The fast component of the barium fluoride (BaF2) crystal luminescence with the emission peak at 220 nm allows those crystals to be employed in fast calorimeters operating in harsh radiation ...environment. However, the slow component with the emission peak at 330 nm and about 85% of the total emission light could create big problems when working at a high radiation rate. In this work we report results of tests of multilayer filters that can suppress luminescence in the range from 250 nm to 400 nm, which covers most of the BaF2 slow component luminescence. The filters are made by spraying layers of rare earth oxides on a quartz glass substrate. Filters typically comprise 200-220 layers. A few filters were prepared by spraying thin layers on quartz glass. The filters have a peak transmittance of about 70-80% in the range of 200-250 nm. Measurements of the light output of the BaF2 crystal with and without a filter between the crystal readout end and the PMT demonstrate substancial suppression of the slow component. To our knowledge, this kind of filters are produced and tested for the first time.
On correlators for high multiplicity events Budagov, J. A.; Kulchitsky, Yu. A.; Manjavidze, J. ...
Physics of atomic nuclei,
1/2004, Letnik:
67, Številka:
1
Journal Article
A new radiation stable plastic scintillator Senchishin, V.G.; Markley, F.; Lebedev, V.N. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
10/1995, Letnik:
364, Številka:
2
Journal Article
Recenzirano
The influence of various components of a plastic scintillator (high concentrations of primary dopant, secondary fluor, diffusion enhancer and stabilizer) on its radiation hardness has been ...experimentally determined. The diffusion enhancing technique was shown to be the most powerful tool for improving radiation hardness. A new polystyrene scintillator that decreases its light output by only 4% after 2.8 Mrad irradiation has been produced.
Using a Monte Carlo code based on the GEANT package the energy resolution of a scintillating fibre calorimeter was investigated as a function of the volume ratio of passive (absorber) to active ...(fibres) material, fibre radius, light reflection coefficient at fibre end, fibre transparency, and incident particle tilt angle. The obtained MC results were confronted with the existing experimental data. Good agreement between the simulation and experiment was found in most cases. A simple formula describing the stochastic term of the energy resolution as a function of the calorimeter basic parameters has been found.
An electromagnetic (EM) calorimeter constructed from high-pressure gas-ionization tubes with sinusoid-like longitudinal profile (wiggler tubes) has been assembled, and tested in an electron beam at ...the CERN SPS. This design greatly improves the EM energy resolution compared to a calorimeter constructed from straight tubes and eliminates the resolution dependence on the beam angle. An EM energy resolution of δ
E/
E (32.0 ± 1.6)% / √
E ⊕ (2.9 ± 0.3)% has been achieved. Further improvements of the EM energy resolution are discussed. The calorimeter is very radiation hard, has a fast response, and it is stable and mechanically robust; it is intended for the forward region of the LHC collider detectors.
Beam test of a hadron calorimeter made of high-pressure gas-ionization tubes
Nuclear instruments and methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment/Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment
Journal Article
A high-pressure gas-ionization tube calorimeter for forward detectors
Nuclear instruments and methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment/Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
09/1993
Journal Article
A measurement of W± boson production in Pb+Pb collisions at √sNN=5.02 TeV is reported using data recorded by the ATLAS experiment at the LHC in 2015, corresponding to a total integrated luminosity of ...0.49nb-1. The W± bosons are reconstructed in the electron or muon leptonic decay channels. Production yields of leptonically decaying W± bosons, normalised by the total number of minimum-bias events and the nuclear thickness function, are measured within a fiducial region defined by the detector acceptance and the main kinematic requirements. These normalised yields are measured separately for W+ and W- bosons, and are presented as a function of the absolute value of pseudorapidity of the charged lepton and of the collision centrality. The lepton charge asymmetry is also measured as a function of the absolute value of lepton pseudorapidity. In addition, nuclear modification factors are calculated using the W± boson production cross-sections measured in pp collisions. The results are compared with predictions based on next-to-leading-order calculations with CT14 parton distribution functions as well as with predictions obtained with the EPPS16 and nCTEQ15 nuclear parton distribution functions. No dependence of normalised production yields on centrality and a good agreement with predictions are observed for mid-central and central collisions. For peripheral collisions, the data agree with predictions within 1.7 (0.9) standard deviations for W- (W+) bosons.
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