Search results for "Computer Science Applications"
showing 10 items of 3993 documents
The backward end-cap for the PANDA electromagnetic calorimeter
2015
The PANDA experiment at the new FAIR facility will cover a broad experimental programme in hadron structure and spectroscopy. As a multipurpose detector, the PANDA spectrometer needs to ensure almost 4π coverage of the scattering solid angle, full and accurate multiple-particle event reconstruction and very good particle identification capabilities. The electromagnetic calorimeter (EMC) will be a key item for many of these aspects. Particle energies ranging from some MeVs to several GeVs have to be measured with a relative resolution of 1% ⊕ 2%/√E/GeV . It will be a homogeneous calorimeter made of PbWO4 crystals and will be operated at -25°C, in order to improve the scintillation light yiel…
Teacher professional development in the context of the “Open Discovery of STEM laboratories” project: Is the MOOC methodology suitable for teaching p…
2020
Abstract The “Open Discovery of STEM Laboratories” (ODL) project, funded by the European Erasmus+ KA2 program, was aimed at introducing the use of MOOCs in school curricula. In particular, it fostered teacher collaboration in creating and using micro-MOOCs for the inclusion of STEM (Science, Technology, Engineering and Mathematics) online remote or virtual laboratories in the everyday teaching practice. The project focused on teachers, educators and curriculum designers with the aim to strengthen their profile by supporting them to deliver high quality teaching practices and to adopt new methods and tools. Thanks to the project, in service and pre-service teachers had the opportunity to ext…
The isomeric structure of132Pr
2012
The isomeric structure of the neutron deficient nucleus 132Pr, located in the rare-earth region of the nuclear chart, has been studied with the 98Mo(40Ar,5pn)132Pr reaction at beam energies of 150, 158 and 165 MeV. The experiment was performed at the University of Jyvaskyla, Finland where the 40Ar beam was accelerated onto the target by the K130 cyclotron. The JUROGAM II HPGe detector array was employed in conjunction with the RITU gas-filled recoil separator. The focal-plane chamber housed a multi wire proportional counter and a position-sensitive silicon strip detector used for the implantation and identification of recoiling nuclei. The recoil-isomer tagging technique was used to correla…
Channeling and Radiation of Electrons in Silicon Single Crystals and Si1−xGexCrystalline Undulators
2013
The phenomenon of channeling and the basic features of channeling radiation emission are introduced in a pedestrian way. Both, radiation spectra as well as dechanneling length measurements at electron beam energies between 195 and 855 MeV feature quantum state phenomena for the (110) planar potential of the silicon single crystals. Radiation from a crystalline undulator, produced at the Aarhus University (UAAR), has been investigated at the Mainz Microtron electron accelerator facility MAMI. The 4-period epitaxially grown strained layer Si1−xGex undulator had a period length λu = 9.9 μm. At a beam energy of 375 MeV a broad excess yield around the theoretically expected photon energy of 0.13…
The SAGE spectrometer: A tool for combined in-beam gamma-ray and conversion electron spectroscopy
2010
International audience; The sage spectrometer allows simultaneous in-beam -ray and internal conversion electron measurements, by combining a germanium detector array with a highly segmented silicon detector and an electron transport system. sage is coupled with the ritu gas- lled recoil separator and the great focal-plane spectrometer for recoil-decay tagging studies. Digital electronics are used both for the ray and the electron parts of the spectrometer. sage was commissioned in the Accelerator Laboratory of the University of Jyvaskyla in the beginning of 2010.
The development of the KATRIN magnet system
2006
The Karlsruhe Tritium Neutrino Experiment KATRIN aims to measure the mass of the electron neutrino with unprecedented accuracy. For this experiment a special magnet system with about 30 LHe bath cooled superconducting magnets grouped in 10 different sections needs to be developed. The magnetic fields required for the electron transport and spectrometer resolution have a level between 3 and 6 T and must be constant in time over months. Further requirements for field homogeneity and tritium compatibility lead to a unique magnet system. A challenging task of this system is to keep the 10 m beam tube of the source magnet at a constant temperature of 30 K with extremely high temperature stabilit…
Time-resolved photoabsorption in finite systems: A first-principles NEGF approach
2016
We describe a first-principles NonEquilibrium Green’s Function (NEGF) approach to time-resolved photoabsortion spectroscopy in atomic and nanoscale systems. The method is used to highlight a recently discovered dynamical correlation effect in the spectrum of a Krypton gas subject to a strong ionizing pump pulse. We propose a minimal model that captures the effect, and study the performance of time-local approximations versus time-nonlocal ones. In particular we implement the time-local Hartree-Fock and Markovian second Born (2B) approximation as well as the exact adiabatic approximation within the Time-Dependent Density Functional Theory framework. For the time-nonlocal approximation we ins…
High-precision studies of domain-wall properties in the 2D Gaussian Ising spin glass
2019
In two dimensions, short-range spin glasses order only at zero temperature, where efficient combinatorial optimization techniques can be used to study these systems with high precision. The use of large system sizes and high statistics in disorder averages allows for reliable finite-size extrapolations to the thermodynamic limit. Here, we use a recently introduced mapping of the Ising spin-glass ground-state problem to a minimum-weight perfect matching problem on a sparse auxiliary graph to study square-lattice samples of up to 10 000 × 10 000 spins. We propose a windowing technique that allows to extend this method, that is formally restricted to planar graphs, to the case of systems with …
Spin polarized electron transport and partial localization of photoelectrons in highly doped photocathodes
2011
The results of experimental and theoretical studies of spin polarized electron transport in semiconductor SL used for photoemitter application are presented. The experimental study is based on the time resolved measurements of electron emission from the cathode after its photoexcitation by fs laser pulse. The response and spin relaxation times have been determined by means of measured time dependent intensity and polarization of electron emission. We also performed theoretical calculations of photocathode pulse response and compared the obtained results with experimental data. Our analysis testifies the presence of partial electron localization in SL. Electron capture by localized states le…
Dynamics for a simple graph using the U(N) framework for loop quantum gravity
2012
The implementation of the dynamics in loop quantum gravity (LQG) is still an open problem. Here, we discuss a tentative dynamics for the simplest class of graphs in LQG: Two vertices linked with an arbitrary number of edges. We find an interesting global U(N) symmetry in this model that selects the homogeneous/isotropic sector. Then, we propose a quantum Hamiltonian operator for this reduced sector. Finally, we introduce the spinor representation for LQG in order to propose a classical effective dynamics for this model.