The Tile Calorimeter (TileCal) is the central section of the hadronic calorimeter of ATLAS. It is a key detector for the reconstruction of hadrons, jets, tau leptons and missing transverse energy. ...TileCal is a sampling calorimeter using steel as an absorber and plastic scintillators as an active medium. The scintillators are read-out by wavelength shifting fibers coupled to photomultiplier tubes (PMTs). The analogue signals from the PMTs are amplified, shaped and digitized by sampling the signal every 25ns. The read-out system is designed to reconstruct the data in real time fulfilling the tight time constraint imposed by the ATLAS first level trigger rate (100kHz). The signal amplitude and phases for each channel are measured using Optimal Filtering algorithms both at online and offline level. We present the performances of these techniques on the data collected in the proton–proton collisions at center-of-mass energy of 7TeV. We show in particular the measurements of low amplitudes, close to the pedestal value, using as probe high transverse momenta muons produced in the proton–proton collisions.
Hadron detection with a dual-readout fiber calorimeter Lee, S.; Cardini, A.; Cascella, M. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
09/2017, Letnik:
866, Številka:
C
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In this paper, we describe measurements of the response functions of a fiber-based dual-readout calorimeter for pions, protons and multiparticle “jets” with energies in the range from 20 to 180 GeV. ...The calorimeter uses lead as absorber material and has a total mass of 1350 kg. It is complemented by leakage counters made of scintillating plastic, with a total mass of 500 kg. The effects of these leakage counters on the calorimeter performance are studied as well. In a separate section, we investigate and compare different methods to measure the energy resolution of a calorimeter. Using only the signals provided by the calorimeter, we demonstrate that our dual-readout calorimeter, calibrated with electrons, is able to reconstruct the energy of proton and pion beam particles to within a few percent at all energies. The fractional widths of the signal distributions for these particles (σ∕E) scale with the beam energy as 30%∕E, without any additional contributing terms.
The electromagnetic performance of the RD52 fiber calorimeter Akchurin, N.; Bedeschi, F.; Cardini, A. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
2014, Letnik:
735
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The RD52 calorimeter is an instrument intended to detect both electromagnetic and hadronic showers, as well as muons, using the dual-readout principle. Scintillation and Cherenkov light provide the ...two signals which, in combination, allow for superior hadronic performance. In this paper, we report on the electromagnetic performance of this instrument, and compare this performance with that of other calorimeters that were constructed with similar goals in mind.
The RD52 dual-readout calorimeter is a longitudinally unsegmented instrument intended for the detection of both electromagnetically and hadronically interacting particles with unprecedented ...precision. In this paper, the identification of the showering particles and, in particular, the identification of electrons and gamma s with this instrument are investigated. The techniques used for this purpose include differences in the shower development observed with scintillation light and Cherenkov radiation, the radial shower profile of the particles and the time structure (including the starting point) of the calorimeter signals. It turns out that, at 60 GeV, electrons can be correctly identified in 99.8% of the cases, by means of criteria that eliminate 99.8% of the hadrons.
The small-angle performance of a dual-readout fiber calorimeter Cardini, A.; Cascella, M.; Choi, S. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
02/2016, Letnik:
808, Številka:
C
Journal Article
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The performance of the RD52 dual-readout calorimeter is measured for very small angles of incidence between the 20GeV electron beam particles and the direction of the fibers that form the active ...elements of this calorimeter. The calorimeter response is observed to be independent of the angle of incidence for both the scintillating and the Čerenkov fibers, whereas significant differences are found between the angular dependence of the energy resolution measured with these two types of fibers. The experimental results are on crucial points at variance with the predictions of GEANT4 Monte Carlo simulations.
The RD52 calorimeter uses the dual-readout principle to detect both electromagnetic and hadronic showers, as well as muons. Scintillation and Cherenkov light provide the two signals which, in ...combination, allow for superior hadronic performance. In this paper, we report on detailed, GEANT4 based Monte Carlo simulations of the performance of this instrument. The results of these simulations are compared in great detail to measurements that have been carried out and published by the DREAM Collaboration. This comparison makes it possible to understand subtle details of the shower development in this unusual particle detector. It also allows for predictions of the improvement in the performance that may be expected for larger detectors of this type. These studies also revealed some inadequacies in the GEANT4 simulation packages, especially for hadronic showers, but also for the Cherenkov signals from electromagnetic showers.
A comparison of BGO and BSO crystals used in the dual-readout mode Akchurin, N.; Bedeschi, F.; Cardini, A. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
06/2011, Letnik:
640, Številka:
1
Journal Article
Recenzirano
We report on a systematic study of the properties of two high-
Z scintillating crystals, bismuth germanate (BGO) and bismuth silicate (BSO), in view of the possible application of such crystals in ...dual-readout calorimeters. Whereas the light attenuation characteristics of both crystals are about the same, BSO offers a considerably higher Cherenkov light yield, and with a given UV filter the separation between the Cherenkov and scintillation signals is substantially better in this crystal.
Detection of electron showers in dual-readout crystal calorimeters Akchurin, N.; Bedeschi, F.; Cardini, A. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
09/2012, Letnik:
686
Journal Article
Recenzirano
Some high-Z scintillating crystals offer the possibility to distinguish the contributions from the scintillation and Čherenkov mechanisms to the generated signals. Among these crystals are BGO and ...PbWO4. We have tested matrices of these crystals as electromagnetic calorimeters and studied the properties of the Čherenkov and scintillation components of the signals generated by high-energy electrons showering in these detectors.
Separation of crystal signals into scintillation and Cherenkov components Akchurin, N.; Astwood, A.; Cardini, A. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
10/2008, Letnik:
595, Številka:
2
Journal Article
Recenzirano
The signals from high-
Z scintillating crystals such as PbWO
4 and BGO contain a significant Cherenkov component. We investigate methods to determine the contribution of Cherenkov light to the ...signals generated by high-energy electrons and pions (mips), both statistically and event-by-event. These methods are based on differences in the spectra, the time structure and/or the directionality of the two types of light. The electron signals, and their composition, are also analyzed as a function of the age (or depth) of the shower.
New crystals for dual-readout calorimetry Akchurin, N.; Bedeschi, F.; Cardini, A. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
06/2009, Letnik:
604, Številka:
3
Journal Article
Recenzirano
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Lead tungstate crystals doped with small fractions of praesodynium or molybdenum have been tested in beams of high-energy electrons. The goal of these tests was to study the effects of such dopants ...on the capability to separate the signal components deriving from the Cherenkov and scintillation light generated by the beam particles. These studies were carried out in view of the possible application of such crystals in dual-readout calorimeters.
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