orthohelium

orthohelium

[¦ȯr·thō′hē·lē·əm]
(atomic physics)
Those states of helium atoms in which the spins of the two electrons are parallel.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.
References in periodicals archive ?
Rhino Correct is made of orthohelium and easily fits all nose shapes.
1 electron in the N = 1 shell, and the second electron in any of the N>1 shells), helium can exist either as a singlet (parahelium--spins remaining antiparallel to one another) or as a triplet (orthohelium --spins assume a parallel configuration).
Expulsion of an activated helium atom ([He.sup.*]) can lead to two conditions, depending on whether the electrons within this species are antiparallel (parahelium) or parallel (orthohelium).
As for the excited orthohelium, it is unable to relax, as its two electrons have the same spin (either both spin up or both spin down).
Importantly, since excited orthohelium cannot fully relax back to the ground state, it remains available to recondense with atomic hydrogen in the chromosphere.
Physically, [H.sub.[theta]] is the first-order energy perturbation experienced by an orthohelium atom in an electric field of orthorhombic symmetry; cf.
The generation of many triplet forms of orthohelium [HeI.sup.*] will demand energies of ~20eV.
Helium in this case is known as orthohelium (or triplet state helium), emphasizing that its two electrons have spins with the same orientation.
Since orthohelium is trapped in the excited triplet state, it has an opportunity to once again react with hydrogen, as displayed in the lower portion of Fig.
1, once the doubly excited helium atom has partially relaxed to regenerate orthohelium, it can react once again with atomic hydrogen, leading to the renewed synthesis of excited helium hydride, HeH*.