Results 11 to 20 of about 558,215 (330)
EJNMMI Physics, 2022 Background This study evaluated the physical performance of a positron emission tomography (PET) system dedicated to the head and breast according to the National Electrical Manufacturers Association (NEMA) NU2-2012 standard.
Daisuke Morimoto-Ishikawa +10 more
doaj +1 more source
Deep Minimum and a Vortex for Positronium Formation in Low-Energy Positron-Helium Collisions
Atoms, 2021 We find a zero in the positronium formation scattering amplitude and a deep minimum in the logarithm of the corresponding differential cross section for positron–helium collisions for an energy just above the positronium formation threshold ...
Albandari W. Alrowaily +2 more
doaj +1 more source
Energetics of positron states trapped at vacancies in solids [PDF]
, 2007 We report a computational first-principles study of positron trapping at vacancy defects in metals and semiconductors. The main emphasis is on the energetics of the trapping process including the interplay between the positron state and the defect's ...
G. Kresse +7 more
core +2 more sources
Atoms, 2021 Triply differential data are presented for the 200 eV positron and electron impact ionization of argon. Six electron emission energies between 2.6 and 19 eV, and for scattering angles of 2, 3, and 4 degrees cover a momentum transfer range of 0.16 to 0.31
R. D. DuBois, O. G. de Lucio
doaj +1 more source
Vibrational Feshbach Resonances Mediated by Nondipole Positron-Molecule Interactions [PDF]
, 2017 Measurements of energy-resolved positron-molecule annihilation show the existence of positron binding and vibrational Feshbach resonances. The existing theory describes this phenomenon successfully for the case of infrared-active vibrational modes which ...
Danielson, J. R. +4 more
core +2 more sources
ELECTRON-POSITRON- COLLIDERS [PDF]
International Journal of Modern Physics A, 2002 An electron-positron linear collider in the energy range between 500 and 1000 GeV is of crucial importance to precisely test the Standard Model and to explore the physics beyond it. The physics program is complementary to that of the Large Hadron Collider.
openaire +2 more sources
Merkuriev Cut-off in e+ − H Multichannel Scattering Calculations
Atoms, 2016 We present the results of positron-Hydrogen multichannel scattering calculations performed on the base of Faddeev-Merkuriev equations. We discuss an optimal choice of the Merkuriev’s Coulomb splitting parameters.
Vitaly A. Gradusov +2 more
doaj +1 more source
Positron-electron annihilation momentum transfer to trapped deuterons
AIP Advances, 2019 The probability of positron annihilation momentum transfer to a trapped deuteron is calculated based on neutron measurements from 2H(d,n)3He reactions in deuterated palladium thin films. Deuterium gas loading in Pd thin films creates a high D/Pd fraction
Ryan Weed +4 more
doaj +1 more source
Current imaging techniques in large vessel vasculitis
Научно-практическая ревматология, 2022 Instrumental imaging modalities play an important role in the diagnosis, evaluation of treatment efficacy and early detection of recurrences in patients with large vessel systemic vasculitis (SV). There’s no currently available universal imaging modality
T. V. Beketova +2 more
doaj +1 more source
Positrons from dark matter annihilation in the galactic halo: theoretical uncertainties [PDF]
, 2008 Indirect detection signals from dark matter annihilation are studied in the positron channel. We discuss in detail the positron propagation inside the galactic medium: we present novel solutions of the diffusion and propagation equations and we focus on ...
Delahaye, T. +4 more
core +3 more sources