Search results for "elektronit"
showing 10 items of 42 documents
Measurement of the production of high-pT electrons from heavy-flavour hadron decays in Pb–Pb collisions at √sNN = 2.76 TeV
2017
Electrons from heavy-flavour hadron decays (charm and beauty) were measured with the ALICE detector in Pb–Pb collisions at a centre-of-mass of energy √sNN = 2.76 TeV. The transverse momentum (pT) differential production yields at mid-rapidity were used to calculate the nuclear modification factor RAA in the interval 3 < pT < 18 GeV/c. The RAA shows a strong suppression compared to binary scaling of pp collisions at the same energy (up to a factor of 4) in the 10% most central Pb–Pb collisions. There is a centrality trend of suppression, and a weaker suppression (down to a factor of 2) in semi-peripheral (50–80%) collisions is observed. The suppression of electrons in this broad pT interval …
Production of muons from heavy-flavour hadron decays in p–Pb collisions at √sNN = 5.02 TeV
2017
The production of muons from heavy-flavour hadron decays in p–Pb collisions at √sNN = 5.02 TeV was studied for 2 < pT < 16 GeV/c with the ALICE detector at the CERN LHC. The measurement was performed at forward (p-going direction) and backward (Pb-going direction) rapidity, in the ranges of rapidity in the centre-of-mass system (cms) 2.03 < ycms < 3.53 and −4.46 < ycms < −2.96, respectively. The production cross sections and nuclear modification factors are presented as a function of transverse momentum (pT). At forward rapidity, the nuclear modification factor is compatible with unity while at backward rapidity, in the interval 2.5 < pT < 3.5 GeV/c, it is above unity by more than 2σ. The r…
Revealing lattice disorder, oxygen incorporation and pore formation in laser induced two-photon oxidized graphene
2019
Abstract Laser induced two-photon oxidation has proven to be a reliable method to pattern and control the level of oxidation of single layer graphene, which in turn allows the development of graphene-based electronic and optoelectronic devices with an all-optical method. Here we provide a full structural and chemical description of modifications of air-suspended graphene during the oxidation process. By using different laser irradiation doses, we were able to show via transmission electron microscopy, electron energy loss spectroscopy, electron diffraction and Raman spectroscopy how graphene develops from its pristine form up to a completely oxidized, porous and amorphous carbon layer. Furt…
Measurement of electrons from heavy-flavour hadron decays in p–Pb collisions at √sNN = 5.02 TeV
2016
The production of electrons from heavy-flavour hadron decays was measured as a function of transverse momentum (pT) in minimum-bias p–Pb collisions at √sNN = 5.02 TeV using the ALICE detector at the LHC. The measurement covers the pT interval 0.5 < pT < 12 GeV/c and the rapidity range −1.065 < ycms < 0.135 in the centre-of-mass reference frame. The contribution of electrons from background sources was subtracted using an invariant mass approach. The nuclear modification factor RpPb was calculated by comparing the pT-differential invariant cross section in p–Pb collisions to a pp reference at the same centre-of-mass energy, which was obtained by interpolating measurements at √s = 2.76 TeV an…
Electron spectroscopy with the SAGE spectrometer
2016
A device called the SAGE (Silicon And GErmanium) spectrometer, designed for in-beam electron spectroscopy, is introduced in this work. A detailed description to the technical aspects of the device is given along with several examples of analytical procedures related to work done with the device. The radial ltering method and veto/add-back algorithms are tools for improving the quality of the electron-gamma data whilst the time-gate selection procedure helps in determining absolute internal conversion coe cients without reference points. Two very di erent types of experiments with results obtained from the electron data are introduced and analysed. Coulomb excitation is used to probe 154Sm a…
Photoinduced Electron Transfer in a Porphyrin-Fullerene Dyad at a Liquid Interface
2022
The excited-state properties of an amphiphilic porphyrin–fullerene dyad and of its porphyrin analogue adsorbed at the dodecane/water interface are investigated by using surface second-harmonic generation. Although the porphyrin is formally centrosymmetric, the second-harmonic spectra of both compounds are dominated by the intense Soret band of the porphyrin. Polarization-selective measurements and molecular dynamics simulations suggest an angle of about 45° between the donor–acceptor axis and the interfacial plane, with the porphyrin interacting mostly with the nonpolar phase. Time-resolved measurements reveal a marked concentration dependence of the dynamics of both compounds upon Q-band e…
Many-particle theory for time-dependent quantum transport in nanostructures
2012
During the recent decades, molecular electronics has established its place as one of the promising fields in the nanoscience. The possibility to manufacture and control molecular junctions where single molecules are squeezed between the conducing electrodes has opened up new possibilities to develop nanoscale devices which could be employed as building blocks for future nanoelectronic applications. The driving force for this new branch of physics has been the experimental advances but also theoretical methods have been under intensive study and many theoretical tools have been developed to understand the electron transport processes in the nanoscale systems. This thesis focuses on developin…
A Homoleptic Alkynyl‐Ligated [Au13Ag16L24]3‐ Cluster as a Catalytically Active Eight‐Electron Superatom
2021
A brand new alkynylated cluster [Au 13 Ag 16 (C 10 H 6 NO) 24 ] 3- is prepared by NaBH 4 mediated reduction method. The AuAg clusters are confirmed by various sophisticated characterization techniques. It manifested the unique metal framework of “Au center @Ag 12 @Au 12 Ag 4 ” is protected by 24 atypical alkyne ligands L (L = C 10 H 6 NO). The ligands were found to construct a unique type of motif L-(Ag)-Au-(Ag)-L at the cluster interface, where, the alkyne (C≡C) group of each L was linked by sharing an Au atom through the σ bonds and each C≡C group was discretely connected to chemically different Ag atom (Ag icosahedral /Ag cap ) through π bonds. The electronic and optical properties of [A…
Optical Fiber Based Dosimeter Data From RADEF Pulsed Electron Beams - Oscilloscope Traces
2021
These data are from tests of fiber optic based dosimetry systems. The purpose of the collected data is to use it for characterizing the different tested samples responses against pulsed electron radiation, for different electron bunch sizes. The tested samples are sol-gel silica glass rods doped with Ce, Cu, or Gd ions, making the rods radioluminescent. The samples were connected to a multimode pure-silica core optical fiber, which transported the radiation induced luminescence (RIL) to a photomultiplier tube (PMT) with an optical band pass filter in front of it. The samples were subject to a pulsed 20 MeV electron beam. The resulting output pulses from the PMT from the induced RIL light we…
Developments in many-body theory of quantum transport and spectroscopy with non-equilibrium Green's functions and time-dependent density functional t…
2015
The problem of quantum dynamics in open systems has gained attention in recent decades and not the least due to the advances made in quantum transport in molecular systems. The main motivation behind quantum transport and molecular electronics is the futuristic goal to be able at some point to replace, or to complement, the silicon-based technology and to make the electronic devices faster. On a fundamental level, one has to deal with time-dependent processes where electron-electron or electron- phonon interactions are of great importance, and they can cause profound quantitative and qualitative changes on the physical and dynamical properties of electronic systems compared to the non-inter…