduced
trapping probability (thinned and 3D sensors), maximized sensitive area (active
edge sensors) and enhanced charge carrier generation (sensors with intrinsic
gain). A review of the recent results from both measurements and TCAD
simulations of several detector technologies and silicon materials at radiation
levels expected for HL-LHC will be presented.Comment: 7 pages, 9 figures, 10th International Conference on Radiation
Effects on Semiconductor Materials, Detectors and Devices (RESMDD14), 8-10
October, Firenze, Ital
EUDAQ - A data acquisition software framework for common beam telescopes
EUDAQ is a generic data acquisition software developed for use in conjunction with common beam telescopes at charged particle beam lines. Providing high-precision reference tracks for performance studies of new sensors, beam telescopes are essential for the research and development towards future detectors for high-energy physics. As beam time is a highly limited resource, EUDAQ has been designed with reliability and ease-of-use in mind. It enables flexible integration of different independent devices under test via their specific data acquisition systems into a top-level framework. EUDAQ controls all components globally, handles the data flow centrally and synchronises and records the data streams. Over the past decade, EUDAQ has been deployed as part of a wide range of successful test beam campaigns and detector development applications
Performance of ALICE AD modules in the CERN PS test beam
Two modules of the AD detector have been studied with the test beam at the T10 facility at CERN. The AD detector is made of scintillator pads read out by wave-length shifters (WLS) coupled to clean fibres that carry the produced light to photo-multiplier tubes (PMTs). In ALICE the AD is used to trigger and study the physics of diffractive and ultra-peripheral collisions as well as for a variety of technical tasks like beam-gas background monitoring or as a luminometer. The position dependence of the modules' efficiency has been measured and the effect of hits on the WLS or PMTs has been evaluated. The charge deposited by pions and protons has been measured at different momenta of the test beam. The time resolution is determined as a function of the deposited charge. These results are important ingredients to better understand the AD detector, to benchmark the corresponding simulations, and very importantly they served as a baseline for a similar device, the Forward Diffractive Detector (FDD), being currently built and that will be in operation in ALICE during the LHC Runs 3 and 4.Peer reviewe
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