A spark-resistant bulk-micromegas chamber for high-rate applications Alexopoulos, T.; Burnens, J.; de Oliveira, R. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
06/2011, Letnik:
640, Številka:
1
Journal Article
Recenzirano
Odprti dostop
We report on the design and performance of a spark-resistant bulk-micromegas chamber. The principle of this design lends itself to the construction of large-area muon chambers for the upgrade of the ...detectors at the Large Hadron Collider at CERN for luminosities in excess of 10
34
cm
−2
s
−1 or other high-rate applications.
First look at the physics case of TLEP Bicer, M.; Duran Yildiz, H.; Coignet, G. ...
The journal of high energy physics,
01/2014, Letnik:
2014, Številka:
1
Journal Article
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A
bstract
The discovery by the ATLAS and CMS experiments of a new boson with mass around 125 GeV and with measured properties compatible with those of a Standard-Model Higgs boson, coupled with the ...absence of discoveries of phenomena beyond the Standard Model at the TeV scale, has triggered interest in ideas for future Higgs factories. A new circular e
+
e
−
collider hosted in a 80 to 100 km tunnel, TLEP, is among the most attractive solutions proposed so far. It has a clean experimental environment, produces high luminosity for top-quark, Higgs boson, W and Z studies, accommodates multiple detectors, and can reach energies up to the
threshold and beyond. It will enable measurements of the Higgs boson properties and of Electroweak Symmetry-Breaking (EWSB) parameters with unequalled precision, offering exploration of physics beyond the Standard Model in the multi-TeV range. Moreover, being the natural precursor of the VHE-LHC, a 100 TeV hadron machine in the same tunnel, it builds up a long-term vision for particle physics. Altogether, the combination of TLEP and the VHE-LHC offers, for a great cost effectiveness, the best precision and the best search reach of all options presently on the market. This paper presents a first appraisal of the salient features of the TLEP physics potential, to serve as a baseline for a more extensive design study.
O-rings made from foam rubber are often used in sealing applications. Foam rubber have low (macroscopic) elastic modulus
E
0
resulting in a low nominal contact pressure when squeezed against a ...countersurface. In most cases the foam rubber is covered by a thin surface film with the effective elastic modulus
E
1
>
E
0
. We show that the nominal contact pressure may not be high enough for the contact area to percolate and the O-ring seal will leak. For the leakage calculations we use the Persson multiscale contact mechanics theory, and the (modified) Bruggeman effective medium theory for the fluid flow conductivity. The experimental input for the theory are surface roughness power spectrum, which was obtained from stylus topography measurements, and the elastic properties (
E
0
and
E
1
) of the rubber O-ring. As an application of this calculation method, we have used the preliminary as well as the final results of the laboratory gas tightness tests of the 136 New Small Wheel Micromegas Quadruplets performed at CERN, from February 2019 to May 2021, in the framework of the ATLAS Experiment upgrade. In the integration quality control, a novel method for gas tightness measurement, that we have called “Flow Rate Loss”, has been used as a baseline method.
Graphical Abstract
The ATLAS collaboration at the Large Hadron Collider at CERN has endorsed the resistive-strip micromegas technology for the high luminosity upgrade of the first muon station in the high-rapidity ...region, the so called “New Small Wheel” project. It requires detectors with a spatial resolution of ∼100μm, fully efficient up to a particle rate of ∼20kHz/cm2. In order to demonstrate that the resistive-strip micromegas technology fulfils these requirements, small resistive bulk micromegas have been studied with radioactive sources and with high energy beams. The micromegas chambers were operated with an Ar+7%CO2 gas mixture and read out using the APV25 chip. Results on the detection efficiency and the position resolution are presented for track impact angles from 0° to 40°. A position reconstruction method has been developed for inclined tracks, called the “micro-TPC method”. A description of the method along with performance studies is presented. In addition, the impact of the unavoidable presence of pillars and the relative alignment of readout and resistive strips on the micromegas performance has been quantified. In view of the fact that the micromegas detectors will also contribute to the trigger in ATLAS their time response has been studied.
The VMM readout system Alexopoulos, T.; Antrim, D.; Bakalis, C. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
03/2020, Letnik:
955, Številka:
C
Journal Article
Recenzirano
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The New Small Wheel Upgrade of the ATLAS experiment at CERN, planned to take place at 2020, requires a new generation of front-end electronics that will support its data acquisition requirements. The ...VMM Application-Specific Integrated Circuit has been in development for the last seven years to serve as the foundation of the New Small Wheel’s readout scheme. It has gone through three major revisions and a minor one, the latter being the production version. To facilitate the testing and readout of the VMM, as well as to study its detector performance, a complete readout system has been developed. It consists of flexible Field-Programmable Gate Array logic with extensive functionality, and an efficient software framework providing the user interface. This system, referred to as the ”The VMM Readout System”, has been used in test-beam campaigns at CERN, as well as in bench calibration and testing measurement scenarios for the past several years, supporting all readout modes and features of the VMM.
The magnetized steel and scintillator calorimeters of the MINOS experiment Allison, W.W.M.; Andreopoulos, C.; Ayres, D.S. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
11/2008, Letnik:
596, Številka:
2
Journal Article
Recenzirano
Odprti dostop
The Main Injector Neutrino Oscillation Search (MINOS) experiment uses an accelerator-produced neutrino beam to perform precision measurements of the neutrino oscillation parameters in the ...“atmospheric neutrino” sector associated with muon neutrino disappearance. This long-baseline experiment measures neutrino interactions in Fermilab's NuMI neutrino beam with a near detector at Fermilab and again 735
km downstream with a far detector in the Soudan Underground Laboratory in northern Minnesota. The two detectors are magnetized steel-scintillator tracking calorimeters. They are designed to be as similar as possible in order to ensure that differences in detector response have minimal impact on the comparisons of event rates, energy spectra and topologies that are essential to MINOS measurements of oscillation parameters. The design, construction, calibration and performance of the far and near detectors are described in this paper.
Abstract
The innovative FEL design by the CompactLight Collaboration is briefly presented. The major contribution of our team, mainly from Greece cooperating with the team of ESS-ERIC, is emphasised ...to the material selection of the proper photocathode illuminated with the relevant laser, the magnet and solenoid design of the injector for optimum beam conditions, the 3D CAD model design of the baseline FEL facility including the machine, the tunnel, the beam dump and the experimental hall. Additionally, the exploitation assets of the project with the transfer technology are presented.
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