Spin-dipole-induced lifetime of the least-bound {sup 5}{sigma}{sub g}{sup +} state of He(2 {sup 3}S{sub 1})+He(2 {sup 3}S{sub 1})

Journal Article · Sat Jul 15 00:00:00 EDT 2006 · Physical Review. A

DOI:https://doi.org/10.1103/PHYSREVA.74.014702· OSTI ID:20852986

Beams, Timothy J; Whittingham, Ian B ^[1]; Peach, Gillian ^[2]

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1. School of Mathematical and Physical Sciences, James Cook University, Townsville, Australia 4811 (Australia)
2. Department of Physics and Astronomy, University College London, Gower Street, London, WC1E 6BT (United Kingdom)

The properties of the least-bound vibrational level (v=14) of the {sup 5}{sigma}{sub g}{sup +} state formed during the ultracold collision of two spin-polarized metastable 2 {sup 3}S{sub 1} helium atoms are crucial to studies of photoassociation spectroscopy of metastable helium. We report a calculation of the autoionization lifetime {tau}{sub g} of this state induced by spin-dipole coupling of the {sup 5}{sigma}{sub g}{sup +} state to the {sup 1}{sigma}{sub g}{sup +} state from which Penning and associative ionization processes are highly probable. We find {tau}{sub g}{approx_equal}150 {mu}s, significantly larger than the recent experimental estimates of (0.5-3) {mu}s.

• OSTI ID: 20852986
• Journal Information: Physical Review. A, Vol. 74, Issue 1; Other Information: DOI: 10.1103/PhysRevA.74.014702; (c) 2006 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); ISSN 1050-2947
• Country of Publication: United States
• Language: English

Related Subjects

74 ATOMIC AND MOLECULAR PHYSICS
ATOMS
AUTOIONIZATION
BOUND STATE
COUPLING
DIPOLES
HELIUM
LIFETIME
METASTABLE STATES
PHOTON-ATOM COLLISIONS
S STATES
SPECTROSCOPY
SPIN
SPIN ORIENTATION
VIBRATIONAL STATES