A new design of a detector plane of sub-millimetre thickness for an electromagnetic sampling calorimeter is presented. It is intended to be used in the luminometers LumiCal and BeamCal in future ...linear e
+
e
-
collider experiments. The detector planes were produced utilising novel connectivity scheme technologies. They were installed in a compact prototype of the calorimeter and tested at DESY with an electron beam of energy 1–5 GeV. The performance of a prototype of a compact LumiCal comprising eight detector planes was studied. The effective Molière radius at 5 GeV was determined to be (8.1 ± 0.1 (stat) ± 0.3 (syst)) mm, a value well reproduced by the Monte Carlo (MC) simulation (8.4 ± 0.1) mm. The dependence of the effective Molière radius on the electron energy in the range 1–5 GeV was also studied. Good agreement was obtained between data and MC simulation.
Despite rather long-term theoretical and experimental study, the hypothesis of the non-zero intrinsic (or valence-like) heavy quark component of the proton distribution functions has not yet been ...confirmed or rejected. The LHC with pp-collisions at s=7–14 TeV will obviously supply extra unique information concerning the above-mentioned component of the proton. To use the LHC potential, first of all, one should select the parton-level (sub)processes (and final-state signatures) that are the most sensitive to the intrinsic heavy quark contributions. To this end inclusive production of c(b)-jets accompanied by photons is considered. On the basis of performed theoretical study it is demonstrated that investigation of the intrinsic heavy quark contributions looks very promising at the LHC in processes like pp→γ+c(b)+X.
In order to follow relative yields of
Bi(
) reactions, samples of natural bismuth were exposed in LINAC-200 bremsstrahlung beam at four different energies. Activities of eight obtained photonuclear ...reaction products with neutron multiplicity up to (
) were observed. Reaction yields normalized to the
Bi yield were calculated. The measured relative yields of
Bi isotopes were compared with the theoretical evaporation model based on the microscopically calculated level densities and with GEANT4 simulation.
At present, there are two Micromegas detector production sites at the Dzhelepov Laboratory of Nuclear Problems, Joint Institute for Nuclear Research (DLNP JINR). The first site provides the ...production and testing of Micromegas chambers for the outer part of the large sectors (LM2) of the New Small Wheels for the ATLAS Muon spectrometer. It will produce and test 64 double-sided readout panels with a surface area of 3 m
2
each and 32 Micromegas chambers based on them. Component materials for all project participants are centrally delivered from CERN. The second site is for a complete production cycle and intended for the research and development of Micromegas detectors with widths reaching 60 cm.
Boronated Scintillator Detector (BSD) for use in space with ionization calorimeters was suggested. BSD improved e/h showers separation, which are initiated in the ionization calorimeter in ...interaction it with high energy particles. Improve the rejection is based on the hadron-induced showers tend to be accompanied by significantly more neutron activity than electromagnetic showers. The detector is composed of natural boron-loaded (5%) castable plastic scintillation plates. To collect light using wavelength-shifting (WLS) fibers. The experiment showed that the photoelectron yield is ∼ 40 ph.el./MeV with using PMT EMI 9954KB. Simulation on GEANT4 was obtained neutron detection efficiency. The simulation was conducted in the assumption that neutrons have the spectrum 252Cf and fall plane-parallel on the entry surface of the detector.
The LHC with pp-collisions at radicals = 7-14 TeV will obviously supply extra unique information concerning the non-zero intrinsic (or valence-like) heavy quark component of the proton distribution ...functions component of the proton. On the basis of theoretical study it is demonstrated that investigaton of the intrinsic heavy quark contributions looks very promising at the LHC in processes like pp arrow right y + c(b) + X.
The flux weighted average cross sections 〈σ〉 and cross sections per equivalent photon σq were first measured for the photonuclear multiparticle reactions natSe(γ, xnyp) at end-point bremsstrahlung ...gamma energies ranging from 20 to 80 MeV. The experiments were performed with the beam from the electron linear accelerator LINAC-200 with the use of the γ-activation technique. The bremsstrahlung photon flux was calculated with the program Geant4. The theoretical values of the flux weighted average cross sections 〈σ〉 and the cross sections per equivalent photon σq were calculated using the partial cross section σ(E) computed with the TALYS package code and the combined model of photonuclear reactions.
Accurate determination of the energy of LINAC-200 fast electrons was performed using several photonuclear reactions carried out on natural Indium after conversion of electron energy in bremsstrahlung ...in thick Tungsten target. Natural Indium was used as an activation detector and the ratios of saturation activities R(113mIn)/R(115mIn), R(114mIn)/R(115mIn) and R(111In)/R (115mIn) were used as a measure of the endpoint energy of the bremsstrahlung beam (and energy of electrons striking the bremsstrahlung target as well). Energy dependence of the three ratios of saturation activities were determined by using the bremsstrahlung produced by electrons accelerated by Microtron to the energies known with accuracy not worse than 0.1 MeV. Three types of scintillation detectors (LaBr3:Ce, BGO and plastic) were calibrated using electrons having energies from 1.17 MeV to 25 MeV. In low energy region photoelectrons produced by 60Co gamma radiation in the detector itself were used, as well as high energy electrons (from 11 MeV to 25 MeV) accelerated by LINAC-200.
The interest in using the radiation detectors based on high resistive chromium-compensated GaAs (GaAs:Cr) in high energy physics and others applied fields has been growing steadily due to its ...numerous advantages over others classical materials. High radiation hardness at room temperature stands out and needs to be systematically investigated. In this paper an experimental study of the effect of 20.9 MeV electrons generated by the LINAC-200 accelerator on some properties of GaAs:Cr based sensors is presented. In parallel, Si sensors were irradiated at the same conditions, measured and analyzed in order to perform a comparative study. The target sensors were irradiated with the dose up to 1.5 MGy. The current–voltage characteristics, resistivity, charge collection efficiency and their dependences on the bias voltage and temperature were measured at different absorbed doses. An analysis of the possible microscopic mechanisms leading to the observed effects in GaAs:Cr sensors is presented in the article.
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