The construction and performance of a modular hadron calorimeter prototype is described. The prototype consists of 9 individual lead/scintillator sandwich modules with the sampling satisfying the ...compensating condition. The light from the individual scintillator tiles is captured and transported with the WLS-fibers embedded in the scintillator and extended along the lateral side to the rear end of the module. Set of 6 WLS-fibers from the neighboring tiles is grouped in one bundle and viewed by a 3×3
mm
2 avalanche micro-pixel photodiode. The construction ensures a longitudinal segmentation of the module in 10 independent sections. The results of beam tests of the calorimeter prototype are presented. The energy resolution
σ
/
E
≈
53
%
/
E
(
GeV
)
was obtained.
Development of FARICH-detector for ALICE experiment at CERN Berlev, A.I.; Danilyuk, A.F.; Karavicheva, T.L. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
2009, 2009-1-00, Letnik:
598, Številka:
1
Journal Article
Recenzirano
In order to extend the momentum range of the charged particle identification up to 10
GeV
/c for pion–kaon separation and to 14
GeV
/c for kaon–proton separation of the ALICE experiment at LHC ...(CERN), the focusing aerogel ring imaging Cherenkov (FARICH) detector employing a multi-layer silica aerogel as radiator has been proposed. The design project of the FARICH Prototype is presented.
Results of the test of the avalanche photo-diodes with metal-resistance-semiconductor structure produced by the Centre of Perspective Technology and Apparatus (CPTA MRS APDs) are shown. Preliminary data of tests of the light-collecting capability for aluminum and stainless steel Winston cone holes of different types are presented.
The performance of the proposed detector was estimated using the GEANT4 simulation. Results of the optimization of characteristics of the aerogel radiators, CPTA MRS APDs with and without wavelength shifter paint are discussed.
ALICE (A Large Ion Collider Experiment) is a detector dedicated to the studies with heavy ion collisions exploring the physics of strongly interacting nuclear matter and the quark-gluon plasma at the ...CERN LHC (Large Hadron Collider). After the second long shutdown of the LHC, the ALICE Experiment will be upgraded to make high precision measurements of rare probes at low pT, which cannot be selected with a trigger, and therefore require a very large sample of events recorded on tape. The online computing system will be completely redesigned to address the major challenge of sampling the full 50 kHz Pb-Pb interaction rate increasing the present limit by a factor of 100. This upgrade will also include the continuous un-triggered read-out of two detectors: ITS (Inner Tracking System) and TPC (Time Projection Chamber)) producing a sustained throughput of 1 TB/s. This unprecedented data rate will be reduced by adopting an entirely new strategy where calibration and reconstruction are performed online, and only the reconstruction results are stored while the raw data are discarded. This system, already demonstrated in production on the TPC data since 2011, will be optimized for the online usage of reconstruction algorithms. This implies much tighter coupling between online and offline computing systems. An R&D program has been set up to meet this huge challenge. The object of this paper is to present this program and its first results.
to conduct a comprehensive assessment of features of combined course NASH and functional constipation using laboratory parameters, the data of instrumental methods, indicators of quality of life in ...comparison with patients with Nash without proven pathology of the intestine.
In the cross-sectional comparative study involving 102 patients with NASH, among which identified patients with functional constipation, there were formed two groups: study group (patients with NASH and functional constipation) and comparison group (patients with NASH without pathology of the intestine). All patients underwent a comprehensive assessment of laboratory data (markers of cytolysis, cholestasis, lipid and carbohydrate metabolism), results of instrumental methods (hydrogen breath test), quality of life (questionnaire SF-36).
All patients with NASH, regardless of the presence of functional bowel pathology was characterized by hyperlipidemia with a tendency to lower HDL and raise LDL with normal levels of triglycerides, fasting hyperglycemia, increased postprandial glucose, glycated hemoglobin and HOMA--IR higher than normal values and the availability of the SIBO. NASH is often associated with functional constipation (68.6%). Patients with functional constipation and NASH have a significantly higher average level of ALT (127.3 ± 58.4 U/I in the control group and to 103.5 ± 74.6 U/I in the comparison group, p = 0.02), more frequent association with the SIBO (65.7% in the main group opposed to 43.7% in the comparison group, p = 0.014) and a lower quality of life compared with patients without pathology of the intestine.
NASH has frequent association with functional constipation, worsens its course, resulting in a significant increase in the level of the marker of cytolysis (ALT), the more expressed SIBO and a palpable decline in the quality of life of patients, therefore the impaired intestinal function in these patients requires close attention.
The problem of electron/pion identification in the CBM experiment based on the measurements of energy losses and transition radiation in the TRD detector is discussed. Earlier we analyzed a ...possibility to solve such a problem using an artificial neural network (ANN) 1. Here we consider an approach based on a nonparametric ω
n
k
goodness-of-fit criterion, and comparison with the ANN method is also performed. We show that both methods provide a comparable level of pion suppression and electron identification, the ω
n
k
test is more simple for practical applications, the ANN method provides the needed level of pions suppression only if “clever” variables are used. We demonstrate that application of the ω
n
k
-criterion to the
J/Ψ
reconstruction provides a high level of pion background suppression and significantly improves a signal-to-background ratio.
New data on forward neutron emission in fragmentation of 30A-GeV {sup 208}Pb ions on Al, Cu, Sn, and Pb nuclei are presented. The measurements were performed at the CERN SPS in the framework of the ...ALICE-LUMI experiment. The measured cross sections are compared with predictions of the RELDIS model for electromagnetic interactions and with results of the abrasion-ablation model for hadronic interactions. The electromagnetic excitation of a Pb projectile followed by single- and double-neutron emission is found to be the dominant process in full agreement with theoretical estimations. The measured 1nX cross sections are generally well described. The measured 2nX data, which are 4-5 times lower than the 1nX data, are slightly underestimated by theory. Nevertheless, the sum of 1nX and 2nX cross sections is in good agreement with theory. This confirms the predictive power of the RELDIS model, which can be used to calculate the sum of 1nX and 2nX emission rates for the purpose of calibration of luminosity measurements in PbPb collisions at the Large Hadron Collider at CERN.
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