171 research outputs found
Modelling of chemical reactions in plasma
The paper is devoted to theoretical investigation of interaction of pulsed high current electron beam with gas substance. As a result of the interaction the formation of chemical active plasma can be observed. One of the key parameter for theoretical analyze of the process is the electron distribution function. Within the framework of the Boltzmann approach we obtained the dynamical equation for electron distribution function depending on the electron energy, coordinate and time
Study of the structure of crater at the surface of 12Cr18Ni10Ti steel irradiated by high-power pulsed ion beam
The topography of surface layers of 12Cr18Ni10Ti (AISI 321) steel after pulsed high-power Cn+ ion beams irradiation was investigated by scanning electron microscopy. A thin foil was prepared from the cross section of a crater with the use of a focused ion beam in the column of a two-beam electron-ion microscope. The microstructure and chemical composition of the crater were studied by transmission electron microscop
Development of technology and investigation of structure and properties of composites on the basis of shungit and polymer resins
The technology for manufacturing of composites based on polymer (epoxy) resins and shungites was developed by using of the electron irradiation and experienced samples with different percentages of the components a) 90 and 10 %, b) 70 and 30 %, c) 50 and 50 %, were manufactured respectively. It was carried out the series of experimental studies of the structure and properties of the obtained materials, including the atomic force microscope images were obtained and Raman spectra of these composites were measured and their analysis was per-formed
Effect of high-power ion beams on the surface topography and structure of the subsurface layer of sun microcrystalline titanium alloys
A rather homogeneous grain structure with equiaxial grains is formed for both alloys already after the effect of one pulse of the high-power ion bea
CsI(Tl) Pulse Shape Discrimination with the Belle II Electromagnetic Calorimeter as a Novel Method to Improve Particle Identification at Electron-Positron Colliders
This paper describes the implementation and performance of CsI(Tl) pulse
shape discrimination for the Belle II electromagnetic calorimeter, representing
the first application of CsI(Tl) pulse shape discrimination for particle
identification at an electron-positron collider. The pulse shape
characterization algorithms applied by the Belle II calorimeter are described.
Control samples of , , , and are
used to demonstrate the significant insight into the secondary particle
composition of calorimeter clusters that is provided by CsI(Tl) pulse shape
discrimination. Comparisons with simulation are presented and provide further
validation for newly developed CsI(Tl) scintillation response simulation
techniques, which when incorporated with GEANT4 simulations allow the particle
dependent scintillation response of CsI(Tl) to be modelled. Comparisons between
data and simulation also demonstrate that pulse shape discrimination can be a
new tool to identify sources of improvement in the simulation of hadronic
interactions in materials. The efficiency and photon-as-hadron
fake-rate of a multivariate classifier that is trained to use pulse shape
discrimination is presented and comparisons are made to a shower-shape based
approach. CsI(Tl) pulse shape discrimination is shown to reduce the
photon-as-hadron fake-rate by over a factor of 3 at photon energies of 0.2 GeV
and over a factor 10 at photon energies of 1 GeV
The change in the surface topography of magnesium under high-flux C ion irradiation
The topography of the surface of the magnesium sample after irradiation by the high-intensity pulsed ion beam of a TEMP-4M accelerator was studied. The irradiation causes the formation of a regular comb structure and the creation of craters, their depth reaches 1-1.5 μ
Near-term experiments and long-term goals at INURA pulsed ion accelerator in Nazarbayev University
Nazarbayev University works on
establishing a research program on inertial
confinement fusion, high energy physics and
critical states of matter. Long term plans
include building a new multi-MV, ~10 to
several hundred GW/cm2 ion accelerator
facility which will be used in studies of
material properties at extreme conditions.
Two design options are being considered..
Search for Axionlike Particles Produced in e⁺ e⁻ Collisions at Belle II
International audienceWe present a search for the direct production of a light pseudoscalar a decaying into two photons with the Belle II detector at the SuperKEKB collider. We search for the process e+e-→γa, a→γγ in the mass range 0.2
Search for Axionlike Particles Produced in e+e- Collisions at Belle II
We present a search for the direct production of a light pseudoscalar a decaying into two photons with the Belle II detector at the SuperKEKB collider. We search for the process e+e-→γa, a→γγ in the mass range 0.2<9.7 GeV/c2 using data corresponding to an integrated luminosity of (445±3) pb-1. Light pseudoscalars interacting predominantly with standard model gauge bosons (so-called axionlike particles or ALPs) are frequently postulated in extensions of the standard model. We find no evidence for ALPs and set 95% confidence level upper limits on the coupling strength gaγγ of ALPs to photons at the level of 10-3 GeV-1. The limits are the most restrictive to date for 0.2<1 GeV/c2
Tests of light-lepton universality in angular asymmetries of decays
We present the first comprehensive tests of light-lepton universality in the
angular distributions of semileptonic \Bz-meson decays to charged spin-1
charmed mesons. We measure five angular-asymmetry observables as functions of
the decay recoil that are sensitive to lepton-universality-violating
contributions. We use events where one neutral \B is fully reconstructed in
\PUpsilonFourS{} \to\B\overline{B} decays in data corresponding to \lumion
integrated luminosity from electron-positron collisions collected with the
\belletwo detector. We find no significant deviation from the standard model
expectations
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