positronium

(redirected from Ortho-positronium)
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pos·i·tro·ni·um

 (pŏz′ĭ-trō′nē-əm)
n.
A short-lived association of an electron and a positron bound together in a configuration resembling the hydrogen atom.

positronium

(ˌpɒzɪˈtrəʊnɪəm)
n
(Atomic Physics) physics a short-lived entity consisting of a positron and an electron bound together. It decays by annihilation to produce two or three photons
[C20: from positron + -ium]

pos•i•tro•ni•um

(ˌpɒz ɪˈtroʊ ni əm)

n.
a short-lived atomic system consisting of a positron and an electron bound together.
[1945; positron + -ium2]
Translations
positronium
References in periodicals archive ?
v] Relative Free Volume Fractions NMR Nuclear Magnetic Resonance PALS Positron Annihilation Lifetime Spectroscopy PEO Polyethylene Oxide PMMA Poly methyl Methacrylatc PS Polystyrene Ps Positronium o-Ps Ortho-positronium SAXS Small Angle X-ray Scattering SBS Styrene-Buladiene-Styrenc Copolymer SEM Scanning Electron Microscopy TEM Transmission Electron Microscopy [V.
Positronium atoms form two states: the singlet state, called para-positronium and the triplet state called ortho-positronium (o-Ps).
The free volume can be evaluated in terms of ortho-positronium (o-Ps) lifetime according to the Eqs.
The ortho-Positronium (o-Ps) in which spins are parallel and annihilates with a lifetime of 140 ns in free space.